WorldWideScience

Sample records for chemical exposure challenges

  1. Tooth matrix analysis for biomonitoring of organic chemical exposure: Current status, challenges, and opportunities.

    Science.gov (United States)

    Andra, Syam S; Austin, Christine; Arora, Manish

    2015-10-01

    Epidemiological evidence supports associations between prenatal exposure to environmental organic chemicals and childhood health impairments. Unlike the common choice of biological matrices such as urine and blood that can be limited by short half-lives for some chemicals, teeth provide a stable repository for chemicals with half-life in the order of decades. Given the potential of the tooth bio-matrix to study long-term exposures to environmental organic chemicals in human biomonitoring programs, it is important to be aware of possible pitfalls and potential opportunities to improve on the current analytical method for tooth organics analysis. We critically review previous results of studies of this topic. The major drawbacks and challenges in currently practiced concepts and analytical methods in utilizing tooth bio-matrix are (i) no consideration of external (from outer surface) or internal contamination (from micro-odontoblast processes), (ii) the misleading assumption that whole ground teeth represent prenatal exposures (latest formed dentine is lipid rich and therefore would absorb and accumulate more organic chemicals), (iii) reverse causality in exposure assessment due to whole ground teeth, and (iv) teeth are a precious bio-matrix and grinding them raises ethical concerns about appropriate use of a very limited resource in exposure biology and epidemiology studies. These can be overcome by addressing the important limitations and possible improvements with the analytical approach associated at each of the following steps: (i) tooth sample preparation to retain exposure timing, (ii) organics extraction and pre-concentration to detect ultra-trace levels of analytes, (iii) chromatography separation, (iv) mass spectrometric detection to detect multi-class organics simultaneously, and (v) method validation, especially to exclude chance findings. To highlight the proposed improvements we present findings from a pilot study that utilizes tooth matrix biomarkers

  2. Setting Occupational Exposure Limits for Chemical Allergens—Understanding the Challenges

    OpenAIRE

    Dotson, G. S.; Maier, A.; Siegel, P. D.; Anderson, S E; Green, B.J.; Stefaniak, A. B.; Codispoti, C. D.; Kimber, I.

    2015-01-01

    Chemical allergens represent a significant health burden in the workplace. Exposures to such chemicals can cause the onset of a diverse group of adverse health effects triggered by immune-mediated responses. Common responses associated with workplace exposures to low molecular weight (LMW) chemical allergens range from allergic contact dermatitis to life-threatening cases of asthma. Establishing occupational exposure limits (OELs) for chemical allergens presents numerous difficulties for occu...

  3. Information resources for assessing health effects from chemical exposure: Challenges, priorities, and future issues

    Energy Technology Data Exchange (ETDEWEB)

    Seigel, S. [National Library of Medicine, Bethesda, MD (United States)

    1990-12-31

    Issues related to developing information resources for assessing the health effects from chemical exposure include the question of how to address the individual political issues relevant to identifying and determining the timeliness, scientific credibility, and completeness of such kinds of information resources. One of the important ways for agencies to share information is through connection tables. This type of software is presently being used to build information products for some DHHS agencies. One of the challenges will be to convince vendors of data of the importance of trying to make data files available to communities that need them. In the future, information processing will be conducted with neural networks, object-oriented database management systems, and fuzzy-set technologies, and meta analysis techniques.

  4. Predictive models for the assessment of occupational exposure to chemicals: A new challenge for employers

    Directory of Open Access Journals (Sweden)

    Jan Piotr Gromiec

    2013-10-01

    Full Text Available Employers are obliged to carry out and document the risk associated with the use of chemical substances. The best but the most expensive method is to measure workplace concentrations of chemicals. At present no "measureless" method for risk assessment is available in Poland, but predictive models for such assessments have been developed in some countries. The purpose of this work is to review and evaluate the applicability of selected predictive methods for assessing occupational inhalation exposure and related risk to check the compliance with Occupational Exposure Limits (OELs, as well as the compliance with REACH obligations. Based on the literature data HSE COSHH Essentials, EASE, ECETOC TRA, Stoffenmanager, and EMKG-Expo-Tool were evaluated. The data on validation of predictive models were also examined. It seems that predictive models may be used as a useful method for Tier 1 assessment of occupational exposure by inhalation. Since the levels of exposure are frequently overestimated, they should be considered as "rational worst cases" for selection of proper control measures. Bearing in mind that the number of available exposure scenarios and PROC categories is limited, further validation by field surveys is highly recommended. Predictive models may serve as a good tool for preliminary risk assessment and selection of the most appropriate risk control measures in Polish small and medium size enterprises (SMEs providing that they are available in the Polish language. This also requires an extensive training of their future users. Med Pr 2013;64(5:699–716

  5. Chemical Weapons Exposures in Iraq: Challenges of a Public Health Response a Decade Later.

    Science.gov (United States)

    Baird, Coleen; Mirza, Raul; Sharkey, Jessica M; Teichman, Ron; Longmire, Romarius; Harkins, Deanna; Llanos, Joseph; Abraham, Joseph; McCannon, Charles; Heller, Jack; Tinklepaugh, Carole; Rice, William

    2016-01-01

    An October 14, 2014 article in The New York Times reported that the US Department of Defense (DoD) concealed, for nearly a decade, circumstances surrounding service members' exposure to chemical warfare agents (CWA) while deployed to Iraq in support of Operations Iraqi Freedom and New Dawn from March 13, 2003, to December 31, 2011, and alleged failure of the DoD to provide expedient and adequate medical care. This report prompted the DoD to devise a public health investigation, with the Army Public Health Center (Provisional) as the lead agency to identify, evaluate, document, and track CWA casualties of the Iraq war. Further, the DoD revisited and revised clinical guidelines and health policies concerning CWA exposure based on current evidence-based guidelines and best practices. PMID:27613213

  6. Personal Chemical Exposure informatics

    Science.gov (United States)

    Chemical Exposure science is the study of human contact with chemicals (from manufacturing facilities, everyday products, waste) occurring in their environments and advances knowledge of the mechanisms and dynamics of events that cause or prevent adverse health outcomes. (adapted...

  7. Challenge toward breakage of RLS trade-off for EUV lithography by Photosensitized Chemically Amplified Resist (PSCAR) with flood exposure

    Science.gov (United States)

    Nagahara, Seiji; Carcasi, Michael; Nakagawa, Hisashi; Buitrago, Elizabeth; Yildirim, Oktay; Shiraishi, Gosuke; Terashita, Yuichi; Minekawa, Yukie; Yoshihara, Kosuke; Tomono, Masaru; Mizoguchi, Hironori; Estrella, Joel; Nagai, Tomoki; Naruoka, Takehiko; Dei, Satoshi; Hori, Masafumi; Oshima, Akihiro; Vockenhuber, Michaela; Ekinci, Yasin; Meeuwissen, Marieke; Verspaget, Coen; Hoefnagels, Rik; Rispens, Gijsbert; Maas, Raymond; Nakashima, Hideo; Tagawa, Seiichi

    2016-03-01

    This paper proposes a promising approach to break the resolution (R), line-edge-roughness (LER), and sensitivity (S) trade-off (RLS trade-off) relationships that limit the ultimate lithographic performance of standard chemically amplified resists (CAR). This is accomplished in a process that uses a Photosensitized Chemically Amplified Resist (PSCAR) in combination with a flood-exposure in an in-line track connected to a pattern exposure tool. PSCAR is a modified CAR which contains a photosensitizer precursor (PP) in addition to other standard CAR components such as a protected polymer, a photo acid generator (PAG) and a quencher. In this paper, the PSCAR concept and the required conditions in resist formulation are carefully explained. In the PSCAR process, the sensitivity improvement is accomplished by PAG decomposition to selectively generate more acid at the pattern exposed areas during the flood exposure. The selective photosensitization happens through the excitation of the photosensitizer (PS) generated by the deprotection of the PP at the pattern exposed areas. A higher resist chemical gradient which leads to an improved resolution and lower LER values is also predicted using the PSCAR simulator. In the PSCAR process, the improved chemical gradient can be realized by dual acid quenching steps with the help of increased quencher concentration. Acid quenching first happens simultaneously with acid catalytic PP to PS reactions. As a result, a sharpened PS latent image is created in the PSCAR. This image is subsequently excited by the flood exposure creating additional acid products at the pattern exposed areas only. Much the same as in the standard CAR system, unnecessary acid present in the non-pattern exposed areas can be neutralized by the remaining quencher to therefore produce sharper acid latent images. EUV exposure results down to 15 nm half pitch (HP) line/space (L/S) patterns using a PSCAR resist indicate that the use of PSCAR has the potential to

  8. Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead

    Science.gov (United States)

    Goodson, William H.; Lowe, Leroy; Carpenter, David O.; Gilbertson, Michael; Manaf Ali, Abdul; Lopez de Cerain Salsamendi, Adela; Lasfar, Ahmed; Carnero, Amancio; Azqueta, Amaya; Amedei, Amedeo; Charles, Amelia K.; Collins, Andrew R.; Ward, Andrew; Salzberg, Anna C.; Colacci, Anna Maria; Olsen, Ann-Karin; Berg, Arthur; Barclay, Barry J.; Zhou, Binhua P.; Blanco-Aparicio, Carmen; Baglole, Carolyn J.; Dong, Chenfang; Mondello, Chiara; Hsu, Chia-Wen; Naus, Christian C.; Yedjou, Clement; Curran, Colleen S.; Laird, Dale W.; Koch, Daniel C.; Carlin, Danielle J.; Felsher, Dean W.; Roy, Debasish; Brown, Dustin G.; Ratovitski, Edward; Ryan, Elizabeth P.; Corsini, Emanuela; Rojas, Emilio; Moon, Eun-Yi; Laconi, Ezio; Marongiu, Fabio; Al-Mulla, Fahd; Chiaradonna, Ferdinando; Darroudi, Firouz; Martin, Francis L.; Van Schooten, Frederik J.; Goldberg, Gary S.; Wagemaker, Gerard; Nangami, Gladys N.; Calaf, Gloria M.; Williams, Graeme P.; Wolf, Gregory T.; Koppen, Gudrun; Brunborg, Gunnar; Lyerly, H. Kim; Krishnan, Harini; Ab Hamid, Hasiah; Yasaei, Hemad; Sone, Hideko; Kondoh, Hiroshi; Salem, Hosni K.; Hsu, Hsue-Yin; Park, Hyun Ho; Koturbash, Igor; Miousse, Isabelle R.; Scovassi, A.Ivana; Klaunig, James E.; Vondráček, Jan; Raju, Jayadev; Roman, Jesse; Wise, John Pierce; Whitfield, Jonathan R.; Woodrick, Jordan; Christopher, Joseph A.; Ochieng, Josiah; Martinez-Leal, Juan Fernando; Weisz, Judith; Kravchenko, Julia; Sun, Jun; Prudhomme, Kalan R.; Narayanan, Kannan Badri; Cohen-Solal, Karine A.; Moorwood, Kim; Gonzalez, Laetitia; Soucek, Laura; Jian, Le; D’Abronzo, Leandro S.; Lin, Liang-Tzung; Li, Lin; Gulliver, Linda; McCawley, Lisa J.; Memeo, Lorenzo; Vermeulen, Louis; Leyns, Luc; Zhang, Luoping; Valverde, Mahara; Khatami, Mahin; Romano, Maria Fiammetta; Chapellier, Marion; Williams, Marc A.; Wade, Mark; Manjili, Masoud H.; Lleonart, Matilde E.; Xia, Menghang; Gonzalez Guzman, Michael J.; Karamouzis, Michalis V.; Kirsch-Volders, Micheline; Vaccari, Monica; Kuemmerle, Nancy B.; Singh, Neetu; Cruickshanks, Nichola; Kleinstreuer, Nicole; van Larebeke, Nik; Ahmed, Nuzhat; Ogunkua, Olugbemiga; Krishnakumar, P.K.; Vadgama, Pankaj; Marignani, Paola A.; Ghosh, Paramita M.; Ostrosky-Wegman, Patricia; Thompson, Patricia A.; Dent, Paul; Heneberg, Petr; Darbre, Philippa; Leung, Po Sing; Nangia-Makker, Pratima; Cheng, Qiang (Shawn); Robey, R.Brooks; Al-Temaimi, Rabeah; Roy, Rabindra; Andrade-Vieira, Rafaela; Sinha, Ranjeet K.; Mehta, Rekha; Vento, Renza; Di Fiore, Riccardo; Ponce-Cusi, Richard; Dornetshuber-Fleiss, Rita; Nahta, Rita; Castellino, Robert C.; Palorini, Roberta; Hamid, Roslida A.; Langie, Sabine A.S.; Eltom, Sakina E.; Brooks, Samira A.; Ryeom, Sandra; Wise, Sandra S.; Bay, Sarah N.; Harris, Shelley A.; Papagerakis, Silvana; Romano, Simona; Pavanello, Sofia; Eriksson, Staffan; Forte, Stefano; Casey, Stephanie C.; Luanpitpong, Sudjit; Lee, Tae-Jin; Otsuki, Takemi; Chen, Tao; Massfelder, Thierry; Sanderson, Thomas; Guarnieri, Tiziana; Hultman, Tove; Dormoy, Valérian; Odero-Marah, Valerie; Sabbisetti, Venkata; Maguer-Satta, Veronique; Rathmell, W.Kimryn; Engström, Wilhelm; Decker, William K.; Bisson, William H.; Rojanasakul, Yon; Luqmani, Yunus; Chen, Zhenbang; Hu, Zhiwei

    2015-01-01

    Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety ‘Mode of Action’ framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology. PMID:26106142

  9. Challenges and Perspectives of Nanoparticle Exposure Assessment

    OpenAIRE

    Lee, Ji Hyun; Moon, Min Chaul; Lee, Joon Yeob; Yu, Il Je

    2010-01-01

    Nanoparticle exposure assessment presents a unique challenge in the field of occupational and environmental health. With the commercialization of nanotechnology, exposure usually starts from the workplace and then spreads to environment and consumer exposure. This report discusses the current trends of nanoparticle exposure assessment, including the definition of nanotechnology relevant terms, essential physicochemical properties for nanomaterial characterization, current international activi...

  10. Dow's chemical exposure index guide

    International Nuclear Information System (INIS)

    A number of events in the 1970's and 1980's impacted the course of process safety. Incidents such as Flixborough, Seveso, Three-Mile Island, and Bhopal are well known throughout industry and are recognized as examples of major disasters. Even though events leading up to these disasters were completely different they had one common element between them: a substance was released from a manufacturing unit, became airborne and presented a hazard of such magnitude as to place the safety of both employees and the surrounding public in jeopardy. As a result, industry became increasingly concerned regarding potential loss, in human and economic terms, as plants and equipment grew in size. The Flixborough incident raised the level of concern for process safety, particularly in terms of the hazards presented by fire and explosion. Seveso and Three-Mile Island emphasized the need to consider far-field exposure. The Bhopal incident created an urgent need to recognize and understand the expected downwind impact of potential releases of acutely toxic substances to the air. In order to meet this need, the Dow Chemical Company, a recognized leader in the area of safety and loss prevention, presented a Chemical Exposure Index in 1986. AIChE has recently published an updated version entitled Dow's Chemical Exposure Index Guide. 7 refs., 5 figs

  11. Medical exposures, challenge and impacts

    International Nuclear Information System (INIS)

    The medical exposures have a significant contribution to the doses received by the population, reasons for what has not been considered during time its risks. In such sense in the last years the scientific community and international organizations have defined requirements for contribute to that the doses to those patients are the minimum ones necessary to achieve its diagnostic objective. The work exposes the radiological contribution, risks, uses and the actions for to improve the safety of the medical exposures. (Author)

  12. Medical exposures: challenges and impacts

    International Nuclear Information System (INIS)

    Good medical care that is practiced in the safety and welfare of the patient with the medical radiation is analyzed. The attention to patients includes: exposures to patients as part of their diagnosis or treatment, exposures to people that consciously help to the patients and exposures to volunteers included in biomedical research programs. The good medical treatment allows the improvement of the human health, the necessary doses of radiation are benefits for the patients. 2000 million are performed annually in radiodiagnosis, 32 million of nuclear medicine studies and 5.5 million of radiotherapy treatment. Ionizing medical radiations have increased considerably by reports of Unsa in 2000, since 1988 the radiation has been used to provide diagnoses and therapies in patients. The radiation is used both in children and adults to prevent and control different diseases, for example the cancer. In this report, the Cuban experience in relation to the subject is told, their progress, rights and wrongs. Finally, there are surprising data about how radiation has damaged human health and in some cases the doctors have been using the wrong dose and the wrong drug in patients

  13. Current chemical exposures among Ontario construction workers.

    Science.gov (United States)

    Verma, Dave K; Kurtz, Lawrence A; Sahai, Dru; Finkelstein, Murray M

    2003-12-01

    Current occupational exposures to chemical agents were assessed as part of an epidemiological study pertaining to the cancer and mortality patterns of Ontario construction workers. The task-based exposure assessment involved members from nine construction trade unions. Air samples were taken using personal sampling pumps and collection media. A DustTrak direct-reading particulate monitor was also employed. Exposure assessments included measurements of airborne respirable, inhalable, total, and silica dust; solvents; metals; asbestos; diesel exhaust and man-made mineral fibers (MMMF). In total, 396 single- or multi-component (filter/tube), 798 direct-reading, and 71 bulk samples were collected. The results showed that Ontario construction workers are exposed to potentially hazardous levels of chemical agents. The findings are similar to those reported by other researchers, except for silica exposure. In our study, silica exposure is much lower than reported elsewhere. The difficulty associated with assessing construction workers' exposures is highlighted. PMID:14612300

  14. Chemical exposure and leukemia clusters

    International Nuclear Information System (INIS)

    This paper draws attention to the heterogeneous distribution of leukemia in childhood and in adults. The topic of cluster reports and generalized clustering is addressed. These issues are applied to what is known of the risk factor for both adult and childhood leukemia. Finally, the significance of parental occupational exposure and childhood leukemia is covered. (author). 23 refs

  15. Modelling Human Exposure to Chemicals in Food

    NARCIS (Netherlands)

    Slob W

    1993-01-01

    Exposure to foodborne chemicals is often estimated using the average consumption pattern in the human population. To protect the human population instead of the average individual, however, interindividual variability in consumption behaviour must be taken into account. This report shows how food

  16. HANFORD CHEMICAL VAPORS WORKER CONCERNS & EXPOSURE EVALUATION

    Energy Technology Data Exchange (ETDEWEB)

    ANDERSON, T.J.

    2006-12-20

    Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank headspaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns. risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits-(OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors.

  17. Controlling exposure to chemicals: a simple guide.

    Science.gov (United States)

    Hay, Alastair

    2006-09-01

    Controlling exposure to chemicals in the workplace has been made easier by the use of a guide published by the U.K. Health and Safety Executive (HSE). Known as COSHH (Control of Substances Hazardous to Health Regulations) Essentials, the guide is a simple five-step procedure to devise appropriate control strategies to reduce exposures to various substances under different conditions. U.K. health and safety law requires risk assessments prior to use of hazardous substances and installation of appropriate control strategies before work commences. A 1996 survey of 1500 safety managers and trade union safety representatives revealed that the majority had little understanding of occupational safety limits for chemicals. Small- and medium-sized companies had little understanding of limits, and most could not develop control strategies. A new approach was required. COSHH Essentials is it. Developed over 3 years by a working group of hygienists and toxicologists representing HSE, industry, trade unions, and independent experts, the guide is now available in both paper-based and internet versions. It applies a hazard banding approach validated by data for 111 substances that have well-founded U.K. occupational exposure limits. New users select an appropriate hazard band for chemicals based on risk phrases. Details about dustiness for powders or volatility for liquids are inserted, and the guide allocates substances to one of four exposure bands linked, in turn, to specific control strategies. Now accessible through the HSE web site, COSHH Essentials will offer control strategies for both single chemicals and whole processes. To date over 300,000 risk assessments have been carried out using the internet version of COSHH Essentials. PMID:17119256

  18. Exploring consumer exposure pathways and patterns of use for chemicals in the environment

    OpenAIRE

    Dionisio, Kathie L; Frame, Alicia M; Goldsmith, Michael-Rock; Wambaugh, John F; Liddell, Alan; Cathey, Tommy; Smith, Doris; Vail, James; Ernstoff, Alexi; Fantke, Peter; Jolliet, Olivier; Judson, Richard S.

    2015-01-01

    Humans are exposed to thousands of chemicals in the workplace, home, and via air, water, food, and soil. A major challenge in estimating chemical exposures is to understand which chemicals are present in these media and microenvironments. Here we describe the Chemical/Product Categories Database (CPCat), a new, publically available (http://actor.epa.gov/cpcat) database of information on chemicals mapped to “use categories” describing the usage or function of the chemical. CPCat was created by...

  19. Nuclear industry - challenges in chemical engineering

    International Nuclear Information System (INIS)

    Chemical engineering processes and operations are closely involved in every step of the nuclear fuel cycle. Starting from mining and milling of the ore through the production of fuel and other materials and their use in nuclear reactors, fuel reprocessing, fissile material recycle and treatment and disposal of fission product wastes, each step presents a challenge to the chemical engineer to evolve and innovate processes and techniques for more efficient utilization of the energy in the atom. The requirement of high recovery of the desired components at high purity levels is in itself a challenge. ''Nuclear Grade'' specifications for materials put a requirement which very few industries can satisfy. Recovery of uranium and thorium from low grade ores, of heavy water from raw water, etc. are examples. Economical and large scale separation of isotopes particularly those of heavy elements is a task for which processess are under various stages of development. Further design of chemical plants such as fuel reprocessing plants and high level waste treatment plants, which are to be operated and maintained remotely due to the high levels of radio-activity call for engineering skills which are being continually evolved. In the reactor, analysis of the fluid mechanics and optimum design of heat removal system are other examples where a chemical engineer can play a useful role. In addition to the above, the activities in the nuclear industry cover a very wide range of chemical engineering applications, such as desalination and other energy intensive processes, radioisotope and radiation applications in industry, medicine and agriculture. (auth.)

  20. Environmental chemical exposures and breast cancer

    Directory of Open Access Journals (Sweden)

    E. Stanley

    2016-02-01

    Full Text Available As a hormone-sensitive condition with no single identifiable cause, breast cancer is a major health problem. It is characterized by a wide range of contributing factors and exposures occurring in different combinations and strengths across a lifetime that may be amplified during periods of enhanced developmental susceptibility and impacted by reproductive patterns and behaviours. The vast majority of cases are oestrogen-receptor positive and occur in women with no family history of the disease suggesting that modifiable risk factors are involved. A substantial body of evidence now links oestrogen-positive breast cancer with environmental exposures. Synthetic chemicals capable of oestrogen mimicry are characteristic of industrial development and have been individually and extensively assessed as risk factors for oestrogen-sensitive cancers. Existing breast cancer risk assessment tools do not take such factors into account. In the absence of consensus on causation and in order to better understand the problem of escalating incidence globally, an expanded, integrated approach broadening the inquiry into individual susceptibility breast cancer is proposed. Applying systems thinking to existing data on oestrogen-modulating environmental exposures and other oestrogenic factors characteristic of Westernisation and their interactions in the exposure, encompassing social, behavioural, environmental, hormonal and genetic factors, can assist in understanding cancer risks and the pursuit of prevention strategies. A new conceptual framework based on a broader understanding of the “system” that underlies the development of breast cancer over a period of many years, incorporating the factors known to contribute to breast cancer risk, could provide a new platform from which government and regulators can promulgate enhanced and more effective prevention strategies.

  1. Energy and environmental challenges to chemical engineers

    International Nuclear Information System (INIS)

    The National Research Council's report, Frontiers in Chemical Engineering, was written four years ago. Three high-priority research areas concerned with energy and the environment were identified in the report: in situ processing, liquid fuels for the future, and responsible management of hazardous wastes. As outlined in the recently released National Energy Strategy, in situ processing is viewed by the Department of Energy (DOE) primarily through its use in enhanced oil recovery, and some research is still funded. Industry, driven by the economics of low oil prices, is doing little research on in situ processing but much more on reservoir characterization, a prerequisite to processing. Research on liquid fuels for the future is driven more by environmental concerns now than by energy security concerns. It appears to be wise policy for the future to try to solve the alternative fuel problem as quickly and simply as possible. Otherwise, the nation will find itself with a costly and complex fuel and vehicle system that may have to be changed again in a generation. For the interim, we should look closely at reformulated gasoline followed by compressed natural gas, if necessary. In the long run, vehicle systems based on electricity seem most promising for the middle of the next century. To deliver this technology we need to capitalize on three new high-priority research areas: batteries, fuel cells, and nuclear power. For chemical engineers, future challenges of a different sort will be added to the technical challenges, among them are explaining to a skeptical public the wisdom of proceeding to design the interim system of alternative fuel(s) and to move expeditiously to a final solution

  2. Emerging Challenges in the Management of Public and Emergency Exposure

    International Nuclear Information System (INIS)

    The direction of radiological protection thinking has been developing and evolving since the very beginning of the ICRP in 1928. This evolution has been both episodic (e.g. new risk factors from epidemiology studies) and continuous (changing social values, gaining experience in implementing radiological protection) and provides us with significant historical backup. This historical perspective puts us in a good position to assess current challenges in the areas of public and emergency exposure management. In public exposure, challenges include adapting to increasing stakeholder involvement in decision making processes, the management of radon exposure, and integrating new and emerging scientific knowledge into radiation protection practice. In emergency management, challenges include the incorporation of stakeholder input into consequence management, developing approaches to optimisation of protection strategies, and better understanding of objectives and processes for recovery. (author)

  3. Sources of toxicity and exposure information for identifying chemicals of high concern to children

    International Nuclear Information System (INIS)

    Due to the large number of chemicals in commerce without adequate toxicity characterization data, coupled with an ineffective federal policy for chemical management in the United States, many states are grappling with the challenge to identify toxic chemicals that may pose a risk to human health and the environment. Specific populations (e.g., children, elderly) are particularly sensitive to these toxic chemicals. In 2008, the Children's Safe Product Act (CSPA) was passed in Washington State. The CSPA included specific requirements to identify High Priority Chemicals (HPCs) and Chemicals of High Concern to Children (CHCCs). To implement this legislation, a methodology was developed to identify HPCs from authoritative scientific and regulatory sources on the basis of toxicity criteria. Another set of chemicals of concern was then identified from authoritative sources, based on their potential exposure to children. Exposure potential was evaluated by identifying chemicals detected in biomonitoring studies (i.e., human tissues), as well as those present in residential exposure media (e.g., indoor air, house dust, drinking water, consumer products). Accordingly, CHCCs were defined as HPCs that also appear in biomonitoring studies or relevant exposure media. For chemicals with unique Chemical Abstracts Service (CAS) numbers, we identified 2044 HPCs and 2219 chemicals with potential exposure to children, resulting in 476 CHCCs. The process of chemical identification is dynamic, so that chemicals may be added or subtracted as new information becomes available. Although beyond the scope of this paper, the 476 CHCCs will be prioritized in a more detailed assessment, based on the strength and weight of evidence of toxicity and exposure data. Our approach was developed to be flexible which allows the addition or removal of specific sources of toxicity or exposure information, as well as transparent to allow clear identification of inputs. Although the methodology was

  4. Managing Exposure to Natural Sources: International Standards and New Challenges

    International Nuclear Information System (INIS)

    Radiation protection in exposure to natural sources has been evolving for decades. In the last two decades, developments concerning exposure to NORM have resulted in progress towards achieving broad international consensus on managing exposure to NORM. However, the standards and regulatory approaches being adopted at the national level still need to be harmonized, especially in developing countries with limited regulatory resources. A large effort is underway at the national and international level to assess exposure to NORM and to develop strategies to address existing situations that give rise to exposures. The United Nations Scientific Committee on the Effects of Atomic Radiation, in its 2008 report, encourages further development of inventories and methodologies for dose assessment in order to have a more comprehensive view over the topic. The revised International Basic Safety Standards (BSS) published by the IAEA in 2011 provides requirements reflecting the concepts of planned exposure situations, emergency exposure situations and existing exposure situations. Exposure to natural sources is generally subject to the requirements for existing exposure situations, with some exceptions to be considered as planned exposure situations. The BSS provides numerical criteria for exemption and clearance for regulatory purposes as well as reference levels for control of exposure to radon in workplaces. From a global perspective, the new radiation protection challenges for natural sources include the following: the harmonization of standards and regulatory approaches; the diverse nature of the industries and the need for an industry specific approach in determining radiation protection measures; the identification of situations that could be classified as either existing exposure situations or planned exposure situations; and the extent to which exposures should be optimized using, as appropriate, reference levels or dose constraints. The use of a graded approach in

  5. Regulating Chemicals: A Public Policy Challenge

    OpenAIRE

    Archibald, Sandra O.

    1990-01-01

    Policy and regulatory decisions about the use of chemicals in food production and processing are unavoidable. However, scientific and economic information upon which to base these decisions is limited. At the same time many people have stakes in the benefits or costs associated with the use of these chemicals. Consumers are increasingly concerned that current regulations do not emphasize health risks sufficiently and give too much emphasis to current economic benefits from chemicals. Producer...

  6. Biomonitoring of occupational exposure to chemical carcinogens

    Czech Academy of Sciences Publication Activity Database

    Šrám, Radim; Binková, Blanka

    Amsterdam : IOS Press, 2003 - (Cebulska-Wasilewska, A.; Au, W.; Šrám, R.), s. 44-48 - (NATO Sci. Series I.. 351) Grant ostatní: EC(XE) QLK4-CT-2002-02831 Institutional research plan: CEZ:AV0Z5039906 Keywords : polycyclic aromatic hydrocarbons * occupational exposure * biomarkers of exposure Subject RIV: EB - Genetics ; Molecular Biology

  7. Developmental Exposure to Environmental Chemicals and Metabolic Changes in Children.

    Science.gov (United States)

    Russ, Karin; Howard, Sarah

    2016-08-01

    The incidence of childhood obesity, type 2 diabetes, and other forms of metabolic disease have been rising over the past several decades. Although diet and physical activity play important roles in these trends, other environmental factors also may contribute to this significant public health issue. In this article, we discuss the possibility that widespread exposure to endocrine-disrupting chemicals (EDCs) may contribute to the development of metabolic diseases in children. We summarize the epidemiological evidence on exposure to environmental chemicals during early development and metabolic outcomes in infants and children. Prenatal exposure to EDCs, particularly the persistent organic pollutant DDT and its metabolite DDE, may influence growth patterns during infancy and childhood. The altered growth patterns associated with EDCs vary according to exposure level, sex, exposure timing, pubertal status, and age at which growth is measured. Early exposure to air pollutants also is linked to impaired metabolism in infants and children. As a result of these and other studies, professional health provider societies have called for a reduction in environmental chemical exposures. We summarize the resources available to health care providers to counsel patients on how to reduce chemical exposures. We conclude with a discussion of environmental policies that address chemical exposures and ultimately aim to improve public health. PMID:27401018

  8. The NIH Countermeasures Against Chemical Threats Program: overview and special challenges.

    Science.gov (United States)

    Jett, David A

    2016-06-01

    Intentional exposures to toxic chemicals can stem from terrorist attacks, such as the release of sarin in the Tokyo subway system in 1995, as well as from toxic industrial accidents that are much more common. Developing effective medical interventions is a critical component of the overall strategy to overcome the challenges of chemical emergencies. These challenges include the rapid and lethal mode of action of many toxic chemicals that require equally fast-acting therapies, the large number of chemicals that are considered threats, and the diverse demographics and vulnerabilities of those who may be affected. In addition, there may be long-term deleterious effects in survivors of a chemical exposure. Several U.S. federal agencies are invested in efforts to improve preparedness and response capabilities during and after chemical emergencies. For example, the National Institutes of Health (NIH) Countermeasures Against Chemical Threats (CounterACT) Program supports investigators who are developing therapeutics to reduce mortality and morbidity from chemical exposures. The program awards grants to individual laboratories and includes contract resource facilities and interagency agreements with Department of Defense laboratories. The range of high-quality research within the NIH CounterACT Program network is discussed. PMID:27398820

  9. CHEMDNER: The drugs and chemical names extraction challenge

    OpenAIRE

    Krallinger, M.; Leitner, F.; Rabal, O.; Vazquez, M.; Oyarzabal, J.; Valencia, A.

    2015-01-01

    Natural language processing (NLP) and text mining technologies for the chemical domain (ChemNLP or chemical text mining) are key to improve the access and integration of information from unstructured data such as patents or the scientific literature. Therefore, the BioCreative organizers posed the CHEMDNER (chemical compound and drug name recognition) community challenge, which promoted the development of novel, competitive and accessible chemical text mining systems. This task allowed a comp...

  10. Optimal Exposure Biomarkers for Nonpersistent Chemicals in Environmental Epidemiology.

    Science.gov (United States)

    Calafat, Antonia M; Longnecker, Matthew P; Koch, Holger M; Swan, Shanna H; Hauser, Russ; Goldman, Lynn R; Lanphear, Bruce P; Rudel, Ruthann A; Engel, Stephanie M; Teitelbaum, Susan L; Whyatt, Robin M; Wolff, Mary S

    2015-07-01

    We discuss considerations that are essential when evaluating exposure to nonpersistent, semivolatile environmental chemicals such as phthalates and phenols (e.g., bisphenol A). A biomarker should be chosen to best represent usual personal exposures and not recent, adventitious, or extraneous exposures. Biomarkers should be selected to minimize contamination arising from collection, sampling, or analysis procedures. Pharmacokinetics should be considered; for example, nonpersistent, semivolatile chemicals are metabolized quickly, and urine is the compartment with the highest concentrations of metabolites. Because these chemicals are nonpersistent, knowledge of intraindividual reliability over the biologic window of interest is also required. In recent years researchers have increasingly used blood as a matrix for characterizing exposure to nonpersistent chemicals. However, the biologic and technical factors noted above strongly support urine as the optimal matrix for measuring nonpersistent, semivolatile, hydrophilic environmental agents. PMID:26132373

  11. Biomonitoring human exposure to environmental carcinogenic chemicals

    DEFF Research Database (Denmark)

    Farmer, P.B.; Sepai, O.; Lawrence, R.;

    1996-01-01

    detecting carcinogen-induced damage to DNA and proteins, and subsequent biological effects. These methods were validated with the occupational exposures, which showed evidence of DNA and/or protein and/or chromosome damage in workers in a coke oven plant, garage workers exposed to diesel exhaust and workers...

  12. Chemical exposure and lung function in fragrance industry employees

    OpenAIRE

    Dix, Garry R.

    2012-01-01

    Introduction Production employees within the UK fragrance industry are exposed to large quantities of chemical substances and mixtures over working shifts. Occupational respiratory exposure within this industry is managed in line with relevant legislation and guidelines. There is a lack, however, of published literature studying the effects of respiratory exposure to chemicals on fragrance production employees. A multi-site cross-sectional study was conducted using employees from the ...

  13. Optimal Exposure Biomarkers for Nonpersistent Chemicals in Environmental Epidemiology

    OpenAIRE

    Calafat, Antonia M.; Longnecker, Matthew P.; Koch, Holger M.; Swan, Shanna H.; HAUSER Russ; Goldman, Lynn R.; Lanphear, Bruce P; Rudel, Ruthann A.; Engel, Stephanie M.; Teitelbaum, Susan L.; Whyatt, Robin M.; Wolff, Mary S.

    2015-01-01

    Summary We discuss considerations that are essential when evaluating exposure to nonpersistent, semivolatile environmental chemicals such as phthalates and phenols (e.g., bisphenol A). A biomarker should be chosen to best represent usual personal exposures and not recent, adventitious, or extraneous exposures. Biomarkers should be selected to minimize contamination arising from collection, sampling, or analysis procedures. Pharmacokinetics should be considered; for example, nonpersistent, sem...

  14. Exposure to formaldehyde: a challenge of occupational health significance

    International Nuclear Information System (INIS)

    The use of formaldehyde as the fixative for general microscopic demonstration of tissues in medical laboratory establishments is as significant as the diagnosis of the underlying ailment. Instantaneous human exposure to formaldehyde elicits symptoms that may include watery eyes, headache, inflamed throat and dyspnea. The gaseous chemical is toxic, allergenic and carcinogenic. A study to determine the incidence of human exposure to formaldehyde was carried out at the University Teaching Hospital in Lusaka, Zambia from January to December, 2007. Anonymous questionnaires on various aspects of human exposure to formaldehyde were given to laboratory technical personnel. Exposure to formaldehyde was determined using general consideration model comprising points awarded to participants according to their responses. Five points represented the maximum level of exposure, while one point denoted the minimum encounter. There were 8 incidents of formaldehyde pollution, with five being emissions from 210-litre formalin receptacles whose stoppers were inadvertently left loose overnight, while three involved accidental breakage of Winchester bottles of formalin. A total of 115 people were exposed during the year. Fifteen (13.0 percent) participants scored one point each, while 20 (17.4 percent) participants obtained 2 points each. Thirty-five (30.4 percent) participants got 3 points each, while 30 (26.0 percent) participants received 4 points each. Twenty-five (21.7 percent) participants attained 5 points each. Human exposure to formaldehyde is an issue of occupational health concern. Participants with a score of 3 points or more need regular medical check ups in order to safeguard their health. Programs on effective management of hazardous chemicals are worth setting up.(author)

  15. Biotechnology for Chemical Production: Challenges and Opportunities.

    Science.gov (United States)

    Burk, Mark J; Van Dien, Stephen

    2016-03-01

    Biotechnology offers a new sustainable approach to manufacturing chemicals, enabling the replacement of petroleum-based raw materials with renewable biobased feedstocks, thereby reducing greenhouse gas (GHG) emissions, toxic byproducts, and the safety risks associated with traditional petrochemical processing. Development of such bioprocesses is enabled by recent advances in genomics, molecular biology, and systems biology, and will continue to accelerate as access to these tools becomes faster and cheaper. PMID:26683567

  16. Chemical and physical knowledge about radiation exposure

    International Nuclear Information System (INIS)

    Easily explained is the title subject about the electromagnetic wave, photon, neutron, particle line, linear energy transfer and unit. The electromagnetic wave is a waving particle, photon, without mass and generally involves radio, infrared, visible, ultraviolet and gamma (and X) rays. The interaction between photon and material atom involves effects photoelectric, yielding electron pair, Compton scattering and nuclear in the order of photon energy: respectively important in low energy imaging like mammography vs high exposure dose; positron emit tomography (PET); cause of image fading or source of radiation therapy; and at >7 MeV photon (e.g., linac therapy), the nuclear reaction-generated neutron, hazardous to radiological staff. Neutron has no electric charge and should be shielded by light atoms like H and C as energy loss by collision is efficient. Alpha ray generated by the reaction 10B(n, alpha) 7Li can effectively kill cancer cells. Particle line involves alpha and beta rays. Alpha particle from Rn is sometimes problematic for human health because Ra contained in building materials produces Rn. Beta ray is one of causes of exposure and produces Bremsstrahlung X-ray at its stoppage, which is used for imaging of 89Sr and so on. Beta ray from 40K is important in the internal exposure as the atom in the body amounts to 55 Bq/kg body weight. Effects of radiation depend on its range and ionization in the body: the linear energy transfer (LET) describes the degree of the effects. Unit contains that of the exposure (dose of irradiation) and absorption, and of the radioactivity: the first is expressed by R (roentgen), measurable with the direct ionization effect; the second, Gy (gray), calculable from R; and the third, the decay rate of radionuclide, disintegration per sec (dps) =1 Bq (becquerel). The equivalent doses are expressed by Sv (sievert). (T.T.)

  17. Challenges and opportunities in synthetic biology for chemical engineers

    OpenAIRE

    Luo, Yunzi; Lee, Jung-Kul; Zhao, Huimin

    2012-01-01

    Synthetic biology provides numerous great opportunities for chemical engineers in the development of new processes for large-scale production of biofuels, value-added chemicals, and protein therapeutics. However, challenges across all scales abound. In particular, the modularization and standardization of the components in a biological system, so-called biological parts, remain the biggest obstacle in synthetic biology. In this perspective, we will discuss the main challenges and opportunitie...

  18. A decision analytic approach to exposure-based chemical prioritization.

    Directory of Open Access Journals (Sweden)

    Jade Mitchell

    Full Text Available The manufacture of novel synthetic chemicals has increased in volume and variety, but often the environmental and health risks are not fully understood in terms of toxicity and, in particular, exposure. While efforts to assess risks have generally been effective when sufficient data are available, the hazard and exposure data necessary to assess risks adequately are unavailable for the vast majority of chemicals in commerce. The US Environmental Protection Agency has initiated the ExpoCast Program to develop tools for rapid chemical evaluation based on potential for exposure. In this context, a model is presented in which chemicals are evaluated based on inherent chemical properties and behaviorally-based usage characteristics over the chemical's life cycle. These criteria are assessed and integrated within a decision analytic framework, facilitating rapid assessment and prioritization for future targeted testing and systems modeling. A case study outlines the prioritization process using 51 chemicals. The results show a preliminary relative ranking of chemicals based on exposure potential. The strength of this approach is the ability to integrate relevant statistical and mechanistic data with expert judgment, allowing for an initial tier assessment that can further inform targeted testing and risk management strategies.

  19. Challenges for chemical sciences in the 21st century

    Directory of Open Access Journals (Sweden)

    Čeković Živorad

    2004-01-01

    Full Text Available Chemistry and chemical engineering have changed very significantly in the last half century. From classical sciences they have broadened their scope into biology, medicine, physics, material science, nanotechnology, computation and advanced methods of process engineering and control. The applications of chemical compounds, materials and knowledge have also dramatically increased. The development of chemical sciences in the scientifically most advanced countries, at the end of the last century was extrapolated to the next several decades in this review and challenges for chemists and chemical engineers are described. Research, discovery and invention across the entire spectrum of activities in the chemical sciences, from fundamental molecular-level chemistry to large-scale chemical processing technology are summarized. The strong integration of chemical science and engineering into all other natural sciences, agriculture, environmental science, medicine, as well as into physics, material science and information technology is discussed. Some challenges for chemists and chemical engineers are reviewed in the following fields: i synthesis and manufacturing of chemical products, ii chemistry for medicine and biology, iii new materials, iv chemical and physical transformations of materials, v chemistry in the solving of energy problems (generation and savings, vi environmental chemistry: fundamental and practical challenges.

  20. Chemical exposure during pregnancy and oral clefts in newborns

    Directory of Open Access Journals (Sweden)

    Leite Isabel Cristina Gonçalves

    2002-01-01

    Full Text Available This article presents a literature review on the risk factors for oral clefts (lip and/or palate, emphasizing discussion of maternal exposure to endocrine disruptors. Several studies have identified the risk of cigarette smoking and alcohol consumption, use of anticonvulsivant drugs, and exposure to organic solvents. A protective effect has been shown for supplementation with folic acid. As with other chemicals, the risk associated with exposure to sex hormones is still obscure, although some authors describe a moderate risk level. New studies addressing this hypothesis need to be conducted, while the population exposed to these endocrine disrupters is increasing.

  1. Chemical exposure during pregnancy and oral clefts in newborns

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Gonçalves Leite

    2002-02-01

    Full Text Available This article presents a literature review on the risk factors for oral clefts (lip and/or palate, emphasizing discussion of maternal exposure to endocrine disruptors. Several studies have identified the risk of cigarette smoking and alcohol consumption, use of anticonvulsivant drugs, and exposure to organic solvents. A protective effect has been shown for supplementation with folic acid. As with other chemicals, the risk associated with exposure to sex hormones is still obscure, although some authors describe a moderate risk level. New studies addressing this hypothesis need to be conducted, while the population exposed to these endocrine disrupters is increasing.

  2. High Throughput Exposure Forecasts for Environmental Chemical Risk (SOT RASS)

    Science.gov (United States)

    Email Announcement to RASS: On December 11th we have rescheduled the webinar regarding progress and advances in exposure assessment, which was cancelled due to the government shutdown in October. Dr. Elaine Hubal, Deputy Director of the Chemical Safety for Sustainability (CSS) n...

  3. Risk management of exposure to chemicals under operational conditions

    NARCIS (Netherlands)

    Langenberg, J.P.

    2007-01-01

    The HFM panel has decided to install an Exploratory Team, ET-078, which should advise whether or not a Technical Group (TG) should be established on the subject of risk management of exposure to chemicals under operational conditions. This paper described the context and approach of ET-078.

  4. Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cowan-Ellsberry, Christina E.; McLachlan, Michael S.; Arnot, Jon A.; MacLeod, Matthew; McKone, Thomas E.; Wania, Frank

    2008-11-01

    Fate and exposure modeling has not thus far been explicitly used in the risk profile documents prepared to evaluate significant adverse effect of candidate chemicals for either the Stockholm Convention or the Convention on Long-Range Transboundary Air Pollution. However, we believe models have considerable potential to improve the risk profiles. Fate and exposure models are already used routinely in other similar regulatory applications to inform decisions, and they have been instrumental in building our current understanding of the fate of POP and PBT chemicals in the environment. The goal of this paper is to motivate the use of fate and exposure models in preparing risk profiles in the POP assessment procedure by providing strategies for incorporating and using models. The ways that fate and exposure models can be used to improve and inform the development of risk profiles include: (1) Benchmarking the ratio of exposure and emissions of candidate chemicals to the same ratio for known POPs, thereby opening the possibility of combining this ratio with the relative emissions and relative toxicity to arrive at a measure of relative risk. (2) Directly estimating the exposure of the environment, biota and humans to provide information to complement measurements, or where measurements are not available or are limited. (3) To identify the key processes and chemical and/or environmental parameters that determine the exposure; thereby allowing the effective prioritization of research or measurements to improve the risk profile. (4) Predicting future time trends including how quickly exposure levels in remote areas would respond to reductions in emissions. Currently there is no standardized consensus model for use in the risk profile context. Therefore, to choose the appropriate model the risk profile developer must evaluate how appropriate an existing model is for a specific setting and whether the assumptions and input data are relevant in the context of the application

  5. Modeling exposure to persistent chemicals in hazard and risk assessment.

    Science.gov (United States)

    Cowan-Ellsberry, Christina E; McLachlan, Michael S; Arnot, Jon A; Macleod, Matthew; McKone, Thomas E; Wania, Frank

    2009-10-01

    Fate and exposure modeling has not, thus far, been explicitly used in the risk profile documents prepared for evaluating the significant adverse effect of candidate chemicals for either the Stockholm Convention or the Convention on Long-Range Transboundary Air Pollution. However, we believe models have considerable potential to improve the risk profiles. Fate and exposure models are already used routinely in other similar regulatory applications to inform decisions, and they have been instrumental in building our current understanding of the fate of persistent organic pollutants (POP) and persistent, bioaccumulative, and toxic (PBT) chemicals in the environment. The goal of this publication is to motivate the use of fate and exposure models in preparing risk profiles in the POP assessment procedure by providing strategies for incorporating and using models. The ways that fate and exposure models can be used to improve and inform the development of risk profiles include 1) benchmarking the ratio of exposure and emissions of candidate chemicals to the same ratio for known POPs, thereby opening the possibility of combining this ratio with the relative emissions and relative toxicity to arrive at a measure of relative risk; 2) directly estimating the exposure of the environment, biota, and humans to provide information to complement measurements or where measurements are not available or are limited; 3) to identify the key processes and chemical or environmental parameters that determine the exposure, thereby allowing the effective prioritization of research or measurements to improve the risk profile; and 4) forecasting future time trends, including how quickly exposure levels in remote areas would respond to reductions in emissions. Currently there is no standardized consensus model for use in the risk profile context. Therefore, to choose the appropriate model the risk profile developer must evaluate how appropriate an existing model is for a specific setting and

  6. Developing a Semi-Quantitative Occupational Risk Prediction Model for Chemical Exposures and Its Application to a National Chemical Exposure Databank

    Directory of Open Access Journals (Sweden)

    Chiu-Ying Chen

    2013-07-01

    Full Text Available In this study, a semi-quantitative occupational chemical exposure risk prediction model, based on the calculation of exposure hazard indexes, was proposed, corrected, and applied to a national chemical exposure databank. The model comprises one factor used to describe toxicity (i.e., the toxicity index, and two factors used to reflect the exposure potential (i.e., the exposure index and protection deficiency index of workers exposed to chemicals. An expert system was used to correct the above proposed model. By applying the corrected model to data obtained from a national occupational chemical hazard survey program, chemical exposure risks of various manufacturing industries were determined and a national control strategy for the abatement of occupational chemical exposures was proposed. The results of the present study would provide useful information for governmental agencies to allocate their limited resources effectively for reducing chemical exposures of workers.

  7. Health effects assessment of chemical exposures: ARIES methodology

    International Nuclear Information System (INIS)

    In this work, we present ARIES* update: a system designed in order to facilitate the human health effects assessment produced by accidental release of toxic chemicals. The first version of ARIES was developed in relation to 82/501/EEC Directive about mayor accidents in the chemical industry. So, the first aim was the support of the effects assessment derived for the chemicals included into this directive. From this establishment, it was considered acute exposures for high concentrations. In this report, we present the actual methodology for considering other type of exposures, such as environmental and occupational. Likewise other versions, the methodology comprises two approaches: quantitative and qualitative assessments. Quantitative assessment incorporates the mathematical algorithms useful to evaluate the effects produced by the most important routes of exposure: inhalation, ingestion, eye contact and skin absorption, in a short, medium and long term. It has been included models that realizes an accurate quantification of doses, effects,... and so on, such as simple approaches when the available information is not enough. Qualitative assessment, designed in order to complement or replace the previous one, is incorporated into an informatics system, developed in Clipper. It executes and displays outstanding and important toxicological information of about 100 chemicals. This information comes from ECDIN (Environmental Chemicals Data and Information Network) database through a collaboration with JRC-ISPRA working group. (Author) 24 refs

  8. Health effects assessment of chemical exposures: ARIES methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, L; Montero, M.; Rabago, I.; Vidania, R.

    1995-07-01

    In this work, we present ARIES* update: a system designed in order to facilitate the human health effects assessment produced by accidental release of toxic chemicals. The first version of ARIES was developed in relation to 82/501/EEC Directive about mayor accidents in the chemical industry. So, the first aim was the support of the effects assessment derived for the chemicals included into this directive. From this establishment, it was considered acute exposures for high concentrations. In this report, we present the actual methodology for considering other type of exposures, such as environmental and occupational. Likewise other versions, the methodology comprises two approaches: quantitative and qualitative assessments. Quantitative assessment incorporates the mathematical algorithms useful to evaluate the effects produced by the most important routes of exposure: inhalation, ingestion, eye contact and skin absorption, in a short, medium and long term. It has been included models that realizes an accurate quantification of doses, effects,... and so on, such as simple approaches when the available information is not enough. Qualitative assessment, designed in order to complement or replace the previous one, is incorporated into an informatics system, developed in Clipper. It executes and displays outstanding and important toxicological information of about 100 chemicals. This information comes from ECDIN (Environmental Chemicals Data and Information Network) database through a collaboration with JRC-ISPRA working group. (Author) 24 refs.

  9. HANFORD CHEMICAL VAPORS WORKER CONCERNS and EXPOSURE EVALUATION

    International Nuclear Information System (INIS)

    Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank headspaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns. risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits-(OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors

  10. Chemosensory perception, symptoms and autonomic responses during chemical exposure in multiple chemical sensitivity

    DEFF Research Database (Denmark)

    Andersson, Linus; Claeson, Anna Sara; Dantoft, Thomas Meinertz;

    2016-01-01

    Purpose: Multiple chemical sensitivity (MCS) is a prevalent medically unexplained symptom characterized by symptom reactions to everyday chemical exposure below hygienic thresholds. The aim of this study was to investigate the expressions of hyper-reactivity in MCS during whole-body exposure to l...... found for breathing rate or tonic electrodermal activity responses. Conclusions: We conclude that MCS sufferers differ from healthy controls in terms of autonomic responses, symptoms and chemosensory perception during chemical exposure......./m3. Results: MCS participants, compared with controls, reported greater perceived odor intensities, more unpleasantness to the exposure and increasing symptoms over time. MCS participants also expressed higher pulse rate and lower pulse rate variability than controls did. No group differences were...

  11. Historical Exposures to Chemicals at the Rocky Flats Nuclear Weapons Plant: A Pilot Retrospective Exposure Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Janeen Denise Robertson

    1999-02-01

    In a mortality study of white males who had worked at the Rocky Flats Nuclear Weapons Plant between 1952 and 1979, an increased number of deaths from benign and unspecified intracranial neoplasms was found. A case-control study nested within this cohort investigated the hypothesis that an association existed between brain tumor death and exposure to either internally deposited plutonium or external ionizing radiation. There was no statistically significant association found between estimated radiation exposure from internally deposited plutonium and the development of brain tumors. Exposure by job or work area showed no significant difference between the cohort and the control groups. An update of the study found elevated risk estimates for (1) all lymphopoietic neoplasms, and (2) all causes of death in employees with body burdens greater than or equal to two nanocuries of plutonium. There was an excess of brain tumors for the entire cohort. Similar cohort studies conducted on worker populations from other plutonium handling facilities have not yet shown any elevated risks for brain tumors. Historically, the Rocky Flats Nuclear Weapons Plant used large quantities of chemicals in their production operations. The use of solvents, particularly carbon tetrachloride, was unique to Rocky Flats. No investigation of the possible confounding effects of chemical exposures was done in the initial studies. The objectives of the present study are to (1) investigate the history of chemical use at the Rocky Flats facility; (2) locate and analyze chemical monitoring information in order to assess employee exposure to the chemicals that were used in the highest volume; and (3) determine the feasibility of establishing a chemical exposure assessment model that could be used in future epidemiology studies.

  12. Molecular epidemiology of childhood leukemia with emphasis on chemical exposures

    Energy Technology Data Exchange (ETDEWEB)

    Buffler, P.A.; Smith, M.T.; Wood, S. [Univ. of California, Berkeley, CA (United States); Reynolds, P. [California Dept. of Health Services, Emeryville, CA (United States)

    1996-12-31

    Developing markets in the Pacific Basin depend heavily on the production and export of consumer goods. The generation of hazardous waste as a by-product of industrial production can be linked to adverse health outcomes, such as childhood leukemia, in ways that are presently unknown. In California, exposures resulting from hazardous waste disposal are of concern in the etiology of childhood cancer. Approximately 63% of the 57 hazardous waste sites that the U.S. Environmental Protection Agency (USEPA) included in the national priority list under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) statute were in the six-county San Francisco Bay area. This area includes California`s Silicon Valley, where a disproportionate majority of these sites are located. Although only one study links hazardous waste disposal to childhood leukemia evidence is accumulating that in utero and maternal pesticide exposures as well as chemical exposures during childhood are important in the etiology of childhood leukemia. This study investigates whether children with leukemia have common genetic changes, whether children with genetic changes experience common chemical exposures, and whether the occurrences of these genetic changes correspond to the same temporal sequence as exposure. The purpose of this paper is to describe the study design and report on the status of research activity. 10 refs., 1 fig., 3 tabs.

  13. CHEMDNER: The drugs and chemical names extraction challenge.

    Science.gov (United States)

    Krallinger, Martin; Leitner, Florian; Rabal, Obdulia; Vazquez, Miguel; Oyarzabal, Julen; Valencia, Alfonso

    2015-01-01

    Natural language processing (NLP) and text mining technologies for the chemical domain (ChemNLP or chemical text mining) are key to improve the access and integration of information from unstructured data such as patents or the scientific literature. Therefore, the BioCreative organizers posed the CHEMDNER (chemical compound and drug name recognition) community challenge, which promoted the development of novel, competitive and accessible chemical text mining systems. This task allowed a comparative assessment of the performance of various methodologies using a carefully prepared collection of manually labeled text prepared by specially trained chemists as Gold Standard data. We evaluated two important aspects: one covered the indexing of documents with chemicals (chemical document indexing - CDI task), and the other was concerned with finding the exact mentions of chemicals in text (chemical entity mention recognition - CEM task). 27 teams (23 academic and 4 commercial, a total of 87 researchers) returned results for the CHEMDNER tasks: 26 teams for CEM and 23 for the CDI task. Top scoring teams obtained an F-score of 87.39% for the CEM task and 88.20% for the CDI task, a very promising result when compared to the agreement between human annotators (91%). The strategies used to detect chemicals included machine learning methods (e.g. conditional random fields) using a variety of features, chemistry and drug lexica, and domain-specific rules. We expect that the tools and resources resulting from this effort will have an impact in future developments of chemical text mining applications and will form the basis to find related chemical information for the detected entities, such as toxicological or pharmacogenomic properties. PMID:25810766

  14. Low level exposure to chemicals and immune system

    International Nuclear Information System (INIS)

    Industrialized countries are facing an increase of diseases attributable to an alteration of the immune system function, and concern is growing that this trend could be at least partially attributable to new and modified patterns of exposure to chemicals. Among chemicals matter of concern, pesticides can be included. The Authors have reviewed the existing evidence of pesticide immunotoxicity in humans, showing that existing data are inadequate to raise conclusions on the immunotoxic risk related to these compounds. The limits of existing studies are: poor knowledge on exposure levels, heterogeneity of the approach, and difficulty in giving a prognostic significance to the slight changes often observed. To overcome these limits, the Authors have proposed a tier approach, based on three steps: the first, addressed at pointing out a possible immunomodulation; the second, at refining the results and the third one, when needed, to finalize the study and to point out concordance with previous results. Studies should preferably be carried out through comparison of pre- and post-exposure findings in the same groups of subjects to be examined immediately after the end of the exposure. A simplification of the first step approach can be used by the occupational health physician and the occupational toxicologist. Conclusions on the prognostic significance of the slight changes often observed will be reached only by validating the hypothesis generated by field studies with an epidemiological approach. In this field, the most useful option is represented by longitudinal perspective studies

  15. Harmonization of exposure assessment for food chemicals: the international perspective.

    Science.gov (United States)

    Luetzow, Manfred

    2003-04-11

    The assessment of human exposure to chemicals present in the diet is a rapidly developing discipline. The formulation of the "risk analysis paradigm" by the Codex Alimentarius Commission in 1994 defined the exposure assessment as an essential step of the risk assessment process. This has re-enforced demands to those joint FAO/WHO scientific bodies who evaluate the safety of chemicals in foods to estimate routinely intakes for food additives, flavors, contaminants, and residues of pesticides and veterinary drugs as part of their safety assessments. The approaches chosen by the Joint FAO/WHO Expert Committee for Food Additives (JECFA) and the Joint FAO/WHO Expert Meeting on Pesticide Residues (JMPR) for these compounds are considerably different. These differences can only be understood when considering the different risk policies of the Codex Alimentarius Committees involved. Specific problems emerge if global intake assessments are requested; lack of representative regional data for consumption patterns and insufficient knowledge about levels of chemicals occurring in foods in many countries bear the risk that exposure assessments do not provide risk managers with a true global picture. There is a need to improve the collection and dissemination of such data. PMID:12676490

  16. Chemical composition dependence of exposure buildup factors for some polymers

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Tejbir [Department of Physics, S.D.D.I.E.T., Barwala, District Panchkula, Haryana 134 118 (India)], E-mail: tejbir.s@rediffmail.com; Kumar, Naresh [Department of Physics, Lovely Professional University, Phagwara 144 402 (India)], E-mail: naresh20dhiman@yahoo.com; Singh, Parjit S. [Department of Physics, Punjabi University, Patiala 147 002 (India)], E-mail: dr_parjit@hotmail.com

    2009-01-15

    Exposure buildup factors for some polymers such as poly-acrylo-nitrile (PAN), poly-methyl-acrylate (PMA), poly-vinyl-chloride (PVC), synthetic rubber (SR), tetra-fluro-ethylene (Teflon) have been computed using the G.P. fitting method in the energy range of 0.015-15.0 MeV, up to the penetration of 40 mean free paths (mfp). The variation of exposure buildup factors for all the selected polymers with incident photon energy at the fixed penetration depths has been studied, mainly emphasizing on chemical composition (equivalent atomic number) of the selected polymers. It has been observed that for the lower penetration depths (below 10 mfp), the exposure buildup factor decreases with the increase in equivalent atomic number of the selected polymers at all the incident photon energies. However, at the penetration depth of 10 mfp and incident photon energy above 3 MeV, the exposure buildup factor becomes almost independent of the equivalent atomic number of the selected polymers. Further, above the fixed penetration depth of 15 mfp of the selected polymers and above the incident photon energy of 3 MeV, reversal in the trend has been observed, i.e., the exposure buildup factor increases with the increase in equivalent atomic number.

  17. Biological effects of low level exposures to chemicals and radiation

    International Nuclear Information System (INIS)

    In May 1990 a group of scientists representing several federal agencies, the International Society of Regulatory Toxicology and Pharmacology, the private sector, and academia met to develop a strategy to encourage the study of the biological effects of low level exposures (BELLE) to chemical agents and radioactivity. A workshop was held in 1991 with seven invited speakers focusing on the toxicological implications of biological adaptations. The selection of topics and speakers was designed to consider critically the concept of hormesis, not only in a broad, conceptual manner, but also at the molecular and biochemical levels. These presentations offered a complementary perspective on the diverse range of molecular mechanisms that can become activated at low levels of toxicant exposure. In addition to chemical toxicology research, an overview of current research on 'Effects of low-dose radiation on the immune response' was presented as well as 'Cellular adaptation as an important response during chemical carcinogenesis'. The final presentation was devoted to biostatistical considerations when designing studies that address issues associated with the biological responses to low doses of chemicals and radiation, as well as issues in interpretation of the findings from such studies

  18. [Amplified chemical disasters: a challenge for public health].

    Science.gov (United States)

    de Freitas, C M; de S Porte, M F; Gomez, C M

    1995-12-01

    Chemical accidents involving explosions, large fires and leakages of hazardous substances occurring during transport, storage and industrial production of chemicals constitute a real challenge to health, environmental and industrial safety professionals. The aim of this article is to discuss the main questions that this kind of accident provokes, in terms of public health, particularly in developing countries such as Brazil. The paper defines and characterises these accidents and the various health risk they involve excluding the leakages of hazardous substances during "normal" production in industry--through the combination of quantitative and qualitative information drawn from the international literature on the subject. From some examples of chemical accidents such as occurred in Bhopal (India), Vila Socó (Brazil), São Paulo (México) and data of the World Health Organization (WHO), the authors seek to show that these events present a worsening, in terms of immediate deaths and injuries, in developing countries. The statistics of chemical accidents which occurred during the last ten years (1984 to 1993) in the State of Rio de Janeiro are used taken as a frame reference for the purpose of bringing to light the great number of occurrences made with no registration of basic information regarding assessment or surveillance. The complexity of causes and consequences, together with the structural problems of developing countries, present public health professionals and institutions, with some important tasks especially those of health risk assessment and the formulation of strategies to prevent and control future major chemical accidents. PMID:8734976

  19. Diagnosis of exposure to chemical warfare agents: An essential tool to counteract chemical terrorism

    NARCIS (Netherlands)

    Noort, D.; Schans, M.J. van der; Bikker, F.J.; Benschop, H.P.

    2009-01-01

    Methods to analyze chemical warfare agents (CW-agents) and their decomposition products in environmental samples were developed over the last decades. In contrast herewith, procedures for analysis in biological samples have only recently been developed. Retrospective detection of exposure to CW-agen

  20. Occupational exposure to airborne chemical substances in paintings conservators

    Directory of Open Access Journals (Sweden)

    Anna Jeżewska

    2014-02-01

    Full Text Available Background: This paper presents the results of the quantitative study of the airborne chemical substances detected in the conservator's work environment. Material and Methods: The quantitative tests were carried out in 6 museum easel paintings conservation studios. The air test samples were taken at various stages of restoration works, such as cleaning, doubling, impregnation, varnishing, retouching, just to name a few. The chemical substances in the sampled air were measured by the GC-FID (gas chromatography with flame ionization detector test method. Results: The study results demonstrated that concentrations of airborne substances, e.g., toluene, 1,4-dioxane, turpentine and white spirit in the work environment of paintings conservators exceeded the values allowed by hygiene standards. It was found that exposure levels to the same chemical agents, released during similar activities, varied for different paintings conservation studios. It is likely that this discrepancy resulted from the indoor air exchange system for a given studio (e.g. type of ventilation and its efficiency, the size of the object under maintenance, and also from the methodology and protection used by individual employees. Conclusions: The levels of organic solvent vapors, present in the workplace air in the course of painting conservation, were found to be well above the occupational exposure limits, thus posing a threat to the worker's health. Med Pr 2014;65(1:33–41

  1. Chemical markers of occupational exposure to teak wood dust.

    Science.gov (United States)

    Carrieri, Mariella; Bartolucci, Giovanni Battista; Lee, Taekhee; Barbero, Ana; Harper, Martin

    2014-06-01

    A novel high-performance liquid chromatographic/ultraviolet method was developed to detect lapachol (LP) and deoxylapachol (DLP) in wood dust as chemical markers of teak wood (a suspected human carcinogen). The specificity of this analysis was determined by noting the absence of LP and DLP in 12 other specimens of different woods belonging to the angiosperm family. The consistency was examined by analyzing teak from three different sources, where the percentages (wt/wt) of the chemicals ranged from 0.006 to 0.261 for LP and from 0.038 to 0.497 for DLP, respectively. Although the LP and DLP components of teak varied according to source, a very high correlation coefficient (r (2) > 0.98 always) was found between the content of the two markers in the bulk specimens and in bulk dust derived from them. The method was then applied to teak dust collected on polyvinylchloride filters from aerosol in an exposure chamber in the range of mass loadings between 0.03 and 3.65 mg, which corresponds to a dust exposure between 0.124 and 8.703 mg m(-3) for a sampling time of 2h. A field test was also carried out in a small factory where teak was used. A good correlation was confirmed between LP and DLP versus the dust collected on the filter in both cases. LP and DLP can be markers to estimate the true quantities of teak dust inhaled in a workplace with mixed wood dust, provided the results are matched to the content of LP and DLP in the bulk wood. LP and DLP have also been proposed as the agents responsible for allergic reaction to teak dust. Therefore, it would be useful to evaluate the exposure to these two substances even without a relationship to teak dust exposure. PMID:24671613

  2. Toxicology of chemical mixtures: a challenging quest along empirical sciences.

    Science.gov (United States)

    Groten, John P; Heijne, Wilbert H M; Stierum, Rob H; Freidig, Andreas P; Feron, Victor J

    2004-12-01

    This paper describes the "quest" of our institute trying to assess the toxicology of chemical mixtures. In this overview, we will discuss some critical developments in hazard identification and risk assessment of chemical mixtures during these past 15 years. We will stand still at empirical and mechanistic modeling. "Empirical" means that only information on doses or concentrations and effects is available in addition to an often empirically selected quantitative dose-response relationship. Empirical models have played a dominant role in the last decade to identify health and safety characteristics of chemical mixtures. Many of these models are based on the work of pioneers in mixture toxicology who defined three basic types of action for combinations of chemicals: simple similar action, simple dissimilar action and interaction. Nowadays, empirical models are mainly based on response-surface analysis and make use of advanced statistical designs. However, possible interactions between components in a mixture can also be given in terms of mechanistic models. In terms of "mechanistic" (or biological) understanding, interactions between compounds may occur in the kinetic phase (processes of uptake, distribution, metabolism and excretion) or in the dynamic phase (effects of chemicals on the receptor, cellular target or organ). A biological phenomenon such as competitive agonism as described for mixtures of drugs (biotransformation enzymes) or sensory irritants (nerve receptors) can accurately predict the effect of any of these mixtures. Thus, far mechanistic and empirical analyses of interactions are usually unrelated. It is one of the future challenges for mixtures research to combine information from both approaches. Also, our current biology-based models have their limitations, since they cannot integrate every relevant biological mechanism. In this respect, mechanistic modeling of mixtures may benefit from the developments coming from the arena of molecular biology

  3. Color stability and staining of silorane after prolonged chemical challenges

    DEFF Research Database (Denmark)

    de Jesus, Vivian CBR; Martinelli, Nata Luiz; Poli-Frederico, Regina Célia;

    Objectives: The purpose of this study was to investigate the effect of prolonged chemical challenges on color stability and staining susceptibility of a silorane-based composite material when compared to methacrylate-based composites. Methods: Cylindrical specimens (n=24) were fabricated from...... acid, 75% ethanol or distilled water (control) for 7, 14, 21, and 180 days, when new measurements were performed. A staining test was performed (n=12) after 21 days of chemical challenge by immersion in coffee during 3 weeks at 37°C. Color changes (¿E) were characterized using the CIEL*a*b* color...... methacrylate-based resins stored in ethanol were significantly (p<0.05) more stained by coffee (Filtek Z250 ¿E=24.1±1.1; Filtek Z350XT ¿E=24.0±2.9; Master Fill ¿E=12.8±0.6) than the ones stored in other media, while the silorane-based material demonstrated no staining (Filtek P90 ¿E=2.0±0.6), regardless of the...

  4. Medical exposures, challenge and impacts; Exposiciones medicas, retos e impactos

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas H, J.; Molina P, D.; Martinez G, A. [Centro de Proteccion e Higiene de las Radiaciones, Calle 20 No. 4113 e/41 y 47 Playa, 11300 La Habana, Direccion Postal A.P. 6195, C.P. 10600 (Cuba)

    2006-07-01

    The medical exposures have a significant contribution to the doses received by the population, reasons for what has not been considered during time its risks. In such sense in the last years the scientific community and international organizations have defined requirements for contribute to that the doses to those patients are the minimum ones necessary to achieve its diagnostic objective. The work exposes the radiological contribution, risks, uses and the actions for to improve the safety of the medical exposures. (Author)

  5. Harmonization of risk management approaches: radiation and chemical exposures

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, P. [Bhabha Atomic Research Centre, Radiation Safety Systems Div., Mumbai (India)

    2006-07-01

    Assessment of occupational and public risk from the environmental pollutants like chemicals, radiation, etc demands that the effects be considered not only from each individual pollutant, but from the combination of all the pollutants. An integrated risk assessment system needs to be in place to have an overall risk perspective for the benefit of policy makers and decision takers to try to achieve risk reduction in totality. The basis for risk-based radiation dose limits is derived from epidemiological studies, which provide a rich source of data largely unavailable to chemical risk assessors. In addition, use of the principle of optimization as expressed in the ALARA concept has resulted in a safety culture, which is much more than just complying with stipulated limits. The conservative hypothesis of no-threshold dose-effect relation (ICRP) is universally assumed. The end-points and the severity of different classes of pollutants and even different pollutants in a same class vary over a wide range. Hence, it is difficult to arrive at a quantitative value for the net detriment that weighs the various types of end-points and various classes of pollutants. Once the risk due to other pollutants is quantified by some acceptable methodology, it can be expressed in terms of the Risk Equivalent Radiation Dose (R.E.R.D.) for easy comparison with options involving radiation exposure. This paper is an effort to use to quantify and present the risk due to exposure to chemicals and radiation in a common scale for the purpose of easy comparison to facilitate decision taking. (authors)

  6. Harmonization of risk management approaches: radiation and chemical exposures

    International Nuclear Information System (INIS)

    Assessment of occupational and public risk from the environmental pollutants like chemicals, radiation, etc demands that the effects be considered not only from each individual pollutant, but from the combination of all the pollutants. An integrated risk assessment system needs to be in place to have an overall risk perspective for the benefit of policy makers and decision takers to try to achieve risk reduction in totality. The basis for risk-based radiation dose limits is derived from epidemiological studies, which provide a rich source of data largely unavailable to chemical risk assessors. In addition, use of the principle of optimization as expressed in the ALARA concept has resulted in a safety culture, which is much more than just complying with stipulated limits. The conservative hypothesis of no-threshold dose-effect relation (ICRP) is universally assumed. The end-points and the severity of different classes of pollutants and even different pollutants in a same class vary over a wide range. Hence, it is difficult to arrive at a quantitative value for the net detriment that weighs the various types of end-points and various classes of pollutants. Once the risk due to other pollutants is quantified by some acceptable methodology, it can be expressed in terms of the Risk Equivalent Radiation Dose (R.E.R.D.) for easy comparison with options involving radiation exposure. This paper is an effort to use to quantify and present the risk due to exposure to chemicals and radiation in a common scale for the purpose of easy comparison to facilitate decision taking. (authors)

  7. Biochar physico-chemical properties as affected by environmental exposure.

    Science.gov (United States)

    Sorrenti, Giovambattista; Masiello, Caroline A; Dugan, Brandon; Toselli, Moreno

    2016-09-01

    To best use biochar as a sustainable soil management and carbon (C) sequestration technique, we must understand the effect of environmental exposure on its physical and chemical properties because they likely vary with time. These properties play an important role in biochar's environmental behavior and delivery of ecosystem services. We measured biochar before amendment and four years after amendment to a commercial nectarine orchard at rates of 5, 15 and 30tha(-1). We combined two pycnometry techniques to measure skeletal (ρs) and envelope (ρe) density and to estimate the total pore volume of biochar particles. We also examined imbibition, which can provide information about soil hydraulic conductivity. Finally, we investigated the chemical properties, surface, inner layers atomic composition and C1s bonding state of biochar fragments through X-ray photoelectron spectroscopy (XPS). Ageing increased biochar skeletal density and reduced the water imbibition rate within fragments as a consequence of partial pore clogging. However, porosity and the volume of water stored in particles remained unchanged. Exposure reduced biochar pH, EC, and total C, but enhanced total N, nitrate-N, and ammonium-N. X-ray photoelectron spectroscopy analyses showed an increase of O, Si, N, Na, Al, Ca, Mn, and Fe surface (0-5nm) atomic composition (at%) and a reduction of C and K in aged particles, confirming the interactions of biochar with soil inorganic and organic phases. Oxidation of aged biochar fragments occurred mainly in the particle surface, and progressively decreased down to 75nm. Biochar surface chemistry changes included the development of carbonyl and carboxylate functional groups, again mainly on the particle surface. However, changes were noticeable down to 75nm, while no significant changes were measured in the deepest layer, up to 110nm. Results show unequivocal shifts in biochar physical and chemical properties/characteristics over short (~years) timescales. PMID

  8. The Role of Exposure History on HIV Acquisition: Insights from Repeated Low-dose Challenge Studies

    OpenAIRE

    Regoes, Roland R.

    2012-01-01

    To assess the efficacy of HIV vaccine candidates or preventive treatment, many research groups have started to challenge monkeys repeatedly with low doses of the virus. Such challenge data provide a unique opportunity to assess the importance of exposure history for the acquisition of the infection. I developed stochastic models to analyze previously published challenge data. In the mathematical models, I allowed for variation of the animals' susceptibility to infection across challenge repea...

  9. Effect of prolonged chemical challenges on selected properties of silorane

    DEFF Research Database (Denmark)

    de Jesus, Vivian CBR; Martinelli, Natan Luiz; Pascotto, Renata Corrêa;

    Objectives: The purpose of this study was to investigate the effect of prolonged chemical challenges on water sorption, solubility, and roughness of a silorane-based material when compared to methacrylate-based composites. Methods: Initial roughness and mass were registered for specimens (n=24...... phosphoric acid, 75% ethanol or distilled water for 7, 14, 21, and 180 days, when new measurements were performed. Subsequently, specimens were dehydrated until a constant mass was obtained. Water sorption and solubility were calculated after 180 days of immersion in the different solutions. Data were...... differences in water sorption and solubility were detected amongst the investigated composites (p<0.001). The silorane-based composite demonstrated low water sorption (with similar values to Filtek Z250 and Filtek Z350XT) and low solubility (with similar values to Filtek Z250) after prolonged immersion in the...

  10. Nanotechnology in the Chemical Industry - Opportunities and Challenges

    International Nuclear Information System (INIS)

    The traditional chemical industry has become a largely mature industry with many commodity products based on established technologies. Therefore, new product and market opportunities will more likely come from speciality chemicals, and from new functionalities obtained from new processing technologies as well as new microstructure control methodologies. It is a well-known fact that in addition to its molecular structure, the microstructure of a material is key to determining its properties. Controlling structures at the micro- and nano-levels is therefore essential to new discoveries. For this article, we define nanotechnology as the controlled manipulation of nanomaterials with at least one dimension less than 100nm.Nanotechnology is emerging as one of the principal areas of investigation that is integrating chemistry and materials science, and in some cases integrating these with biology to create new and yet undiscovered properties that can be exploited to gain new market opportunities. In this article market opportunities for nanotechnology will be presented from an industrial perspective covering electronic, biomedical, performance materials, and consumer products. Manufacturing technology challenges will be identified, including operations ranging from particle formation, coating, dispersion, to characterization, modeling, and simulation. Finally, a nanotechnology innovation roadmap is proposed wherein the interplay between the development of nanoscale building blocks, product design, process design, and value chain integration is identified. A suggestion is made for an R and D model combining market pull and technology push as a way to quickly exploit the advantages in nanotechnology and translate these into customer benefits

  11. Cea-Expo: A facility exposure matrix to assess passed exposure to chemical carcinogens and radionuclides of nuclear workers

    International Nuclear Information System (INIS)

    A 'Facility-Exposure Matrix' (FEM) is proposed to assess exposure to chemical carcinogens and radionuclides in a cohort of nuclear workers. Exposures are to be attributed in the following way: a worker reports to an administrative unit and/or is monitored for exposure to ionising radiation in a specific workplace. These units are connected with a list of facilities for which exposure is assessed through a group of experts. The entire process of the FEM applied in one of the nuclear centres included in the study shows that the FEM is feasible: exposure durations as well as groups of correlated exposures are presented but have to be considered as possible rather than positive exposures. Considering the number of facilities to assess (330), ways to simplify the method are proposed: (i) the list of exposures will be restricted to 18 chemical products retained from an extensive bibliography study; (ii) for each of the following classes of facilities: nuclear reactors, fuel fabrication, high-activity laboratories and radiation chemistry, accelerators and irradiators, waste treatment, biology, reprocessing, fusion, occupational exposure will be deduced from the information already gathered by the initial method. Besides taking into account confusion factors in the low doses epidemiological study of nuclear workers, the matrix should help in the assessment of internal contamination and chemical exposures in the nuclear industry. (author)

  12. Occupational exposure to pesticides : challenges for research, evaluation and prevention

    OpenAIRE

    Laurent, Catherine; Baldi, Isabelle; Bergerac, Gérard; Berthet, Aurélie; Colosio, Claudio; Garrigou, Alain; Grimbuhler, Sonia; Guichard, Laurence; Jas, Nathalie; Jouzel, Jean-Noël; Lebailly, Pierre; Milhaus, Guy; Oni, Samuel; Spinosi, Johan; Wavresky, Pierre

    2014-01-01

    The mission of the Working Group on "Agricultural workers and pesticides", set up by ANSES in 2012, is to identify and characterise the situations in which people working on French farms (family labour, permanent and part-time employees, outside workers, etc.) are exposed to pesticides. The WG brings to bear expertise from a wide range of disciplines (agronomy, economics, epidemiology, ergonomics, exposure assessment, history, metrology, sociology and toxicology). The term "Pesticides" is und...

  13. Bystander effects, genomic instability, adaptive response, and cancer risk assessment for radiation and chemical exposures

    International Nuclear Information System (INIS)

    There is an increased interest in utilizing mechanistic data in support of the cancer risk assessment process for ionizing radiation and environmental chemical exposures. In this regard, the use of biologically based dose-response models is particularly advocated. The aim is to provide an enhanced basis for describing the nature of the dose-response curve for induced tumors at low levels of exposure. Cellular responses that might influence the nature of the dose-response curve at low exposures are understandably receiving attention. These responses (bystander effects, genomic instability, and adaptive responses) have been studied most extensively for radiation exposures. The former two could result in an enhancement of the tumor response at low doses and the latter could lead to a reduced response compared to that predicted by a linear extrapolation from high dose responses. Bystander responses, whereby cells other than those directly traversed by radiation tracks are damaged, can alter the concept of target cell population per unit dose. Similarly, induced genomic instability can alter the concept of total response to an exposure. There appears to be a role for oxidative damage and cellular signaling in the etiology of these cellular responses. The adaptive response appears to be inducible at very low doses of radiation or of some chemicals and reduces the cellular response to a larger challenge dose. It is currently unclear how these cellular toxic responses might be involved in tumor formation, if indeed they are. In addition, it is not known how widespread they are as regards inducing agents. Thus, their impact on low dose cancer risk remains to be established

  14. Multi-pathway exposure modelling of chemicals in cosmetics with application to shampoo

    DEFF Research Database (Denmark)

    Ernstoff, Alexi S.; Fantke, Peter; Csiszar, Susan A.;

    2016-01-01

    We present a novel multi-pathway, mass balance based, fate and exposure model compatible with life cycle and high-throughput screening assessments of chemicals in cosmetic products. The exposures through product use as well as post-use emissions and environmental media were quantified based on the...... and critical advancement for life cycle assessments and high-throughput exposure screening of chemicals in cosmetic products demonstrating the importance of consistent consideration of near- and far-field multi-pathway exposures....

  15. Diagnostic chelation challenge with DMSA: a biomarker of long-term mercury exposure?

    OpenAIRE

    Frumkin, H; Manning, C C; Williams, P. L.; Sanders, A; Taylor, B.B.; Pierce, M; Elon, L; Hertzberg, V S

    2001-01-01

    Chelation challenge testing has been used to assess the body burden of various metals. The best-known example is EDTA challenge in lead-exposed individuals. This study assessed diagnostic chelation challenge with dimercaptosuccinic acid (DMSA) as a measure of mercury body burden among mercury-exposed workers. Former employees at a chloralkali plant, for whom detailed exposure histories were available (n = 119), and unexposed controls (n = 101) completed 24-hr urine collections before and afte...

  16. Emerging Challenges in the Management of Occupational Exposures

    International Nuclear Information System (INIS)

    The paper outlines key challenges for the future from the perspective of constituent parties of regulatory bodies, workers, employers and the IAEA and ILO. A key theme is the need to ensure the establishment and implementation of harmonised international policies, standards and guidance in the field of occupational radiation protection, and the close involvement of workers and employers and their organizations in reaching that goal. All parties recognize that there has been improvement in the level of protection and safety of occupationally exposed workers in many areas of work with ionising radiation but that this is largely in countries with well developed regulatory and operational infrastructure utilising sources of ionising radiation. Increasingly, the development of new techniques and use of ionising radiation in both the medical arena and for energy generation to meet societal needs presents challenges to all involved parties. The ILO - in collaboration with other international organizations - seeks global promotion of the basic principles for radiation protection of workers embodied in the Radiation Protection Convention (No. 115) in both developed and developing nations

  17. The Relationship between Vibrotactile Perception and Chemical Exposure among Vehicle Service Technicians in Klang Valley, Malaysia

    OpenAIRE

    Shamsul Bahri MOHD TAMRIN; Nurul Ain ZALI; Karmegam KARUPPIAH

    2016-01-01

    Background: Hazardous chemicals, which give detrimental effect to the central nervous system, are widely used in the vehicle services industry. The use of Vibrotactile Perception Threshold (VPT) as a screening tool for chemical exposure is new in developing country such as Malaysia. Therefore, this study determined the relationship between VPT and chemical exposure among vehicle service technicians in Klang Valley.Methods: Chemical Health Risk Assessment (CHRA) was conducted in 2014 at Klang ...

  18. Chemical mixtures: Evaluation of risk for child-specific exposures in a multi-stressor environment

    International Nuclear Information System (INIS)

    Evaluating the health impact from exposure to chemical mixtures is multifaceted. One component is exposure. Exposure, and consequently risk assessment for mixtures and chemicals in general, are often viewed in terms of a given exposure to a given population at a given location over a given time period. However, environmental exposures are present throughout human lifetime. As a result, an evaluation of risk must include the distinctive characteristics related to chemical exposures which will impact risk depending upon the particular life stage where exposure occurs. Risks to offspring may be associated with unique exposures in utero, during infancy, childhood, or adolescent periods. For example, exposure of infants to anthropogenic chemicals via breast milk may be of concern. The Agency for Toxic Substances and Disease Registry's (ATSDR's) approach to evaluating risks associated with exposure to mixtures of chemicals is presented. In addition to the breast milk issues, indoor exposure to combined air pollutants, drinking water contaminants, and soil and dust contaminants are discussed. The difference between a mixture's risk evaluation for children and adults is in the distinct exposure scenarios resulting from variations in behavior, physiology, and/or pharmacokinetics between adults and children rather than in the method for the specific mixtures evaluation per se

  19. Epigenome: A Biomarker or Screening Tool to Evaluate Health Impact of Cumulative Exposure to Chemical and Non-Chemical Stressors.

    Science.gov (United States)

    Olden, Kenneth; Lin, Yu-Sheng; Bussard, David

    2016-06-01

    Current risk assessment practices and toxicity information are hard to utilize for assessing the health impact of combined or cumulative exposure to multiple chemical and non-chemical stressors encountered in the "real world" environment. Non-chemical stressors such as heat, radiation, noise, humidity, bacterial and viral agents, and social factors, like stress related to violence and socioeconomic position generally cannot be currently incorporated into the risk assessment paradigm. The Science and Decisions report released by the National Research Council (NRC) in 2009 emphasized the need to characterize the effects of multiple stressors, both chemical and non-chemical exposures. One impediment to developing information relating such non-chemical stressors to health effects and incorporating them into cumulative assessment has been the lack of analytical tools to easily and quantitatively monitor the cumulative exposure to combined effects of stressors over the life course. PMID:27534725

  20. Threshold limit values and their applicability in the realms of chemical exposure control

    International Nuclear Information System (INIS)

    Chemicals are useful and indispensable in every walk of our life. Nuclear industry is no exception to this fact. A number of chemicals are in use in the nuclear fuel cycle. Thus, hazards due to exposure to chemicals coexist with radiological hazards in a nuclear fuel cycle industrial or research set-up. In the realms of control of chemical exposure, limits on concentration of chemicals in workplace are prescribed. These are known as occupational exposure limits. Threshold Limit Value (TLV) is one such occupational exposure limit. American Conference of Governmental Industrial Hygienists (ACGIH) prescribes TLVs as guideline values for various chemicals and also for physical agents. The discussion is confined to philosophy of chemical TLV, its applicability, and its limitations. (author)

  1. Preventing Agricultural Chemical Exposure: A Safety Program Manual. Participatory Education with Farmworkers in Pesticide Safety.

    Science.gov (United States)

    Wake Forest Univ., Winston-Salem, NC. Dept. of Family and Community Medicine.

    Preventing Agricultural Chemical Exposure among North Carolina Farmworkers (PACE) is a project designed to describe farmworker pesticide exposure and to develop an educational intervention to reduce farmworker pesticide exposure. The PACE project used a community participation framework to ensure that the community played a significant role in…

  2. Occupational Chemical Exposures Among Cosmetologists: Risk of Reproductive Disorders

    OpenAIRE

    Pak, Victoria M; Powers, Martha; Liu, Jianghong

    2013-01-01

    More research is needed to understand possible occupational reproductive risks for cosmetologists, specifically hairdressers and nail technicians, two occupations that often share workspace and exposure to hair dyes and nail polish. Cosmetologists are predominantly females of reproductive age; thus, they may be at higher risk for the effects of exposure to reproductive toxins. The purpose of this article is to inform nurses and public health professionals about occupational exposures for cosm...

  3. Access and use of information resources in assessing health risks from chemical exposure: Proceedings

    International Nuclear Information System (INIS)

    Health risk assessment is based on access to comprehensive information about potentially hazardous agents in question. Relevant information is scattered throughout the literature, and often is not readily accessible. To be useful in assessment efforts, emerging scientific findings, risk assess parameters, and associated data must be compiled and evaluated systemically. The US Environmental Protection Agency (EPA) and Oak Ridge National Laboratory (ORNL) are among the federal agencies heavily involved in this effort. This symposium was a direct response by EPA and ORNL to the expressed needs of individuals involved in assessing risks from chemical exposure. In an effort to examine the state of the risk assessment process, the availability of toxicological information, and the future development and transfer of this information, the symposium provided an excellent cadre of speakers and participants from state and federal agencies, academia and research laboratories to address these topics. This stimulating and productive gathering discussed concerns associated with (1) environmental contamination by chemicals; (2) laws regulating chemicals; (3) information needs and resources; (4) applications; (5) challenges and priorities; and (6)future issues. Individual reports are processed separately for the data bases

  4. Access and use of information resources in assessing health risks from chemical exposure: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    Health risk assessment is based on access to comprehensive information about potentially hazardous agents in question. Relevant information is scattered throughout the literature, and often is not readily accessible. To be useful in assessment efforts, emerging scientific findings, risk assess parameters, and associated data must be compiled and evaluated systemically. The US Environmental Protection Agency (EPA) and Oak Ridge National Laboratory (ORNL) are among the federal agencies heavily involved in this effort. This symposium was a direct response by EPA and ORNL to the expressed needs of individuals involved in assessing risks from chemical exposure. In an effort to examine the state of the risk assessment process, the availability of toxicological information, and the future development and transfer of this information, the symposium provided an excellent cadre of speakers and participants from state and federal agencies, academia and research laboratories to address these topics. This stimulating and productive gathering discussed concerns associated with (1) environmental contamination by chemicals; (2) laws regulating chemicals; (3) information needs and resources; (4) applications; (5) challenges and priorities; and (6)future issues. Individual reports are processed separately for the data bases.

  5. Immune effects of respiratory exposure to fragrance chemicals

    OpenAIRE

    Ezendam J; de Klerk A; Cassee FR; Fokkens PHB; van der Zee Park M; van Loveren H; Jong WH de; GBO

    2007-01-01

    Inhalation of the fragrance chemicals, isoeugenol and cinnamal, by mice resulted in immune reactions in the respiratory tract. This was observed in experiments performed by the RIVM (National Institute for Public Health and the Enviroment) of which results indicate that inhalation of some fragrance chemicals could induce unwanted effects on the immune system. Fragrance chemicals are common ingredients in such consumer products as cosmetics and scented products. Several fragrance chemicals are...

  6. Chemical Product Design: A new challenge of applied thermodynamics

    DEFF Research Database (Denmark)

    Abildskov, Jens; Kontogeorgis, Georgios

    2004-01-01

    Chemical products involving specialty chemicals and microstructured materials are often multicomponent systems. A number of five to 20 molecules is not unusual, comprising a range of different chemical compounds e.g. polymers, surfactants, solid particles and water. Milk is an example of such a p......Chemical products involving specialty chemicals and microstructured materials are often multicomponent systems. A number of five to 20 molecules is not unusual, comprising a range of different chemical compounds e.g. polymers, surfactants, solid particles and water. Milk is an example...... of such a product involving both solid-liquid phases and (non-equilibrium) metastable states. Thus, many of these products are colloidal systems of different types, e.g. liquid-liquid emulsions, suspensions, powders, solid and liquid dispersions, aerosols and sprays. The physical chemistry (thermodynamics...

  7. Challenges for chemical sciences in the 21st century

    OpenAIRE

    Čeković Živorad

    2004-01-01

    Chemistry and chemical engineering have changed very significantly in the last half century. From classical sciences they have broadened their scope into biology, medicine, physics, material science, nanotechnology, computation and advanced methods of process engineering and control. The applications of chemical compounds, materials and knowledge have also dramatically increased. The development of chemical sciences in the scientifically most advanced countries, at the end of the last century...

  8. HExpoChem: a systems biology resource to explore human exposure to chemicals

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Jacobsen, Ulrik Plesner; Kalhauge, Christian Gram;

    2013-01-01

    of computational biology approaches are needed to assess the health risks of chemical exposure. Here we present HExpoChem, a tool based on environmental chemicals and their bioactivities on human proteins with the objective of aiding the qualitative exploration of human exposure to chemicals. The......Summary: Humans are exposed to diverse hazardous chemicals daily. Although an exposure to these chemicals is suspected to have adverse effects on human health, mechanistic insights into how they interact with the human body are still limited. Therefore, acquisition of curated data and development...... chemical–protein interactions have been enriched with a quality-scored human protein–protein interaction network, a protein–protein association network and a chemical–chemical interaction network, thus allowing the study of environmental chemicals through formation of protein complexes and phenotypic...

  9. Epigenome: A Biomarker or Screening Tool to Evaluate Health Impact of Cumulative Exposure to Chemical and Non-Chemical Stressors

    OpenAIRE

    Kenneth Olden; Yu-Sheng Lin; David Bussard

    2016-01-01

    Current risk assessment practices and toxicity information are hard to utilize for assessing the health impact of combined or cumulative exposure to multiple chemical and non-chemical stressors encountered in the “real world” environment. Non-chemical stressors such as heat, radiation, noise, humidity, bacterial and viral agents, and social factors, like stress related to violence and socioeconomic position generally cannot be currently incorporated into the risk assessment paradigm. The Scie...

  10. Developing, Applying, and Evaluating Models for Rapid Screening of Chemical Exposures

    DEFF Research Database (Denmark)

    Arnot, J.; Shin, H.; Ernstoff, Alexi;

    2015-01-01

    limited exposure data there is limited information on chemical use patterns and production and emission quantities. These data gaps require the application of mass balance, statistical and quantitative structure-activity relationship (QSAR) models to predict exposure and exposure potential for humans and...... provides an introduction to underlying principles of some models used for exposure- and risk-based HTS for chemical prioritization for human health, including tools used in the ExpoDat project (USEtox, RAIDAR, CalTox) and other initiatives (SHEDS-HT). Case study examples of HTS include(i) model...... applications for screening thousands of chemicals for far-field human exposure, (ii) comparisons of far-field and near-field human exposure model results, and (iii) model evaluations with biomonitoring and monitoring data. These illustrations show how the current tools can be used in a regulatory setting and...

  11. Modeling the effects of chemical exposure on avian seasonal productivity: Importance of differences in breeding strategies

    Science.gov (United States)

    Agencies that regulate the use of chemicals are increasingly interested in understanding the magnitude of effects of those chemicals on wildlife populations. While laboratory toxicity tests provide insights into the types of effects caused by chemical exposure, they do not alway...

  12. Treatment of Challenging Behavior Exhibited by Children with Prenatal Drug Exposure

    Science.gov (United States)

    Kurtz, Patricia F.; Chin, Michelle D.; Rush, Karena S.; Dixon, Dennis R.

    2008-01-01

    A large body of literature exists describing the harmful effects of prenatal drug exposure on infant and child development. However, there is a paucity of research examining strategies to ameliorate sequelae such as externalizing behavior problems. In the present study, functional analysis procedures were used to assess challenging behavior…

  13. Detecting Chemical Weapons: Threats, Requirements, Solutions, and Future Challenges

    Science.gov (United States)

    Boso, Brian

    2011-03-01

    Although chemicals have been reportedly used as weapons for thousands of years, it was not until 1915 at Ypres, France that an industrial chemical, chlorine, was used in World War I as an offensive weapon in significant quantity, causing mass casualties. From that point until today the development, detection, production and protection from chemical weapons has be an organized endeavor of many of the world's armed forces and in more recent times, non-governmental terrorist organizations. The number of Chemical Warfare Agents (CWAs) has steadily increased as research into more toxic substances continued for most of the 20 th century. Today there are over 70 substances including harassing agents like tear gas, incapacitating agents, and lethal agents like blister, blood, chocking, and nerve agents. The requirements for detecting chemical weapons vary depending on the context in which they are encountered and the concept of operation of the organization deploying the detection equipment. The US DoD, for example, has as a requirement, that US forces be able to continue their mission, even in the event of a chemical attack. This places stringent requirements on detection equipment. It must be lightweight (chemical warfare agents and toxic industrial chemicals, detect and warn at concentration levels and time duration to prevent acute health effects, meet military ruggedness specifications and work over a wide range of temperature and humidity, and have a very high probability of detection with a similarly low probability of false positives. The current technology of choice to meet these stringent requirements is Ion Mobility Spectrometry. Many technologies are capable of detecting chemicals at the trace levels required and have been extensively developed for this application, including, but not limited to: mass spectroscopy, IR spectroscopy, RAMAN spectroscopy, MEMs micro-cantilever sensors, surface acoustic wave sensors, differential mobility spectrometry, and

  14. Multi-pathway exposure modeling of chemicals in cosmetics with application to shampoo.

    Science.gov (United States)

    Ernstoff, Alexi S; Fantke, Peter; Csiszar, Susan A; Henderson, Andrew D; Chung, Susie; Jolliet, Olivier

    2016-01-01

    We present a novel multi-pathway, mass balance based, fate and exposure model compatible with life cycle and high-throughput screening assessments of chemicals in cosmetic products. The exposures through product use as well as post-use emissions and environmental media were quantified based on the chemical mass originally applied via a product, multiplied by the product intake fractions (PiF, the fraction of a chemical in a product that is taken in by exposed persons) to yield intake rates. The average PiFs for the evaluated chemicals in shampoo ranged from 3×10(-4) up to 0.3 for rapidly absorbed ingredients. Average intake rates ranged between nano- and micrograms per kilogram bodyweight per day; the order of chemical prioritization was strongly affected by the ingredient concentration in shampoo. Dermal intake and inhalation (for 20% of the evaluated chemicals) during use dominated exposure, while the skin permeation coefficient dominated the estimated uncertainties. The fraction of chemical taken in by a shampoo user often exceeded, by orders of magnitude, the aggregated fraction taken in by the population through post-use environmental emissions. Chemicals with relatively high octanol-water partitioning and/or volatility, and low molecular weight tended to have higher use stage exposure. Chemicals with low intakes during use (cosmetic products demonstrating the importance of consistent consideration of near- and far-field multi-pathway exposures. PMID:27062422

  15. High-throughput exposure modeling to support prioritization of chemicals in personal care products

    DEFF Research Database (Denmark)

    Csiszar, Susan A.; Ernstoff, Alexi; Fantke, Peter;

    2016-01-01

    We demonstrate the application of a high-throughput modeling framework to estimate exposure to chemicals used in personal care products (PCPs). As a basis for estimating exposure, we use the product intake fraction (PiF), defined as the mass of chemical taken by an individual or population per mass...... highest intakes were associated with body lotion. Bioactive doses derived from high-throughput in vitro toxicity data were combined with the estimated PiFs to demonstrate an approach to estimate bioactive equivalent chemical content and to screen chemicals for risk....

  16. Co-Exposure with Fullerene May Strengthen Health Effects of Organic Industrial Chemicals

    DEFF Research Database (Denmark)

    Lehto, M.; Karilainen, T.; Rog, T.;

    2014-01-01

    In vitro toxicological studies together with atomistic molecular dynamics simulations show that occupational co-exposure with C-60 fullerene may strengthen the health effects of organic industrial chemicals. The chemicals studied are acetophenone, benzaldehyde, benzyl alcohol, m-cresol, and toluene...... which can be used with fullerene as reagents or solvents in industrial processes. Potential co-exposure scenarios include a fullerene dust and organic chemical vapor, or a fullerene solution aerosolized in workplace air. Unfiltered and filtered mixtures of C-60 and organic chemicals represent different...

  17. Chemical Markers of Occupational Exposure to Teak Wood Dust

    OpenAIRE

    Carrieri, Mariella; Bartolucci, Giovanni Battista; Lee, Taekhee; Barbero, Ana; Harper, Martin

    2014-01-01

    A novel high-performance liquid chromatographic/ultraviolet method was developed to detect lapachol (LP) and deoxylapachol (DLP) in wood dust as chemical markers of teak wood (a suspected human carcinogen). The specificity of this analysis was determined by noting the absence of LP and DLP in 12 other specimens of different woods belonging to the angiosperm family. The consistency was examined by analyzing teak from three different sources, where the percentages (wt/wt) of the chemicals range...

  18. Galantamine is a novel post-exposure therapeutic against lethal VX challenge

    International Nuclear Information System (INIS)

    The ability of galantamine hydrobromide (GAL HBr) treatment to antagonize O-ethyl-S-(2-diisopropylaminoethyl) methylphosphonothiolate (VX)-induced lethality, impairment of muscle tension, and electroencephalographic (EEG) changes was assessed in guinea pigs. Guinea pigs were challenged with 16.8 μg/kg VX (2LD50). One min after challenge, animals were administered 0.5 mg/kg atropine sulfate (ATR) and 25 mg/kg pyridine-2-aldoxime methochloride (2-PAM). In addition, guinea pigs were given 0, 1, 2, 4, 8 or 10 mg/kg GAL as a post-exposure treatment immediately prior to ATR and 2-PAM. Animals were either monitored for 24-h survival, scheduled for electroencephalography (EEG) recording, or euthanized 60 min later for measurement of indirectly-elicited muscle tension in the hemidiaphragm. Post-exposure GAL therapy produced a dose-dependent increase in survival from lethal VX challenge. Optimal clinical benefits were observed in the presence of 10 mg/kg GAL, which led to 100% survival of VX-challenged guinea pigs. Based on muscle physiology studies, GAL post-exposure treatment protected the guinea pig diaphragm, the major effector muscle of respiration, from fatigue, tetanic fade, and muscular paralysis. Protection against the paralyzing effects of VX was dose-dependent. In EEG studies, GAL did not alter seizure onset for all doses tested. At the highest dose tested (10 mg/kg), GAL decreased seizure duration when administered as a post-exposure treatment 1 min after VX. GAL also reduced the high correlation associated between seizure activity and lethality after 2LD50 VX challenge. GAL may have additional benefits both centrally and peripherally that are unrelated to its established mechanism as a reversible acetylcholinesterase inhibitor (AChEI).

  19. Challenge '89: Interfacing of Chemical Instruments to Computers.

    Science.gov (United States)

    Lyons, Jim; Lamarre, Colin

    This project involved interfacing of microcomputers with three chemical instruments--Nuclear Magnetic Resonance (NMR), Infrared Spectroscopy (IR), and the spectrophotometer. A Pascal program called "Spectrum" allows data from the NMR to be read and graphed, a specific area of the graph zoomed, ratios of specified areas of the graph measured, the…

  20. Use of comparative genomics approaches to characterize interspecies differences in response to environmental chemicals: Challenges, opportunities, and research needs

    International Nuclear Information System (INIS)

    A critical challenge for environmental chemical risk assessment is the characterization and reduction of uncertainties introduced when extrapolating inferences from one species to another. The purpose of this article is to explore the challenges, opportunities, and research needs surrounding the issue of how genomics data and computational and systems level approaches can be applied to inform differences in response to environmental chemical exposure across species. We propose that the data, tools, and evolutionary framework of comparative genomics be adapted to inform interspecies differences in chemical mechanisms of action. We compare and contrast existing approaches, from disciplines as varied as evolutionary biology, systems biology, mathematics, and computer science, that can be used, modified, and combined in new ways to discover and characterize interspecies differences in chemical mechanism of action which, in turn, can be explored for application to risk assessment. We consider how genetic, protein, pathway, and network information can be interrogated from an evolutionary biology perspective to effectively characterize variations in biological processes of toxicological relevance among organisms. We conclude that comparative genomics approaches show promise for characterizing interspecies differences in mechanisms of action, and further, for improving our understanding of the uncertainties inherent in extrapolating inferences across species in both ecological and human health risk assessment. To achieve long-term relevance and consistent use in environmental chemical risk assessment, improved bioinformatics tools, computational methods robust to data gaps, and quantitative approaches for conducting extrapolations across species are critically needed. Specific areas ripe for research to address these needs are recommended

  1. Use of comparative genomics approaches to characterize interspecies differences in response to environmental chemicals: Challenges, opportunities, and research needs

    Energy Technology Data Exchange (ETDEWEB)

    Burgess-Herbert, Sarah L., E-mail: sarah.burgess@alum.mit.edu [American Association for the Advancement of Science (AAAS) Science and Technology Policy Fellow at the US Environmental Protection Agency (EPA), 2009–10 (United States); Euling, Susan Y. [National Center for Environmental Assessment, Office of Research and Development, US Environmental Protection Agency, Washington, DC 20460 (United States)

    2013-09-15

    A critical challenge for environmental chemical risk assessment is the characterization and reduction of uncertainties introduced when extrapolating inferences from one species to another. The purpose of this article is to explore the challenges, opportunities, and research needs surrounding the issue of how genomics data and computational and systems level approaches can be applied to inform differences in response to environmental chemical exposure across species. We propose that the data, tools, and evolutionary framework of comparative genomics be adapted to inform interspecies differences in chemical mechanisms of action. We compare and contrast existing approaches, from disciplines as varied as evolutionary biology, systems biology, mathematics, and computer science, that can be used, modified, and combined in new ways to discover and characterize interspecies differences in chemical mechanism of action which, in turn, can be explored for application to risk assessment. We consider how genetic, protein, pathway, and network information can be interrogated from an evolutionary biology perspective to effectively characterize variations in biological processes of toxicological relevance among organisms. We conclude that comparative genomics approaches show promise for characterizing interspecies differences in mechanisms of action, and further, for improving our understanding of the uncertainties inherent in extrapolating inferences across species in both ecological and human health risk assessment. To achieve long-term relevance and consistent use in environmental chemical risk assessment, improved bioinformatics tools, computational methods robust to data gaps, and quantitative approaches for conducting extrapolations across species are critically needed. Specific areas ripe for research to address these needs are recommended.

  2. Challenges and trends in the determination of selected chemical contaminants and allergens in food.

    Science.gov (United States)

    Krska, Rudolf; Becalski, Adam; Braekevelt, Eric; Koerner, Terry; Cao, Xu-Liang; Dabeka, Robert; Godefroy, Samuel; Lau, Ben; Moisey, John; Rawn, Dorothea F K; Scott, Peter M; Wang, Zhongwen; Forsyth, Don

    2012-01-01

    This article covers challenges and trends in the determination of some major food chemical contaminants and allergens, which-among others-are being monitored by Health Canada's Food Directorate and for which background levels in food and human exposure are being analyzed and calculated. Eleven different contaminants/contaminant groups and allergens have been selected for detailed discussion in this paper. They occur in foods as a result of: use as a food additive or ingredient; processing-induced reactions; food packaging migration; deliberate adulteration; and/or presence as a chemical contaminant or natural toxin in the environment. Examples include acrylamide as a food-processing-induced contaminant, bisphenol A as a food packaging-derived chemical, melamine and related compounds as food adulterants and persistent organic pollutants, and perchlorate as an environmental contaminant. Ochratoxin A, fumonisins, and paralytic shellfish poisoning toxins are examples of naturally occurring toxins whereas sulfites, peanuts, and milk exemplify common allergenic food additives/ingredients. To deal with the increasing number of sample matrices and analytes of interest, two analytical approaches have become increasingly prevalent. The first has been the development of rapid screening methods for a variety of analytes based on immunochemical techniques, utilizing ELISA or surface plasmon resonance technology. The second is the development of highly sophisticated multi-analyte methods based on liquid chromatography coupled with multiple-stage mass spectrometry for identification and simultaneous quantification of a wide range of contaminants, often with much less requirement for tedious cleanup procedures. Whereas rapid screening methods enable testing of large numbers of samples, the multi analyte mass spectrometric methods enable full quantification with confirmation of the analytes of interest. Both approaches are useful when gathering surveillance data to determine

  3. Proposed Occupational Exposure Limits for Non-Carcinogenic Hanford Waste Tank Vapor Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Poet, Torka S.; Timchalk, Chuck

    2006-03-24

    A large number of volatile chemicals have been identified in the headspaces of tanks used to store mixed chemical and radioactive waste at the U.S. Department of Energy (DOE) Hanford Site, and there is concern that vapor releases from the tanks may be hazardous to workers. Contractually established occupational exposure limits (OELs) established by the Occupational Safety and Health Administration (OSHA) and American Conference of Governmental Industrial Hygienists (ACGIH) do not exist for all chemicals of interest. To address the need for worker exposure guidelines for those chemicals that lack OSHA or ACGIH OELs, a procedure for assigning Acceptable Occupational Exposure Limits (AOELs) for Hanford Site tank farm workers has been developed and applied to a selected group of 57 headspace chemicals.

  4. Assessing chronic fish health: An application to a case of an acute exposure to chemically treated crude oil.

    Science.gov (United States)

    Mauduit, F; Domenici, P; Farrell, A P; Lacroix, C; Le Floch, S; Lemaire, P; Nicolas-Kopec, A; Whittington, M; Zambonino-Infante, J L; Claireaux, G

    2016-09-01

    Human alteration of marine ecosystems is substantial and growing. Yet, no adequate methodology exists that provides reliable predictions of how environmental degradation will affect these ecosystems at a relevant level of biological organization. The primary objective of this study was to develop a methodology to evaluate a fish's capacity to face a well-established environmental challenge, an exposure to chemically dispersed oil, and characterize the long-term consequences. Therefore, we applied high-throughput, non-lethal challenge tests to assess hypoxia tolerance, temperature susceptibility and maximal swimming speed as proxies for a fish's functional integrity. These whole animal challenge tests were implemented before (1 month) and after (1 month) juvenile European sea bass (Dicentrarchus labrax) had been acutely exposed (48h) to a mixture containing 0.08gL(-1) of weathered Arabian light crude oil plus 4% dispersant (Corexit© EC9500A), a realistic exposure concentration during an oil spill. In addition, experimental populations were then transferred into semi-natural tidal mesocosm ponds and correlates of Darwinian fitness (growth and survival) were monitored over a period of 4 months. Our results revealed that fish acutely exposed to chemically dispersed oil remained impaired in terms of their hypoxia tolerance and swimming performance, but not in temperature susceptibility for 1 month post-exposure. Nevertheless, these functional impairments had no subsequent ecological consequences under mildly selective environmental conditions since growth and survival were not impacted during the mesocosm pond study. Furthermore, the earlier effects on fish performance were presumably temporary because re-testing the fish 10 months post-exposure revealed no significant residual effects on hypoxia tolerance, temperature susceptibility and maximal swimming speed. We propose that the functional proxies and correlates of Darwinian fitness used here provide a useful

  5. Meeting the challenges related to material issues in chemical industries

    Indian Academy of Sciences (India)

    Baldev Raj; U Kamachi Mudali; T Jayakumar; K V Kasiviswanathn; K Natarajan

    2000-12-01

    Reliable performance and profitability are two important requirements for any chemical industry. In order to achieve high level of reliability and excellent performance, several issues related to design, materials selection, fabrication, quality assurance, transport, storage, inputs from condition monitoring, failure analysis etc. have to be adequately addressed and implemented. Technology related to nondestructive testing and monitoring of the plant is also essential for precise identification of defect sites and to take appropriate remedial decision regarding repair, replacement or modification of process conditions. The interdisciplinary holistic approach enhances the life of critical engineering components in chemical plants. Further, understanding the failure modes of the components through the analysis of failed components throws light on the choice of appropriate preventive measures to be taken well in advance, to have a control over the overall health of the plant. The failure analysis also leads to better design modification and condition monitoring methodologies, for the next generation components and plants. At the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, a unique combination of the expertise in design, materials selection, fabrication, NDT development, condition monitoring, life prediction and failure analysis exists to obtain desired results for achieving high levels of reliability and performance assessment of critical engineering components in chemical industries. Case studies related to design, materials selection and fabrication aspects of critical components in nuclear fuel reprocessing plants, NDT development and condition monitoring of various components of nuclear power plants, and important failure investigations on critical engineering components in chemical and allied industries are discussed in this paper. Future directions are identified and planned approaches are briefly described.

  6. Coupled near-field and far-field exposure assessment framework for chemicals in consumer products

    DEFF Research Database (Denmark)

    Fantke, Peter; Ernstoff, Alexi; Huang, Lei;

    2016-01-01

    efficient way to rapidly compare exposure pathways for adult and child users and for the general population. This framework constitutes a user-friendly approach to develop, compare and interpret multiple human exposure scenarios in a coupled system of near-field ('user' environment), far-field and human......Humans can be exposed to chemicals in consumer products through product use and environmental emissions over the product life cycle. Exposure pathways are often complex, where chemicals can transfer directly from products to humans during use or exchange between various indoor and outdoor...

  7. Prenatal exposures to perfluorinated chemicals and anthropometric measures in infancy

    DEFF Research Database (Denmark)

    Andersen, Camilla Schou; Fei, Chunyuan; Gamborg, Michael;

    2010-01-01

    Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) are persistent chemicals that may affect growth early in life. The authors estimated the associations between maternal plasma levels of PFOS and PFOA and infants' weight, length, and body mass index development during the first year of...

  8. Association between chemical pattern in breast milk and congenital cryptorchidism: modelling of complex human exposures

    DEFF Research Database (Denmark)

    Krysiak-Baltyn, Konrad; Toppari, J.; Skakkebaek, N. E.;

    2012-01-01

    been too rapid to be explained by genetics alone. To study the association between complex chemical exposures of humans and congenital cryptorchidism, the most common malformation of the male genitalia, we measured 121 environmental chemicals with suspected or known endocrine disrupting properties in...

  9. High Throughput Exposure Modeling of Semi-Volatile Chemicals in Articles of Commerce (SOT)

    Science.gov (United States)

    Chemical components of consumer products and articles of commerce such as carpet and clothing are key drivers of exposure in the near-field environment. These chemicals include semi-volatile organic compounds (SVOCs), some of which have been shown to alter endocrine functionality...

  10. Information resources for assessing health effects from chemical exposure: Office of pesticides programs

    Energy Technology Data Exchange (ETDEWEB)

    Fenner-Crisp, P. [Environmental Protection Agency, Washington, DC (United States)

    1990-12-31

    The US Environmental Protection Agency (EPA) Office of Pesticide Programs is trying to develop a complete picture of a chemical`s toxicity and exposure profile. It is also important to share information in the office`s files because of pesticides, particularly as a consequence of agricultural use, find their way into places not necessarily intended.

  11. Analysis of determination modalities concerning the exposure and emission limits values of chemical and radioactive substances

    International Nuclear Information System (INIS)

    This document presents the generic approach adopted by various organizations for the determination of the public exposure limits values to chemical and radioactive substances and for the determination of limits values of chemical products emissions by some installations. (A.L.B.)

  12. International Frameworks Dealing with Human Risk Assessment of Combined Exposure to Multiple Chemicals

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2013-07-01

    Full Text Available The development of harmonised terminology and frameworks for the human risk assessment of combined exposure to multiple chemicals (“chemical mixtures” is an important area for EFSA and a number of activities have already been undertaken, i.e. in the fields of pesticides and contaminants. The first step prior to a risk assessment of combined exposure to multiple chemicals is problem formulation defining the relevant exposure, hazard and population to be considered. In practice, risk assessment of multiple chemicals is conducted using a tiered approach for exposure assessment, hazard assessment and risk characterisation. Higher tiers require increasing knowledge about the group of chemicals under assessment and the tiers can range from tier 0 (default values, data poor situation to tier 3 (full probabilistic models. This scientific report reviews the terminology, methodologies and frameworks developed by national and international agencies for the human risk assessment of combined exposure to multiple chemicals and provides recommendations for future activities at EFSA in this area.

  13. Occupational exposure to endocrine-disrupting chemicals and the risk of uveal melanoma

    DEFF Research Database (Denmark)

    Behrens, Thomas; Lynge, Elsebeth; Cree, Ian;

    2012-01-01

    -disrupting agents. We constructed several exposure scores, taking into account intensity of exposure, use of personal protective equipment, and exposure duration. We calculated unconditional logistic regression analyses, adjusting for country, age, sex, eye color and a history of ocular damage due to intense......OBJECTIVES: We investigated the association between occupational exposure to endocrine-disrupting chemicals (EDC) and the risk of uveal melanoma using international data of a case-control study from nine European countries. METHODS: After exclusion of proxy interviews, 280 cases and 3084 control...

  14. Quantitative Exposure Assessment of Various Chemical Substances in a Wafer Fabrication Industry Facility

    OpenAIRE

    Park, Hyunhee; Jang, Jae-Kil; Shin, Jung-Ah

    2011-01-01

    Objectives This study was designed to evaluate exposure levels of various chemicals used in wafer fabrication product lines in the semiconductor industry where work-related leukemia has occurred. Methods The research focused on 9 representative wafer fabrication bays among a total of 25 bays in a semiconductor product line. We monitored the chemical substances categorized as human carcinogens with respect to leukemia as well as harmful chemicals used in the bays and substances with hematologi...

  15. Human exposures to volatile halogenated organic chemicals in indoor and outdoor air.

    OpenAIRE

    Andelman, J B

    1985-01-01

    Volatile halogenated organic chemicals are found in indoor and outdoor air, often at concentrations substantially above those in remote, unpopulated areas. The outdoor ambient concentrations vary considerably among sampling stations throughout the United States, as well as diurnally and daily. The vapor pressures and air-water equilibrium (Henry's Law) constants of these chemicals influence considerably the likely relative human exposures for the air and water routes. Volatilization of chemic...

  16. Incorporating Health Impacts from Exposure to Chemicals in Food Packaging in LCA

    OpenAIRE

    Ernstoff, Alexi; Trier, Xenia; Jolliet, Oliver; Fantke, Peter

    2014-01-01

    Life cycle assessments (LCA) on the environmental and public health impacts of food and beverage packaging materials have found some advantages to plastic over glass. Entirely missing from these evaluations are the health impacts of possible chemical, e.g. endocrine dis-ruptor, exposure through migration of chemicals from the packaging into the food product. We build a framework based on a life cycle perspective to predict which chemicals may be in a package that are not intentionally added i...

  17. Teaching chemical product design to engineering students: course contents and challenges

    OpenAIRE

    Skov, Anne Ladegaard; Kiil, Søren

    2011-01-01

    Chemical product design is not taught in the same way as traditional engineering courses like unit operations or transport phenomena. This paper gives an overview of the challenges that we, as teachers, have faced when teaching chemical product design to engineering students. Specific course contents and relevant teaching methods are discussed.

  18. Teaching chemical product design to engineering students: course contents and challenges

    DEFF Research Database (Denmark)

    Skov, Anne Ladegaard; Kiil, Søren

    Chemical product design is not taught in the same way as traditional engineering courses like unit operations or transport phenomena. This paper gives an overview of the challenges that we, as teachers, have faced when teaching chemical product design to engineering students. Specific course...

  19. Challenges in simulation of chemical processes in combustion furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M.; Kilpinen, P. [Aabo Akademi, Turku (Finland)

    1996-12-31

    The presentation gives an introduction to some of the present issues and problems in treating the complex chemical processes in combustion. The focus is in the coupling of the hydrocarbon combustion process with nitrogen oxide formation and destruction chemistry in practical furnaces or flames. Detailed kinetic modelling based on schemes of elementary reactions are shown to be a useful novel tool for identifying and studying the key reaction paths for nitrogen oxide formation and destruction in various systems. The great importance of the interaction between turbulent mixing and combustion chemistry is demonstrated by the sensitivity of both methane oxidation chemistry and fuel nitrogen conversion chemistry to the reactor and mixing pattern chosen for the kinetic calculations. The fluidized bed combustion (FBC) nitrogen chemistry involves several important heterogeneous reactions. Particularly the char in the bed plays an essential role. Recent research has advanced rapidly and the presentation proposes an overall picture of the fuel nitrogen reaction routes in circulating FBC conditions. (author)

  20. Exposure assessment and other challenges in non-ionizing radiation studies of childhood leukaemia

    International Nuclear Information System (INIS)

    Studies of electromagnetic fields (EMF) and the development of childhood leukaemia face unique difficulties. EMF are imperceptible, ubiquitous, have multiple sources, and can vary greatly over time and distances. Childhood leukaemia and high average exposures to magnetic fields are both quite rare. Thus, a major challenge in EMF epidemiology is the small number of highly exposed cases and the necessity for retrospective assessment of exposure. Only studies designed to minimize bias while maximizing our ability to detect an association, should one exist, would have a potential to contribute to our understanding. New approaches are needed; the most promising in the extremely low-frequency range involves a study of a highly exposed cohort of children who have lived in apartments next to built-in transformers or electrical equipment rooms. Another promising avenue is an investigation of possible joint effects of environmental exposures and genetic co-factors. An exposure assessment methodology for residential radiofrequency fields is still in its infancy. Rapid changes in technology and exponential increases in its use make exposure assessment more difficult and urgent. (authors)

  1. Carpet-dust chemicals as measures of exposure: Implications of variability

    Directory of Open Access Journals (Sweden)

    Whitehead Todd P

    2012-03-01

    Full Text Available Abstract Background There is increasing interest in using chemicals measured in carpet dust as indicators of chemical exposures. However, investigators have rarely sampled dust repeatedly from the same households and therefore little is known about the variability of chemical levels that exist within and between households in dust samples. Results We analyzed 9 polycyclic aromatic hydrocarbons, 6 polychlorinated biphenyls, and nicotine in 68 carpet-dust samples from 21 households in agricultural communities of Fresno County, California collected from 2003-2005. Chemical concentrations (ng per g dust ranged from Conclusions Our findings suggest that attenuation bias should be relatively modest when using these semi-volatile carpet-dust chemicals as exposure surrogates in epidemiologic studies.

  2. Incorporating Health Impacts from Exposure to Chemicals in Food Packaging in LCA

    DEFF Research Database (Denmark)

    Ernstoff, Alexi; Trier, Xenia; Jolliet, Oliver;

    2014-01-01

    Life cycle assessments (LCA) on the environmental and public health impacts of food and beverage packaging materials have found some advantages to plastic over glass. Entirely missing from these evaluations are the health impacts of possible chemical, e.g. endocrine dis-ruptor, exposure through...... migration of chemicals from the packaging into the food product. We build a framework based on a life cycle perspective to predict which chemicals may be in a package that are not intentionally added ingredients, and we apply this approach to the US EPA’s CPCAT database. In total we find 1,154 chemicals...... within the CPCAT database related to food-contact materials; out of these 107 are potential endocrine disruptors according to the TEDX list of endocrine disruptors. We also build a framework in an effort to begin harmonizing LCA to include health impacts of chemical exposure related to food packaging in...

  3. Functional status of liverin conditions of radiation and chemical exposure

    Directory of Open Access Journals (Sweden)

    O. V. Severynovs’ka

    2005-09-01

    Full Text Available Chronic influences of low-intensity X-rays in doses of 0.15 and 0.25 Gr and mix of heavy metals salts in a dose of 2 EPC (extreme permissible concentrations for each metal, as a single factor or as a combination of factors, on the state of pro-/antioxidative system in a rat liver have been studied. Analysis of the data concerning combined influences allows to conclude that effects under these doses have some differences: a splash of processes of lipid peroxidation are observed in both causes, but under the lower dose an additivity takes place, and under the dose of 0.25 Gr a synergism of the agent effects in relation to the development of peroxidative reactions is registered. The results testify that technogenic contamination of water with heavy metals worsens the action of radiation factor, specifically, eliminates a hormetic splash of antioxidative activity at 0.15 Gr. Biochemical indexes of the liver activity, as a central organ of a general metabolism, and a structure of morbidity have been studied in liquidators of the Chernobyl accident from industrial Prydnieprovie region. Disturbances of liver functions have been shown, especially in persons obtained the exposure dose about 0.25 Gr. A comparison of these results and data of tests with laboratory animals reveals their mutual accordance and supports a relevancy of extrapolation of data of model experiments on a person health state, which undergone a similar influence.

  4. The Relationship between Vibrotactile Perception and Chemical Exposure among Vehicle Service Technicians in Klang Valley, Malaysia

    Directory of Open Access Journals (Sweden)

    Shamsul Bahri MOHD TAMRIN

    2016-03-01

    Full Text Available Background: Hazardous chemicals, which give detrimental effect to the central nervous system, are widely used in the vehicle services industry. The use of Vibrotactile Perception Threshold (VPT as a screening tool for chemical exposure is new in developing country such as Malaysia. Therefore, this study determined the relationship between VPT and chemical exposure among vehicle service technicians in Klang Valley.Methods: Chemical Health Risk Assessment (CHRA was conducted in 2014 at Klang Valley Vehicle Service Centers among the technicians using the method from Department of Occupational Safety and Health (DOSH Malaysia. HavLab Tactile Vibrometer, UK was used to determine the VPT at the fingertip for the assessment peripheral nerve impairment. Questionnaires were used to obtain the respondents’ background.Results: Results showed the Log VPT 31.5Hz & 125Hz for workers exposed to chemicals was significantly higher compared to the non-exposed workers (31.5Hz: T=4.776 (P<0.001, 125Hz: T=4.775(P<0.001. There was significant relationship between VPT at Log 31.5Hz, Log 125Hz and overall VPT with diesel, mixture of gasoline and benzene, gasoline only, and the use of personal protective equipment.Conclusion: The overall VPT model demonstrated that the exposure to an organic solvent and the usage of PPE contributed to vibro tactile threshold among vehicle service technicians in Malaysia. Keywords: Chemical exposure, VPT, Vehicle service technicians

  5. Combined Effects of Prenatal Exposures to Environmental Chemicals on Birth Weight

    Science.gov (United States)

    Govarts, Eva; Remy, Sylvie; Bruckers, Liesbeth; Den Hond, Elly; Sioen, Isabelle; Nelen, Vera; Baeyens, Willy; Nawrot, Tim S; Loots, Ilse; Van Larebeke, Nick; Schoeters, Greet

    2016-01-01

    Prenatal chemical exposure has been frequently associated with reduced fetal growth by single pollutant regression models although inconsistent results have been obtained. Our study estimated the effects of exposure to single pollutants and mixtures on birth weight in 248 mother-child pairs. Arsenic, copper, lead, manganese and thallium were measured in cord blood, cadmium in maternal blood, methylmercury in maternal hair, and five organochlorines, two perfluorinated compounds and diethylhexyl phthalate metabolites in cord plasma. Daily exposure to particulate matter was modeled and averaged over the duration of gestation. In single pollutant models, arsenic was significantly associated with reduced birth weight. The effect estimate increased when including cadmium, and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) co-exposure. Combining exposures by principal component analysis generated an exposure factor loaded by cadmium and arsenic that was associated with reduced birth weight. MECPP induced gender specific effects. In girls, the effect estimate was doubled with co-exposure of thallium, PFOS, lead, cadmium, manganese, and mercury, while in boys, the mixture of MECPP with cadmium showed the strongest association with birth weight. In conclusion, birth weight was consistently inversely associated with exposure to pollutant mixtures. Chemicals not showing significant associations at single pollutant level contributed to stronger effects when analyzed as mixtures. PMID:27187434

  6. Determinants of exposure to chemical pollutants in wet X-ray film processing in Iran.

    Science.gov (United States)

    Kakooei, Hossein; Ardakani, Mehdi B; Sadighi, Alireza

    2007-07-15

    The aim of the current study was to measure glutaraldehyde, acetic acid and sulfur dioxide and levels inside wet x-ray processing areas in a developing country and comparing data with those in developed countries. Forty-five radiographers from 10 educational hospitals affiliated to the Tehran University of Medical Sciences (TUMS) in Tehran, Iran participated in this descriptive-analytical study. Exposure to glutaraldehyde (a constituent of developer chemistry), acetic acid (a constituent of fixer chemistry) and sulfur dioxide (a byproduct of sulfites present in both developer and fixer solutions) was measured in all participants as well as area exposure. Average full-shift exposure to glutaraldehyde, acetic acid and sulfur dioxide were 0.0018, 2.65 and 1.64 mg m(-1), respectively. The results showed that the TUMS radiographers full-shift exposures are generally lower than the American Conference of Governmental Industrial Hygienists (ACGIH) recommended levels. The concentration of glutaraldehyde collected by area sampling (darkroom) was almost five times (0.0104 mg m(-3)) greater than taken by personal sampling. Exposure to the chemical pollutants in the currents study were generally higher than in developed countries. Identification of these key exposure determinants is useful in targeting exposure evaluation and controls to reduce developer and fixer chemicals exposures in the radiology departments. Employing of a digital imaging system that do not involve wet x-ray processing of photographic film would be a useful device for radiographers protection. PMID:19070154

  7. Chemical Exposure Assessment Program at Los Alamos National Laboratory: A risk based approach

    International Nuclear Information System (INIS)

    The University of California Contract And DOE Order 5480.10 require that Los Alamos National Laboratory (LANL) perform health hazard assessments/inventories of all employee workplaces. In response to this LANL has developed the Chemical Exposure Assessment Program. This program provides a systematic risk-based approach to anticipation, recognition, evaluation and control of chemical workplace exposures. Program implementation focuses resources on exposures with the highest risks for causing adverse health effects. Implementation guidance includes procedures for basic characterization, qualitative risk assessment, quantitative validation, and recommendations and reevaluation. Each component of the program is described. It is shown how a systematic method of assessment improves documentation, retrieval, and use of generated exposure information

  8. Assessment of Occupational Symptoms and Chemical Exposures for Nail Salon Technicians in Daegu City, Korea

    OpenAIRE

    Park, Sung-Ae; Gwak, Sugyeong; Choi, Sangjun

    2014-01-01

    Objectives This study aimed to evaluate occupational symptoms and chemical exposures of nail salon technicians. Methods Work-related symptoms of nail salon technicians in Daegu City were surveyed using a researcher-administered questionnaire, and responses were compared to those of non-exposed office workers as controls. Personal exposure level of airborne volatile organic compounds was also monitored using passive samplers. Results A total of 159 subjects in 120 salons were interviewed. Aver...

  9. Occupational cancers with chemical exposure and their prevention in Korea: a literature review.

    Science.gov (United States)

    Rim, Kyung-Taek

    2013-01-01

    The usage and types of chemicals being developed, with diversified new exposure of workers, are of natural concern to occupational disease. In Korea, with industrialization, application of many chemicals has increased. A large proportion of mortality and disease is due to cancer, and the causal hazardous agents include chemical agents, like heavy metals and so on. Due to the long latency period with malignancies and the fact they are usually found after workers' retirement, it is suggested that management policies must be established to prevent occupational cancers occurring among workers in Korea. To give a general description about the efforts to prevent the occupational cancer with exposure to chemicals, articles on the trends of occupational cancers were reviewed and summarized with related research and efforts for prevention in Korea. It is important to improve the understanding of occupational cancer and help to maintain sustainable and appropriate measures to guarantee workers safety and health. PMID:23886117

  10. Viscoelasticity of biofilms and their recalcitrance to mechanical and chemical challenges

    OpenAIRE

    Peterson, Brandon W.; He, Yan; Ren, Yijin; Zerdoum, Aidan; Libera, Matthew R.; Sharma, Prashant K.; Winkelhoff, Arie-Jan van; Neut, Danielle; Stoodley, Paul; van der Mei, Henny C; Busscher, Henk J.

    2015-01-01

    We summarize different studies describing mechanisms through which bacteria in a biofilm mode of growth resist mechanical and chemical challenges. Acknowledging previous microscopic work describing voids and channels in biofilms that govern a biofilms response to such challenges, we advocate a more quantitative approach that builds on the relation between structure and composition of materials with their viscoelastic properties. Biofilms possess features of both viscoelastic solids and liquid...

  11. Environmental Chemical Exposures and Autism Spectrum Disorders: A Review of the Epidemiological Evidence

    Science.gov (United States)

    Kalkbrenner, Amy E.; Schmidt, Rebecca J.; Penlesky, Annie C.

    2016-01-01

    In the past decade, the number of epidemiological publications addressing environmental chemical exposures and autism has grown tremendously. These studies are important because it is now understood that environmental factors play a larger role in causing autism than previously thought and because they address modifiable risk factors that may open up avenues for the primary prevention of the disability associated with autism. In this review, we covered studies of autism and estimates of exposure to tobacco, air pollutants, volatile organic compounds and solvents, metals (from air, occupation, diet, dental amalgams, and thimerosal-containing vaccines), pesticides, and organic endocrine-disrupting compounds such as flame retardants, non-stick chemicals, phthalates, and bisphenol A. We included studies that had individual-level data on autism, exposure measures pertaining to pregnancy or the 1st year of life, valid comparison groups, control for confounders, and adequate sample sizes. Despite the inherent error in the measurement of many of these environmental exposures, which is likely to attenuate observed associations, some environmental exposures showed associations with autism, especially traffic-related air pollutants, some metals, and several pesticides, with suggestive trends for some volatile organic compounds (e.g., methylene chloride, trichloroethylene, and styrene) and phthalates. Whether any of these play a causal role requires further study. Given the limited scope of these publications, other environmental chemicals cannot be ruled out, but have not yet been adequately studied. Future research that addresses these and additional environmental chemicals, including their most common routes of exposures, with accurate exposure measurement pertaining to several developmental windows, is essential to guide efforts for the prevention of the neurodevelopmental damage that manifests in autism symptoms. PMID:25199954

  12. Chemical dependency in women. Meeting the challenges of accurate diagnosis and effective treatment.

    OpenAIRE

    Unger, K B

    1988-01-01

    Women dependent on alcohol or prescribed or nonprescribed psychoactive drugs present special diagnostic challenges to physicians. Chemical dependency likewise has adverse effects on women who are nonusers through the disease of co-dependency. The natural history of chemical dependency in women includes sex-specific differences in presenting signs and symptoms. Collateral medical history may come from a variety of community sources. Diagnoses may also use sex-specific criteria, with simultaneo...

  13. Animal Use and Lessons Learned in the U.S. High Production Volume Chemicals Challenge Program

    OpenAIRE

    Bishop, Patricia L.; Manuppello, Joseph R.; Willett, Catherine E.; Sandler, Jessica T.

    2012-01-01

    Background: Launched by the U.S. Environmental Protection Agency (EPA) in 1998, the High Production Volume (HPV) Challenge Program was developed to address the perceived gap in basic hazard information for the 2,800 chemicals produced or imported into the United States in quantities of ≥ 1 million pounds per year. Health and environmental effects data obtained from either existing information or through new vertebrate animal testing were voluntarily submitted by chemical companies (sponsors) ...

  14. Development of the chemical exposure monitor with indoor positioning (CEMWIP) for workplace VOC surveys.

    Science.gov (United States)

    Brown, K K; Shaw, P B; Mead, K R; Kovein, R J; Voorhees, R T; Brandes, A R

    2016-06-01

    The purpose of this article was to research and develop a direct-reading exposure assessment method that combined a real-time location system with a wireless direct-reading personal chemical sensor. The personal chemical sensor was a photoionization device for detecting volatile organic compounds. The combined system was calibrated and tested against the same four standard gas concentrations and calibrated at one standard location and tested at four locations that included the standard locations. Data were wirelessly collected from the chemical sensor every 1.4 sec, for volatile organic compounds concentration, location, temperature, humidity, and time. Regression analysis of the photo-ionization device voltage response against calibration gases showed the chemical sensor had a limit of detection of 0.2 ppm. The real-time location system was accurate to 13 cm ± 6 cm (standard deviation) in an open area and to 57 cm ± 31 cm in a closed room where the radio frequency has to penetrate drywall-finished walls. The streaming data were collected and graphically displayed as a three-dimensional hazard map for assessment of peak exposure with location. A real-time personal exposure assessment device with indoor positioning was practical and provided new knowledge on direct reading exposure assessment methods. PMID:26786234

  15. Information resources for assessing health effects from chemical exposure: Office of pesticides programs

    International Nuclear Information System (INIS)

    The US Environmental Protection Agency (EPA) Office of Pesticide Programs is trying to develop a complete picture of a chemical's toxicity and exposure profile. It is also important to share information in the office's files because of pesticides, particularly as a consequence of agricultural use, find their way into places not necessarily intended

  16. Self-reported occupational exposure to chemical and physical factors and risk of skin problems

    DEFF Research Database (Denmark)

    Alfonso, Jose Hernan; Thyssen, Jacob P; Tynes, Tore;

    2015-01-01

    Prospective studies on occupational dermatoses in the general working population are sparse. This study investigated prospectively the impact of self-reported occupational exposure to chemicals and physical factors on the risk of skin problems. The cohort comprised respondents drawn randomly from...... in the general working population of Norway....

  17. Patterns of chemical use and exposure control in the Semiconductor Health Study.

    Science.gov (United States)

    Hallock, M F; Hammond, S K; Hines, C J; Woskie, S R; Schenker, M B

    1995-12-01

    Information on chemical use and exposure control between 1986 and 1990 was collected from 14 companies participating in the Semiconductor Health Study. Questionnaires and site visits provided data used to develop exposure categories for three epidemiological studies: prospective, historical, and cross-sectional. Patterns of use of target chemicals were compiled for 82 silicon-wafer fabrication rooms (fabs), including 47 from which subjects were selected for study. Chemical use was examined by operation, year, and epidemiological component. Target agents for epidemiological analyses were present in more than 50% of fabs. Use of these agents was fairly constant from 1986 to 1990, except for a moderate increase in use of propylene glycol monomethyl ether acetate, a solvent being substituted for ethylene-based glycol ethers (EGE) in photoresists. The distribution of personal protective equipment, engineering controls, and other factors potentially affecting employee exposure was also examined. Controls designed to manage processes or high acute toxicity were present in most fabs; their prevalence remained unchanged from 1986 through 1990. Controls designed to reduce exposures to chemicals with low acute toxicity were less widely distributed; their prevalence increased moderately from 1986 to 1990. PMID:8588557

  18. 75 FR 4402 - Notice of National Conversation on Public Health and Chemical Exposures Leadership Council...

    Science.gov (United States)

    2010-01-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Notice of National Conversation on Public Health and Chemical Exposures Leadership Council Conference Call Time and Date: 1 p.m.-3 p.m., Friday, January 29, 2010. Location: Teleconference....

  19. High-Throughput Dietary Exposure Predictions for Chemical Migrants from Food Packaging Materials

    Science.gov (United States)

    United States Environmental Protection Agency researchers have developed a Stochastic Human Exposure and Dose Simulation High -Throughput (SHEDS-HT) model for use in prioritization of chemicals under the ExpoCast program. In this research, new methods were implemented in SHEDS-HT...

  20. Comparison of radiographic and necropsy findings of lung lesions in calves after challenge exposure with Pasteurella multocida

    International Nuclear Information System (INIS)

    Objectives-To test suitability of radiographic evaluation of lung lesions as a substitute for lung lesion scores derived by examination at necropsy in challenge-exposure models of bovine pneumonia. Animals-10 calves selected by body weight from 20 multiple-source male Holstein calves approximately 1 to 2 months old enrolled in a Pasteurella multocida challenge-exposure study. Procedure-Calves were paired on the basis of weight and randomly assigned within pairs to vaccine or control (saline solution) group. By use of deep tracheal cannulation, calves were challenge exposed with a culture of virulent P. multocida, observed for 10 days, euthanatized, and necropsied, and the lungs were scored for pneumonic lesions. Radiographic views of the lung fields of the calves were taken before challenge exposure and before necropsy and were evaluated for alveolar disease by a veterinary radiologist. Lung lesion scores were compared with radiographic evaluations. Results-There was a strong and significant correlation (R2 = 0.91, P < 0.001) between results of the evaluation of postchallenge-exposure radiographs and necropsy results. There also was also strong and significant correlation (R2 = 0.90, P < 0.001) between evaluation of the prechallenge-exposure radiographs-and necropsy results. Conclusions-Radiographic evaluation of lung lesions correlates well with lung lesions found at necropsy. The findings emphasize the need for caution in interpreting the results of challenge-exposure studies of bovine respiratory tract disease in which small numbers of calves are studied

  1. Response of Differentiated Human Airway Epithelia to Alcohol Exposure and Klebsiella pneumoniae Challenge

    Directory of Open Access Journals (Sweden)

    Sammeta V. Raju

    2013-07-01

    Full Text Available Alcohol abuse has been associated with increased susceptibility to pulmonary infection. It is not fully defined how alcohol contributes to the host defense compromise. Here primary human airway epithelial cells were cultured at an air-liquid interface to form a differentiated and polarized epithelium. This unique culture model allowed us to closely mimic lung infection in the context of alcohol abuse by basolateral alcohol exposure and apical live bacterial challenge. Application of clinically relevant concentrations of alcohol for 24 h did not significantly alter epithelial integrity or barrier function. When apically challenged with viable Klebsiella pneumoniae, the cultured epithelia had an enhanced tightness which was unaffected by alcohol. Further, alcohol enhanced apical bacterial growth, but not bacterial binding to the cells. The cultured epithelium in the absence of any treatment or stimulation had a base-level IL-6 and IL-8 secretion. Apical bacterial challenge significantly elevated the basolateral secretion of inflammatory cytokines including IL-2, IL-4, IL-6, IL-8, IFN-γ, GM-CSF, and TNF-α. However, alcohol suppressed the observed cytokine burst in response to infection. Addition of adenosine receptor agonists negated the suppression of IL-6 and TNF-α. Thus, acute alcohol alters the epithelial cytokine response to infection, which can be partially mitigated by adenosine receptor agonists.

  2. From exposure to effect: a comparison of modeling approaches to chemical carcinogenesis.

    Science.gov (United States)

    van Leeuwen, I M; Zonneveld, C

    2001-10-01

    Standardized long-term carcinogenicity tests aim to reveal the relationship between exposure to a chemical and occurrence of a carcinogenic response. The analysis of such tests may be facilitated by the use of mathematical models. To what extent current models actually achieve this purpose is difficult to evaluate. Various aspects of chemically induced carcinogenesis are treated by different modeling approaches, which proceed very much in isolation of each other. With this paper we aim to provide for the non-mathematician a comprehensive and critical overview of models dealing with processes involved in chemical carcinogenesis. We cover the entire process of carcinogenesis, from exposure to effect. We succinctly summarize the biology underlying the models and emphasize the relationship between model assumptions and model formulations. The use of mathematics is restricted as far as possible with some additional information relegated to boxes. PMID:11673088

  3. Grand Challenges and Chemical Engineering Curriculum--Developments at TU Dortmund University

    Science.gov (United States)

    Kockmann, Norbert; Lutze, Philip; Gorak, Andrzej

    2016-01-01

    Chemical processing industry is progressively focusing their research activities and product placements in the areas of Grand Challenges (or Global Megatrends) such as mobility, energy, communication, or health care and food. Innovation in all these fields requires solving high complex problems, rapid product development as well as dealing with…

  4. Indoor Residential Chemical Exposures as Risk Factors for Asthmaand Allergy in Infants and Children: a Review

    Energy Technology Data Exchange (ETDEWEB)

    Mendell, M.J.

    2006-03-01

    Most research into effects of residential indoor air exposures on asthma and allergies has focused on exposures to biologic allergens, moisture and mold, endotoxin, or combustion byproducts. This paper briefly reviews reported findings on associations of asthma or allergy in infants or children with risk factors related to indoor chemical emissions from residential materials or surface coatings. Associations, some strong (e.g., odds ratios up to 13), were reported. The most frequently identified risk factors were formaldehyde, aromatic organic compounds such as toluene and benzene, plastic materials and plasticizers, and recent painting. Exposures and consequent effects from indoor sources may be exacerbated by decreased ventilation. Identified risk factors may be proxies for correlated exposures. Findings suggest the frequent occurrence of important but preventable effects on asthma and allergy in infants and children worldwide from modern residential building materials and coatings.

  5. Bridging the gap between sample collection and laboratory analysis: using dried blood spots to identify human exposure to chemical agents

    Science.gov (United States)

    Hamelin, Elizabeth I.; Blake, Thomas A.; Perez, Jonas W.; Crow, Brian S.; Shaner, Rebecca L.; Coleman, Rebecca M.; Johnson, Rudolph C.

    2016-05-01

    Public health response to large scale chemical emergencies presents logistical challenges for sample collection, transport, and analysis. Diagnostic methods used to identify and determine exposure to chemical warfare agents, toxins, and poisons traditionally involve blood collection by phlebotomists, cold transport of biomedical samples, and costly sample preparation techniques. Use of dried blood spots, which consist of dried blood on an FDA-approved substrate, can increase analyte stability, decrease infection hazard for those handling samples, greatly reduce the cost of shipping/storing samples by removing the need for refrigeration and cold chain transportation, and be self-prepared by potentially exposed individuals using a simple finger prick and blood spot compatible paper. Our laboratory has developed clinical assays to detect human exposures to nerve agents through the analysis of specific protein adducts and metabolites, for which a simple extraction from a dried blood spot is sufficient for removing matrix interferents and attaining sensitivities on par with traditional sampling methods. The use of dried blood spots can bridge the gap between the laboratory and the field allowing for large scale sample collection with minimal impact on hospital resources while maintaining sensitivity, specificity, traceability, and quality requirements for both clinical and forensic applications.

  6. International Federation of Gynecology and Obstetrics opinion on reproductive health impacts of exposure to toxic environmental chemicals.

    Science.gov (United States)

    Di Renzo, Gian Carlo; Conry, Jeanne A; Blake, Jennifer; DeFrancesco, Mark S; DeNicola, Nathaniel; Martin, James N; McCue, Kelly A; Richmond, David; Shah, Abid; Sutton, Patrice; Woodruff, Tracey J; van der Poel, Sheryl Ziemin; Giudice, Linda C

    2015-12-01

    Exposure to toxic environmental chemicals during pregnancy and breastfeeding is ubiquitous and is a threat to healthy human reproduction. There are tens of thousands of chemicals in global commerce, and even small exposures to toxic chemicals during pregnancy can trigger adverse health consequences. Exposure to toxic environmental chemicals and related health outcomes are inequitably distributed within and between countries; universally, the consequences of exposure are disproportionately borne by people with low incomes. Discrimination, other social factors, economic factors, and occupation impact risk of exposure and harm. Documented links between prenatal exposure to environmental chemicals and adverse health outcomes span the life course and include impacts on fertility and pregnancy, neurodevelopment, and cancer. The global health and economic burden related to toxic environmental chemicals is in excess of millions of deaths and billions of dollars every year. On the basis of accumulating robust evidence of exposures and adverse health impacts related to toxic environmental chemicals, the International Federation of Gynecology and Obstetrics (FIGO) joins other leading reproductive health professional societies in calling for timely action to prevent harm. FIGO recommends that reproductive and other health professionals advocate for policies to prevent exposure to toxic environmental chemicals, work to ensure a healthy food system for all, make environmental health part of health care, and champion environmental justice. PMID:26433469

  7. Perinatal exposure to mixtures of anti-androgenic chemicals causes proliferative lesions in rat prostate

    DEFF Research Database (Denmark)

    Boberg, Julie; Johansson, Hanna Katarina Lilith; Hadrup, Niels;

    2015-01-01

    BACKGROUND: Elevated levels of endogenous or exogenous estrogens during fetal life can induce permanent disturbances in prostate growth and predispose to precancerous lesions. Recent studies have indicated that also early anti-androgen exposure may affect prostate cancer risk. METHODS: We examined...... the influence of perinatal exposure to mixtures of anti-androgenic and estrogenic chemicals on prostate development. Wistar rats were exposed from gestation day 7 to postnatal day 22 to a mixture of 8 anti-androgenic compounds (AAMix), a mixture of four estrogenic compounds (EMix), or paracetamol or a...

  8. Soft-tissue sarcomas and exposure to chemical substances: a case-referent study.

    OpenAIRE

    Eriksson, M.; Hardell, L; Berg, N O; T. Möller; Axelson, O

    1981-01-01

    In 1977 several patients were seen with soft-tissue sarcomas and previous exposure to phenoxy acids. This clinical observation resulted in a cases-referent (case-control) study being undertaken which showed that exposure to phenoxy acids or chlorophenols, which are chemically related, gave a roughly six-fold increase in the risk for this type of tumour. A further case-referent study of soft-tissue sarcomas has now been performed to confirm these earlier findings and also to obtain further inf...

  9. Human health issues for combined exposures to plutonium and chemicals - an experimental toxicology approach

    International Nuclear Information System (INIS)

    Workers throughout the U.S. Department of Energy (DOE) complex may be exposed to combinations of various agents. The possibility that chemicals and/or radiation may interact in producing deleterious effects in exposed individuals has been recognized for some time. Although there is a substantial body of knowledge on how specific interactions influence various biological endpoints, no comprehensive framework exists that allows one to reliably predict health effect outcomes from combined exposures. As a result, regulators have relied on simple additive models for setting exposure standards

  10. Prenatal exposure to environmental chemical contaminants and asthma and eczema in school-age children

    DEFF Research Database (Denmark)

    Smit, L A M; Lenters, V; Høyer, B B;

    2015-01-01

    BACKGROUND: Emerging evidence suggests that prenatal or early-life exposures to environmental contaminants may contribute to an increased risk of asthma and allergies in children. We aimed to the explore associations of prenatal exposures to a large set of environmental chemical contaminants with...... asthma, eczema, and wheeze. We applied principal components analysis (PCA) to sixteen contaminants in maternal serum sampled during pregnancy, including perfluoroalkyl substances (PFASs), metabolites of diethylhexyl (DEHP) and diisononyl (DiNP) phthalates, PCB-153, and p,p'-DDE. Scores of five principal...

  11. Highly time-variable exposure to chemicals--toward an assessment strategy.

    Science.gov (United States)

    Ashauer, Roman; Brown, Colin D

    2013-07-01

    Organisms in the environment experience fluctuating, pulsed, or intermittent exposure to pollutants. Accounting for effects of such exposures is an important challenge for environmental risk assessment, particularly given the simplified design of standard ecotoxicity tests. Dynamic simulation using toxicokinetic-toxicodynamic (TK-TD) models describes the processes that link exposure with effects in an organism and provides a basis for extrapolation to a range of exposure scenarios. In so doing, TK-TD modeling makes the risk assessment more robust and aids use and interpretation of experimental data. Toxicokinetic-toxicodynamic models are well-developed for predicting survival of individual organisms and are increasingly applied to sublethal endpoints. In the latter case particularly, linkage to individual-based models (IBMs) allows extrapolation to population level as well as accounting for differences in effects of toxicant exposure at different stages in the life cycle. Extrapolation between species remains an important constraint because there is currently no systematic understanding of species traits that cause differences in the relevant processes. Toxicokinetic-toxicodynamic models allow interrogation of exposure profiles to determine intrinsic toxicity potential rather than using absolute maximum concentrations or time-weighted averages as surrogates. A decision scheme is proposed to guide selection of risk assessment approaches using dose extrapolation based on Haber's Law, TK-TD models, and/or IBMs depending on the nature of toxic effect and timing in relation to life history. PMID:23564608

  12. Globalization : the challenge of the 1990s for the chemical industry

    International Nuclear Information System (INIS)

    The challenges facing the chemical industry in Canada were discussed. In recent years, Canada has scored low in polls measuring public confidence in the chemical industry. The industry is also suffering from continuing recession, global competition, increased environmental demands and strict legislation. The impact of globalization, total quality management, free trade, environmental concerns, and government policies on the chemical industry were reviewed. In the view of this author (President and CEO of Dow Chemicals) globalization is not a matter of choice, it is an industry imperative. Survival in the globalized economy will require not only to be successful competitors, but even more importantly to be successful cooperators with other stakeholders, and successful in forming partnerships with customers

  13. Using Physiologically-Based Pharmacokinetic Models to Incorporate Chemical and Non-Chemical Stressors into Cumulative Risk Assessment: A Case Study of Pesticide Exposures

    Directory of Open Access Journals (Sweden)

    Jonathan I. Levy

    2012-05-01

    Full Text Available Cumulative risk assessment has been proposed as an approach to evaluate the health risks associated with simultaneous exposure to multiple chemical and non-chemical stressors. Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD models can allow for the inclusion and evaluation of multiple stressors, including non-chemical stressors, but studies have not leveraged PBPK/PD models to jointly consider these disparate exposures in a cumulative risk context. In this study, we focused on exposures to organophosphate (OP pesticides for children in urban low-income environments, where these children would be simultaneously exposed to other pesticides (including pyrethroids and non-chemical stressors that may modify the effects of these exposures (including diet. We developed a methodological framework to evaluate chemical and non-chemical stressor impacts on OPs, utilizing an existing PBPK/PD model for chlorpyrifos. We evaluated population-specific stressors that would influence OP doses or acetylcholinesterase (AChE inhibition, the relevant PD outcome. We incorporated the impact of simultaneous exposure to pyrethroids and dietary factors on OP dose through the compartments of metabolism and PD outcome within the PBPK model, and simulated combinations of stressors across multiple exposure ranges and potential body weights. Our analyses demonstrated that both chemical and non-chemical stressors can influence the health implications of OP exposures, with up to 5-fold variability in AChE inhibition across combinations of stressor values for a given OP dose. We demonstrate an approach for modeling OP risks in the presence of other population-specific environmental stressors, providing insight about co-exposures and variability factors that most impact OP health risks and contribute to children’s cumulative health risk from pesticides. More generally, this framework can be used to inform cumulative risk assessment for any compound impacted by

  14. Development of short, acute exposure hazard estimates: a tool for assessing the effects of chemical spills in aquatic environments.

    Science.gov (United States)

    Bejarano, Adriana C; Farr, James K

    2013-08-01

    Management decisions aimed at protecting aquatic resources following accidental chemical spills into rivers and coastal estuaries require estimates of toxic thresholds derived from realistic spill conditions: acute pulse exposures of short duration (h), information which often is unavailable. Most existing toxicity data (median lethal concentration or median effective concentration) come from tests performed under constant exposure concentrations and exposure durations in the 24-h to 96-h range, conditions not typical of most chemical spills. Short-exposure hazard concentration estimates were derived for selected chemicals using empirical toxicity data. Chemical-specific 5th percentile hazard concentrations (HC5) of species sensitivity distributions (SSD) from individual exposure durations (6-96 h) were derived via bootstrap resampling and were plotted against their original exposure durations to estimate HC5s and 95% confidence intervals (CIs) at shorter exposures (1, 2, and 4 h). This approach allowed the development of short-exposure HC5s for 12 chemicals. Model verification showed agreement between observed and estimated short-exposure HC5s (r(2) adjusted = 0.95, p overprotective, these were derived from environmentally realistic exposure durations, providing risk-assessors with a tool to manage field decisions. Environ Toxicol Chem 2013;32:1918-1927. © 2013 SETAC. PMID:23625642

  15. Health Outcomes of Exposure to Biological and Chemical Components of Inhalable and Respirable Particulate Matter.

    Science.gov (United States)

    Morakinyo, Oyewale Mayowa; Mokgobu, Matlou Ingrid; Mukhola, Murembiwa Stanley; Hunter, Raymond Paul

    2016-01-01

    Particulate matter (PM) is a key indicator of air pollution and a significant risk factor for adverse health outcomes in humans. PM is not a self-contained pollutant but a mixture of different compounds including chemical and biological fractions. While several reviews have focused on the chemical components of PM and associated health effects, there is a dearth of review studies that holistically examine the role of biological and chemical components of inhalable and respirable PM in disease causation. A literature search using various search engines and (or) keywords was done. Articles selected for review were chosen following predefined criteria, to extract and analyze data. The results show that the biological and chemical components of inhalable and respirable PM play a significant role in the burden of health effects attributed to PM. These health outcomes include low birth weight, emergency room visit, hospital admission, respiratory and pulmonary diseases, cardiovascular disease, cancer, non-communicable diseases, and premature death, among others. This review justifies the importance of each or synergistic effects of the biological and chemical constituents of PM on health. It also provides information that informs policy on the establishment of exposure limits for PM composition metrics rather than the existing exposure limits of the total mass of PM. This will allow for more effective management strategies for improving outdoor air quality. PMID:27314370

  16. Determinants of Exposure to Fragranced Product Chemical Mixtures in a Sample of Twins

    Directory of Open Access Journals (Sweden)

    Matthew O. Gribble

    2015-01-01

    Full Text Available Fragranced product chemical mixtures may be relevant for environmental health, but little is known about exposure. We analyzed results from an olfactory challenge with the synthetic musk fragrance 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopento-γ-2-benzopyran (HHCB, and a questionnaire about attitudes toward chemical safety and use of fragranced products, in a sample of 140 white and 17 black twin pairs attending a festival in Ohio. Data for each product were analyzed using robust ordered logistic regressions with random intercepts for “twin pair” and “sharing address with twin”, and fixed effects for sex, age, education, and “ever being bothered by fragrances”. Due to the small number of black participants, models were restricted to white participants except when examining racial differences. Overall patterns of association were summarized across product-types through random-effects meta-analysis. Principal components analysis was used to summarize clustering of product use. The dominant axis of variability in fragranced product use was “more vs. less”, followed by a distinction between household cleaning products and personal care products. Overall, males used fragranced products less frequently than females (adjusted proportionate odds ratio 0.55, 95% confidence interval 0.33, 0.93. This disparity was driven by personal care products (0.42, 95% CI: 0.19, 0.96, rather than household cleaning products (0.79, 95% CI: 0.49, 1.25 and was particularly evident for body lotion (0.12, 95% CI: 0.05, 0.27. Overall usage differed by age (0.64, 95% CI: 0.43, 0.95 but only hand soap and shampoo products differed significantly. “Ever being bothered by fragrance” had no overall association (0.92, 95% CI: 0.65, 1.30 but was associated with laundry detergent use (0.46, 95% CI: 0.23, 0.93. Similarly, black vs. white differences on average were not significant (1.34, 95% CI: 0.55, 3.28 but there were apparent differences in use of

  17. Cultured human peripheral blood mononuclear cells alter their gene expression when challenged with endocrine-disrupting chemicals

    International Nuclear Information System (INIS)

    Endocrine disrupting chemicals (EDCs) have the potential to interfere with the hormonal system and may negatively influence human health. Microarray analysis was used in this study to investigate differential gene expression in human peripheral blood cells (PBMCs) after in vitro exposure to EDCs. PBMCs, isolated from blood samples of four male and four female healthy individuals, were exposed in vitro for 18 h to either a dioxin-like polychlorinated biphenyl (PCB126, 1 μM), a non-dioxin-like polychlorinated biphenyl (PCB153, 10 μM), a brominated flame retardant (BDE47, 10 μM), a perfluorinated alkyl acid (PFOA, 10 μM) or bisphenol (BPA, 10 μM). ANOVA analysis revealed a significant change in the expression of 862 genes as a result of EDC exposure. The gender of the donors did not affect gene expression. Hierarchical cluster analysis created three groups and clustered: (1) PCB126-exposed samples, (2) PCB153 and BDE47, (3) PFOA and BPA. The number of differentially expressed genes varied per compound and ranged from 60 to 192 when using fold change and multiplicity corrected p-value as filtering criteria. Exposure to PCB126 induced the AhR signaling pathway. BDE47 and PCB153 are known to disrupt thyroid metabolism and exposure influenced the expression of the nuclear receptors PPARγ and ESR2, respectively. BPA and PFOA did not induce significant changes in the expression of known nuclear receptors. Overall, each compound produced a unique gene expression signature affecting pathways and GO processes linked to metabolism and inflammation. Twenty-nine genes were significantly altered in expression under all experimental conditions. Six of these genes (HSD11B2, MMP11, ADIPOQ, CEL, DUSP9 and TUB) could be associated with obesity and metabolic syndrome. In conclusion, microarray analysis identified that PBMCs altered their gene expression response in vitro when challenged with EDCs. Our screening approach has identified a number of gene candidates that warrant

  18. Neurodevelopmental toxicity risks due to occupational exposure to industrial chemicals during pregnancy

    DEFF Research Database (Denmark)

    Julvez, Jordi; Grandjean, Philippe

    2009-01-01

    Exposure to neurotoxic chemicals is of particular concern when it occurs during early development. The immature brain is highly vulnerable prenatally and is therefore at risk due to occupational exposures incurred by pregnant women. A systematic search of the literature has been performed with...... emphasis on epidemiological studies on female workers and the neurodevelopment of their children. The majority of recent occupational studies focused on organic solvents and pesticides, which were associated with neurobehavioral impairments in the progeny. Additional evidence on environmental exposures...... occupational health researchers and practitioners from the need to protect pregnant workers. Due to the vulnerability of the brain during early development, a precautionary approach to neurodevelopmental toxicity needs to be applied in occupational health....

  19. The Relationship between Drug-and Chemical-exposure and Birth Defects during Pregnancy

    Institute of Scientific and Technical Information of China (English)

    沈启芳; 张忠恕; 方可娟; 丁亦诺; 顾江; 王仁礼; 杨跃英; 李海放; 蒋秀蓉; 薛寿征

    1994-01-01

    A case-control study was conductedin 36 hospitals of the urban and suburban areas of Shanghai about the relationships between birth defects and drug use and chemieal exposures during pregnancy in the period of July 1987-December 1990. The case group was composed of 1.609 subjects, and the control group 3,218 cases. On statistical analysis, it was found that a correlation existed between birth defects and the intake of APC and diazepam, and the exposure to pesticides, organic soh, ents, benzene, synthetic resin and physical factors (noises) on the part of the mother, and the exposure to harmful chemicals and physical factors and the smoking of 20 or more cigarettes a day on the part of the father. It is also found that the familial hereditary history of the parents and muhigravidio,, malnutrition, common colds, hepatitis and diarrhea during pregnancy may also be related to the birth defects.

  20. Process techniques for improving post-exposure delay stability in chemically amplified resists

    Science.gov (United States)

    Nour, Sassan; Pavelchek, Edward K.; Lindsay, Tracy K.; Moynihan, Matthew L.; Gambin, Lori

    1997-07-01

    The post-exposure delay (PED) stability of several chemically amplified DUV resists in unfiltered environments is shown to be strongly dependent on the standing wave intensity. The use of a bottom antireflective layer diminishes the rate of CD change for UVIIHSTM, UVIIITM, APEX-E and UV5TM resists by a factor of three or greater. Increasing the post exposure bake to diffuse outstanding waves results in a three to six fold improvement with UVIIHS, UVIII, UV5 and UV6TM. These resists show the greatest stability when soft baked at high temperatures to reduce the diffusion rate of airborne contaminants, and post-exposure baked at high temperatures to diffuse out the standing wave pattern.

  1. Challenges of infrared reflective spectroscopy of solid-phase explosives and chemicals on surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Mark C.; Suter, Jonathan D.; Bernacki, Bruce E.; Johnson, Timothy J.

    2012-09-01

    Reliable active and passive hyperspectral imaging and detection of explosives and solid-phase chemical residue on surfaces remains a challenge and an active area of research and development. Both methods rely on reference libraries for material identification, but in many cases the reference spectra do not sufficiently resemble those instrumental signals scattered from real-world objects. We describe a physics-based model using the dispersive complex dielectric constant to explain what is often thought of as anomalous behavior of scattered or non-specular signatures encountered in active and passive sensing of explosives or chemicals on surfaces and show modeling and experimental results for RDX.

  2. Prenatal Exposure to Perfluorinated Chemicals and Behavioral or Coordination Problems at Age 7 Years

    OpenAIRE

    Fei, Chunyuan; Olsen, Jørn

    2010-01-01

    Objective Potential neurotoxic effects of perfluorinated compounds (PFCs) have been reported in highly exposed animals, but whether these chemicals are neurotoxic in humans is not known. We therefore investigated whether prenatal exposure to perfluorooctanoic acid (PFOA) or perfluorooctane sulfate (PFOS), two of the most prevalent PFCs, are associated with behavioral or coordination problems in early childhood. Methods We used data from the Danish National Birth Cohort, which enrolled mothers...

  3. Colour stability, staining and roughness of silorane after prolonged chemical challenges

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Ribeiro de Jesus, Vivian Cristiane Bueno; Martinelli, Natan Luiz;

    2013-01-01

    OBJECTIVES: To investigate the effect of prolonged chemical challenges on colour stability, staining susceptibility, and roughness of a silorane composite material when compared to methacrylate-based composites. METHODS: Initial colour and roughness were registered for specimens fabricated from...... methacrylate or silorane composites. Specimens were individually stored at 37°C in 0.02 N citric acid, 0.02 N phosphoric acid, 75% ethanol or distilled water for 7, 14, 21 and 180 days, when new measurements were performed. A staining test was performed after the chemical challenge by immersion in coffee...... considered acceptable (although significantly different) after immersion in water, citric acid, phosphoric acid or ethanol, but were unacceptable for the silorane composite immersed in ethanol for 180 days. The methacrylate-based resins stored in ethanol were significantly more stained by coffee than those...

  4. Distributions of key exposure factors controlling the uptake of xenobiotic chemicals in an estuarine food web

    Energy Technology Data Exchange (ETDEWEB)

    Iannuzzi, T.J.; Harrington, N.W.; Shear, N.M.; Curry, C.L.; Carlson-Lynch, H.; Henning, M.H. [ChemRisk, Portland, ME (United States); Su, S.H. [Bailey Research Associates, Inc., New York, NY (United States); Rabbe, D.E. [Chemical Land Holdings, Inc., Kearny, NJ (United States)

    1996-11-01

    A critical evaluation of literature on the behavior, physiology, and ecology of common estuarine organisms was conducted in an attempt to develop probabilistic distributions for those variables that influence the uptake of xenobiotic chemicals from sediments, water, and food sources. The ranges, central tendencies, and distributions of several key parameter values were identified for dominant organisms from various trophic levels, including the polychaete Nereis virens, mummichog (Fundulus heteroclitus), blue crab (Callinectes sapidus), and striped bass (Morone saxatilis). The exposure factors of interest included ingestion rate for various food sources, growth rate, respiration rate, excretion rate, body weight, wet/dry weight ratio, lipid content, chemical assimilation efficiency, and food assimilation efficiency. These exposure factors are critical to the execution of mechanistic food web models, which, when properly calibrated, can be used to estimate tissue concentrations of nonionic chemicals in aquatic organisms based on knowledge of the bioenergetics and feeding interactions within a food web and the sediment and water concentrations of chemicals. In this article the authors describe the use of distributions for various exposure factors in the context of a mechanistic bioaccumulation model that is amenable to probabilistic analyses for multiple organisms within a food web. A case study is provided which compares the estimated versus measured concentrations of five polychlorinated biphenyl (PCB) congeners in a representative food web from the tidal portion of the Passaic River, New Jersey, USA. The results suggest that the model is accurate within an order of magnitude or less in estimating the bioaccumulation of PCBs in this food web without calibration. The results of a model sensitivity analysis suggest that the input parameters which most influence the output of the model are both chemical and organism specific.

  5. Association between occupational exposures to pesticides with heterogeneous chemical structures and farmer health in China

    Science.gov (United States)

    Huang, Xusheng; Zhang, Chao; Hu, Ruifa; Li, Yifan; Yin, Yanhong; Chen, Zhaohui; Cai, Jinyang; Cui, Fang

    2016-01-01

    This study analyzed the associations of farmers’ exposure to organophosphates (OPs), organosulfurs (OSs), organonitrogens (ONs) and pyrethroids (PYRs) with parameters of the blood complete counts (CBC), a blood chemistry panel (BCP) and the conventional nerve conduction studies among 224 farmers in China in 2012. Two health examinations and a series of follow-up field surveys were conducted. Multiple linear regression analyses were used to evaluate the associations. The results show considerable associations between multiple groups of pesticides and several CBC parameters, but it was not enough to provide evidence of hematological disorders. The short- and medium-term OPs exposures were mainly associated with liver damage and peripheral nerve impairment, respectively, while OSs exposure might induce liver damage and renal dysfunction. The neurotoxicity of ONs was second only to OPs in addition to its potential liver damage and the induced alterations in glucose. In comparison, the estimated results show that PYRs would be the least toxic in terms of the low-dose application. In conclusion, occupational exposures to pesticides with heterogeneous chemical structures are associated with farmer health in different patterns, and the association between a specific group of pesticides and farmer health also differs between the short- and medium-term exposures. PMID:27117655

  6. The stress response in gametes and embryos after paternal chemical exposures

    International Nuclear Information System (INIS)

    There is increasing concern that paternal exposure to toxic chemicals impacts negatively on progeny outcome. Exposure of male rats to a model male-mediated developmental toxicant and anticancer alkylating agent, cyclophosphamide, resulted in increased pre- and post-implantation loss, as well as in malformations. We hypothesize that the stage specificity of the effects of paternal cyclophosphamide exposure on progeny depends on the ability of germ cells to respond to stress, repair DNA or undergo apoptosis. Acute high dose exposure of male rats to cyclophosphamide increased the expression of heat shock proteins and DNA repair genes, predominantly in round spermatids. In contrast, chronic low dose treatment dramatically decreased the expression of stress response genes in pachytene spermatocytes and round spermatids, but not in elongated spermatids; this reduced ability to respond to stress may allow damage to accumulate, resulting in altered sperm function. Increased DNA damage was maximal 3 weeks after drug exposure, during spermiogenesis, a key point in sperm chromatin remodelling. Drug exposure for 9 weeks increased the frequency of spermatozoa with chromosome 4 disomy and nullisomy. DNA damage found in cyclophosphamide-exposed spermatozoa was imparted to the newly fertilized zygote. Drug-exposed spermatozoa decondensed more rapidly than control spermatozoa and male pronuclear formation was earlier. RNA synthesis was higher in 1-cell embryos sired by drug-treated fathers than in controls. Significantly, the profile of gene expression was altered in embryos sired by drug-treated males as early as the 1-cell stage. Thus, exposure of male rats to cyclophosphamide altered male germ cell quality with a consequent temporal and spatial disruption of the zygotic genome activation

  7. Pattern of Morbidity and Mortality in Kurdistan / Iraq with an Emphasis on Exposure to Chemical Weapon

    International Nuclear Information System (INIS)

    A cross-sectional survey was carried out in kurdistan -Iraq during the period 2000-2001 to determine patterns of morbidity and mortality among kurdistan population with special emphasis on those exposed to bombs and shell injuries and chemical weapons. Kurdistan was divided in to 300 sectors; from each sector, one household was selected randomly. The total study samples were 6805 including number of the household who have died since 1935. They have a male: female ratio of 1.03:1. An interview was carried out using a special questionnaire form. The mean age of the sample was 51.5 ± 0.6 years (51.1 ± 0.75 for males and 52.9 ± 0.97 for females ) 1.5% and 2.8% of surveyed population have been exposed to non - chemical weapons (bomb and shells ) or chemical weapons , respectively; 0.23% of the alive population had cancer at the time of the study. 12.6% in the study sample were complaining from respiratory disease and 6.5 had a history of miscarriage and stillbirth. Both complaints might be attributed to expose to chemical weapons. 869 (12.5 %) of the study have died since 1935, 68.4% of them have died during the period 1980 - 1999. 3 % of all deaths were due to exposure to shells or chemical weapons; 7.9 % were lost in Al - anfal campaign in 1980s of the last century. 8.5 % of all death were due to cancer probably due to exposure to chemical weapons. (author)

  8. Exposure to chemical cocktails before or after conception – The effect of timing on ovarian development☆

    Science.gov (United States)

    Bellingham, Michelle; Amezaga, Maria R.; Mandon-Pepin, Beatrice; Speers, Christopher J.B.; Kyle, Carol E.; Evans, Neil P.; Sharpe, Richard M.; Cotinot, Corinne; Rhind, Stewart M.; Fowler, Paul A.

    2013-01-01

    Exposure of female fetuses to environmental chemicals (ECs) during pregnancy results in a disturbed ovarian adult phenotype. We investigated the influence of pre- and/or post-conception exposure to low-level mixtures of ECs on the structure and function of the fetal ovine ovary. We examined ovarian morphology, expression of oocyte and granulosa cell-specific genes and proteome. Female fetuses were collected at day 110 of gestation, from dams exposed continuously until, and after mating, by grazing in pastures treated with sewage sludge as a fertiliser (TT) or in control fields treated with inorganic fertiliser (CC). In addition, in a cross-over design, fetal ovaries were collected from dams maintained on sludge pastures up to the time of mating but then transferred to control pastures (TC) and, reciprocally, those transferred from control to treated pastures at mating (CT). On examination, the proportion of type 1a follicles (activating primordial follicles) was significantly lower in animals from the CT groups compared with CC and TT groups (P vault protein) and several members of the heat-shock family (HSPA4L, HSP90AA1 and HSF1). The present findings indicate that continuous maternal EC exposure before and during gestation, are less deleterious for fetal ovarian development than a change in maternal EC exposure between pre and post-conception. The pathways by which the ovary responds to this chemical stress were common in TT, CT, TC exposed foetuses. In addition to the period of pregnancy, the pre-conception period appears also as crucial for conditioning long-term effects of EC exposure on ovarian development and primordial follicle reserve and hence future fertility. PMID:23791816

  9. Challenges to developing countries after joining WTO: risk assessment of chemicals in food.

    Science.gov (United States)

    Chen, Junshi

    2004-05-20

    FAO/WHO encourages member countries to develop national food control measures based on risk assessment in order to assure proper protection level to consumers and facilitate fair trade. This is particularly important for developing countries as WTO members because it is clearly stated in the Sanitary and Phytosanitary Measures (SPS) Agreement that: (a) SPS measures should be based on risk assessment techniques developed by relevant international organizations; and (b) Codex standards which is based on risk assessment are regarded as the international norm in trade dispute settlement. When conducting risk assessment on food chemicals (including additives and contaminants) in developing countries, in most cases it is not necessary to conduct their own hazard characterization because the ADIs or PTWIs of food chemicals developed by international expert groups (e.g. JECFA) are universally applicable and also developing countries do not have the resources to repeat those expensive toxicological studies. On the other hand, it is necessary to conduct exposure assessment in developing countries because exposure to food chemicals varies from country to country. This is not only crucial in setting national standards, but also very important for developing countries to participate in the process of developing Codex standards. In addition to food standard development, risk assessment is also useful in setting up priorities in imported food inspection and evaluating the success of various food safety control measures. PMID:15138023

  10. Challenges to developing countries after joining WTO: risk assessment of chemicals in food

    International Nuclear Information System (INIS)

    FAO/WHO encourages member countries to develop national food control measures based on risk assessment in order to assure proper protection level to consumers and facilitate fair trade. This is particularly important for developing countries as WTO members because it is clearly stated in the Sanitary and Phytosanitary Measures (SPS) Agreement that: (a) SPS measures should be based on risk assessment techniques developed by relevant international organizations; and (b) Codex standards which is based on risk assessment are regarded as the international norm in trade dispute settlement. When conducting risk assessment on food chemicals (including additives and contaminants) in developing countries, in most cases it is not necessary to conduct their own hazard characterization because the ADIs or PTWIs of food chemicals developed by international expert groups (e.g. JECFA) are universally applicable and also developing countries do not have the resources to repeat those expensive toxicological studies. On the other hand, it is necessary to conduct exposure assessment in developing countries because exposure to food chemicals varies from country to country. This is not only crucial in setting national standards, but also very important for developing countries to participate in the process of developing Codex standards. In addition to food standard development, risk assessment is also useful in setting up priorities in imported food inspection and evaluating the success of various food safety control measures

  11. Exposure to Gulf War Illness chemicals induces functional muscarinic receptor maladaptations in muscle nociceptors.

    Science.gov (United States)

    Cooper, B Y; Johnson, R D; Nutter, T J

    2016-05-01

    Chronic pain is a component of the multisymptom disease known as Gulf War Illness (GWI). There is evidence that pain symptoms could have been a consequence of prolonged and/or excessive exposure to anticholinesterases and other GW chemicals. We previously reported that rats exposed, for 8 weeks, to a mixture of anticholinesterases (pyridostigmine bromide, chlorpyrifos) and a Nav (voltage activated Na(+) channel) deactivation-inhibiting pyrethroid, permethrin, exhibited a behavior pattern that was consistent with a delayed myalgia. This myalgia-like behavior was accompanied by persistent changes to Kv (voltage activated K(+)) channel physiology in muscle nociceptors (Kv7, KDR). In the present study, we examined how exposure to the above agents altered the reactivity of Kv channels to a muscarinic receptor (mAChR) agonist (oxotremorine-M). Comparisons between muscle nociceptors harvested from vehicle and GW chemical-exposed rats revealed that mAChR suppression of Kv7 activity was enhanced in exposed rats. Yet in these same muscle nociceptors, a Stromatoxin-insensitive component of the KDR (voltage activated delayed rectifier K(+) channel) exhibited decreased sensitivity to activation of mAChR. We have previously shown that a unique mAChR-induced depolarization and burst discharge (MDBD) was exaggerated in muscle nociceptors of rats exposed to GW chemicals. We now provide evidence that both muscle and vascular nociceptors of naïve rats exhibit MDBD. Examination of the molecular basis of the MDBD in naïve animals revealed that while the mAChR depolarization was independent of Kv7, the action potential burst was modulated by Kv7 status. mAChR depolarizations were shown to be dependent, in part, on TRPA1. We argue that dysfunction of the MDBD could be a functional convergence point for maladapted ion channels and receptors consequent to exposure to GW chemicals. PMID:27058124

  12. Assessment of macroinvertebrate health and agricultural chemical exposure on Waterfowl Production Areas in Nebraska’s Rainwater Basin Wetland Management District

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Of the 12 sampled locations, the 6 non-buffered sites appear to be affected by agricultural chemical exposure. Agricultural chemical exposure to these sites include...

  13. [Development of Chemical Exposure Prediction Model for Aerobic Sewage Treatment Plant for Biochemical Wastewaters].

    Science.gov (United States)

    Zhou, Lin-jun; Liu, Ji-ning; Shi, Li-li; Feng, Jie; Xu, Yan-hua

    2016-01-15

    Sewage treatment plant (STP) is a key transfer station for chemicals distributed into different environment compartment, and hence models of exposure prediction play a crucial role in the environmental risk assessment and pollution prevention of chemicals. A mass balance model namely Chinese Sewage treatment plant (C-STP(O)) was developed to predict the fate and exposure of chemicals in a conventional sewage treatment plant. The model was expressed as 9 mixed boxes by compartment of air, water, suspended solids, and settled solids. It was based on the minimum input data required on the notification in new chemicals, such as molecular weight, absorption coefficient, vapor pressure, water solubility, ready or inherent biodegradability. The environment conditions ( Temperature = 283 K, wind speed = 2 m x s(-1)) and the classic STP scenario parameters of China, especially the scenario parameters of water quality and sludge properties were adopted in C-STP( 0) model to reflect Chinese characteristics, these parameters were sewage flow of 35 000 m3 x d(-1), influent BOD5 of 0.15 g x L(-1), influent SS of 0.2 kg x m(-3), effluent SS of 0.02 kg x m(-3), BOD5 removal in aerator of 90% sludge density of 1.6 kg x L(3) and organic carbon content of 0.18-0.19. It adopted the fugacity express for mechanism of linear absorption, first-order degradation, Whitman two resistances. An overall interphase transfer constant which was the sum of surface volatilization and stripping was used to assess the volatilization in aerator. The most important and uncertain input value was the biodegradation rate constant, and determination of which required a tier test strategy from ready or inherent biodegradability data to simulate test in STP. An extrapolated criterion of US EPA to derive biodegradation rate constant using the results of ready and inherent biodegradability was compared with that of EU and was recommended. C-STP ( 0 ) was valid to predict the relative emission of volatilization

  14. Challenges in qualifying environmental acceptable production chemicals for a HPHT field

    Energy Technology Data Exchange (ETDEWEB)

    Oeye, Kristin M. Stiegler; Hustad, Britt Marie

    2006-03-15

    The fact that Kristin is a HPHT field leads to challenges in respect to the selection of effective production chemicals which are also environmentally acceptable. The severity of the various production problems influences the priority on testing and qualifying these chemicals. At the start of the project, we evaluated each application and ranked the chemicals based on the following criteria: 1) Chemicals in category green or yellow according to the SFT classification system 2) criticality to the production system 3) severity of the problem which the chemicals are supposed to mitigate 4) conditions at which the chemicals are supposed to function 5) likely availability of the chemicals. Like all the sub sea installations, hydrate prevention remains the number one priority at Kristin. With insulation coupled with direct electric heating (DEH), the flow lines will be protected during long shutdowns. Mono-ethylene Glycol (MEG) will be injected into the end-zones for long unplanned shutdowns. MEG itself will not be a problem as a hydrate inhibitor for Kristin but it does impose certain compatibility criteria for all the other chemicals. Scale prevention, in particular at the downhole safety valve, is considered to be equally important even though it is ranked number two in the chemical selection hierarchy. At pressure above 400-450 bar Kristin reservoir fluid exhibits the reversed Joule-Thomson effect; i.e. the temperature increases with a decrease in pressure. This heating due to expansion has a significant impact on the flowing wellhead temperature (max. FWHT = 157 deg C) and hence the thermal stability of the scale inhibitor chemical. Scale prevention at Kristin will be achieved via a combination of down hole squeeze treatments and the continuous injection of scale inhibitor chemical at the 'well head'. In this paper, however, the focus is on the continuous injection part. Qualification methods for scale inhibitors, product stability, thermal ageing, dynamic

  15. Screening values for Non-Carcinogenic Hanford Waste Tank Vapor Chemicals that Lack Established Occupational Exposure Limits

    Energy Technology Data Exchange (ETDEWEB)

    Poet, Torka S.; Mast, Terryl J.; Huckaby, James L.

    2006-02-06

    Over 1,500 different volatile chemicals have been reported in the headspaces of tanks used to store high-level radioactive waste at the U.S. Department of Energy's Hanford Site. Concern about potential exposure of tank farm workers to these chemicals has prompted efforts to evaluate their toxicity, identify chemicals that pose the greatest risk, and incorporate that information into the tank farms industrial hygiene worker protection program. Established occupation exposure limits for individual chemicals and petroleum hydrocarbon mixtures have been used elsewhere to evaluate about 900 of the chemicals. In this report headspace concentration screening values were established for the remaining 600 chemicals using available industrial hygiene and toxicological data. Screening values were intended to be more than an order of magnitude below concentrations that may cause adverse health effects in workers, assuming a 40-hour/week occupational exposure. Screening values were compared to the maximum reported headspace concentrations.

  16. Lung Irradiation Increases Mortality After Influenza A Virus Challenge Occurring Late After Exposure

    International Nuclear Information System (INIS)

    Purpose: To address whether irradiation-induced changes in the lung environment alter responses to a viral challenge delivered late after exposure but before the appearance of late lung radiation injury. Methods and Materials: C57BL/6J mice received either lung alone or combined lung and whole-body irradiation (0-15 Gy). At 10 weeks after irradiation, animals were infected with 120 HAU influenza virus strain A/HKx31. Innate and adaptive immune cell recruitment was determined using flow cytometry. Cytokine and chemokine production and protein leakage into the lung after infection were assessed. Results: Prior irradiation led to a dose-dependent failure to regain body weight after infection and exacerbated mortality, but it did not affect virus-specific immune responses or virus clearance. Surviving irradiated animals displayed a persistent increase in total protein in bronchoalveolar lavage fluid and edema. Conclusions: Lung irradiation increased susceptibility to death after infection with influenza virus and impaired the ability to complete recovery. This altered response does not seem to be due to a radiation effect on the immune response, but it may possibly be an effect on epithelial repair

  17. Lung Irradiation Increases Mortality After Influenza A Virus Challenge Occurring Late After Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Manning, Casey M. [Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York (United States); Johnston, Carl J. [Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York (United States); Department of Pediatrics, University of Rochester Medical Center, Rochester, New York (United States); Reed, Christina K. [Department of Pediatrics, University of Rochester Medical Center, Rochester, New York (United States); Lawrence, B. Paige [Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York (United States); Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York (United States); Williams, Jacqueline P. [Department of Radiation Oncology, University of Rochester Medical Center, Rochester, New York (United States); Finkelstein, Jacob N., E-mail: Jacob_Finkelstein@urmc.rochester.edu [Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York (United States); Department of Pediatrics, University of Rochester Medical Center, Rochester, New York (United States); Department of Radiation Oncology, University of Rochester Medical Center, Rochester, New York (United States)

    2013-05-01

    Purpose: To address whether irradiation-induced changes in the lung environment alter responses to a viral challenge delivered late after exposure but before the appearance of late lung radiation injury. Methods and Materials: C57BL/6J mice received either lung alone or combined lung and whole-body irradiation (0-15 Gy). At 10 weeks after irradiation, animals were infected with 120 HAU influenza virus strain A/HKx31. Innate and adaptive immune cell recruitment was determined using flow cytometry. Cytokine and chemokine production and protein leakage into the lung after infection were assessed. Results: Prior irradiation led to a dose-dependent failure to regain body weight after infection and exacerbated mortality, but it did not affect virus-specific immune responses or virus clearance. Surviving irradiated animals displayed a persistent increase in total protein in bronchoalveolar lavage fluid and edema. Conclusions: Lung irradiation increased susceptibility to death after infection with influenza virus and impaired the ability to complete recovery. This altered response does not seem to be due to a radiation effect on the immune response, but it may possibly be an effect on epithelial repair.

  18. Devulcanization of ground tire rubber: Physical and chemical changes after different microwave exposure times

    Directory of Open Access Journals (Sweden)

    P. S. Garcia

    2015-11-01

    Full Text Available Microwave devulcanization is known to be a promising and an efficient rubber recycling method which makes possible for the rubber to regain its fluidity, and makes it capable of being remolded and revulcanized. The focus of this work is to understand the physical and chemical changes that occur in the ground tire rubber after different microwave exposure periods. For this purpose chemical, thermal, rheological and morphological analyses were performed on the tire rubber, which contains natural rubber (NR and styrene-butadiene rubber (SBR as polymeric material. The results showed that the microwave treatment promoted the breaking of sulfur cross-links and consequently increased the rubber fluidity. However, long periods of exposure led to degradation and modification of some properties. At nanoscale, the deformation of the devulcanized NR domain under stress was observed, and the morphology obtained appears to be a droplet dispersion morphology. The most exposed samples presented only one glass transition temperature, and from this it was concluded that the treatment may have played an important role in the compatibilization of the elastomeric blend. Based on the results, it is required to control the microwave exposure time and polymeric degradation in order to achieve a regenerated rubber with satisfactory properties.

  19. Comparison of Chest HRCT in Inspiration and Expiration of patients with Chemical Gas Exposure

    Directory of Open Access Journals (Sweden)

    Kh. Bakhtavar

    2005-08-01

    Full Text Available Background/Objectives: Chemical weapon agents (CWA including Sulfur Mustard (SM, were com-monly used in the Iran-Iraq war and pulmonary complications are known to occur in over half of the exposed patients. Previous studies showed that HRCT in inspiration was normal in most of the patients. In this study comparison between the HRCT findings in deep inspiration and full expiration was carried out. Materials and Method: HRCT in deep inspiration and full expiration in 473 patients with history of chemi-cal gas exposure during the war was performed and the results were compared. The study was prospective during one year since 1382 to 1383. Results: In our study, 366 patients (77% showed normal HRCT in deep inspiration, however in corre-sponding expiration cuts, 54% showed abnormal findings, from which, patchy air trapping was the most common (78%. Other findings in our study were pulmonary fibrotic changes (30%, emphysema (19%, and bronchiectasis (10%. Conclusion: Exposure to SM has pulmonary compli-cations and results in disability in the affected pa-tients. HRCT is normal only in inspiration in most of the affected patients; expiratory HRCT showed patchy air trapping as the most common finding which is suggestive of bronchiolitis obliterans. There-fore, HRCT should be advised to be done both in deep inspiration and full expiration in patients with history of CWA exposure.

  20. Neurotoxic exposure and impairment of the chemical senses of taste and smell.

    Science.gov (United States)

    Doty, Richard L

    2015-01-01

    The chemical senses of taste and smell determine the flavor of foods and beverages, guide appropriate food intake, and warn of such environmental hazards as spoiled or poisonous food, leaking natural gas, smoke, and airborne pollutants. This chapter addresses the influences of neurotoxic exposures on human chemoreception and provides basic information on the adverse influences of such exposures on rodent epithelia. The focus of the chapter is in olfaction, given dearth of empiric research on the effects of neurotoxic chemical exposures on the sense of taste, i.e., sweet, sour, bitter, salty, and savory sensations. As will be apparent from the chapter, numerous neurotoxins--many of which are encountered in industrial workplaces--alter the ability to smell, including solvents, metals, and particulate matter. The olfactory system is particularly vulnerable to such agents since its receptors are more or less directly exposed to the outside environment. Importantly, some such agents can enter the brain via the olfactory nerve or surrounding perineural spaces, bypassing the blood-brain barrier and damaging central nervous system structures and inducing pathologic processes that appear to be similar to those seen in neurodegenerative diseases such as Alzheimer's and Parkinson's. PMID:26563795

  1. Assessment of infant exposure to food chemicals: the French Total Diet Study design.

    Science.gov (United States)

    Hulin, M; Bemrah, N; Nougadère, A; Volatier, J L; Sirot, V; Leblanc, J C

    2014-01-01

    As part of the previous French Total Diet Studies (TDS) focusing on exposure to food chemicals in the population aged 3 years and older, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) launched a specific TDS on infants to complete its overall chemical food safety programme for the general population. More than 500 chemical substances were analysed in food products consumed by children under 3 years old, including nutrients, several endocrine disruptors resulting from human activities (polychlorinated biphenyls, dioxins and furans, brominated flame retardants, perfluoroalkyl acids, pesticide residues, etc.) or migrating from food contact materials such as bisphenol A or phthalates, but also natural substances such as mycotoxins, phytoestrogens and steroids. To obtain a representative and general view of infant food consumption, food items were selected based on results of a national consumption survey conducted specifically on this population. Moreover, a specific study on food was conducted on 429 households to determine which home-cooking practices are employed to prepare food consumed by infants. Overall, the targeted chemical substances were analysed in more than 450 food samples, representing the purchase and home-cooking practices of over 5500 food products. Foods included common foods such as vegetables, fruit or cakes as well as specific infant foods such as infant formula or jarred baby food. The sampling plan covered over 80% of the total diet. Specificities in infant food consumption and habits were therefore considered to define this first infant TDS. This study, conducted on a large scale and focusing on a particularly sensitive population, will provide accurate information on the dietary exposure of children under 3 years to food chemicals, especially endocrine disruptors, and will be particularly useful for risk assessment analysis under the remit of ANSES' expert committees. PMID:24827474

  2. DNA methylation: a mechanism linking environmental chemical exposures to risk of autism spectrum disorders?

    Science.gov (United States)

    Keil, Kimberly P.; Lein, Pamela J.

    2016-01-01

    There is now compelling evidence that gene by environment interactions are important in the etiology of autism spectrum disorders (ASDs). However, the mechanisms by which environmental factors interact with genetic susceptibilities to confer individual risk for ASD remain a significant knowledge gap in the field. The epigenome, and in particular DNA methylation, is a critical gene expression regulatory mechanism in normal and pathogenic brain development. DNA methylation can be influenced by environmental factors such as diet, hormones, stress, drugs, or exposure to environmental chemicals, suggesting that environmental factors may contribute to adverse neurodevelopmental outcomes of relevance to ASD via effects on DNA methylation in the developing brain. In this review, we describe epidemiological and experimental evidence implicating altered DNA methylation as a potential mechanism by which environmental chemicals confer risk for ASD, using polychlorinated biphenyls (PCBs), lead, and bisphenol A (BPA) as examples. Understanding how environmental chemical exposures influence DNA methylation and how these epigenetic changes modulate the risk and/or severity of ASD will not only provide mechanistic insight regarding gene-environment interactions of relevance to ASD but may also suggest potential intervention strategies for these and potentially other neurodevelopmental disorders.

  3. Genotoxic effects of both EMF and radiofrequency alone and in combination with exposure to chemicals

    International Nuclear Information System (INIS)

    Full text: Due to widespread use of electromagnetic sources in industry, medicine and every day life, a great concern exists in biological effects of such non ionising radiation. A great variety of studies both in vivo and in vitro on different biological systems have been published by evaluating several biological functions but the results are not yet conclusive. Among the possible biological effects induced by electromagnetic fields (EMFs), cancer occurrence is one of the most investigated but epidemiological evidence is not univocal. Regarding the genotoxic potential of EMFs, most of the data available in literature indicates absence of effects even if some positive findings have been reported. More recently, following the increasing use of EMFs and the large diffusion of chemical pollution it may be questionable whether combined exposures to such agents could induce cooperative effects on living organisms which, in the real life situation, are exposed every day to more than one chemical and/or physical agents. Moreover it is likely that combined action of different agents is involved in cancerogenesis and the EMFs are suggested to act as co-carcinogens if given in combination with genotoxic and/or non genotoxic carcinogens. The present work deals with more recent results reported in literature on the in vitro investigation of genotoxic effects following exposure to both extremely low frequency and radiofrequency, alone and in combination with chemical treatments. (author)

  4. Oocyte toxicity: female germ-cell loss from radiation and chemical exposures

    International Nuclear Information System (INIS)

    In some mammals, female germ cells are extraordinarily sensitive to killing by exposure to ionizing radiation, especially during development. Immature oocytes, which constitute the lifetime germ-cell pool of the female, have an LD50 in juvenile mice of only 6 rad (compared with typical LD50s of 100-300 rad for most other cell types studied). Essentially, the entire germ-cell supply in female squirrel monkeys is destroyed prenatally by exposure of only 0.7 rad/day. Severe but lesser destruction has been found in other species. However, evidence suggests (though not ruled out for all developmental stages) that unusually high sensitivity probably does not occur in the human female. Germ cells can also be killed by certain chemicals, and similarities exist between chemical and radiation effects. More than 75 compounds have been quantitatively studied in mice, with determination of OTI values (OTI = oocyte toxicity index = mouse LD50/oocyte LD50) to measure the degree of preferential oocyte killing. High sensitivity in mice does not mean necessarily high sensitivity in women. Of special interest is the recent discovery that the lethal target in the extremely sensitive mouse immature oocyte is probably the plasma membrane, not DNA. Since mouse data form the main basis from which human genetic hazard (for both radiation and chemicals) is estimated, this has important implications for the determination of genetic risk in women

  5. Spatial variability versus parameter uncertainty in freshwater fate and exposure factors of chemicals.

    Science.gov (United States)

    Nijhof, Carl O P; Huijbregts, Mark A J; Golsteijn, Laura; van Zelm, Rosalie

    2016-04-01

    We compared the influence of spatial variability in environmental characteristics and the uncertainty in measured substance properties of seven chemicals on freshwater fate factors (FFs), representing the residence time in the freshwater environment, and on exposure factors (XFs), representing the dissolved fraction of a chemical. The influence of spatial variability was quantified using the SimpleBox model in which Europe was divided in 100 × 100 km regions, nested in a regional (300 × 300 km) and supra-regional (500 × 500 km) scale. Uncertainty in substance properties was quantified by means of probabilistic modelling. Spatial variability and parameter uncertainty were expressed by the ratio k of the 95%ile and 5%ile of the FF and XF. Our analysis shows that spatial variability ranges in FFs of persistent chemicals that partition predominantly into one environmental compartment was up to 2 orders of magnitude larger compared to uncertainty. For the other (less persistent) chemicals, uncertainty in the FF was up to 1 order of magnitude larger than spatial variability. Variability and uncertainty in freshwater XFs of the seven chemicals was negligible (k accounting for region-specific environmental characteristics in multimedia fate modelling, as well as accounting for parameter uncertainty, can have a significant influence on freshwater fate factor predictions. Therefore, we conclude that it is important that fate factors should not only account for parameter uncertainty, but for spatial variability as well, as this further increases the reliability of ecotoxicological impacts in LCA. PMID:26855212

  6. Risk-based high-throughput chemical screening and prioritization using exposure models and in vitro bioactivity assays

    DEFF Research Database (Denmark)

    Shin, Hyeong-Moo; Ernstoff, Alexi; Arnot, Jon;

    2015-01-01

    We present a risk-based high-throughput screening (HTS) method to identify chemicals for potential health concerns or for which additional information is needed. The method is applied to 180 organic chemicals as a case study. We first obtain information on how the chemical is used and identify...... intake, food/oral contact, or dermal exposure. The method provides high-throughput estimates of exposure and important input for decision makers to identify chemicals of concern for further evaluation with additional information or more refined models....

  7. Peculiarities of Enhancing Resistant Starch in Ruminants Using Chemical Methods: Opportunities and Challenges

    Directory of Open Access Journals (Sweden)

    Qendrim Zebeli

    2013-06-01

    Full Text Available High-producing ruminants are fed high amounts of cereal grains, at the expense of dietary fiber, to meet their high energy demands. Grains consist mainly of starch, which is easily degraded in the rumen by microbial glycosidases, providing energy for rapid growth of rumen microbes and short-chain fatty acids (SCFA as the main energy source for the host. Yet, low dietary fiber contents and the rapid accumulation of SCFA lead to rumen disorders in cattle. The chemical processing of grains has become increasingly important to confer their starch resistances against rumen microbial glycosidases, hence generating ruminally resistant starch (RRS. In ruminants, unlike monogastric species, the strategy of enhancing resistant starch is useful, not only in lowering the amount of carbohydrate substrates available for digestion in the upper gut sections, but also in enhancing the net hepatic glucose supply, which can be utilized by the host more efficiently than the hepatic gluconeogenesis of SCFA. The use of chemical methods to enhance the RRS of grains and the feeding of RRS face challenges in the practice; therefore, the present article attempts to summarize the most important achievements in the chemical processing methods used to generate RRS, and review advantages and challenges of feeding RRS to ruminants

  8. Structural, Chemical and Biological Aspects of Antioxidants for Strategies Against Metal and Metalloid Exposure

    Directory of Open Access Journals (Sweden)

    Swaran J. S. Flora

    2009-01-01

    Full Text Available Oxidative stress contributes to the pathophysiology of exposure to heavy metals/metalloid. Beneficial renal effects of some medications, such as chelation therapy depend at least partially on the ability to alleviate oxidative stress. The administration of various natural or synthetic antioxidants has been shown to be of benefit in the prevention and attenuation of metal induced biochemical alterations. These include vitamins, N-acetylcysteine, α-lipoic acid, melatonin, dietary flavonoids and many others. Human studies are limited in this regard. Under certain conditions, surprisingly, the antioxidant supplements may exhibit pro-oxidant properties and even worsen metal induced toxic damage. To date, the evidence is insufficient to recommend antioxidant supplements in subject with exposure to metals. Prospective, controlled clinical trials on safety and effectiveness of different therapeutic antioxidant strategies either individually or in combination with chelating agent are indispensable. The present review focuses on structural, chemical and biological aspects of antioxidants particularly related to their chelating properties.

  9. Demonstration of real-time monitoring of a photolithographic exposure process using chemical ionization mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mowry, C.D. [Sandia National Labs., Albuquerque, NM (United States). Analytical Chemistry Dept.

    1998-02-01

    Silicon wafers are coated with photoresist and exposed to ultraviolet (UV) light in a laboratory to simulate typical conditions expected in an actual semiconductor manufacturing process tool. Air is drawn through the exposure chamber and analyzed using chemical ionization mass spectrometry (CI/MS). Species that evaporate or outgas from the wafer are thus detected. The purpose of such analyses is to determine the potential of CI/MS as a real-time process monitoring tool. Results demonstrate that CI/MS can remotely detect the products evolved before, during, and after wafer UV exposure; and that the quantity and type of products vary with the photoresist coated on the wafer. Such monitoring could provide semiconductor manufacturers benefits in quality control and process analysis. Tool and photoresist manufacturers could also realize benefits from this measurement technique with respect to new tool, method, or photoresist development. The benefits realized can lead to improved device yields and reduced product and development costs.

  10. How to secure sustainable competitiveness of Chemical Industry Parks:global competitive challenges and a systematic, customer-centric response

    OpenAIRE

    Behrendt, C

    2013-01-01

    The central question of the following paper is how Chemical Industry Park operators could systematically integrate the external investors' perspective into their decisions about the park's future competitive positioning and continuous improvement of operational excellence. In today's chemical industry landscape, Chemical Industry Parks and their operators face great challenges. On the one hand, they have to meet increased and more complex demands of globally-active chemical companies. On the ...

  11. A simple procedure for estimating pseudo risk ratios from exposure to non-carcinogenic chemical mixtures.

    Science.gov (United States)

    Scinicariello, Franco; Portier, Christopher

    2016-03-01

    Non-cancer risk assessment traditionally assumes a threshold of effect, below which there is a negligible risk of an adverse effect. The Agency for Toxic Substances and Disease Registry derives health-based guidance values known as Minimal Risk Levels (MRLs) as estimates of the toxicity threshold for non-carcinogens. Although the definition of an MRL, as well as EPA reference dose values (RfD and RfC), is a level that corresponds to "negligible risk," they represent daily exposure doses or concentrations, not risks. We present a new approach to calculate the risk at exposure to specific doses for chemical mixtures, the assumption in this approach is to assign de minimis risk at the MRL. The assigned risk enables the estimation of parameters in an exponential model, providing a complete dose-response curve for each compound from the chosen point of departure to zero. We estimated parameters for 27 chemicals. The value of k, which determines the shape of the dose-response curve, was moderately insensitive to the choice of the risk at the MRL. The approach presented here allows for the calculation of a risk from a single substance or the combined risk from multiple chemical exposures in a community. The methodology is applicable from point of departure data derived from quantal data, such as data from benchmark dose analyses or from data that can be transformed into probabilities, such as lowest-observed-adverse-effect level. The individual risks are used to calculate risk ratios that can facilitate comparison and cost-benefit analyses of environmental contamination control strategies. PMID:25667015

  12. A decision support framework for characterizing and managing dermal exposures to chemicals during Emergency Management and Operations

    OpenAIRE

    Dotson, G. Scott; Hudson, Naomi L.; Maier, Andrew

    2015-01-01

    Emergency Management and Operations (EMO) personnel are in need of resources and tools to assist in understanding the health risks associated with dermal exposures during chemical incidents. This article reviews available resources and presents a conceptual framework for a decision support system (DSS) that assists in characterizing and managing risk during chemical emergencies involving dermal exposures. The framework merges principles of three decision-making techniques: 1...

  13. Subtleties of human exposure and response to chemical mixtures from spills.

    Science.gov (United States)

    Phetxumphou, Katherine; Dietrich, Andrea M; Shanaiah, Narasimhamurthy; Smiley, Elizabeth; Gallagher, Daniel L

    2016-07-01

    Worldwide, chemical spills degrade drinking water quality and threaten human health through ingestion and inhalation. Spills are often mixtures of chemicals; thus, understanding the interaction of chemical and biological properties of the major and minor components is critical to assessing human exposure. The crude (4-methylcyclohexyl)methanol (MCHM) spill provides an opportunity to assess such subtleties. This research determined the relative amounts, volatilization, and biological odor properties of minor components cis- and trans-methyl-4-methylcyclohexanecarboxylate (MMCHC) isomers and major components cis- and trans-4-MCHM, then compared properties and human exposure differences among them. (1)H nuclear magnetic resonance and chromatography revealed that the minor MMCHC isomers were about 1% of the major MCHM isomers. At typical showering temperature of 40 °C, Henry's law constants were 1.50 × 10(-2) and 2.23 × 10(-2) for cis- and trans-MMCHC, respectively, which is 20-50 fold higher than for 4-MCHM isomers. The odor thresholds were 1.83 and 0.02 ppb-v air for cis- and trans-MMCHC, which were both described as predominantly sweet. These data are compared to the higher 120 ppb-v air and 0.06 ppb-v odor thresholds for cis- and trans-4-MCHM, for which the trans-isomer had a dominant licorice descriptor. Application of a shower model demonstrated that while MMCHC isomers are only about 1% of the MCHM isomers, during showering, the MMCHC isomers are 13.8% by volume (16.3% by mass) because of their higher volatility. Trans-4-MCHM contributed about 82% of the odor because of higher volatility and lower odor threshold, trans-MMCHC, which represents 0.3% of the mass, contributed 18% of the odor. This study, with its unique human sensory component to assess exposure, reaffirmed that hazard assessment must not be based solely on relative concentration, but also consider the chemical fate, transport, and biological properties to determine the actual levels of

  14. Autoantibodies associated with prenatal and childhood exposure to environmental chemicals in faroese children

    DEFF Research Database (Denmark)

    Osuna, Christa E; Grandjean, Philippe; Weihe, Pál; El-Fawal, Hassan A N

    2014-01-01

    to both neural (neurofilaments, cholineacetyltransferase, astrocyte glial fibrillary acidic protein, and myelin basic protein) and non-neural (actin, desmin, and keratin) antigens were measured and the associations of these autoantibody concentrations with chemical exposures were assessed using...... linear regression. Age-7 blood-mercury concentrations were positively associated with titers of multiple neural- and non-neural-specific antibodies, mostly of the IgM isotype. Additionally, prenatal blood-mercury and -PCBs were negatively associated with anti-keratin IgG and prenatal PFOS was negatively...

  15. [Analysis of exposure to pepper spray as a part of preparing hospital to help victims of mass chemical incidents].

    Science.gov (United States)

    Chwaluk, Paweł; Topczewska, Elzbieta; Barwina, Małgorzata

    2012-01-01

    We analyzed an incident of exposure to pepper spray 35 persons, including 29 children. Medical procedures were difficult because of the lack of reliable information about the nature of exposure, lack of hospital action plan for chemical accidents and established principles of cooperation with poison control center, as well as the need of extensive medical documentation for each patient. PMID:23243951

  16. Concurrent Fetal Exposure to Multiple Environmental Chemicals along the U.S.—Mexico Border: An Exploratory Study in Brownsville, Texas

    Directory of Open Access Journals (Sweden)

    Ken Sexton

    2014-09-01

    Full Text Available There is mounting concern that cumulative exposure to diverse chemicals in the environment may contribute to observed adverse health outcomes in the Lower Rio Grande Valley of Texas. To investigate this situation, biomarker concentrations of organochlorine (OC pesticides/metabolites, polychlorinated biphenyls (PCBs, and polycyclic aromatic hydrocarbons (PAHs were measured in maternal and umbilical cord blood from pregnant Hispanic women in Brownsville, TX. Results show that both mothers and fetuses were exposed concurrently to a variety of relatively low-level, hazardous environmental chemicals. Approximately 10% of the blood specimens had comparatively high concentrations of specific OC pesticides, PCBs and PAHs. Because many pregnant women in Brownsville live in socioeconomically-disadvantaged and environmentally-challenging circumstances, there is appropriate concern that exposure to these exogenous substances, either individually or in combination, may contribute to endemic health problems in this population, including cardiovascular disease, obesity, and diabetes.  The challenge is to identify individuals at highest comparative risk and then implement effective programs to either prevent or reduce cumulative exposures that pose significant health-related threats.

  17. Risk-based high-throughput chemical screening and prioritization using exposure models and in vitro bioactivity assays

    International Nuclear Information System (INIS)

    We present a risk-based high-throughput screening (HTS) method to identify chemicals for potential health concerns or for which additional information is needed. The method is applied to 180 organic chemicals as a case study. We first obtain information on how the chemical is used and identify relevant use scenarios (e.g., dermal application, indoor emissions). For each chemical and use scenario, exposure models are then used to calculate a chemical intake fraction, or a product intake fraction, accounting for chemical properties and the exposed population. We then combine these intake fractions with use scenario-specific estimates of chemical quantity to calculate daily intake rates (iR; mg/kg/day). These intake rates are compared to oral equivalent doses (OED; mg/kg/day), calculated from a suite of ToxCast in vitro bioactivity assays using in vitro-to-in vivo extrapolation and reverse dosimetry. Bioactivity quotients (BQs) are calculated as iR/OED to obtain estimates of potential impact associated with each relevant use scenario. Of the 180 chemicals considered, 38 had maximum iRs exceeding minimum OEDs (i.e., BQs > 1). For most of these compounds, exposures are associated with direct intake, food/oral contact, or dermal exposure. The method provides high-throughput estimates of exposure and important input for decision makers to identify chemicals of concern for further evaluation with additional information or more refined models

  18. Estimating Burden and Disease Costs of Exposure to Endocrine-Disrupting Chemicals in the European Union

    DEFF Research Database (Denmark)

    Trasande, Leonardo; Zoeller, R. Thomas; Hass, Ulla;

    2015-01-01

    Rapidly increasing evidence has documented that endocrine-disrupting chemicals (EDCs) contribute substantially to disease and disability. Objective: The objective was to quantify a range of health and economic costs that can be reasonably attributed to EDC exposures in the European Union (EU......). Design: A Steering Committee of scientists adapted the Intergovernmental Panel on Climate Change weight-of-evidence characterization for probability of causation based upon levels of available epidemiological and toxicological evidence for one or more chemicals contributing to disease by an endocrine...... Environmental Protection Agency for evaluating laboratory and animal evidence of endocrine disruption. Expert panels used the Delphi method to make decisions on the strength of the data. Results: Expert panels achieved consensus at least for probable (>20%) EDC causation for IQ loss and associated intellectual...

  19. Regulation and practice of workers' protection from chemical exposures during container handling

    DEFF Research Database (Denmark)

    Nørgaard Fløe Pedersen, Randi; Jepsen, Jørgen Riis; Ádám, Balázs

    2014-01-01

    containers was investigated in a qualitative study based on a series of semi-structured interviews with key informants, including managers and health and safety representatives of organizations that handle containers. Results: Although several international and national regulations and local safety...... instructions relate to container handling, the provided information is not sufficiently detailed to conduct safe practice in many aspects. In accordance with the scientific literature, the interviewees estimate that there is a high frequency (5 to 50%) of containers with hazardous chemical exposure that are...... regarded as potentially damaging to health, although recognisable health effects are rare. There is limited knowledge about the types of chemicals, which mostly cannot be measured by available devices at the worksite. Aeration and use of personal protective equipment are typical preventive measures in...

  20. Design, development and validation of software for modelling dietary exposure to food chemicals and nutrients.

    Science.gov (United States)

    McNamara, C; Naddy, B; Rohan, D; Sexton, J

    2003-10-01

    The Monte Carlo computational system for stochastic modelling of dietary exposure to food chemicals and nutrients is presented. This system was developed through a European Commission-funded research project. It is accessible as a Web-based application service. The system allows and supports very significant complexity in the data sets used as the model input, but provides a simple, general purpose, linear kernel for model evaluation. Specific features of the system include the ability to enter (arbitrarily) complex mathematical or probabilistic expressions at each and every input data field, automatic bootstrapping on subjects and on subject food intake diaries, and custom kernels to apply brand information such as market share and loyalty to the calculation of food and chemical intake. PMID:14555354

  1. Effect of pH and dissociation on the fate and exposure of ionizable chemicals

    DEFF Research Database (Denmark)

    Franco, Antonio; Trapp, Stefan

    2010-01-01

    Ionizable organic chemicals comprise an important fraction of pharmaceuticals, pesticides as well as industrial chemicals. It has been estimated that 33% of the preregistered REACH substances is mostly ionized at pH 7. To extend the appliccability of existing exposure models, a Multimedia Activity...... Model for Ionics (MAMI) was recently developed and tested. In the present study, the impact of the parameters describing ionization was assessed by performing the sensitivity and the uncertainty analysis on MAMI for the acids 2,4-D, pentachlorophenol, bisphenol-A, perfluorooctanoic acid and the bases...... parameters. The sensitivity analysis showed that the parameters describing ionization, pH and the dissociation constant (pKa), are among the most sensitive model parameters. The uncertainty analysis, however, indicated that these parameters are not the major source of uncertainty, which statistically...

  2. Assessment of environmental exposures from agricultural pesticides in childhood leukaemia studies: Challenges and opportunities

    International Nuclear Information System (INIS)

    Pesticides are ubiquitous in environments of many rural communities due to drift from agricultural applications and home/garden use. Studies of childhood leukaemia predominantly relied on retrospective pesticide exposure assessment and parental recall of use or proximity to fields or pesticide applications. Sample size requirements mostly preclude the collection of individual-level exposure information, bio-markers or environmental measurements of pesticides prospectively in cohorts. Yet such measures can be used in nested case-control approaches or for validating exposure models that can be applied to large populations. Recently developed models incorporate geographic information system technology and environmental databases of pesticide and/or crop data to assess exposure. Models developed in California to estimate residential exposures are presented by linking addresses to agricultural pesticide application data and land-use maps. Results from exposure validation and simulation studies and exposure measurement error issues are discussed. (authors)

  3. Implementing systematic review techniques in chemical risk assessment: Challenges, opportunities and recommendations.

    Science.gov (United States)

    Whaley, Paul; Halsall, Crispin; Ågerstrand, Marlene; Aiassa, Elisa; Benford, Diane; Bilotta, Gary; Coggon, David; Collins, Chris; Dempsey, Ciara; Duarte-Davidson, Raquel; FitzGerald, Rex; Galay-Burgos, Malyka; Gee, David; Hoffmann, Sebastian; Lam, Juleen; Lasserson, Toby; Levy, Len; Lipworth, Steven; Ross, Sarah Mackenzie; Martin, Olwenn; Meads, Catherine; Meyer-Baron, Monika; Miller, James; Pease, Camilla; Rooney, Andrew; Sapiets, Alison; Stewart, Gavin; Taylor, David

    2016-01-01

    Systematic review (SR) is a rigorous, protocol-driven approach designed to minimise error and bias when summarising the body of research evidence relevant to a specific scientific question. Taking as a comparator the use of SR in synthesising research in healthcare, we argue that SR methods could also pave the way for a "step change" in the transparency, objectivity and communication of chemical risk assessments (CRA) in Europe and elsewhere. We suggest that current controversies around the safety of certain chemicals are partly due to limitations in current CRA procedures which have contributed to ambiguity about the health risks posed by these substances. We present an overview of how SR methods can be applied to the assessment of risks from chemicals, and indicate how challenges in adapting SR methods from healthcare research to the CRA context might be overcome. Regarding the latter, we report the outcomes from a workshop exploring how to increase uptake of SR methods, attended by experts representing a wide range of fields related to chemical toxicology, risk analysis and SR. Priorities which were identified include: the conduct of CRA-focused prototype SRs; the development of a recognised standard of reporting and conduct for SRs in toxicology and CRA; and establishing a network to facilitate research, communication and training in SR methods. We see this paper as a milestone in the creation of a research climate that fosters communication between experts in CRA and SR and facilitates wider uptake of SR methods into CRA. PMID:26687863

  4. Exposure of Salmonella enterica serovar Typhimurium to high level biocide challenge can select multidrug resistant mutants in a single step.

    Directory of Open Access Journals (Sweden)

    Rebekah N Whitehead

    Full Text Available BACKGROUND: Biocides are crucial to the prevention of infection by bacteria, particularly with the global emergence of multiply antibiotic resistant strains of many species. Concern has been raised regarding the potential for biocide exposure to select for antibiotic resistance due to common mechanisms of resistance, notably efflux. METHODOLOGY/PRINCIPAL FINDINGS: Salmonella enterica serovar Typhimurium was challenged with 4 biocides of differing modes of action at both low and recommended-use concentration. Flow cytometry was used to investigate the physiological state of the cells after biocide challenge. After 5 hours exposure to biocide, live cells were sorted by FACS and recovered. Cells recovered after an exposure to low concentrations of biocide had antibiotic resistance profiles similar to wild-type cells. Live cells were recovered after exposure to two of the biocides at in-use concentration for 5 hours. These cells were multi-drug resistant and accumulation assays demonstrated an efflux phenotype of these mutants. Gene expression analysis showed that the AcrEF multidrug efflux pump was de-repressed in mutants isolated from high-levels of biocide. CONCLUSIONS/SIGNIFICANCE: These data show that a single exposure to the working concentration of certain biocides can select for mutant Salmonella with efflux mediated multidrug resistance and that flow cytometry is a sensitive tool for identifying biocide tolerant mutants. The propensity for biocides to select for MDR mutants varies and this should be a consideration when designing new biocidal formulations.

  5. Pathway analysis and exposure assessment: MEPAS modeling for nonradiological chemical contaminants at the Hanford Site

    International Nuclear Information System (INIS)

    A Chemical Pathway Analysis and Exposure Assessment was performed by the Surface Environmental Surveillance Project (SESP). The SESP monitors air, surface water, sediment, agricultural products, vegetation, soil, and wildlife in order to assess onsite of offsite environmental impacts and offsite human health risk at the Hanford Site. The objectives of this study are (1) determine if a nonradiological chemical monitoring program is warranted for the Hanford Site, (2) ensure that the selection of surveillance parameters such as media, sampling location, and analytes are chosen in a manner that is scientifically sound and cost-efficient, and (3) identify specific nonradiological chemicals of concern (COC) for the Hanford Site. The basis for identification of COC for the Hanford Site was an extensive literature review. The model was also used to predict COC concentrations required onsite to achieve an offsite cancer incidence of 1 E-6 and a hazard quotient of 1.0. This study indicated that nonradiological chemical contamination occurring onsite does not pose a significant offsite human health risk. The highest cancer incidence to the offsite maximally exposed individual from COC was from arsenic (1.76E-1 0); the highest hazard quotient was chromium VI (1.48E-04)

  6. Neonatal lipopolysaccharide exposure does not diminish the innate immune response to a subsequent lipopolysaccharide challenge in Holstein bull calves.

    Science.gov (United States)

    Benjamin, A L; Korkmaz, F T; Elsasser, T H; Kerr, D E

    2016-07-01

    The innate immune response following experimental mastitis is quite variable between individual dairy cattle. An inflammatory response that minimizes collateral damage to the mammary gland while still effectively resolving the infection following pathogen exposure is beneficial to dairy producers. The ability of a lipopolysaccharide (LPS) exposure in early life to generate a low-responding phenotype and thus reduce the inflammatory response to a later-life LPS challenge was investigated in neonatal bull calves. Ten Holstein bull calves were randomly assigned to either an early life LPS (ELL) group (n=5) or an early life saline (ELS) group (n=5). At 7d of age, calves received either LPS or saline, and at 32d of age, all calves were challenged with an intravenous dose of LPS to determine the effect of the early life treatment (LPS or saline) on the immune response generated toward a subsequent LPS challenge. Dermal fibroblast and monocyte-derived macrophage cultures from each calf were established at age 20 and 27d, respectively, to model sustained effects from the early life LPS exposure on gene expression and protein production of components within the LPS response pathway. The ELL calves had greater levels of plasma IL-6 and tumor necrosis factor-α than the ELS calves following the early life LPS or saline treatments. However, levels of these 2 immune markers were similar between ELL and ELS calves when both groups were subsequently challenged with LPS. A comparison of the in vitro LPS responses of the ELL and ELS calves revealed similar patterns of protein production and gene expression following an LPS challenge of both dermal fibroblast and monocyte-derived macrophage cultures established from the treatment groups. Whereas an early life exposure to LPS did not result in a dampened inflammatory response toward a later LPS challenge in these neonatal bull calves, the potential that exposure to inflammation or stress in early life or in utero can create an

  7. The Role of Molecular Biology in the Biomonitoring of Human Exposure to Chemicals

    Directory of Open Access Journals (Sweden)

    Balam Muñoz

    2010-11-01

    Full Text Available Exposure to different substances in an occupational environment is of utmost concern to global agencies such as the World Health Organization and the International Labour Organization. Interest in improving work health conditions, particularly of those employees exposed to noxious chemicals, has increased considerably and has stimulated the search for new, more specific and selective tests. Recently, the field of molecular biology has been indicated as an alternative technique for monitoring personnel while evaluating work-related pathologies. Originally, occupational exposure to environmental toxicants was assessed using biochemical techniques to determine the presence of higher concentrations of toxic compounds in blood, urine, or other fluids or tissues; results were used to evaluate potential health risk. However, this approach only estimates the presence of a noxious chemical and its effects, but does not prevent or diminish the risk. Molecular biology methods have become very useful in occupational medicine to provide more accurate and opportune diagnostics. In this review, we discuss the role of the following common techniques: (1 Use of cell cultures; (2 evaluation of gene expression; (3 the “omic” sciences (genomics, transcriptomics, proteomics and metabolomics and (4 bioinformatics. We suggest that molecular biology has many applications in occupational health where the data can be applied to general environmental conditions.

  8. [Technology upgrades and exposure to chemical agents: results of the PPTP study in the footwear industry].

    Science.gov (United States)

    Gianoli, Enrica; Brusoni, Daniela; Cornaggia, Nicoletta; Saretto, Gianni

    2012-01-01

    In the present work the chemical compositions of the products used in shoes manufacturing are reported. The data were collected over the period 2004-2007 in 156 shoe factories in Vigevano area during a study aiming the evaluation of safety conditions and occupational exposure to hazardous chemicals of the employees. The study was part of a regional project for "Occupational cancer prevention in the footwear industry". In the first phase of the study an information form on production cycle, products used and their composition was filled during preliminary audit. In the second phase of the study an in depth qualitative/quantitative evaluation of professional exposure was conducted in 13 selected shoe factories. Data analysis showed the increase in use of water-based adhesives at expense of solvent-based adhesives, the reduction to less than 3.5 weight %, and up to 1 weight %, of n-hexane concentration in solvent mixtures, the increase in use of products containing less hazardous ketones, esters, cyclohexane and heptane. Only in very few cases, products containing from 4 to 12 weight% of toluene were used. These data attest a positive trend in workers risks prevention in shoes industry. PMID:22697030

  9. The commuters' exposure to volatile chemicals and carcinogenic risk in Mexico City

    Science.gov (United States)

    Shiohara, Naohide; Fernández-Bremauntz, Adrián A.; Blanco Jiménez, Salvador; Yanagisawa, Yukio

    The commuters' exposure levels to volatile organic compounds were investigated in the following public transport modes: private car, microbus, bus, and metro along three commuting routes in the Metropolitan Area of Mexico City. The target chemicals were benzene, toluene, ethylbenzene, m/ p-xylene, and formaldehyde. Integrated samples were taken while traveling during the morning rush hour (weekdays 7:00-9:00 a.m.) for six consecutive weeks in June and July, 2002. Scheffe test showed that the average concentrations of all chemicals inside cars and microbuses were statistically higher than in metro trains ( Pautomobiles were significantly higher than in metro trains and buses ( Pcar, bus, and metro ( Pcar and microbus passengers are exposed to higher levels of volatile organic compounds than bus and metro commuters. These findings are consistent with previous studies looking at exposure of commuters to carbon monoxide. The lifetime carcinogenic risk from commuting by car was 2.0×10 -5-3.1×10 -5, that by microbus was 3.1×10 -5-4.0×10 -5, that by bus was 2.0×10 -5-2.7×10 -5, and that by metro was 1.3×10 -5-1.7×10 -5 in Mexico City.

  10. Implications of pulsed chemical exposures for aquatic life criteria and wastewater permit limits.

    Science.gov (United States)

    Diamond, Jerome M; Klaine, Stephen J; Butcher, Jonathan B

    2006-08-15

    Subacute effects of pulsed copper, zinc, or ammonia exposures were examined, including a range of pulse concentrations, durations, frequencies, and recovery times between pulses, using short-term chronic Pimephales promelas and 21-d Daphnia magna tests. Sublethal effects were rarely observed independent of mortality. Effects were observed only at concentrations near the species continuous exposure 48 h LC50 for each chemical. Daphnia often rebounded from temporary reproduction effects, meeting or exceeding control responses by the end of the test. Effects of 24 h ammonia or copper pulses were diminished soon after the pulse was removed, while 24 h zinc pulses caused continued effects for several days following removal of the pulse, indicating a slower uptake and/or depuration rate for zinc. D. magna exhibited less mortality as copper pulses were spaced further apart, while fish were equally or more affected with longer recovery times between copper pulses, indicative of different adaptation mechanisms between the two species. Responses were not predictable based on either average concentration or a combination of duration and concentration. Chronic water quality criteria and effluent permit limits, expressed as a 4- or 30-d average concentration, respectively, may not be appropriate for protecting against effects of pulsed exposures, depending on the frequency, magnitude, and duration of pulses, as well as the recovery period between events. PMID:16955918

  11. History of the occupational exposure to chemical substances in workers with laryngeal cancer

    International Nuclear Information System (INIS)

    A case-control study was realized to 400 patients, 200 of them histologically confirmed as incident cases of larynx cancer by the National Institute for Oncology and Radiobiology of Havana, and the others 200 as controls, coming from another hospitals. A survey was applied to both groups, collecting every theirs worker histories with emphasis on occupational exposure, that were codified by an expert group taking into account the carcinogens present according to the guided code of the Epidemiological Units of Environmental Cancer and the Fields Studies and Intervention of International Agency for Research on Cancer (IARC). According to the results obtained, all the patients, cases and controls, presented 1 526 tasks in their labour histories, that represented an average greater than 3 tasks for each one of them. They main activities were in the agriculture, the defence and the sugar cane industry. The most predominant exposures were to the abrasive dusts, motor emissions, mists of mineral oils, gasoline/petroleum/diesel/kerosene and pesticides. In general, the valuation of the chemical risk was considered of low intensity, 1-5% of the real time to the exposure and all had the certain probability of the agent's aggressor presence.

  12. The Effect of Perfluorooctane Sulfonate, Exposure Time, and Chemical Mixtures on Methanogenic Community Structure and Function.

    Science.gov (United States)

    McNamara, Patrick J; LaPara, Timothy M; Novak, Paige J

    2015-01-01

    A plethora of organic micropollutant mixtures are found in untreated municipal wastewater. Anaerobic digesters receive large loadings of hydrophobic micropollutants that sorb to wastewater biosolids. Despite micropollutants being pervasive as mixtures, little research is available to explain the impact that mixtures of compounds, as well as exposure time, have on microbial communities in anaerobic digesters. Perfluorooctane sulfonate (PFOS) was added to anaerobic enrichment cultures in both short-term (14 days) and long-term (140 days) studies to determine the impact of exposure time. Additionally, triclosan was added during the experiments to investigate the impact of mixtures on community structure and function. PFOS did not alter methane production in short-term studies, but in long-term studies, methane production increased, consistent with our hypothesis that PFOS may act as a metabolic uncoupler. The impact of triclosan on methane production was exacerbated when PFOS was already present in the anaerobic enrichment cultures. Triclosan also had greater impacts on microbial community structures in the bottles that had been exposed to PFOS long-term. These results demonstrate that both chemical mixtures and exposure time are important parameters to address when trying to define the impacts of micropollutants on anaerobic microbial communities. PMID:26462249

  13. The Effect of Perfluorooctane Sulfonate, Exposure Time, and Chemical Mixtures on Methanogenic Community Structure and Function

    Science.gov (United States)

    McNamara, Patrick J; LaPara, Timothy M; Novak, Paige J

    2015-01-01

    A plethora of organic micropollutant mixtures are found in untreated municipal wastewater. Anaerobic digesters receive large loadings of hydrophobic micropollutants that sorb to wastewater biosolids. Despite micropollutants being pervasive as mixtures, little research is available to explain the impact that mixtures of compounds, as well as exposure time, have on microbial communities in anaerobic digesters. Perfluorooctane sulfonate (PFOS) was added to anaerobic enrichment cultures in both short-term (14 days) and long-term (140 days) studies to determine the impact of exposure time. Additionally, triclosan was added during the experiments to investigate the impact of mixtures on community structure and function. PFOS did not alter methane production in short-term studies, but in long-term studies, methane production increased, consistent with our hypothesis that PFOS may act as a metabolic uncoupler. The impact of triclosan on methane production was exacerbated when PFOS was already present in the anaerobic enrichment cultures. Triclosan also had greater impacts on microbial community structures in the bottles that had been exposed to PFOS long-term. These results demonstrate that both chemical mixtures and exposure time are important parameters to address when trying to define the impacts of micropollutants on anaerobic microbial communities. PMID:26462249

  14. In vitro methods for hazard assessment of industrial chemicals – opportunities and challenges

    Directory of Open Access Journals (Sweden)

    Chin Lin eWong

    2015-05-01

    Full Text Available Allergic contact dermatitis (ACD is a delayed-type hypersensitivity immune reaction mediated by T-lymphocytes as a result of repeated exposure of an allergen primarily on skin. ACD accounts for up to 95% of occupational skin diseases (OSDs, with epoxy resins implicated as one of the most common causes of ACD. Efficient high-throughput in vitro screening for accurate identification of compounds and materials that may pose hazardous risks in the workplace is crucial. At present, the murine local lymph node assay (LLNA is the ‘method of choice’ for predicting the sensitizing potency of contact allergens. As the 3Rs principles of reduction, refinement and replacement in animal testing has gained political and economic momentum, several in vitro screening methods have been developed for identifying potential contact allergens. To date, these latter methods have been utilized primarily to assess the skin sensitizing potential of the chemical components of cosmetic products with scant research attention as to the applicability of these methods to industrial chemicals, particularly epoxy resins. Herein we review the currently utilized in vitro methods and identify the knowledge gaps with regard to assessing the generalizability of in vitro screening methods for assessing the skin sensitizing potential of industrial chemicals.

  15. In vitro methods for hazard assessment of industrial chemicals – opportunities and challenges

    Science.gov (United States)

    Wong, Chin Lin; Ghassabian, Sussan; Smith, Maree T.; Lam, Ai-Leen

    2015-01-01

    Allergic contact dermatitis (ACD) is a delayed-type hypersensitivity immune reaction mediated by T-lymphocytes as a result of repeated exposure of an allergen primarily on skin. ACD accounts for up to 95% of occupational skin diseases, with epoxy resins implicated as one of the most common causes of ACD. Efficient high-throughput in vitro screening for accurate identification of compounds and materials that may pose hazardous risks in the workplace is crucial. At present, the murine local lymph node assay is the ‘method of choice’ for predicting the sensitizing potency of contact allergens. As the 3Rs principles of reduction, refinement, and replacement in animal testing has gained political and economic momentum, several in vitro screening methods have been developed for identifying potential contact allergens. To date, these latter methods have been utilized primarily to assess the skin sensitizing potential of the chemical components of cosmetic products with scant research attention as to the applicability of these methods to industrial chemicals, particularly epoxy resins. Herein we review the currently utilized in vitro methods and identify the knowledge gaps with regard to assessing the generalizability of in vitro screening methods for assessing the skin sensitizing potential of industrial chemicals. PMID:25999858

  16. In vitro methods for hazard assessment of industrial chemicals - opportunities and challenges.

    Science.gov (United States)

    Wong, Chin Lin; Ghassabian, Sussan; Smith, Maree T; Lam, Ai-Leen

    2015-01-01

    Allergic contact dermatitis (ACD) is a delayed-type hypersensitivity immune reaction mediated by T-lymphocytes as a result of repeated exposure of an allergen primarily on skin. ACD accounts for up to 95% of occupational skin diseases, with epoxy resins implicated as one of the most common causes of ACD. Efficient high-throughput in vitro screening for accurate identification of compounds and materials that may pose hazardous risks in the workplace is crucial. At present, the murine local lymph node assay is the 'method of choice' for predicting the sensitizing potency of contact allergens. As the 3Rs principles of reduction, refinement, and replacement in animal testing has gained political and economic momentum, several in vitro screening methods have been developed for identifying potential contact allergens. To date, these latter methods have been utilized primarily to assess the skin sensitizing potential of the chemical components of cosmetic products with scant research attention as to the applicability of these methods to industrial chemicals, particularly epoxy resins. Herein we review the currently utilized in vitro methods and identify the knowledge gaps with regard to assessing the generalizability of in vitro screening methods for assessing the skin sensitizing potential of industrial chemicals. PMID:25999858

  17. Exposure Forecaster

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Exposure Forecaster Database (ExpoCastDB) is EPA's database for aggregating chemical exposure information and can be used to help with chemical exposure...

  18. Biodiesel biorefinery: opportunities and challenges for microbial production of fuels and chemicals from glycerol waste

    Directory of Open Access Journals (Sweden)

    Almeida João R M

    2012-07-01

    Full Text Available Abstract The considerable increase in biodiesel production worldwide in the last 5 years resulted in a stoichiometric increased coproduction of crude glycerol. As an excess of crude glycerol has been produced, its value on market was reduced and it is becoming a “waste-stream” instead of a valuable “coproduct”. The development of biorefineries, i.e. production of chemicals and power integrated with conversion processes of biomass into biofuels, has been singled out as a way to achieve economically viable production chains, valorize residues and coproducts, and reduce industrial waste disposal. In this sense, several alternatives aimed at the use of crude glycerol to produce fuels and chemicals by microbial fermentation have been evaluated. This review summarizes different strategies employed to produce biofuels and chemicals (1,3-propanediol, 2,3-butanediol, ethanol, n-butanol, organic acids, polyols and others by microbial fermentation of glycerol. Initially, the industrial use of each chemical is briefly presented; then we systematically summarize and discuss the different strategies to produce each chemical, including selection and genetic engineering of producers, and optimization of process conditions to improve yield and productivity. Finally, the impact of the developments obtained until now are placed in perspective and opportunities and challenges for using crude glycerol to the development of biodiesel-based biorefineries are considered. In conclusion, the microbial fermentation of glycerol represents a remarkable alternative to add value to the biodiesel production chain helping the development of biorefineries, which will allow this biofuel to be more competitive.

  19. Chemical and microstructural transformations in lithium iron phosphate battery electrodes following pulsed laser exposure

    International Nuclear Information System (INIS)

    Highlights: • Lithium iron phosphate battery electrodes are exposed to pulsed laser radiation. • Raman spectroscopy is performed on regions approaching the incisions and cuts. • Chemical and microstructural changes in the active electrode layers are limited to the visible HAZ. • Some oxidation and degradation of the olive LiFePO4 cathode active material takes place in the HAZ. • The anode polycrystalline graphite structure becomes less ordered (higher D/G ratio) in the HAZ. - Abstract: Multi-layer lithium iron phosphate (LFP) battery electrodes are exposed to nanosecond pulsed laser radiation of wavelength 1064 nm. Test parameters are chosen to achieve characteristic interaction types ranging from partial incision of the active coating layers only to complete penetration of the electrodes with high visual cut quality. Raman spectroscopy is performed on unexposed regions and at points approaching each incision, highlighting changes in chemical composition and microstructure in the heat affected zone (HAZ). Thermogravimetric analysis is performed on the unexposed electrode active materials to distinguish the development of compositional changes under conditions of slow heating below the melting and sublimation temperatures. A brief theoretical description of the physical phenomena taking place during laser exposure is provided in terms of direct ablation during each laser pulse and vaporization or thermal degradation due to conductive heat transfer on a much longer time-scale, with characteristics of the HAZ reported in terms of these changes. For all laser exposures carried out in the study, chemical and microstructural changes are limited to the visible HAZ. Some degree of oxidation and LFP olivine phase degradation is observed in the cathode, while the polycrystalline graphite structure becomes less ordered in the anode. Where complete penetration is achieved, melting of the cathode active layer and combustion of the anode active layer take place near

  20. Assessment of serum biomarkers in rats after exposure to pesticides of different chemical classes

    International Nuclear Information System (INIS)

    There is increasing emphasis on the use of biomarkers of adverse outcomes in safety assessment and translational research. We evaluated serum biomarkers and targeted metabolite profiles after exposure to pesticides (permethrin, deltamethrin, imidacloprid, carbaryl, triadimefon, fipronil) with different neurotoxic actions. Adult male Long–Evans rats were evaluated after single exposure to vehicle or one of two doses of each pesticide at the time of peak effect. The doses were selected to produce similar magnitude of behavioral effects across chemicals. Serum or plasma was analyzed using commercial cytokine/protein panels and targeted metabolomics. Additional studies of fipronil used lower doses (lacking behavioral effects), singly or for 14 days, and included additional markers of exposure and biological activity. Biomarker profiles varied in the number of altered analytes and patterns of change across pesticide classes, and discriminant analysis could separate treatment groups from control. Low doses of fipronil produced greater effects when given for 14 days compared to a single dose. Changes in thyroid hormones and relative amounts of fipronil and its sulfone metabolite also differed between the dosing regimens. Most cytokine changes reflected alterations in inflammatory responses, hormone levels, and products of phospholipid, fatty acid, and amino acid metabolism. These findings demonstrate distinct blood-based analyte profiles across pesticide classes, dose levels, and exposure duration. These results show promise for detailed analyses of these biomarkers and their linkages to biological pathways. - Highlights: • Pesticides typical of different classes produced distinct patterns of change in biomarker panels. • Based on the panels used, alterations suggest impacts on immune, metabolism, and homeostasis functions. • Some changes may reflect actions on neurotransmitter systems involved in immune modulation. • Fipronil effects on thyroid and kinetics

  1. Assessment of serum biomarkers in rats after exposure to pesticides of different chemical classes

    Energy Technology Data Exchange (ETDEWEB)

    Moser, Virginia C., E-mail: Moser.ginger@epa.gov [Neurotoxicology Branch/Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Stewart, Nicholas; Freeborn, Danielle L. [Neurotoxicology Branch/Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Crooks, James; MacMillan, Denise K. [Analytical Chemistry Research Core/Research Cores Unit, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Hedge, Joan M.; Wood, Charles E. [Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); McMahen, Rebecca L. [ORISE fellow, Human Exposure and Atmospheric Sciences Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Strynar, Mark J. [Human Exposure and Atmospheric Sciences Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Herr, David W. [Neurotoxicology Branch/Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States)

    2015-01-15

    There is increasing emphasis on the use of biomarkers of adverse outcomes in safety assessment and translational research. We evaluated serum biomarkers and targeted metabolite profiles after exposure to pesticides (permethrin, deltamethrin, imidacloprid, carbaryl, triadimefon, fipronil) with different neurotoxic actions. Adult male Long–Evans rats were evaluated after single exposure to vehicle or one of two doses of each pesticide at the time of peak effect. The doses were selected to produce similar magnitude of behavioral effects across chemicals. Serum or plasma was analyzed using commercial cytokine/protein panels and targeted metabolomics. Additional studies of fipronil used lower doses (lacking behavioral effects), singly or for 14 days, and included additional markers of exposure and biological activity. Biomarker profiles varied in the number of altered analytes and patterns of change across pesticide classes, and discriminant analysis could separate treatment groups from control. Low doses of fipronil produced greater effects when given for 14 days compared to a single dose. Changes in thyroid hormones and relative amounts of fipronil and its sulfone metabolite also differed between the dosing regimens. Most cytokine changes reflected alterations in inflammatory responses, hormone levels, and products of phospholipid, fatty acid, and amino acid metabolism. These findings demonstrate distinct blood-based analyte profiles across pesticide classes, dose levels, and exposure duration. These results show promise for detailed analyses of these biomarkers and their linkages to biological pathways. - Highlights: • Pesticides typical of different classes produced distinct patterns of change in biomarker panels. • Based on the panels used, alterations suggest impacts on immune, metabolism, and homeostasis functions. • Some changes may reflect actions on neurotransmitter systems involved in immune modulation. • Fipronil effects on thyroid and kinetics

  2. Dietary Exposure of Nigerians to Mutagens and Estrogen-Like Chemicals

    Directory of Open Access Journals (Sweden)

    Iyekhoetin Matthew Omoruyi

    2014-08-01

    Full Text Available Food and drinking water are poorly delineated sources of human exposure to chemical food mutagens and endocrine-disrupting chemicals. In this study, we investigated the presence of mutagens and chemicals exhibiting estrogenic activity in the daily diet of Nigerians, using in vitro assays. Commercially processed foods or snacks and various brands of pure water sachets were extracted by solid-phase extraction and liquid-liquid extraction, respectively. Mutagenicity was determined by the conventional Ames test and two complementary assays on two strains of Salmonella (TA 100 and TA 98, while the estrogenic activity was assessed by a yeast bioluminescent assay, using two recombinant yeast strains (Saccharomyces cerevisiae BMAEREluc/ERα and S. cerevisiae BMA64/luc. A third of the food varieties investigated (chin-chin, hamburger, suya and bean cake were mutagenic in all three assays, either in the presence or absence of S9 mix. Of the packed water samples, five out of the sixteen investigated (31%, were found to be estrogenic, with estradiol and bisphenol A equivalents ranging from 0.79 to 44.0 ng/L and 124.2 to 1,000.8 ng/L, respectively. Hence, although the current situation in Nigeria does not appear to be substantially worse than, e.g., in Europe, regular monitoring is warranted in the future.

  3. Potential for MERLIN-Expo, an advanced tool for higher tier exposure assessment, within the EU chemical legislative frameworks.

    Science.gov (United States)

    Suciu, Nicoleta; Tediosi, Alice; Ciffroy, Philippe; Altenpohl, Annette; Brochot, Céline; Verdonck, Frederik; Ferrari, Federico; Giubilato, Elisa; Capri, Ettore; Fait, Gabriella

    2016-08-15

    MERLIN-Expo merges and integrates advanced exposure assessment methodologies, allowing the building of complex scenarios involving several pollution sources and targets. The assessment of exposure and risks to human health from chemicals is of major concern for policy and ultimately benefits all citizens. The development and operational fusion of the advanced exposure assessment methodologies envisaged in the MERLIN-Expo tool will have a significant impact in the long term on several policies dealing with chemical safety management. There are more than 30 agencies in Europe related to exposure and risk evaluation of chemicals, which have an important role in implementing EU policies, having especially tasks of technical, scientific, operational and/or regulatory nature. The main purpose of the present paper is to introduce MERLIN-Expo and to highlight its potential for being effectively integrated within the group of tools available to assess the risk and exposure of chemicals for EU policy. The main results show that the tool is highly suitable for use in site-specific or local impact assessment, with minor modifications it can also be used for Plant Protection Products (PPPs), biocides and REACH, while major additions would be required for a comprehensive application in the field of consumer and worker exposure assessment. PMID:27107646

  4. Chemical and mechanical consequences of environmental barrier coating exposure to calcium-magnesium-aluminosilicate.

    Energy Technology Data Exchange (ETDEWEB)

    Harder, B.; Ramirez-Rico, J.; Almer, J. D.; Kang, L.; Faber, K. (X-Ray Science Division); (NASA Glenn Research Center); (Univ. of Seville); (Rolls-Royce Corp.); (Northwestern Univ.)

    2011-06-01

    The success of Si-based ceramics as high-temperature structural materials for gas turbine applications relies on the use of environmental barrier coatings (EBCs) with low silica activity, such as Ba{sub 1-x}Sr{sub x}Al{sub 2}Si{sub 2}O{sub 8} (BSAS), which protect the underlying components from oxidation and corrosion in combustion environments containing water vapor. One of the current challenges concerning EBC lifetime is the effect of sandy deposits of calcium-magnesium-aluminosilicate (CMAS) glass that melt during engine operation and react with the EBC, changing both its composition and stress state. In this work, we study the effect of CMAS exposure at 1300 C on the residual stress state and composition in BSAS-mullite-Si-SiC multilayers. Residual stresses were measured in BSAS multilayers exposed to CMAS for different times using high-energy X-ray diffraction. Their microstructure was studied using a combination of scanning electron microscopy and transmission electron microscopy techniques. Our results show that CMAS dissolves the BSAS topcoat preferentially through the grain boundaries, dislodging the grains and changing the residual stress state in the topcoat to a nonuniform and increasingly compressive stress state with increasing exposure time. The presence of CMAS accelerates the hexacelsian-to-celsian phase transformation kinetics in BSAS, which reacts with the glass by a solution-reprecipitation mechanism. Precipitates have crystallographic structures consistent with Ca-doped celsian and Ba-doped anorthite.

  5. Imaging challenges: a US perspective on controlling exposure to ionizing radiation in children with cancer

    International Nuclear Information System (INIS)

    Issues pertaining to control of radiation dose exposures in pediatric imaging are on the forefront of patient care worldwide. Certain factors contribute to appropriate - or inappropriate - use of ionizing radiation in pediatric medical imaging. Such issues include naivete regarding cancer risk and the role of medical imaging in its development, misinformation about exposure to ionizing radiation, resource availability, staffing, scheduling ''snags,'' costs, limited evidence-based imaging practice information and shrinking funding. These issues will be introduced in this paper. (orig.)

  6. Technical Challenges and Progress in Fluidized Bed Chemical Vapor Deposition of Polysilicon

    Institute of Scientific and Technical Information of China (English)

    李建隆; 陈光辉; 张攀; 王伟文; 段继海

    2011-01-01

    Various methods for production of polysilicon have been proposed for lowering the production cost andenergy consumption, and enhancing productivity, which are critical for industrial applications. The fluidized bed chemical vapor deposition (FBCVD) method is a most promising alternative to conventional ones, but the homogeneous reaction of silane in FBCVD results in unwanted formation of fines, which will affect the product qualityand output. There are some other problems, such as heating degeneration due to undesired polysilicon deposition on the walls of the reactor and the heater. This article mainly reviews the technological development on FBCVD of polycrystalline silicon and the research status for solving the above problems. It also identifies a number of challenges to tackle and principles should be followed in the design ofa FBCVD reactor.

  7. Chemical engineering challenges in driving thermochemical hydrogen processes with the tandem mirror reactor

    International Nuclear Information System (INIS)

    The Tandem Mirror Reactor is described and compared with Tokamaks, both from a basic physics viewpoint and from the suitability of the respective reactor for synfuel production. Differences and similarities between the TMR as an electricity producer or a synfuel producer are also cited. The Thermochemical cycle chosen to link with the fusion energy source is the General Atomic Sulfur-Iodine Cycle, which is a purely thermal-driven process with no electrochemical steps. There are real chemical engineering challenges of getting this high quality heat into the large thermochemical plant in an efficient manner. We illustrate with some of our approaches to providing process heat via liquid sodium to drive a 1050 K, highly-endothermic, catalytic and fluidized-bed SO3 Decomposition Reactor. The technical, economic, and safety tradeoffs that arise are discussed

  8. Metamorphosis of the invasive ascidian Ciona savignyi: environmental variables and chemical exposure.

    Science.gov (United States)

    Cahill, Patrick L; Atalah, Javier; Selwood, Andrew I; Kuhajek, Jeanne M

    2016-01-01

    In this study, the effects of environmental variables on larval metamorphosis of the solitary ascidian Ciona savignyi were investigated in a laboratory setting. The progression of metamorphic changes were tracked under various temperature, photoperiod, substrate, larval density, and vessel size regimes. Metamorphosis was maximised at 18 °C, 12:12 h subdued light:dark, smooth polystyrene substrate, and 10 larvae mL(-1) in a twelve-well tissue culture plate. Eliminating the air-water interface by filling culture vessels to capacity further increased the proportion of metamorphosed larvae; 87 ± 5% of larvae completed metamorphosis within 5 days compared to 45 ± 5% in control wells. The effects of the reference antifouling compounds polygodial, portimine, oroidin, chlorothalonil, and tolylfluanid on C. savignyi were subsequently determined, highlighting (1) the sensitivity of C. savignyi metamorphosis to chemical exposure and (2) the potential to use C. savignyi larvae to screen for bioactivity in an optimised laboratory setting. The compounds were bioactive in the low ng mL(-1) to high µg mL(-1) range. Polygodial was chosen for additional investigations, where it was shown that mean reductions in the proportions of larvae reaching stage E were highly repeatable both within (repeatability = 14 ± 9%) and between (intermediate precision = 17 ± 3%) independent experiments. An environmental extract had no effect on the larvae but exposing larvae to both the extract and polygodial reduced potency relative to polygodial alone. This change in potency stresses the need for caution when working with complex samples, as is routinely implemented when isolating natural compounds from their biological source. Overall, the outcomes of this study highlight the sensitivity of C. savignyi metamorphosis to environmental variations and chemical exposure. PMID:26966668

  9. Opportunities and challenges in GaN metal organic chemical vapor deposition for electron devices

    Science.gov (United States)

    Matsumoto, Koh; Yamaoka, Yuya; Ubukata, Akinori; Arimura, Tadanobu; Piao, Guanxi; Yano, Yoshiki; Tokunaga, Hiroki; Tabuchi, Toshiya

    2016-05-01

    The current situation and next challenge in GaN metal organic chemical vapor deposition (MOCVD) for electron devices of both GaN on Si and GaN on GaN are presented. We have examined the possibility of increasing the growth rate of GaN on 200-mm-diameter Si by using a multiwafer production MOCVD machine, in which the vapor phase parasitic reaction is well controlled. The impact of a high-growth-rate strained-layer-superlattice (SLS) buffer layer is presented in terms of material properties. An SLS growth rate of as high as 3.46 µm/h, which was 73% higher than the current optimum, was demonstrated. As a result, comparable material properties were obtained. Next, a typical result of GaN doped with Si of 1 × 1016 cm‑3 grown at the growth rate of 3.7 µm/h is shown. For high-voltage application, we need a thick high-purity GaN drift layer with a low carbon concentration, of less than 1016 cm‑3. It is shown that achieving a high growth rate by precise control of the vapor phase reaction is still challenge in GaN MOCVD.

  10. Does chemically dispersing crude oil increase the exposure of fish to polynuclear aromatic hydrocarbons (PAH)?

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, S.D.; Khan, C.W.; Hodson, P.V. [Queen' s Univ., Kingston, ON (Canada). Dept. of Biology; Lee, K. [Department of Fisheries and Oceans, Dartmouth, NS (Canada). Bedford Inst. of Oceanography

    2002-07-01

    Dispersants or surfactants are often used to clean up oil spills on water to minimize the impact of oil pollution. Their use as an oil spill countermeasure, however, is controversial because the risk of ecological effects depends on whether the dispersant increases or decreases the exposure of aquatic species to the toxic components of oil. This study involved the measurement of CYP1A induction and bile metabolites of polycyclic aromatic hydrocarbons (PAH) in trout exposed to Corexit 9500 dispersant, water accommodated fractions, and chemically enhanced water accommodated fractions of 3 crude oils. The objective was to see if fish are exposed to more PAH in dispersed oil compared to equivalent amounts of water accommodated fraction. Preliminary results indicated 10 times higher induction in fish exposed to chemically enhanced water accommodated fraction compared to water accommodated fractions. The dispersed oil in water had higher concentrations of alkylated PAH compared to the water accommodated fraction. As hydrocarbon concentrations increased, the trend for medaka embryos was first to hatch earlier, then have mild edema, followed by severe edema and finally mortality.

  11. Does chemically dispersing crude oil increase the exposure of fish to polynuclear aromatic hydrocarbons (PAH)?

    International Nuclear Information System (INIS)

    Dispersants or surfactants are often used to clean up oil spills on water to minimize the impact of oil pollution. Their use as an oil spill countermeasure, however, is controversial because the risk of ecological effects depends on whether the dispersant increases or decreases the exposure of aquatic species to the toxic components of oil. This study involved the measurement of CYP1A induction and bile metabolites of polycyclic aromatic hydrocarbons (PAH) in trout exposed to Corexit 9500 dispersant, water accommodated fractions, and chemically enhanced water accommodated fractions of 3 crude oils. The objective was to see if fish are exposed to more PAH in dispersed oil compared to equivalent amounts of water accommodated fraction. Preliminary results indicated 10 times higher induction in fish exposed to chemically enhanced water accommodated fraction compared to water accommodated fractions. The dispersed oil in water had higher concentrations of alkylated PAH compared to the water accommodated fraction. As hydrocarbon concentrations increased, the trend for medaka embryos was first to hatch earlier, then have mild edema, followed by severe edema and finally mortality

  12. Indoor Air in Beauty Salons and Occupational Health Exposure of Cosmetologists to Chemical Substances

    Directory of Open Access Journals (Sweden)

    Nikos Evlogias

    2010-01-01

    Full Text Available The indoor environment in four beauty salons located in Athens (Greece was examined in order to investigate the occupational health exposure of cosmetologists to various chemical products typically used in their work. Chemical substances chosen for investigation were volatile organic compounds (VOCs, formaldehyde, ozone and carbon dioxide. Total VOCs levels measured showed significant variation (100–1,450 μg m-3 depending on the products used and the number of treatments carried out, as well as ventilation. The main VOCs found in the salons were aromatics (toluene, xylene, esters and ketones (ethyl acetate, acetone, etc. which are used as solvents in various beauty products; terpenes (pinene, limonene, camphor, menthenol which have a particular odor and others like camphor which have specific properties. Ozone concentrations measured in all salons were quite low (0.1 and 13.3 μg m-3 and formaldehyde concentrations detected were lower than the detection limit of the method in all salons (<0.05 ppm. Carbon dioxide levels ranged between 402 and 1,268 ppm, depending on the number of people present in the salons during measurements and ventilation. Cosmetologists may be exposed to high concentrations of a mixture of volatile organic compounds although these levels could be decreased significantly by following certain practices such as good ventilation of the areas, closing the packages of the beauty products when not in use and finally selecting safer beauty products without strong odor.

  13. A survey of airborne and skin exposures to chemicals in footwear and equipment factories in Thailand.

    Science.gov (United States)

    Todd, Lori A; Mottus, Kathleen; Mihlan, Gary J

    2008-03-01

    This research reports on a pilot industrial hygiene study that was performed at four footwear factories and two equipment factories in Thailand. Workers in these factories were exposed through inhalation and dermal contact to a large number of organic vapors from solvents and cements that were hand applied. In addition, these workers were exposed to highly toxic isocyanates primarily through the dermal route. A total of 286 personal air samples were obtained at the four footwear factories using organic vapor monitors; individual job tasks were monitored using a real-time MIRAN Spectrometer. A total of 64 surface, tool, or hand samples were monitored for isocyanates using surface contamination detectors. Real-time measurements were also obtained for organic vapors in two equipment factories. From 8% to 21% of the workers sampled in each footwear factory were overexposed to mixtures of chemicals from solvents and cements. Up to 100% of the workers performing specific job tasks were overexposed to mixtures of chemicals. From 39% to 69% of the surface samples were positive for unreacted isocyanates. Many of the real-time measurements obtained in the equipment factories exceeded occupational exposure limits. Personal protective equipment and engineering controls were inadequate in all of the factories. PMID:18213531

  14. Dermal permeation data and models for the prioritization and screening-level exposure assessment of organic chemicals.

    Science.gov (United States)

    Brown, Trevor N; Armitage, James M; Egeghy, Peter; Kircanski, Ida; Arnot, Jon A

    2016-09-01

    High-throughput screening (HTS) models are being developed and applied to prioritize chemicals for more comprehensive exposure and risk assessment. Dermal pathways are possible exposure routes to humans for thousands of chemicals found in personal care products and the indoor environment. HTS exposure models rely on skin permeability coefficient (KP; cm/h) models for exposure predictions. An initial database of approximately 1000 entries for empirically-based KP data was compiled from the literature and a subset of 480 data points for 245 organic chemicals derived from testing with human skin only and using only water as a vehicle was selected. The selected dataset includes chemicals with log octanol-water partition coefficients (KOW) ranging from -6.8 to 7.6 (median=1.8; 95% of the data range from -2.5 to 4.6) and molecular weight (MW) ranging from 18 to 765g/mol (median=180); only 3% >500g/mol. Approximately 53% of the chemicals in the database have functional groups which are ionizable in the pH range of 6 to 7.4, with 31% being appreciably ionized. The compiled log KP values ranged from -5.8 to 0.1cm/h (median=-2.6). The selected subset of the KP data was then used to evaluate eight representative KP models that can be readily applied for HTS assessments, i.e., parameterized with KOW and MW. The analysis indicates that a version of the SKINPERM model performs the best against the selected dataset. Comparisons of representative KP models against model input parameter property ranges (sensitivity analysis) and against chemical datasets requiring human health assessment were conducted to identify regions of chemical properties that should be tested to address uncertainty in KP models and HTS exposure assessments. PMID:27282209

  15. An in vivo animal study assessing long-term changes in hypothalamic cytokines following perinatal exposure to a chemical mixture based on Arctic maternal body burden

    Directory of Open Access Journals (Sweden)

    Li Nanqin

    2011-07-01

    Full Text Available Abstract Background The geographic distribution of environmental toxins is generally not uniform, with certain northern regions showing a particularly high concentration of pesticides, heavy metals and persistent organic pollutants. For instance, Northern Canadians are exposed to high levels of persistent organic pollutants like polychlorinated biphenyls (PCB, organochlorine pesticides (OCs and methylmercury (MeHg, primarily through country foods. Previous studies have reported associations between neuronal pathology and exposure to such toxins. The present investigation assessed whether perinatal exposure (gestation and lactation of rats to a chemical mixture (27 constituents comprised of PCBs, OCs and MeHg based on Arctic maternal exposure profiles at concentrations near human exposure levels, would affect brain levels of several inflammatory cytokines Methods Rats were dosed during gestation and lactation and cytokine levels were measured in the brains of offspring at five months of age. Hypothalamic cytokine protein levels were measured with a suspension-based array system and differences were determined using ANOVA and post hoc statistical tests. Results The early life PCB treatment alone significantly elevated hypothalamic interleukin-6 (IL-6 levels in rats at five months of age to a degree comparable to that of the entire chemical mixture. Similarly, the full mixture (and to a lesser degree PCBs alone elevated levels of the pro-inflammatory cytokine, IL-1b, as well as the anti-inflammatory cytokine, IL-10. The full mixture of chemicals also moderately increased (in an additive fashion hypothalamic levels of the pro-inflammatory cytokines, IL-12 and tumor necrosis factor (TNF-α. Challenge with bacterial endotoxin at adulthood generally increased hypothalamic levels to such a degree that differences between the perinatally treated chemical groups were no longer detectable. Conclusions These data suggest that exposure at critical

  16. Comparison of the rationale used in setting occupational exposure standards for ionizing radiation and hazardous chemical substances

    International Nuclear Information System (INIS)

    Ten chemicals which create significant occupational hazard are reviewed. They are toluene diisocyanate, hydrogen fluoride, n-hexane, carbon disulphide, cadmium, inorganic mercury, cobalt, nitroglycerol, silica and vinyl chloride. Each is discussed under the headings of physiological intake and elimination in humans, characteristics of acute and chronic toxicity, sites of occupational exposure and rationale for limits of such exposure. Since radioactive substances yield ionizing radiation as the common hazard the treatment of the current permissible levels of exposure is somewhat simpler. Having set out industrial standards for exposure to hazardous substances and radionuclides, a detailed comparison is made. Exposure limits to ioninzing radiation are sufficiently low to remove the appearance of directly related injury. It is expected however that low level exposure may have a stochastic effect, that is, there is the possibility of a slightly increased incidence of neoplasms in a large exposed population, but numbers will be too small to be able to attribute any particular case to the exposure. TLVs on the other hand, depending on the particular chemical, may be high enough in the workplace to permit some directly related signs or symptoms in the exposed individual. 244 refs

  17. Human Rights Engagement and Exposure: New Scales to Challenge Social Work Education

    Science.gov (United States)

    McPherson, Jane; Abell, Neil

    2012-01-01

    Objectives: Advancing human rights is a core competency of U.S. social work education; yet, human rights attitudes and behaviors have never been measured in the social work literature. Thus, this article describes the development and initial validation of two scales, Human Rights Engagement in Social Work (HRESW) and Human Rights Exposure in…

  18. Modelling the impact of the environmental scenario on population recovery from chemical stress exposure: a case study using Daphnia magna.

    Science.gov (United States)

    Gabsi, Faten; Preuss, Thomas G

    2014-11-01

    Recovery of organisms is an important attribute for evaluating the acceptability of chemicals' effects in ecological risk assessment in Europe. Recovery in the field does not depend on the chemical's properties and type of exposure only, but it is strongly linked to important environmental variables and biological interactions as well. Yet, these remain only marginally considered in the European risk assessment of chemicals. Here, we use individual-based modelling to investigate how the environmental scenario affects Daphnia magna population recovery from chemical exposure. Simulation experiments were performed for chemicals with lethality levels ranging from 40% to 90% at different food and temperature conditions. The same toxicity levels were then tested in combination with biological interactions including predation or competition. Results show that for the same chemical effect strength, populations often exhibited different recovery times in a different environmental context. The interactions between the chemical and the environmental variables were the strongest determinants of population recovery. Most important, biotic interactions even induced opposite effects on recovery at low and at high mortality levels. Results of this study infer that no specific role can be attributed to any abiotic or biotic variable in isolation. We conclude that unless the complex interactive mechanisms between the different factors constituting the full environmental scenario are taken into account in risk assessment, we cannot achieve a complete understanding of recovery processes from chemical effects. PMID:25261821

  19. Endocrine-Disrupting Activity of Hydraulic Fracturing Chemicals and Adverse Health Outcomes After Prenatal Exposure in Male Mice.

    Science.gov (United States)

    Kassotis, Christopher D; Klemp, Kara C; Vu, Danh C; Lin, Chung-Ho; Meng, Chun-Xia; Besch-Williford, Cynthia L; Pinatti, Lisa; Zoeller, R Thomas; Drobnis, Erma Z; Balise, Victoria D; Isiguzo, Chiamaka J; Williams, Michelle A; Tillitt, Donald E; Nagel, Susan C

    2015-12-01

    Oil and natural gas operations have been shown to contaminate surface and ground water with endocrine-disrupting chemicals. In the current study, we fill several gaps in our understanding of the potential environmental impacts related to this process. We measured the endocrine-disrupting activities of 24 chemicals used and/or produced by oil and gas operations for five nuclear receptors using a reporter gene assay in human endometrial cancer cells. We also quantified the concentration of 16 of these chemicals in oil and gas wastewater samples. Finally, we assessed reproductive and developmental outcomes in male C57BL/6J mice after the prenatal exposure to a mixture of these chemicals. We found that 23 commonly used oil and natural gas operation chemicals can activate or inhibit the estrogen, androgen, glucocorticoid, progesterone, and/or thyroid receptors, and mixtures of these chemicals can behave synergistically, additively, or antagonistically in vitro. Prenatal exposure to a mixture of 23 oil and gas operation chemicals at 3, 30, and 300 μg/kg · d caused decreased sperm counts and increased testes, body, heart, and thymus weights and increased serum testosterone in male mice, suggesting multiple organ system impacts. Our results suggest possible adverse developmental and reproductive health outcomes in humans and animals exposed to potential environmentally relevant levels of oil and gas operation chemicals. PMID:26465197

  20. Environmental chemicals in human milk: a review of levels, infant exposures and health, and guidance for future research

    International Nuclear Information System (INIS)

    The aim of this review is to introduce the reader to various science and policy aspects of the topic of environmental chemicals in human milk. Although information on environmental chemicals in human milk has been available since the 1950s, it is only relatively recently that public awareness of the issue has grown. This review on environmental chemicals in human milk provides a resource summarizing what is currently known about levels and trends of environmental chemicals in human milk, potential infant exposures, and benefits of breast-feeding relative to the risks of exposures to environmental chemicals. The term 'environmental chemicals', as it pertains to human milk, refers to many classes of exogenous chemicals that may be detected in human milk. For example, pharmaceutical agents and alcohol are environmental chemicals that have been found in human milk. Other chemicals, such as heavy metals and volatile organic compounds, have also been detected in human milk. Most research on environmental chemicals in human milk has concentrated on persistent, bioaccumulative, and toxic (PBT) chemicals. In this review, a description of human milk is provided, including a brief review of endogenous substances in human milk. Determinants of levels of PBTs are discussed, as are models that have been developed to predict levels of PBTs in human milk and associated body burdens in breast-feeding infants. Methodologies for human milk sampling and analysis, and concepts for consideration in interpretation and communication of study results, as developed by the Technical Workshop on Human Milk Surveillance and Research for Environmental Chemicals in the United States are described. Studies which have compared the health risks and benefits associated with breast-feeding and formula-feeding are discussed

  1. Prenatal exposure to perfluorinated chemicals and neurodevelopment in early infancy: The Hokkaido Study.

    Science.gov (United States)

    Goudarzi, Houman; Nakajima, Sonomi; Ikeno, Tamiko; Sasaki, Seiko; Kobayashi, Sachiko; Miyashita, Chihiro; Ito, Sachiko; Araki, Atsuko; Nakazawa, Hiroyuki; Kishi, Reiko

    2016-01-15

    Perfluorinated chemicals (PFCs) are ubiquitous and persistent pollutants widely detected in blood samples of animals and humans across the globe. Although animal studies have shown the potential neurotoxicity of PFCs, there are few epidemiological studies regarding neurological effects of PFCs in humans, and those studies have had inconclusive results. In this study, we conducted a hospital-based prospective birth cohort study between 2002 and 2005 (n=514) to examine the associations between prenatal perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) exposures and the neurodevelopment of infants at 6 (n=173) and 18 (n=133) months of age. Using the second edition of the Bayley Scales of Infant Development (BSID II), the Mental and Psychomotor Developmental Indices (MDI and PDI, respectively) were assessed. PFOS and PFOA were measured in maternal serum samples by liquid chromatography-tandem mass spectrometry. After controlling for confounders, prenatal PFOA concentrations were associated with the MDI of female (but not male) infants at 6 months of age (β=-0.296; 95% confidence interval (CI): -11.96, -0.682). Furthermore, females born to mothers with prenatal concentrations of PFOA in the fourth quartile had MDI scores -5.05 (95% CI: -10.66 to 0.55) lower than females born to mothers with concentrations of PFOA in the first quartile (p for trend=0.045). However, PFOA concentrations were not significantly associated with neurodevelopmental indices at 18 months of age. In addition, we did not observe any significant association between PFOS concentrations and neurodevelopmental outcomes in early infancy. In conclusion, our results suggest that prenatal PFOA exposure may affect female mental scales of neurodevelopment at 6 months of age. Further studies with larger sample sizes and longer observation periods are required to clarify sex difference of the neurodevelopmental effects. PMID:26473702

  2. Measuring youth exposure to alcohol marketing on social networking sites: challenges and prospects.

    Science.gov (United States)

    Jernigan, David H; Rushman, Anne E

    2014-02-01

    Youth exposure to alcohol marketing has been linked to increased alcohol consumption and problems. On relatively new and highly interactive social networking sites (SNS) that are popular with youth, tools for measuring youth exposure to alcohol marketing in traditional media are inadequate. We critically review the existing policies of Facebook, Twitter, and YouTube designed to keep branded alcohol content away from underage youth. Looking at brand and user activity on Facebook for the 15 alcohol brands most popular among US youth, we found activity has grown dramatically in the past 3 years, and underage users may be accounting for some of this activity. Surveys of youth and adult participation in alcohol marketing on SNS will be needed to inform debate over these marketing practices. PMID:24284473

  3. Advancing environmental toxicology through chemical dosimetry: External exposures versus tissue residues

    Science.gov (United States)

    McCarty, L.S.; Landrum, P.F.; Luoma, S.N.; Meador, J.P.; Merten, A.A.; Shephard, B.K.; van Wezelzz, A.P.

    2011-01-01

    The tissue residue dose concept has been used, although in a limited manner, in environmental toxicology for more than 100 y. This review outlines the history of this approach and the technical background for organic chemicals and metals. Although the toxicity of both can be explained in tissue residue terms, the relationship between external exposure concentration, body and/or tissues dose surrogates, and the effective internal dose at the sites of toxic action tends to be more complex for metals. Various issues and current limitations related to research and regulatory applications are also examined. It is clear that the tissue residue approach (TRA) should be an integral component in future efforts to enhance the generation, understanding, and utility of toxicity testing data, both in the laboratory and in the field. To accomplish these goals, several key areas need to be addressed: 1) development of a risk-based interpretive framework linking toxicology and ecology at multiple levels of biological organization and incorporating organism-based dose metrics; 2) a broadly applicable, generally accepted classification scheme for modes/mechanisms of toxic action with explicit consideration of residue information to improve both single chemical and mixture toxicity data interpretation and regulatory risk assessment; 3) toxicity testing protocols updated to ensure collection of adequate residue information, along with toxicokinetics and toxicodynamics information, based on explicitly defined toxicological models accompanied by toxicological model validation; 4) continued development of residueeffect databases is needed ensure their ongoing utility; and 5) regulatory guidance incorporating residue-based testing and interpretation approaches, essential in various jurisdictions. ??:2010 SETAC.

  4. Occupation and occupational exposure to endocrine disrupting chemicals in male breast cancer: a case-control study in Europe

    DEFF Research Database (Denmark)

    Villeneuve, Sara; Cyr, Diane; Lynge, Elsebeth;

    2010-01-01

    Male breast cancer is a rare disease of largely unknown aetiology. In addition to genetic and hormone-related risk factors, a large number of environmental chemicals are suspected of playing a role in breast cancer. The identification of occupations or occupational exposures associated with an...... increased incidence of breast cancer in men may help to identify mammary carcinogens in the environment....

  5. Using Alternative Approaches to Prioritize Testing for the Universe of Chemicals with Potential for Human Exposure (WC9)

    Science.gov (United States)

    One use of alternative methods is to target animal use at only those chemicals and tests that are absolutely necessary. We discuss prioritization of testing based on high-throughput screening assays (HTS), QSAR modeling, high-throughput toxicokinetics (HTTK), and exposure modelin...

  6. Evaluating the Impact of Uncertainties in Clearance and Exposure When Prioritizing Chemicals Screened in High-Throughput Assays

    Science.gov (United States)

    The toxicity-testing paradigm has evolved to include high-throughput (HT) methods for addressing the increasing need to screen hundreds to thousands of chemicals rapidly. Approaches that involve in vitro screening assays, in silico predictions of exposure concentrations, and phar...

  7. Application of a framework for extrapolating chemical effects across species in pathways controlled by estrogen receptor-á

    Science.gov (United States)

    Cross-species extrapolation of toxicity data from limited surrogate test organisms to all wildlife with potential of chemical exposure remains a key challenge in ecological risk assessment. A number of factors affect extrapolation, including the chemical exposure, pharmacokinetic...

  8. Parental occupational exposure to endocrine disrupting chemicals and male genital malformations: A study in the danish national birth cohort study

    Directory of Open Access Journals (Sweden)

    Kaerlev Linda

    2011-01-01

    Full Text Available Abstract Background Sex hormones closely regulate development of the male genital organs during fetal life. The hypothesis that xenobiotics may disrupt endogenous hormonal signalling has received considerable scientific attention, but human evidence is scarce. Objectives We analyse occurrence of hypospadias and cryptorchidism according to maternal and paternal occupational exposure to possible endocrine disrupting chemicals. Methods We conducted a follow-up study of 45,341 male singleton deliveries in the Danish National Birth Cohort during 1997-2009. Information on work during pregnancy was obtained by telephone interviews around gestational week 16. Parents' job titles were classified according to DISCO-88. A job exposure matrix for endocrine disrupting chemicals (EDCs was implemented to assess occupational exposures. The Medical Birth and National Hospital Register provided data on congenital anomalies diagnosed at birth or during follow-up, which ended in 2009. Crude and adjusted hazard ratios (HR were obtained from Cox regression models. Results Among all pregnancies, 6.3% were classified as possibly or probably exposed to EDCs. The most prevalent occupations conferring possible exposure were cleaners, laboratory technicians, hairdressers and agricultural workers (58% of all potentially exposed. The final cumulative incidence of cryptorchidism in boys was 2.2% (1002 cases, and of hypospadias 0.6% (262 cases. The occurrence of hypospadias increased when mothers were probably [HRa = 1.8 (95% CI 1.0-2.6] or possibly exposed to one or more EDCs [HRa = 2.6 (95% CI 1.8-3.4. Possible paternal exposure to heavy metals increased the risk of hypospadias [HRa 2.2 (95% CI: 1.0-3.4] and cryptorchidism [HRa 1.9 (95% CI: 1.1-2.7]. None of the exposure groups reached statistical significance. Conclusion The study provides some but limited evidence that occupational exposure to possible endocrine disrupting chemicals during pregnancy increases the risk of

  9. Chemical exposure-response relationship between air pollutants and reactive oxygen species in the human respiratory tract.

    Science.gov (United States)

    Lakey, Pascale S J; Berkemeier, Thomas; Tong, Haijie; Arangio, Andrea M; Lucas, Kurt; Pöschl, Ulrich; Shiraiwa, Manabu

    2016-01-01

    Air pollution can cause oxidative stress and adverse health effects such as asthma and other respiratory diseases, but the underlying chemical processes are not well characterized. Here we present chemical exposure-response relations between ambient concentrations of air pollutants and the production rates and concentrations of reactive oxygen species (ROS) in the epithelial lining fluid (ELF) of the human respiratory tract. In highly polluted environments, fine particulate matter (PM2.5) containing redox-active transition metals, quinones, and secondary organic aerosols can increase ROS concentrations in the ELF to levels characteristic for respiratory diseases. Ambient ozone readily saturates the ELF and can enhance oxidative stress by depleting antioxidants and surfactants. Chemical exposure-response relations provide a quantitative basis for assessing the relative importance of specific air pollutants in different regions of the world, showing that aerosol-induced epithelial ROS levels in polluted megacity air can be several orders of magnitude higher than in pristine rainforest air. PMID:27605301

  10. Effects of combined exposure of F344 rats to inhaled 239PuO2 and a chemical carcinogen (NNK)

    International Nuclear Information System (INIS)

    Workers in nuclear weapons facilitates have a significant potential for exposure to chemical carcinogens and to radiation from external sources or from internally deposited radionuclides such as 239Pu. Although the carcinogenic effects of inhaled 239Pu and many chemicals have been studied individually, very little information is available on their combined effects. One chemical carcinogen that workers could be exposed to, via tobacco smoke, is the tobacco-specific nitrosamine 4-(N-Methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a product of the curing of tobacco and pyrolysis of nicotine in tobacco. NNK causes lung tumors in rats, regardless of the route of administration and to a lesser extent tumors in the liver, nasal passages, and pancreas. The purpose of this study is to characterize the effects of combined exposure of rats to NNK and internally deposited plutonium, as well as to these agents alone

  11. Chemical exposure-response relationship between air pollutants and reactive oxygen species in the human respiratory tract

    Science.gov (United States)

    Lakey, Pascale S. J.; Berkemeier, Thomas; Tong, Haijie; Arangio, Andrea M.; Lucas, Kurt; Pöschl, Ulrich; Shiraiwa, Manabu

    2016-01-01

    Air pollution can cause oxidative stress and adverse health effects such as asthma and other respiratory diseases, but the underlying chemical processes are not well characterized. Here we present chemical exposure-response relations between ambient concentrations of air pollutants and the production rates and concentrations of reactive oxygen species (ROS) in the epithelial lining fluid (ELF) of the human respiratory tract. In highly polluted environments, fine particulate matter (PM2.5) containing redox-active transition metals, quinones, and secondary organic aerosols can increase ROS concentrations in the ELF to levels characteristic for respiratory diseases. Ambient ozone readily saturates the ELF and can enhance oxidative stress by depleting antioxidants and surfactants. Chemical exposure-response relations provide a quantitative basis for assessing the relative importance of specific air pollutants in different regions of the world, showing that aerosol-induced epithelial ROS levels in polluted megacity air can be several orders of magnitude higher than in pristine rainforest air. PMID:27605301

  12. Development of asthmatic inflammation in mice following early-life exposure to ambient environmental particulates and chronic allergen challenge

    Directory of Open Access Journals (Sweden)

    Cristan Herbert

    2013-03-01

    Childhood exposure to environmental particulates increases the risk of development of asthma. The underlying mechanisms might include oxidant injury to airway epithelial cells (AEC. We investigated the ability of ambient environmental particulates to contribute to sensitization via the airways, and thus to the pathogenesis of childhood asthma. To do so, we devised a novel model in which weanling BALB/c mice were exposed to both ambient particulate pollutants and ovalbumin for sensitization via the respiratory tract, followed by chronic inhalational challenge with a low mass concentration of the antigen. We also examined whether these particulates caused oxidant injury and activation of AEC in vitro. Furthermore, we assessed the potential benefit of minimizing oxidative stress to AEC through the period of sensitization and challenge by dietary intervention. We found that characteristic features of asthmatic inflammation developed only in animals that received particulates at the same time as respiratory sensitization, and were then chronically challenged with allergen. However, these animals did not develop airway hyper-responsiveness. Ambient particulates induced epithelial injury in vitro, with evidence of oxidative stress and production of both pro-inflammatory cytokines and Th2-promoting cytokines such as IL-33. Treatment of AEC with an antioxidant in vitro inhibited the pro-inflammatory cytokine response to these particulates. Ambient particulates also induced pro-inflammatory cytokine expression following administration to weanling mice. However, early-life dietary supplementation with antioxidants did not prevent the development of an asthmatic inflammatory response in animals that were exposed to particulates, sensitized and challenged. We conclude that injury to airway epithelium by ambient environmental particulates in early life is capable of promoting the development of an asthmatic inflammatory response in sensitized and antigen-challenged mice. These

  13. Dietary exposure to endocrine disrupting chemicals in metropolitan population from China: a risk assessment based on probabilistic approach.

    Science.gov (United States)

    He, Dongliang; Ye, Xiaolei; Xiao, Yonghua; Zhao, Nana; Long, Jia; Zhang, Piwei; Fan, Ying; Ding, Shibin; Jin, Xin; Tian, Chong; Xu, Shunqing; Ying, Chenjiang

    2015-11-01

    The intake of contaminated foods is an important exposure pathway for endocrine disrupting chemicals (EDCs). However, data on the occurrence of EDCs in foodstuffs are sporadic and the resultant risk of co-exposure is rarely concerned. In this study, 450 food samples representing 7 food categories (mainly raw and fresh food), collected from three geographic cities in China, were analyzed for eight EDCs using high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Besides estrone (E1), other EDCs including diethylstilbestrol (DES), nonylphenol (NP), bisphenol A (BPA), octylphenol (OP), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), and estriol (E3) were ubiquitous in food. Dose-dependent relationships were found between NP and EE2 (r=0.196, plocal food consumption, dietary EDCs exposure was estimated using the Monte Carlo Risk Assessment (MCRA) system. The 50th and 95th percentile exposure of any EDCs isomer were far below the tolerable daily intake (TDI) value identically. However, the sum of 17β-estradiol equivalents (∑EEQs) exposure in population was considerably larger than the value of exposure to E2, which implied the underlying resultant risk of multiple EDCs in food should be concern. In conclusion, co-exposure via food consumption should be considered rather than individual EDCs during health risk evaluation. PMID:26025473

  14. Challenges in Understanding the Risks to Natural and Semi-Natural Vegetation from Ozone Exposure

    Directory of Open Access Journals (Sweden)

    Gina Mills

    2008-03-01

    Full Text Available The effects of tropospheric ozone on crops and forests have been studied intensively, but effects on natural and semi- natural plant communities are poorly understood. This lack of understanding arises partly from a lack of experimental studies of whole mature communities, and the effects of ozone on competition and interactions with climate, nutrition etc., and partly from a lack of knowledge of the factors which predispose individual plant species to ozone damage. A recent review of the effects of ozone on grasslands (Bassin et al., 2007a has drawn attention to the problems involved; this paper seeks to identify the practical issues that must be addressed in improving our knowledge and thereby identifying the risks associated with ozone exposure. This is a necessary first step before mitigation strategies can be developed.

  15. Exposure of vaccinated and naive cattle to natural challenge from buffalo-derived Theileria parva

    Directory of Open Access Journals (Sweden)

    Tatjana Sitt

    2015-08-01

    Full Text Available Integrative management of wildlife and livestock requires a clear understanding of the diseases transmitted between the two populations. The tick-borne protozoan parasite Theileria parva causes two distinct diseases in cattle, East Coast fever and Corridor disease, following infection with parasites derived from cattle or buffalo, respectively. In this study, cattle were immunized with a live sporozoite vaccine containing three T. parva isolates (the Muguga cocktail, which has been used extensively and successfully in the field to protect against cattle-derived T. parva infection. The cattle were exposed in a natural field challenge site containing buffalo but no other cattle. The vaccine had no effect on the survival outcome in vaccinated animals compared to unvaccinated controls: nine out of the 12 cattle in each group succumbed to T. parva infection. The vaccine also had no effect on the clinical course of the disease. A combination of clinical and post mortem observations and laboratory analyses confirmed that the animals died of Corridor disease. The results clearly indicate that the Muguga cocktail vaccine does not provide protection against buffalo-derived T. parva at this site and highlight the need to evaluate the impact of the composition of challenge T. parva populations on vaccine success in areas where buffalo and cattle are present.

  16. NMR analysis of male fathead minnow urinary metabolites: A potential approach for studying impacts of chemical exposures

    Energy Technology Data Exchange (ETDEWEB)

    Ekman, D.R. [Ecosystems Research Division, U.S. EPA, 960 College Station Road, Athens, GA 30605 (United States)], E-mail: ekman.drew@epa.gov; Teng, Q. [Ecosystems Research Division, U.S. EPA, 960 College Station Road, Athens, GA 30605 (United States); Jensen, K.M.; Martinovic, D.; Villeneuve, D.L.; Ankley, G.T. [Mid-Continent Ecology Division, U.S. EPA, 6201 Congdon Boulevard, Duluth, MN 55804 (United States); Collette, T.W. [Ecosystems Research Division, U.S. EPA, 960 College Station Road, Athens, GA 30605 (United States)

    2007-11-30

    The potential for profiling metabolites in urine from male fathead minnows (Pimephales promelas) to assess chemical exposures was explored using nuclear magnetic resonance (NMR) spectroscopy. Both one-dimensional (1D) and two-dimensional (2D) NMR spectroscopy was used for the assignment of metabolites in urine from unexposed fish. Because fathead minnow urine is dilute, we lyophilized these samples prior to analysis. Furthermore, 1D {sup 1}H NMR spectra of unlyophilized urine from unexposed male fathead minnow and Sprague-Dawley rat were acquired to qualitatively compare rat and fish metabolite profiles and to provide an estimate of the total urinary metabolite pool concentration difference. As a small proof-of-concept study, lyophilized urine samples from male fathead minnows exposed to three different concentrations of the antiandrogen vinclozolin were analyzed by 1D {sup 1}H NMR to assess exposure-induced changes. Through a combination of principal components analysis (PCA) and measurements of {sup 1}H NMR peak intensities, several metabolites were identified as changing with statistical significance in response to exposure. Among those changes occurring in response to exposure to the highest concentration (450 {mu}g/L) of vinclozolin were large increases in taurine, lactate, acetate, and formate. These increases coincided with a marked decrease in hippurate, a combination potentially indicative of hepatotoxicity. The results of these investigations clearly demonstrate the potential utility of an NMR-based approach for assessing chemical exposures in male fathead minnow, using urine collected from individual fish.

  17. NMR analysis of male fathead minnow urinary metabolites: A potential approach for studying impacts of chemical exposures

    International Nuclear Information System (INIS)

    The potential for profiling metabolites in urine from male fathead minnows (Pimephales promelas) to assess chemical exposures was explored using nuclear magnetic resonance (NMR) spectroscopy. Both one-dimensional (1D) and two-dimensional (2D) NMR spectroscopy was used for the assignment of metabolites in urine from unexposed fish. Because fathead minnow urine is dilute, we lyophilized these samples prior to analysis. Furthermore, 1D 1H NMR spectra of unlyophilized urine from unexposed male fathead minnow and Sprague-Dawley rat were acquired to qualitatively compare rat and fish metabolite profiles and to provide an estimate of the total urinary metabolite pool concentration difference. As a small proof-of-concept study, lyophilized urine samples from male fathead minnows exposed to three different concentrations of the antiandrogen vinclozolin were analyzed by 1D 1H NMR to assess exposure-induced changes. Through a combination of principal components analysis (PCA) and measurements of 1H NMR peak intensities, several metabolites were identified as changing with statistical significance in response to exposure. Among those changes occurring in response to exposure to the highest concentration (450 μg/L) of vinclozolin were large increases in taurine, lactate, acetate, and formate. These increases coincided with a marked decrease in hippurate, a combination potentially indicative of hepatotoxicity. The results of these investigations clearly demonstrate the potential utility of an NMR-based approach for assessing chemical exposures in male fathead minnow, using urine collected from individual fish

  18. Profiling 976 ToxCast chemicals across 331 enzymatic and receptor signaling assays (Communities of Practice)

    Science.gov (United States)

    Understanding potential health risks is a significant challenge for large numbers of diverse chemicals with poorly characterized exposures and mechanisms of toxicities. The present study analyzes chemical-target activity profiles of 976 chemicals (including failed pharmaceuticals...

  19. Residential and biological exposure assessment of chemicals from a wood treatment plant.

    Science.gov (United States)

    Dahlgren, James; Takhar, Harpreet; Schecter, Arnold; Schmidt, Reynold; Horsak, Randy; Paepke, Olaf; Warshaw, Raphael; Lee, Alexander; Anderson-Mahoney, Pamela

    2007-04-01

    This paper evaluates the results of contamination of residents and residential homes located in close proximity to a Wood Treatment Plant. The plant has produced treated wood products continuously since 1904. The principle chemicals used to treat the wood, which is primarily used for railroad ties (oblong objects laid perpendicular to the rails to act as a base for the tracks), are creosote and pentachlorophenol. For a number of years, the plant burned treated waste wood products containing creosote and pentachlorophenol. First the plant pressure impregnates the wood with creosote and pentachlorophenol, and then the wood is stacked on open ground to allow it to air dry. Chemicals from recently treated wood ties are allowed to evaporate into the air or drip onto the ground surrounding the stacked wood. Small drainage ditches carry the liquid wastes into larger water channels where eventually the waste streams are discharged into a river adjacent to the plant. The river serves as a source of drinking water for the nearby community. Prevailing wind patterns favor a drift of air emissions from the plant's boiler stack over the nearby community and its residents. Over the past few years, the town's residents have become increasingly concerned about their health status and have voiced concerns regarding multiple health problems (including cancer), possibly associated with plant discharges. The intention of this study is to examine a representative sample of the potentially affected residents and to evaluate their residential environment for the presence of dioxin and/or its congeners. Data obtained from EPA's Toxic Release Information (TRI) database revealed the plant routinely discharged creosote, pentachlorophenol, dioxin and dioxin-like compounds into the ambient air via fugitive air emissions and surface waste waters. Sampling of household dust and water sediment within and outside of residences within a 2-mile radius of the plant revealed the presence of

  20. Sustainable catalysis challenges and practices for the pharmaceutical and fine chemical industries

    CERN Document Server

    Dunn, Peter J; Krische, Michael J; Williams, Michael T

    2013-01-01

    Opens the door to the sustainable production of pharmaceuticals and fine chemicals Driven by both public demand and government regulations, pharmaceutical and fine chemical manufacturers are increasingly seeking to replace stoichiometric reagents used in synthetic transformations with catalytic routes in order to develop greener, safer, and more cost-effective chemical processes. This book supports the discovery, development, and implementation of new catalytic methodologies on a process scale, opening the door to the sustainable production of pharmaceuticals and fine chemicals

  1. Predicting the Future: Opportunities and Challenges for the Chemical Industry to Apply 21st-Century Toxicity Testing

    OpenAIRE

    Settivari, Raja S; Ball, Nicholas; Murphy, Lynea; Rasoulpour, Reza; Boverhof, Darrell R; Carney, Edward W

    2015-01-01

    Interest in applying 21st-century toxicity testing tools for safety assessment of industrial chemicals is growing. Whereas conventional toxicology uses mainly animal-based, descriptive methods, a paradigm shift is emerging in which computational approaches, systems biology, high-throughput in vitro toxicity assays, and high-throughput exposure assessments are beginning to be applied to mechanism-based risk assessments in a time- and resource-efficient fashion. Here we describe recent advances...

  2. Human toxicology of chemical mixtures toxic consequences beyond the impact of one-component product and environmental exposures

    CERN Document Server

    Zeliger, Harold I

    2011-01-01

    In this important reference work, Zeliger catalogs the known effects of chemical mixtures on the human body and also proposes a framework for understanding and predicting their actions in terms of lipophile (fat soluble)/hydrophile (water soluble) interactions. The author's focus is on illnesses that ensue following exposures to mixtures of chemicals that cannot be attributed to any one component of the mixture. In the first part the mechanisms of chemical absorption at a molecular and macromolecular level are explained, as well as the body's methods of defending itself against xenobiotic intrusion. Part II examines the sources of the chemicals discussed, looking at air and water pollution, food additives, pharmaceuticals, etc. Part III, which includes numerous case studies, examines specific effects of particular mixtures on particular body systems and organs and presents a theoretical framework for predicting what the effects of uncharacterized mixtures might be. Part IV covers regulatory requirements and t...

  3. Perceived benefits and challenges of repeated exposure to high fidelity simulation experiences of first degree accelerated bachelor nursing students.

    Science.gov (United States)

    Kaddoura, Mahmoud; Vandyke, Olga; Smallwood, Christopher; Gonzalez, Kristen Mathieu

    2016-01-01

    This study explored perceptions of first-degree entry-level accelerated bachelor nursing students regarding benefits and challenges of exposure to multiple high fidelity simulation (HFS) scenarios, which has not been studied to date. These perceptions conformed to some research findings among Associate Degree, traditional non-accelerated, and second-degree accelerated Bachelor of Science in Nursing (BSN) students faced with one to two simulations. However, first-degree accelerated BSN students faced with multiple complex simulations perceived improvements on all outcomes, including critical thinking, confidence, competence, and theory-practice integration. On the negative side, some reported feeling overwhelmed by the multiple HFS scenarios. Evidence from this study supports HFS as an effective teaching and learning method for nursing students, along with valuable implications for many other fields. PMID:26260522

  4. Association between airborne PM2.5 chemical constituents and birth weight—implication of buffer exposure assignment

    International Nuclear Information System (INIS)

    Several papers reported associations between airborne fine particulate matter (PM2.5) and birth weight, though findings are inconsistent across studies. Conflicting results might be due to (1) different PM2.5 chemical structure across locations, and (2) various exposure assignment methods across studies even among the studies that use ambient monitors to assess exposure. We investigated associations between birth weight and PM2.5 chemical constituents, considering issues arising from choice of buffer size (i.e. distance between residence and pollution monitor). We estimated the association between each pollutant and term birth weight applying buffers of 5 to 30 km in Connecticut (2000–2006), in the New England region of the USA. We also investigated the implication of the choice of buffer size in relation to population characteristics, such as socioeconomic status. Results indicate that some PM2.5 chemical constituents, such as nitrate, are associated with lower birth weight and appear more harmful than other constituents. However, associations vary with buffer size and the implications of different buffer sizes may differ by pollutant. A homogeneous pollutant level within a certain distance is a common assumption in many environmental epidemiology studies, but the validity of this assumption may vary by pollutant. Furthermore, we found that areas close to monitors reflect more minority and lower socio-economic populations, which implies that different exposure approaches may result in different types of study populations. Our findings demonstrate that choosing an exposure method involves key tradeoffs of the impacts of exposure misclassification, sample size, and population characteristics. (letter)

  5. Perinatal exposure to mixtures of endocrine disrupting chemicals reduces female rat follicle reserves and accelerates reproductive aging.

    Science.gov (United States)

    Johansson, Hanna Katarina Lilith; Jacobsen, Pernille Rosenskjold; Hass, Ulla; Svingen, Terje; Vinggaard, Anne Marie; Isling, Louise Krag; Axelstad, Marta; Christiansen, Sofie; Boberg, Julie

    2016-06-01

    Exposure to endocrine disrupting chemicals (EDCs) during development can have negative consequences later in life. In this study we investigated the effect of perinatal exposure to mixtures of human relevant EDCs on the female reproductive system. Rat dams were exposed to a mixture of phthalates, pesticides, UV-filters, bisphenol A, butylparaben, as well as paracetamol. The compounds were tested together (Totalmix) or in subgroups with anti-androgenic (AAmix) or estrogenic (Emix) potentials. Paracetamol was tested separately. In pre-pubertal rats, a significant reduction in primordial follicle numbers was seen in AAmix and PM groups, and reduced plasma levels of prolactin was seen in AAmix. In one-year-old animals, the incidence of irregular estrous cycles was higher after Totalmix-exposure and reduced ovary weights were seen in Totalmix, AAmix, and PM groups. These findings resemble premature ovarian insufficiency in humans, and raises concern regarding potential effects of mixtures of EDCs on female reproductive function. PMID:27049580

  6. Use of Polar Organic Chemical Integrative Samplers to assess the effects of chronic pesticide exposure on biofilms

    OpenAIRE

    Morin, S.; Pesce, S.; Kim Tiam, S.; Libert, X.; Coquery, M.; Mazzella, N.

    2012-01-01

    The responses of aquatic organisms to chronic exposure to environmental concentrations of toxicants, often found in mixtures, are poorly documented. Here passive sampler extracts were used in experimental contamination of laboratory channels, to investigate their effects on natural biofilm communities. A realistic mixture of pesticides extracted from POCIS (Polar Organic Chemical Integrative Samplers) was used to expose biofilms in laboratory channels to total pesticide concentrations averagi...

  7. Environmental monitoring and assessment of short-term exposures to hazardous chemicals of a sterilization process in hospital working environments.

    OpenAIRE

    Koda S; Kumagai S; Ohara H

    1999-01-01

    In order to assess short-term exposures to ethylene oxide, formaldehyde and glutaraldehyde in a sterilization process, the authors conducted continuous environmental monitoring of these chemicals in the breathing zone of workers in 2 hospitals. The arithmetic mean of ethylene oxide was 1.2 ppm near unventilated cabinets housing sterilizing materials, and environmental concentrations of ethylene oxide could not be reduced under threshold limit values time weighted average by only managing gene...

  8. Parental occupational exposure to endocrine disrupting chemicals and male genital malformations: A study in the Danish National Birth Cohort study

    OpenAIRE

    Kaerlev Linda; Ramlau-Hansen Cecilia; Jensen Morten S; Toft Gunnar V; Morales-Suárez-Varela María M; Thulstrup Ane-Marie; Llopis-González Agustín; Olsen Jørn; Bonde Jens P

    2011-01-01

    Abstract Background Sex hormones closely regulate development of the male genital organs during fetal life. The hypothesis that xenobiotics may disrupt endogenous hormonal signalling has received considerable scientific attention, but human evidence is scarce. Objectives We analyse occurrence of hypospadias and cryptorchidism according to maternal and paternal occupational exposure to possible endocrine disrupting chemicals. Methods We conducted a follow-up study of 45,341 male singleton deli...

  9. Survey on methodologies in the risk assessment of chemical exposures in emergency response situations in Europe

    DEFF Research Database (Denmark)

    Heinälä, Milla; Gundert-Remy, Ursula; Wood, Maureen Heraty;

    2013-01-01

    A scientifically sound assessment of the risk to human health resulting from acute chemical releases is the cornerstone for chemical incident prevention, preparedness and response. Although the general methodology to identify acute toxicity of chemicals has not substantially changed in the last...

  10. Human exposure modeling in a life cycle framework for chemicals and products

    Science.gov (United States)

    A chemical enters into commerce to serve a specific function in a product or process. This decision triggers both the manufacture of the chemical and its potential release over the life cycle of the product. Efficiently evaluating chemical safety and sustainability requires combi...

  11. Exploring consumer exposure pathways and patterns of use for chemicals in the environment

    DEFF Research Database (Denmark)

    Dionisio, Kathie L.; Frame, Alicia M.; Goldsmith, Michael-Rock;

    2015-01-01

    (CPCat), a new, publically available (http://actor.epa.gov/cpcat) database of information on chemicals mapped to “use categories” describing the usage or function of the chemical. CPCat was created by combining multiple and diverse sources of data on consumer- and industrial-process based chemical uses...

  12. Noninvasive Biomonitoring Approaches to Determine Dosimetry and Risk Following Acute Chemical Exposure: Analysis of Lead or Organophosphate Insecticide in Saliva

    International Nuclear Information System (INIS)

    There is a need to develop approaches for assessing risk associated with acute exposures to a broad-range of chemical agents and to rapidly determine the potential implications to human health. Non-invasive biomonitoring approaches are being developed using reliable portable analytical systems to quantitate dosimetry utilizing readily obtainable body fluids, such as saliva. Saliva has been used to evaluate a broad range of biomarkers, drugs, and environmental contaminants including heavy metals and pesticides. To advance the application of non-invasive biomonitoring a microfluidic/ electrochemical device has also been developed for the analysis of lead (Pb), using square wave anodic stripping voltammetry. The system demonstrates a linear response over a broad concentration range (1 2000 ppb) and is capable of quantitating saliva Pb in rats orally administered acute doses of Pb-acetate. Appropriate pharmacokinetic analyses have been used to quantitate systemic dosimetry based on determination of saliva Pb concentrations. In addition, saliva has recently been used to quantitate dosimetry following exposure to the organophosphate insecticide chlorpyrifos in a rodent model system by measuring the major metabolite, trichloropyridinol, and saliva cholinesterase inhibition following acute exposures. These results suggest that technology developed for non-invasive biomonitoring can provide a sensitive, and portable analytical tool capable of assessing exposure and risk in real-time. By coupling these non-invasive technologies with pharmacokinetic modeling it is feasible to rapidly quantitate acute exposure to a broad range of chemical agents. In summary, it is envisioned that once fully developed, these monitoring and modeling approaches will be useful for accessing acute exposure and health risk

  13. Pre-exposure prophylaxis for men and transgender women who have sex with men in Brazil: opportunities and challenges

    Directory of Open Access Journals (Sweden)

    Valdilea G Veloso

    2015-07-01

    Full Text Available Introduction: The World Health Organization recently released guidelines on the use of pre-exposure prophylaxis (PrEP for prevention of HIV infection among men and transgender women (TGW who have sex with men based on results of randomized clinical trials. The aim of this commentary is to discuss the opportunities and challenges of incorporating PrEP into the Brazilian continuum of HIV care and prevention for men who have sex with men (MSM and TGW. Discussion: Key aspects of the AIDS epidemic among MSM and TGW in Brazil and the comprehensive Brazilian response to the epidemic are presented. The universal access to health care provided through the Brazilian Unified Health System (SUS and the range of prevention and care services already available countrywide to HIV-positive individuals and at-risk MSM and TGW are identified as the main facilitators for the implementation of PrEP. Limited PrEP awareness among MSM, TGW and health care providers, low HIV testing frequency and low HIV risk perception among MSM and TGW represent the core challenges to be addressed. Data generated by demonstration projects in Brazil will provide an important contribution to PrEP rollout in Brazil. Conclusions: The implementation of PrEP in Brazil is feasible. A synergistic rollout of treatment as prevention and PrEP will maximize public health and individual benefits of the country's comprehensive response to the AIDS epidemic.

  14. Modeling the exposure of children and adults via diet to chemicals in the environment with crop-specific models

    International Nuclear Information System (INIS)

    Exposure to chemicals via diet is a major uptake pathway for many compounds but is often estimated in a rather generic way. We use a new model framework (NMF) with crop-specific models to predict the dietary intake by 4-5-year-old children and 14-75-year-old women of three environmental compounds from their background concentrations in soil and air. Calculated daily intakes of benzo(a)pyrene and 2,3,7,8-TCDD are in good agreement with measured results from diet studies. The major source of both compounds in human diet is deposition from air. Inhalation of air and ingestion of soil play a minor role. Children take up more than twice the amount than adults per kg bodyweight, due to higher consumption per kg bodyweight. Contrary, the methods for indirect human exposure suggested in the Technical Guidance Document (TGD) for chemical risk assessment in the EU lead to overprediction, due to unrealistic consumption data and a false root model. - This paper addresses exposure of children and adults to environmental chemicals via the terrestrial food chain using crop-specific plant uptake models

  15. Effects of combined exposure of F344 rats to inhaled Plutonium-239 dioxide and a chemical carcinogen (NNK)

    Energy Technology Data Exchange (ETDEWEB)

    Lundgren, D.L.; Carlton, W.W. [Purdue Univ., Lafayette, IN (United States); Griffith, W.C. [and others

    1995-12-01

    Workers in nuclear weapons facilities have a significant potential for exposure to chemical carcinogens and to radiation from external sources or from internally deposited radionuclides such as {sup 239}Pu. Although the carcinogenic effects of inhaled {sup 239}Pu and many chemicals have been studied individually, very little information is available on their combined effects. One chemical carcinogen that workers could be exposed to via tobacco smoke is the tobacco-specific nitrosamine 4-(N-methyl-n-nitrosamino)-1-(3-pyridyl)-1(3-pyridyl)-1-butanone (NNK), a product of tobacco curing and the pyrolysis of nicotine in tobacco. NNK causes lung tumors in rats, regardless of the route of administration and to a lesser extent liver, nasal, and pancreatic tumors. From the results presented, it can be concluded that exposure to a chemical carcinogen (NNK) in combination with {alpha}-particle radiation from inhaled {sup 239}PuO{sub 2} acts in, at best, an additive manner in inducing lung cancer in rats.

  16. Harmonisation of food consumption data format for dietary exposure assessments of chemicals analysed in raw agricultural commodities.

    Science.gov (United States)

    Boon, Polly E; Ruprich, Jiri; Petersen, Annette; Moussavian, Shahnaz; Debegnach, Francesca; van Klaveren, Jacob D

    2009-12-01

    In this paper, we present an approach to format national food consumption data at raw agricultural commodity (RAC) level. In this way, the data is both formatted in a harmonised way given the comparability of RACs between countries, and suitable to assess the dietary exposure to chemicals analysed in RACs at a European level. In this approach, consumption data needs to be converted to edible part of RAC (e-RAC) level using a RAC conversion database. To subsequently use this data in exposure assessments, both e-RACs and RACs analysed in chemical control programmes should be classified via a uniform system. Furthermore, chemical concentrations in RACs may need to be converted to e-RAC level using processing factors. To illustrate the use of this approach, we describe how the Dutch RAC conversion database was used to convert consumption data of four national consumption surveys to e-RAC level, and the use of the FAO/WHO Codex Classification system of Foods and Animal Feeds to harmonise the classification. We demonstrate that this approach works well for pesticides and glycoalkaloids, and is an essential step forward in the harmonisation of risk assessment procedures within Europe when addressing chemicals analysed in RACs by all national food control systems. PMID:19682531

  17. China’s Coal Chemical Industry: In the View of Governance Challenges

    OpenAIRE

    Xu, Xiaoran; Wang, Dong

    2013-01-01

    This paper examines the China’s coal chemical strategy. As a part of national energy strategy, China’s coal chemical industry induces conflicts on technical level, economic level and policy level. The analysis of this paper is under the policy framework and discusses the causes and effects of these conflicts and also proposes some possible solutions.

  18. Using Patent Classification to Discover Chemical Information in a Free Patent Database: Challenges and Opportunities

    Science.gov (United States)

    Ha¨rtinger, Stefan; Clarke, Nigel

    2016-01-01

    Developing skills for searching the patent literature is an essential element of chemical information literacy programs at the university level. The present article creates awareness of patents as a rich source of chemical information. Patent classification is introduced as a key-component in comprehensive search strategies. The free Espacenet…

  19. Physico-chemical stability of SiC/SiC fiber ceramic composites after exposure to fusion-relevant conditions

    International Nuclear Information System (INIS)

    The physico-chemical stability of SiC/SiC fiber ceramic composite (SiC/SiCf) in contact with Li2O in fusion-relevant conditions has been experimentally studied at 800 C in flowing helium (0.1 L/min) containing either 0.1% H2 or 100 ppm H2O and for exposure times of up to 4,032 h. The exposed SiC/SiC specimens have been characterized. The results obtained demonstrate that although the surface coating of the specimens is strongly attacked through chemical corrosion processes, the main physico-chemical characteristics of SiC/SiCf are affected to a limited extent only in the case of He + 0.1% H2 flowing gas, the bulk material not being attacked

  20. The prediction of PAHs bioavailability in soils using chemical methods: state of the art and future challenges.

    Science.gov (United States)

    Cachada, A; Pereira, R; da Silva, E Ferreira; Duarte, A C

    2014-02-15

    The evaluation of the available fraction of hydrophobic organic contaminants (HOCs) is extremely important for assessing their risk to the environment and human health. This available fraction, which can be solubilized and/or easily extracted, is believed to be the most accessible for bioaccumulation, biosorption and/or transformation by organisms. Based on this, two main types of chemical methods have been developed, closely related to the concepts of bioaccessibility and freely available concentrations: non-exhaustive extractions and biomimetic methods. Since bioavailability is species and compound specific, this work focused only in one of the most widespread group of HOCs in soils: polycyclic aromatic hydrocarbons (PAHs). This study aims at producing a state of the art knowledge base on bioavailability and chemical availability of PAHs in soils, clarifying which chemical methods can provide a better prediction of an organism exposure, and which are the most promising ones. Therefore, a review of the processes involved on PAHs availability to microorganisms, earthworms and plants was performed and the outputs given by the different chemical methods were evaluated. The suitability of chemical methods to predict bioavailability of the 16 US EPA PAHs in dissimilar naturally contaminated soils was not yet demonstrated, being especially difficult for high molecular weight compounds. Even though the potential to predict microbial mineralization using non-exhaustive extractions is promising, it will be very difficult to achieve for earthworms and plants, due to the complexity of accumulation mechanisms which are not taken into account by chemical methods. Yet, the existing models could be improved by determining compound, species and site specific parameters. Moreover, chemical availability can be very useful to understand the bioavailability processes and the behavior of PAHs in soils. The inclusion of chemical methods on risk assessment has been suggested and it is

  1. Study of chemical element composition dependency of exposure buildup factors in concrete shielding

    International Nuclear Information System (INIS)

    Gamma ray exposure buildup factor mainly dependent on the composition of which it is made therefore the effect of elemental composition has been studied for concrete shielding. The buildup factors are derived by G-P fitting formula in the photon energy range 0.015-15 MeV up to penetration depth of 40 mfp. The exposure buildup factors of the concretes shielding shows sharp variation beyond 3 MeV photon energy for penetration depth above 10 mfp. (author)

  2. Perfluorooctanoic Acid (PFOA) Exposures and Incident Cancers among Adults Living Near a Chemical Plant

    OpenAIRE

    Barry, Vaughn; Winquist, Andrea; Steenland, Kyle

    2013-01-01

    Background: Perfluorooctanoic acid (PFOA) is a synthetic chemical ubiquitous in the serum of U.S. residents. It causes liver, testicular, and pancreatic tumors in rats. Human studies are sparse. Objective: We examined cancer incidence in Mid-Ohio Valley residents exposed to PFOA in drinking water due to chemical plant emissions. Methods: The cohort consisted of adult community residents who resided in contaminated water districts or worked at a local chemical plant. Most participated in a 200...

  3. Health Outcomes of Exposure to Biological and Chemical Components of Inhalable and Respirable Particulate Matter

    OpenAIRE

    Oyewale Mayowa Morakinyo; Matlou Ingrid Mokgobu; Murembiwa Stanley Mukhola; Raymond Paul Hunter

    2016-01-01

    Particulate matter (PM) is a key indicator of air pollution and a significant risk factor for adverse health outcomes in humans. PM is not a self-contained pollutant but a mixture of different compounds including chemical and biological fractions. While several reviews have focused on the chemical components of PM and associated health effects, there is a dearth of review studies that holistically examine the role of biological and chemical components of inhalable and respirable PM in disease...

  4. The Markyt visualisation, prediction and benchmark platform for chemical and gene entity recognition at BioCreative/CHEMDNER challenge.

    Science.gov (United States)

    Pérez-Pérez, Martin; Pérez-Rodríguez, Gael; Rabal, Obdulia; Vazquez, Miguel; Oyarzabal, Julen; Fdez-Riverola, Florentino; Valencia, Alfonso; Krallinger, Martin; Lourenço, Anália

    2016-01-01

    Biomedical text mining methods and technologies have improved significantly in the last decade. Considerable efforts have been invested in understanding the main challenges of biomedical literature retrieval and extraction and proposing solutions to problems of practical interest. Most notably, community-oriented initiatives such as the BioCreative challenge have enabled controlled environments for the comparison of automatic systems while pursuing practical biomedical tasks. Under this scenario, the present work describes the Markyt Web-based document curation platform, which has been implemented to support the visualisation, prediction and benchmark of chemical and gene mention annotations at BioCreative/CHEMDNER challenge. Creating this platform is an important step for the systematic and public evaluation of automatic prediction systems and the reusability of the knowledge compiled for the challenge. Markyt was not only critical to support the manual annotation and annotation revision process but also facilitated the comparative visualisation of automated results against the manually generated Gold Standard annotations and comparative assessment of generated results. We expect that future biomedical text mining challenges and the text mining community may benefit from the Markyt platform to better explore and interpret annotations and improve automatic system predictions.Database URL: http://www.markyt.org, https://github.com/sing-group/Markyt. PMID:27542845

  5. Evaluation of Consumer Product Co-occurrence to Inform Chemical Exposure

    Science.gov (United States)

    Consumer products are an important target of chemical innovation. Used daily for personal hygiene, home care, disinfection and cleaning, consumer products provide a host of benefits, and also an efficient delivery vehicle for a variety of chemicals into our homes and bodies. Al...

  6. Evaluating exposures to complex mixtures of chemicals during a new production process in the plastics industry

    NARCIS (Netherlands)

    Meijster, T.; Burstyn, I.; Wendel de Joode, B. van; Posthumus, M.A.; Kromhout, H.

    2004-01-01

    The goal of this study was to monitor emission of chemicals at a factory where plastics products were fabricated by a new robotic (impregnated tape winding) production process. Stationary and personal air measurements were taken to determine which chemicals were released and at what concentrations.

  7. Institutional review board challenges related to community-based participatory research on human exposure to environmental toxins: A case study

    Directory of Open Access Journals (Sweden)

    Rudel Ruthann A

    2010-07-01

    Full Text Available Abstract Background We report on the challenges of obtaining Institutional Review Board (IRB coverage for a community-based participatory research (CBPR environmental justice project, which involved reporting biomonitoring and household exposure results to participants, and included lay participation in research. Methods We draw on our experiences guiding a multi-partner CBPR project through university and state Institutional Review Board reviews, and other CBPR colleagues' written accounts and conference presentations and discussions. We also interviewed academics involved in CBPR to learn of their challenges with Institutional Review Boards. Results We found that Institutional Review Boards are generally unfamiliar with CBPR, reluctant to oversee community partners, and resistant to ongoing researcher-participant interaction. Institutional Review Boards sometimes unintentionally violate the very principles of beneficence and justice which they are supposed to uphold. For example, some Institutional Review Boards refuse to allow report-back of individual data to participants, which contradicts the CBPR principles that guide a growing number of projects. This causes significant delays and may divert research and dissemination efforts. Our extensive education of our university Institutional Review Board convinced them to provide human subjects protection coverage for two community-based organizations in our partnership. Conclusions IRBs and funders should develop clear, routine review guidelines that respect the unique qualities of CBPR, while researchers and community partners can educate IRB staff and board members about the objectives, ethical frameworks, and research methods of CBPR. These strategies can better protect research participants from the harm of unnecessary delays and exclusion from the research process, while facilitating the ethical communication of study results to participants and communities.

  8. Worker exposures to chemical agents in the manufacture of rubber tires: solvent vapor studies.

    Science.gov (United States)

    Van Ert, M D; Arp, E W; Harris, R L; Symons, M J; Williams, T M

    1980-03-01

    Environmental sampling surveys have been conducted in ten large tire manufacturing plants across the U.S. to characterize the nature and intensity of current exposure to solvent vapors. These plants were chosen to represent a cross-section of the industry and include both old and new plants, plants of four different companies and plants with wide geographic distributions. A variety of organic solvents is used in the manufacture of tires and tubes; accordingly solvent vapors comprise one category of exposure for workers in specific Occupational Title Groups (OTGs). Approximately 1000 determinations of various solvent vapor components in air samples have been made with special emphasis on pentane, hexane, heptane, benzene and toluene vapor levels. Exposures stem from the widespread use of bulk materials including petroleum naphthas, gasoline and aliphatic and rubber solvents in various tire manufacturing operations. PMID:7395732

  9. Burden of disease and costs of exposure to endocrine disrupting chemicals in the European Union: an updated analysis.

    Science.gov (United States)

    Trasande, L; Zoeller, R T; Hass, U; Kortenkamp, A; Grandjean, P; Myers, J P; DiGangi, J; Hunt, P M; Rudel, R; Sathyanarayana, S; Bellanger, M; Hauser, R; Legler, J; Skakkebaek, N E; Heindel, J J

    2016-07-01

    A previous report documented that endocrine disrupting chemicals contribute substantially to certain forms of disease and disability. In the present analysis, our main objective was to update a range of health and economic costs that can be reasonably attributed to endocrine disrupting chemical exposures in the European Union, leveraging new burden and disease cost estimates of female reproductive conditions from accompanying report. Expert panels evaluated the epidemiologic evidence, using adapted criteria from the WHO Grading of Recommendations Assessment, Development and Evaluation Working Group, and evaluated laboratory and animal evidence of endocrine disruption using definitions recently promulgated by the Danish Environmental Protection Agency. The Delphi method was used to make decisions on the strength of the data. Expert panels consensus was achieved for probable (>20%) endocrine disrupting chemical causation for IQ loss and associated intellectual disability; autism; attention deficit hyperactivity disorder; endometriosis; fibroids; childhood obesity; adult obesity; adult diabetes; cryptorchidism; male infertility, and mortality associated with reduced testosterone. Accounting for probability of causation, and using the midpoint of each range for probability of causation, Monte Carlo simulations produced a median annual cost of €163 billion (1.28% of EU Gross Domestic Product) across 1000 simulations. We conclude that endocrine disrupting chemical exposures in the EU are likely to contribute substantially to disease and dysfunction across the life course with costs in the hundreds of billions of Euros per year. These estimates represent only those endocrine disrupting chemicals with the highest probability of causation; a broader analysis would have produced greater estimates of burden of disease and costs. PMID:27003928

  10. Estimation of Apple Intake for the Exposure Assessment of Residual Chemicals Using Korea National Health and Nutrition Examination Survey Database

    Science.gov (United States)

    2016-01-01

    The aims of this study were to develop strategies and algorithms of calculating food commodity intake suitable for exposure assessment of residual chemicals by using the food intake database of Korea National Health and Nutrition Examination Survey (KNHANES). In this study, apples and their processed food products were chosen as a model food for accurate calculation of food commodity intakes uthrough the recently developed Korea food commodity intake calculation (KFCIC) software. The average daily intakes of total apples in Korea Health Statistics were 29.60 g in 2008, 32.40 g in 2009, 34.30 g in 2010, 28.10 g in 2011, and 24.60 g in 2012. The average daily intakes of apples by KFCIC software was 2.65 g higher than that by Korea Health Statistics. The food intake data in Korea Health Statistics might have less reflected the intake of apples from mixed and processed foods than KFCIC software has. These results can affect outcome of risk assessment for residual chemicals in foods. Therefore, the accurate estimation of the average daily intake of food commodities is very important, and more data for food intakes and recipes have to be applied to improve the quality of data. Nevertheless, this study can contribute to the predictive estimation of exposure to possible residual chemicals and subsequent analysis for their potential risks. PMID:27152299

  11. Low accessibility and chemical activity of PAHs restrict bioremediation and risk of exposure in a manufactured gas plant soil

    Energy Technology Data Exchange (ETDEWEB)

    Reichenberg, Fredrik; Karlson, Ulrich Gosewinkel [Department of Environmental Chemistry and Microbiology, National Environmental Research Institute, Aarhus University, P.O. Box 358, 4000 Roskilde (Denmark); Gustafsson, Orjan [Stockholm University, Department of Applied Environmental Science (ITM), 10691 Stockholm (Sweden); Long, Sara M. [Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS (United Kingdom); Pritchard, Parmely H. [Department of Environmental Chemistry and Microbiology, National Environmental Research Institute, Aarhus University, P.O. Box 358, 4000 Roskilde (Denmark); Department of Biology, Portland State University, PO Box 751, Portland, OR 97207 (United States); Mayer, Philipp, E-mail: phm@dmu.d [Department of Environmental Chemistry and Microbiology, National Environmental Research Institute, Aarhus University, P.O. Box 358, 4000 Roskilde (Denmark)

    2010-05-15

    Composting of manufactured gas plant soil by a commercial enterprise had removed most of its polycyclic aromatic hydrocarbons (PAHs), but concentrations remained above regulatory threshold levels. Several amendments and treatments were first tested to restart the PAH degradation, albeit with little success. The working hypothesis was then that PAHs were 'stuck' due to strong sorption to black carbon. Accessibility was measured with cyclodextrin extractions and on average only 4% of the PAHs were accessible. Chemical activity of the PAHs was measured by equilibrium sampling, which confirmed a low exposure level. These results are consistent with strong sorption to black carbon (BC), which constituted 59% of the total organic carbon. Composting failed to remove the PAHs, but it succeeded to minimize PAH accessibility and chemical activity. This adds to accumulating evidence that current regulatory thresholds based on bulk concentrations are questionable and alternative approaches probing actual risk should be considered. - Bioremediation of MGP soil failed to eliminate PAHs but it succeeded to limit their accessibility, chemical activity and the remaining risk of biological exposure.

  12. Environmental monitoring and assessment of short-term exposures to hazardous chemicals of a sterilization process in hospital working environments.

    Directory of Open Access Journals (Sweden)

    Koda S

    1999-10-01

    Full Text Available In order to assess short-term exposures to ethylene oxide, formaldehyde and glutaraldehyde in a sterilization process, the authors conducted continuous environmental monitoring of these chemicals in the breathing zone of workers in 2 hospitals. The arithmetic mean of ethylene oxide was 1.2 ppm near unventilated cabinets housing sterilizing materials, and environmental concentrations of ethylene oxide could not be reduced under threshold limit values time weighted average by only managing general ventilation. Environmental concentration of formaldehyde was lower in a properly ventilated pathology division in which no large specimens were stored (0.3 ppm than in the pathology division where large specimens were stored (2.3 ppm. Although environmental concentrations of glutaraldehyde in an endoscopy unit with proper general ventilation were not detectable, environmental concentration levels in an endoscopy unit without general ventilation system were 0.2 and 0.5 ppm. According to the results of environmental monitoring in the breathing zone of workers, extremely high concentrations were observed in some work practices (ethylene oxide, 300 ppm; formaldehyde, 8.6 ppm; glutaraldehyde, 2.6 ppm. In order to avoid occupational exposures to these chemicals and prevent potential chronic and acute health hazards, good communications with these chemicals, good work practices, appropriate personal protective equipment, and engineering controls should be required.

  13. Low accessibility and chemical activity of PAHs restrict bioremediation and risk of exposure in a manufactured gas plant soil

    International Nuclear Information System (INIS)

    Composting of manufactured gas plant soil by a commercial enterprise had removed most of its polycyclic aromatic hydrocarbons (PAHs), but concentrations remained above regulatory threshold levels. Several amendments and treatments were first tested to restart the PAH degradation, albeit with little success. The working hypothesis was then that PAHs were 'stuck' due to strong sorption to black carbon. Accessibility was measured with cyclodextrin extractions and on average only 4% of the PAHs were accessible. Chemical activity of the PAHs was measured by equilibrium sampling, which confirmed a low exposure level. These results are consistent with strong sorption to black carbon (BC), which constituted 59% of the total organic carbon. Composting failed to remove the PAHs, but it succeeded to minimize PAH accessibility and chemical activity. This adds to accumulating evidence that current regulatory thresholds based on bulk concentrations are questionable and alternative approaches probing actual risk should be considered. - Bioremediation of MGP soil failed to eliminate PAHs but it succeeded to limit their accessibility, chemical activity and the remaining risk of biological exposure.

  14. ESC resistance of commercial grade polycarbonates during exposure to butter and related chemicals

    DEFF Research Database (Denmark)

    Kjellander, Carina Koch; Nielsen, Tenna B; Ghanbari-Siahkali, Afshin;

    2008-01-01

    Three commercial grades of polycarbonates (Lexan (R) 144, Lexan (R) 104 and Makrolon Rx1805) were studied with respect to resistance to environmental stress cracking (ESC) when exposed to butter and related chemicals. The polycarbonates (PCs) were extensively characterised to determine whether...... differences in ESC resistance could be related to their structural or chemical properties. MALDI-TOF mass spectrometry revealed that Makrolon Rx:1805 contains a low molar mass material characterised as poly(propylene glycol)p, which was confirmed by ATR-FTIR and H-1 NMR. Some "non-absorbing" chemicals, such...

  15. Current Challenges in Development of a Database of Three-Dimensional Chemical Structures.

    Science.gov (United States)

    Maeda, Miki H

    2015-01-01

    We are developing a database named 3DMET, a three-dimensional structure database of natural metabolites. There are two major impediments to the creation of 3D chemical structures from a set of planar structure drawings: the limited accuracy of computer programs and insufficient human resources for manual curation. We have tested some 2D-3D converters to convert 2D structure files from external databases. These automatic conversion processes yielded an excessive number of improper conversions. To ascertain the quality of the conversions, we compared IUPAC Chemical Identifier and canonical SMILES notations before and after conversion. Structures whose notations correspond to each other were regarded as a correct conversion in our present work. We found that chiral inversion is the most serious factor during the improper conversion. In the current stage of our database construction, published books or articles have been resources for additions to our database. Chemicals are usually drawn as pictures on the paper. To save human resources, an optical structure reader was introduced. The program was quite useful but some particular errors were observed during our operation. We hope our trials for producing correct 3D structures will help other developers of chemical programs and curators of chemical databases. PMID:26075200

  16. Effect of oxidant concentration, exposure time, and seed particles on secondary organic aerosol chemical composition and yield

    Directory of Open Access Journals (Sweden)

    A. T. Lambe

    2015-03-01

    This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of sulfate seed particles on isoprene SOA yield measurements was examined in the flow reactor. The studies show that seed particles increase the yield of SOA produced in flow reactors by a factor of 3 to 5 and may also account in part for higher SOA yields obtained in the chambers, where seed particles are routinely used.

  17. Modelling effects of chemical exposure on birds wintering in agricultural landscapes: The western burrowing owl (Athene cunicularia hypugaea) as a case study

    Science.gov (United States)

    Engelman, Catherine A.; Grant, William E.; Mora, Miguel A.; Woodin, Marc

    2012-01-01

    We describe an ecotoxicological model that simulates the sublethal and lethal effects of chronic, low-level, chemical exposure on birds wintering in agricultural landscapes. Previous models estimating the impact on wildlife of chemicals used in agro-ecosystems typically have not included the variety of pathways, including both dermal and oral, by which individuals are exposed. The present model contains four submodels simulating (1) foraging behavior of individual birds, (2) chemical applications to crops, (3) transfers of chemicals among soil, insects, and small mammals, and (4) transfers of chemicals to birds via ingestion and dermal exposure. We demonstrate use of the model by simulating the impacts of a variety of commonly used herbicides, insecticides, growth regulators, and defoliants on western burrowing owls (Athene cunicularia hypugaea) that winter in agricultural landscapes in southern Texas, United States. The model generated reasonable movement patterns for each chemical through soil, water, insects, and rodents, as well as into the owl via consumption and dermal absorption. Sensitivity analysis suggested model predictions were sensitive to uncertainty associated with estimates of chemical half-lives in birds, soil, and prey, sensitive to parameters associated with estimating dermal exposure, and relatively insensitive to uncertainty associated with details of chemical application procedures (timing of application, amount of drift). Nonetheless, the general trends in chemical accumulations and the relative impacts of the various chemicals were robust to these parameter changes. Simulation results suggested that insecticides posed a greater potential risk to owls of both sublethal and lethal effects than do herbicides, defoliants, and growth regulators under crop scenarios typical of southern Texas, and that use of multiple indicators, or endpoints provided a more accurate assessment of risk due to agricultural chemical exposure. The model should prove

  18. Evaluating chemical exposure and effect models for aquatic species with a focus on crude oil constituents

    NARCIS (Netherlands)

    Hoop, L. de

    2016-01-01

    The aim of this PhD thesis is to evaluate a suite of exposure and effect models on their applicability in ecological risk assessment for aquatic species and ecosystems. The focus is on oil constituents, as it is largely unknown whether current ecological models are applicable to crude oil and its co

  19. Fish Analysis - a Sensitive Method for Occupational Exposure to Chemical Carcinogens

    Czech Academy of Sciences Publication Activity Database

    Šrám, Radim; Beskid, Olena; Binková, Blanka; Rössner st., Pavel; Rubeš, Jiří

    Alberta : organising comittee, 2001. s. -. [International Symposium on Biological Monitoring in Occupational & Environmental Health. 18.09.2001-21.09.2001, Alberta] Institutional research plan: CEZ:AV0Z5039906 Keywords : biomonitoring * occupational exposure Subject RIV: DN - Health Impact of the Environment Quality

  20. Male Reproductive Disorders, Diseases, and Costs of Exposure to Endocrine-Disrupting Chemicals in the European Union

    DEFF Research Database (Denmark)

    Hauser, Russ; Skakkebaek, Niels E.; Hass, Ulla;

    2015-01-01

    Introduction: Increasing evidence suggests that endocrine-disrupting chemicals (EDCs) contribute to male reproductive diseases and disorders. Purpose: To estimate the incidence/prevalence of selected male reproductive disorders/diseases and associated economic costs that can be reasonably......-old men due to phthalate exposure, with 24 800 associated deaths annually and lost economic productivity of (sic)7.96 billion. Conclusions: EDCs may contribute substantially to male reproductive disorders and diseases, with nearly (sic)15 billion annual associated costs in the EU. These estimates...

  1. Human health risk assessment of exposure to environmental pollutants in the chemical / petrochemical industrial area of Tarragona (Catalonia, Spain)

    OpenAIRE

    Nadal Lomas, Martí

    2005-01-01

    Tesi: Human health risk assessment of exposure to environmental pollutants in the chemical/petrochemical industrial area of Tarragona (Catalonia, Spain).Autor: Martí NadalResum:Un dels complexos químics/ petroquímics més importants del sud d'Europa està ubicat a Tarragona. En els darrers anys, ha augmentat la preocupació pública envers els possibles efectes adversos que el complex industrial podria tenir per a la salut de la població resident a Tarragona. En resposta, el 2002 s'inicià un estu...

  2. Effects of Long Term Thermal Exposure on Chemically Pure (CP) Titanium Grade 2 Room Temperature Tensile Properties and Microstructure

    Science.gov (United States)

    Ellis, David L.

    2007-01-01

    Room temperature tensile testing of Chemically Pure (CP) Titanium Grade 2 was conducted for as-received commercially produced sheet and following thermal exposure at 550 and 650 K for times up to 5,000 h. No significant changes in microstructure or failure mechanism were observed. A statistical analysis of the data was performed. Small statistical differences were found, but all properties were well above minimum values for CP Ti Grade 2 as defined by ASTM standards and likely would fall within normal variation of the material.

  3. The Findings of HRCT of the Lung in Chemical Warfare Veterans with Previous Sulfur Mustard (SM Gas Exposure

    Directory of Open Access Journals (Sweden)

    Saeed Naghibi

    2009-01-01

    Full Text Available "nIntroduction: To identify the findings of High-Resolution Computed Tomography (HRCT of the lung in chemical warfare veterans with previous sulfur mustard (SM gas exposure. "nMaterials and Methods: 93 patients were studied prospectively 22 years after exposure. Demographic and clinical data were recorded. HRCT of the lung was performed during expiration and was reported double blinded by two radiologists. HRCT findings include air trapping, mosaic attenuation, ground glass attenuation, nodules, signet ring, fibrosis, bronchial wall thickening, bronchodilation, tree in bud, interlobular wall thickening, bulla, cavity, air consolidation, honey comb and mediastinal and pleural abnormalities that were analyzed. Final diagnosis was identified according to HRCT findings. The relation between HRCT findings, final diagnosis and the distribution of the abnormalities with duration after exposure were evaluated. Distribution of each finding was also evaluated. "nb The most frequent HRCT finding was air trapping (56.7%. Other common findings were mosaic attenuation (35.1%, ground glass attenuation (20.6%, nodules (17.5%, signet ring (15.5% and fibrosis(12.4%. Distribution of the abnormalities were mostly local (79.4% and bilateral (73%. Abnormalities were mostly in the lower lobe (61.3%. No significant correlation was found between the HRCT findings and the duration after exposure or distribution of the abnormalities. The respiratory complications diagnosed according to HRCT included bronchiolitis obliterans (43%, chronic obstructive pulmonary disease (COPD (27.9%, asthma (23.6%, bronchiectasis (13.9%, interstitial lung disease (ILD (9.6%. All abnormalities were seen more frequently in patients with lesser duration of exposure.( P-value < 0.05. "nConclusion: Focal bilateral air trapping was the most common finding seen in expiratory HRCT in this study, and it is highly suggestive of bronchiolitis obliterance (BO. BO can be a late complication of SM

  4. Challenging conventional risk assessment with respect to human exposure to multiple food contaminants in food: A case study using maize.

    Science.gov (United States)

    Clarke, R; Connolly, L; Frizzell, C; Elliott, C T

    2015-10-01

    Mycotoxins and heavy metals are ubiquitous in the environment and contaminate many foods. The widespread use of pesticides in crop production to control disease contributes further to the chemical contamination of foods. Thus multiple chemical contaminants threaten the safety of many food commodities; hence the present study used maize as a model crop to identify the severity in terms of human exposure when multiple contaminants are present. High Content Analysis (HCA) measuring multiple endpoints was used to determine cytotoxicity of complex mixtures of mycotoxins, heavy metals and pesticides. Endpoints included nuclear intensity (NI), nuclear area (NA), plasma membrane permeability (PMP), mitochondrial membrane potential (MMP) and mitochondrial mass (MM). At concentrations representing legal limits of each individual contaminant in maize (3ng/ml ochratoxin A (OTA), 1μg/ml fumonisin B1 (FB1), 2ng/ml aflatoxin B1 (AFB1), 100ng/ml cadmium (Cd), 150ng/ml arsenic (As), 50ng/ml chlorpyrifos (CP) and 5μg/ml pirimiphos methyl (PM), the mixtures (tertiary mycotoxins plus Cd/As) and (tertiary mycotoxins plus Cd/As/CP/PM) were cytotoxic for NA and MM endpoints with a difference of up to 13.6% (p≤0.0001) and 12% (p≤0.0001) respectively from control values. The most cytotoxic mixture was (tertiary mycotoxins plus Cd/As/CP/PM) across all 4 endpoints (NA, NI, MM and MMP) with increases up to 61.3%, 23.0%, 61.4% and 36.3% (p≤0.0001) respectively. Synergy was evident for two endpoints (NI and MM) at concentrations contaminating maize above legal limits, with differences between expected and measured values of (6.2-12.4% (p≤0.05-p≤0.001) and 4.5-12.3% (p≤0.05-p≤0.001) for NI and MM, respectively. The study introduces for the first time, a holistic approach to identify the impact in terms of toxicity to humans when multiple chemical contaminants are present in foodstuffs. Governmental regulatory bodies must begin to contemplate how to safeguard the population when

  5. Potential Challenges Faced by the U.S. Chemicals Industry under a Carbon Policy

    Directory of Open Access Journals (Sweden)

    Andrea Bassi

    2009-09-01

    Full Text Available Chemicals have become the backbone of manufacturing within industrialized economies. Being energy-intensive materials to produce, this sector is threatened by policies aimed at combating and adapting to climate change. This study examines the worst-case scenario for the U.S. chemicals industry when a medium CO2 price policy is employed. After examining possible industry responses, the study goes on to identify and provide a preliminary evaluation of potential opportunities to mitigate these impacts. If climate regulations are applied only in the United States, and no action is taken to invest in advanced low- and no-carbon technologies to mitigate the impacts of rising energy costs, the examination shows that climate policies that put a price on carbon could have substantial impacts on the competiveness of the U.S. chemicals industry over the next two decades. In the long run, there exist technologies that are available to enable the chemicals sector to achieve sufficient efficiency gains to offset and manage the additional energy costs arising from a climate policy.

  6. Harmonisation of food consumption data format for dietary exposure assessments of chemicals analysed in raw agricultural commodities

    DEFF Research Database (Denmark)

    Boon, Polly E.; Ruprich, Jiri; Petersen, Annette;

    2009-01-01

    in RACs at a European level. In this approach, consumption data needs to be converted to edible part of RAC (e-RAC) level using a RAC conversion database. To subsequently use this data in exposure assessments, both e-RACs and RACs analysed in chemical control programmes should be classified via a...... uniform system. Furthermore, chemical concentrations in RACs may need to be converted to e-RAC level using processing factors. To illustrate the use of this approach, we describe how the Dutch RAC conversion database was used to convert consumption data of four national consumption surveys to e-RAC level......, and the use of the FAO/WHO Codex Classification system of Foods and Animal Feeds to harmonise the classification. We demonstrate that this approach works well for pesticides and glycoalkaloids, and is an essential step forward in the harmonisation of risk assessment procedures within Europe when...

  7. The Role of Epigenetics in the Latent Effects of Early Life Exposure to Obesogenic Endocrine Disrupting Chemicals.

    Science.gov (United States)

    Stel, Jente; Legler, Juliette

    2015-10-01

    Recent research supports a role for exposure to endocrine-disrupting chemicals (EDCs) in the global obesity epidemic. Obesogenic EDCs have the potential to inappropriately stimulate adipogenesis and fat storage, influence metabolism and energy balance and increase susceptibility to obesity. Developmental exposure to obesogenic EDCs is proposed to interfere with epigenetic programming of gene regulation, partly by activation of nuclear receptors, thereby influencing the risk of obesity later in life. The goal of this minireview is to briefly describe the epigenetic mechanisms underlying developmental plasticity and to evaluate the evidence of a mechanistic link between altered epigenetic gene regulation by early life EDC exposure and latent onset of obesity. We summarize the results of recent in vitro, in vivo, and transgenerational studies, which clearly show that the obesogenic effects of EDCs such as tributyltin, brominated diphenyl ether 47, and polycyclic aromatic hydrocarbons are mediated by the activation and associated altered methylation of peroxisome proliferator-activated receptor-γ, the master regulator of adipogenesis, or its target genes. Importantly, studies are emerging that assess the effects of EDCs on the interplay between DNA methylation and histone modifications in altered chromatin structure. These types of studies coupled with genome-wide rather than gene-specific analyses are needed to improve mechanistic understanding of epigenetic changes by EDC exposure. Current advances in the field of epigenomics have led to the first potential epigenetic markers for obesity that can be detected at birth, providing an important basis to determine the effects of developmental exposure to obesogenic EDCs in humans. PMID:26241072

  8. Social disparities in exposures to bisphenol A and polyfluoroalkyl chemicals: a cross-sectional study within NHANES 2003-2006

    Directory of Open Access Journals (Sweden)

    Nelson Jessica W

    2012-03-01

    Full Text Available Abstract Background Bisphenol A (BPA and polyfluoroalkyl chemicals (PFCs are suspected endocrine disrupting compounds known to be ubiquitous in people's bodies. Population disparities in exposure to these chemicals have not been fully characterized. Methods We analyzed data from the 2003-2006 National Health and Nutrition Examination Survey. Using multivariable linear regression we examined the association between urinary concentrations of BPA, serum concentrations of four PFCs, and multiple measures of socioeconomic position (SEP: family income, education, occupation, and food security. We also examined associations with race/ethnicity. Results All four PFCs were positively associated with family income, whereas BPA was inversely associated with family income. BPA concentrations were higher in people who reported very low food security and received emergency food assistance than in those who did not. This association was particularly strong in children: 6-11 year-olds whose families received emergency food had BPA levels 54% higher (95% CI, 13 to 112% than children of families who did not. For BPA and PFCs we saw smaller and less consistent associations with education and occupation. Mexican Americans had the lowest concentrations of any racial/ethnic group of both types of chemicals; for PFCs, Mexican Americans not born in the U.S. had much lower levels than those born in the U.S. Conclusions People with lower incomes had higher body burdens of BPA; the reverse was true for PFCs. Family income with adjustment for family size was the strongest predictor of chemical concentrations among the different measures of SEP we studied. Income, education, occupation, and food security appear to capture different aspects of SEP that may be related to exposure to BPA and PFCs and are not necessarily interchangeable as measures of SEP in environmental epidemiology studies. Differences by race/ethnicity were independent of SEP.

  9. The challenge of plurilingual competence: analysis and teaching tools from the chemical engineering

    OpenAIRE

    Alsina Aubach, Montserrat; Heras Cisa, F. Xavier de las; Lao Luque, Concepción; Gamisans Noguera, Javier

    2012-01-01

    The European Institutions have the challenge and the commitment to enhance plurilingual competence, and teaching curricular subjects in a foreign language is seen as one of the most promising alternatives. However, teaching in a foreign language doesn’t mean just to translate contents, when the quality of the specific subject wants to be guaranteed. Some arrangements are necessary in order to balance the achievement of both, specific and linguistic competences. In ...

  10. Domestic exposure to indoor air chemical pollutants : modeled exposure related to respiratory health effects in infancy : findings from the PARIS (Pollution and Asthma Risk an Infant Study) birth cohort

    OpenAIRE

    Roda, Célina

    2012-01-01

    There is a growing public health concern about indoor air quality due to the time spent indoors and the presence of numerous biological and chemical pollutants. Aims: To assess indoor chemical pollutant levels, to model domestic exposure and to examine the impact of indoor chemical pollutants on the respiratory health of infants from the PARIS birth cohort, during their first year of life. Methods: Multiple self-administered questionnaires were used to gather information from parents about re...

  11. Is case-based learning an effective teaching strategy to challenge students' alternative conceptions regarding chemical kinetics?

    Science.gov (United States)

    Yalçınkaya, Eylem; Taştan-Kırık, Özgecan; Boz, Yezdan; Yıldıran, Demet

    2012-07-01

    Background: Case-based learning (CBL) is simply teaching the concept to the students based on the cases. CBL involves a case, which is a scenario based on daily life, and study questions related to the case, which allows students to discuss their ideas. Chemical kinetics is one of the most difficult concepts for students in chemistry. Students have generally low levels of conceptual understanding and many alternative conceptions regarding it. Purpose: This study aimed to explore the effect of CBL on dealing with students' alternative conceptions about chemical kinetics. Sample: The sample consists of 53 high school students from one public high school in Turkey. Design and methods : Nonequivalent pre-test and post-test control group design was used. Reaction Rate Concept Test and semi-structured interviews were used for data collection. Convenience sampling technique was followed. For data analysis, the independent samples t-test and ANOVA was performed. Results : Both concept test and interview results showed that students instructed with cases had better understanding of core concepts of chemical kinetics and had less alternative conceptions related to the subject matter compared to the control group students, despite the fact that it was impossible to challenge all the alternative conceptions in the experimental group. Conclusions: CBL is an effective teaching method for challenging students' alternative conceptions in the context of chemical kinetics. Since using cases in small groups and whole class discussions has been found to be an effective way to cope with the alternative conceptions, it can be applied to other subjects and grade levels in high schools with a higher sample size. Furthermore, the effect of this method on academic achievement, motivation and critical thinking skills are other variables that can be investigated for future studies in the subject area of chemistry.

  12. Can Exposure to Environmental Chemicals Increase the Risk of Diabetes Type 1 Development?

    OpenAIRE

    Johanna Bodin; Lars Christian Stene; Unni Cecilie Nygaard

    2015-01-01

    Type 1 diabetes mellitus (T1DM) is an autoimmune disease, where destruction of beta-cells causes insulin deficiency. The incidence of T1DM has increased in the last decades and cannot entirely be explained by genetic predisposition. Several environmental factors are suggested to promote T1DM, like early childhood enteroviral infections and nutritional factors, but the evidence is inconclusive. Prenatal and early life exposure to environmental pollutants like phthalates, bisphenol A, perfluori...

  13. The Effect of Perfluorooctane Sulfonate, Exposure Time, and Chemical Mixtures on Methanogenic Community Structure and Function

    OpenAIRE

    McNamara, Patrick J.; LaPara, Timothy M.; Novak, Paige J

    2015-01-01

    A plethora of organic micropollutant mixtures are found in untreated municipal wastewater. Anaerobic digesters receive large loadings of hydrophobic micropollutants that sorb to wastewater biosolids. Despite micropollutants being pervasive as mixtures, little research is available to explain the impact that mixtures of compounds, as well as exposure time, have on microbial communities in anaerobic digesters. Perfluorooctane sulfonate (PFOS) was added to anaerobic enrichment cultures in both s...

  14. Irritancy and allergic responses induced by exposure to the indoor air chemical 4-oxopentanal.

    Science.gov (United States)

    Anderson, Stacey E; Franko, Jennifer; Jackson, Laurel G; Wells, J R; Ham, Jason E; Meade, B J

    2012-06-01

    Over the last two decades, there has been an increasing awareness regarding the potential impact of indoor air pollution on human health. People working in an indoor environment often experience symptoms such as eye, nose, and throat irritation. Investigations into these complaints have ascribed the effects, in part, to compounds emitted from building materials, cleaning/consumer products, and indoor chemistry. One suspect indoor air contaminant that has been identified is the dicarbonyl 4-oxopentanal (4-OPA). 4-OPA is generated through the ozonolysis of squalene and several high-volume production compounds that are commonly found indoors. Following preliminary workplace sampling that identified the presence of 4-OPA, these studies examined the inflammatory and allergic responses to 4-OPA following both dermal and pulmonary exposure using a murine model. 4-OPA was tested in a combined local lymph node assay and identified to be an irritant and sensitizer. A Th1-mediated hypersensitivity response was supported by a positive response in the mouse ear swelling test. Pulmonary exposure to 4-OPA caused a significant elevation in nonspecific airway hyperreactivity, increased numbers of lung-associated lymphocytes and neutrophils, and increased interferon-γ production by lung-associated lymph nodes. These results suggest that both dermal and pulmonary exposure to 4-OPA may elicit irritant and allergic responses and may help to explain some of the adverse health effects associated with poor indoor air quality. PMID:22403157

  15. Differentially expressed genes of Coptotermes formosanus (Isoptera: Rhinotermitidae) challenged by chemical insecticides.

    Science.gov (United States)

    Zhang, Yi; Zhao, Yuanyuan; Qiu, Xuehong; Han, Richou

    2013-08-01

    Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) termites are harmful social insects to wood constructions. The current control methods heavily depend on the chemical insecticides with increasing resistance. Analysis of the differentially expressed genes mediated by chemical insecticides will contribute to the understanding of the termite resistance to chemicals and to the establishment of alternative control measures. In the present article, a full-length cDNA library was constructed from the termites induced by a mixture of commonly used insecticides (0.01% sulfluramid and 0.01% triflumuron) for 24 h, by using the RNA ligase-mediated Rapid Amplification cDNA End method. Fifty-eight differentially expressed clones were obtained by polymerase chain reaction and confirmed by dot-blot hybridization. Forty-six known sequences were obtained, which clustered into 33 unique sequences grouped in 6 contigs and 27 singlets. Sixty-seven percent (22) of the sequences had counterpart genes from other organisms, whereas 33% (11) were undescribed. A Gene Ontology analysis classified 33 unique sequences into different functional categories. In general, most of the differential expression genes were involved in binding and catalytic activity. PMID:24020304

  16. Hypothesis: exposure to endocrine-disrupting chemicals may interfere with timing of puberty

    DEFF Research Database (Denmark)

    Mouritsen, A; Aksglaede, L; Sørensen, K; Mogensen, S Sloth; Leffers, H; Main, K M; Frederiksen, H; Andersson, A-M; Skakkebaek, N E; Juul, A

    2010-01-01

    increasing prevalence of adiposity may contribute, but environmental factors are also likely to be involved. In particular, the widespread presence of endocrine-disrupting chemicals (EDCs) is suspected to contribute to the trend of earlier pubertal onset. The factors regulating the physiological onset of...

  17. Gloves and dermal exposure to chemicals: Proposals for evaluating workplace effectiveness

    NARCIS (Netherlands)

    Cherrie, J.W.; Semple, S.; Brouwer, D.

    2004-01-01

    There are standardized laboratory tests for chemical protective gloves that provide estimates of breakthrough time and steady-state permeation flux. However, there is evidence to suggest that these tests may not be completely relevant to glove usage in the workplace. There is no consensus about how

  18. 76 FR 25376 - Occupational Exposure to Hazardous Chemicals in Laboratories Standard; Extension of the Office of...

    Science.gov (United States)

    2011-05-04

    ... Paperwork Reduction Act of 1995 (44 U.S.C. 3506 et seq.) and Secretary of Labor's Order No. 5-2010 (75 FR... by developing a written Chemical Hygiene Plan (CHP) that describes: Standard operating procedures for... activities before implementation; and medical consultations and examinations. The CHP also...

  19. 76 FR 72216 - Occupational Exposure to Hazardous Chemicals in Laboratories Standard; Extension of the Office of...

    Science.gov (United States)

    2011-11-22

    ... Paperwork Reduction Act of 1995 (44 U.S.C. 3506 et seq.) and Secretary of Labor's Order No. 4-2010 (75 FR... 1910, Subpart Z. They do so by developing a written Chemical Hygiene Plan (CHP) that describes standard... CHP also designates personnel responsible for implementing the CHP and specifies the procedures...

  20. Case–control study of breast cancer and exposure to synthetic environmental chemicals among Alaska Native women

    Directory of Open Access Journals (Sweden)

    Adrianne K. Holmes

    2014-11-01

    Full Text Available Background: Exposure to environmental chemicals may impair endocrine system function. Alaska Native (AN women may be at higher risk of exposure to these endocrine disrupting chemicals, which may contribute to breast cancer in this population. Objective: To measure the association between exposure to select environmental chemicals and breast cancer among AN women. Design: A case–control study of 170 women (75 cases, 95 controls recruited from the AN Medical Center from 1999 to 2002. Participants provided urine and serum samples. Serum was analyzed for 9 persistent pesticides, 34 polychlorinated biphenyl (PCB congeners, and 8 polybrominated diethyl ether (PBDE congeners. Urine was analyzed for 10 phthalate metabolites. We calculated geometric means (GM and compared cases and controls using logistic regression. Results: Serum concentrations of most pesticides and 3 indicator PCB congeners (PCB-138/158; PCB-153, PCB-180 were lower in case women than controls. BDE-47 was significantly higher in case women (GM=38.8 ng/g lipid than controls (GM=25.1 ng/g lipid (p=0.04. Persistent pesticides, PCBs, and most phthalate metabolites were not associated with case status in univariate logistic regression. The odds of being a case were higher for those with urinary mono-(2-ethylhexyl phthalate (MEHP concentrations that were above the median; this relationship was seen in both univariate (OR 2.16, 95% CI 1.16–4.05, p=0.02 and multivariable (OR 2.43, 95% CI 1.13–5.25, p=0.02 logistic regression. Women with oestrogen receptor (ER–/progesterone receptor (PR-tumour types tended to have higher concentrations of persistent pesticides than did ER+/PR+ women, although these differences were not statistically significant. Conclusions: Exposure to the parent compound of the phthalate metabolite MEHP may be associated with breast cancer. However, our study is limited by small sample size and an inability to control for the confounding effects of body mass index

  1. Agricultural chemical exposures and birth defects in the Eastern Cape Province, South Africa A case – control study

    Directory of Open Access Journals (Sweden)

    Tyler Joanne

    2003-10-01

    Full Text Available Abstract Background South Africa is one of the major users of pesticides on the African continent. The Eastern Cape is the second largest province in South Africa. There has been growing concern about the occurrence of certain birth defects which seemed to have increased in the past few years. In this paper we investigate associations between exposure to agricultural chemicals and certain birth defects. Few such studies have been undertaken in the developing world previously. Methods Between September 2000 and March 2001 a case – control study was conducted among rural women in the area of the Eastern cape to investigate the association between women's exposure to pesticides and the occurrence of birth defects. Information on birth defects was obtained from the register of the Paediatrics Department at the Cecilia Makiwane Hospital in Mdantsane, one of the largest referral hospitals in the province. The cases were children who were diagnosed with selected birth defects. The controls were children born in the same areas as the cases. Exposure information on the mothers was obtained by interview concerning from their activities in gardens and fields. Data were analysed using conditional logistic regression. Results A total of 89 case mothers and 178 control mothers was interviewed. Babies with birth defects were seven times more likely to be born to women exposed to chemicals used in gardens and fields compared to no reported exposure (Odds Ratio 7.18, 95% CI 3.99, 13.25; and were almost twice as likely to be born to women who were involved in dipping livestock used to prevent ticks (OR 1.92, 95% CI 1.15, 3.14. They were also 6.5 times more likely to be born to women who were using plastic containers for fetching water (OR 6.5, 95% CI 2.2, 27.9. Some of these containers had previously contained pesticides (OR 1.87, 95% CI 1.06, 3.31. Conclusions These findings suggest a link between exposure to pesticides and certain birth defects among the

  2. Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, J.D.

    1992-06-01

    This project seeks to defining the chromosome segments associated with radiation induced leukemogenesis (treatment-related acute myeloid leukemia, or t-AML). Towards these goals genetic analysis of human chromosomes 5 and 7 continues to investigate correlation of treatment with balanced and unbalanced chromosomal translocations. Progress is being made in cloning the breakpoints in balanced translocations in t-AML, that is to clone the t(9;11) and t(11;19) breakpoints, to clone the t(3;21)(q26;q22) breakpoints and to determine the relationship of these translocations to prior exposure to topoisomerase II inhibitors. 11 figs. 3 figs.

  3. Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation

    International Nuclear Information System (INIS)

    This project seeks to defining the chromosome segments associated with radiation induced leukemogenesis (treatment-related acute myeloid leukemia, or t-AML). Towards these goals genetic analysis of human chromosomes 5 and 7 continues to investigate correlation of treatment with balanced and unbalanced chromosomal translocations. Progress is being made in cloning the breakpoints in balanced translocations in t-AML, that is to clone the t(9;11) and t(11;19) breakpoints, to clone the t(3;21)(q26;q22) breakpoints and to determine the relationship of these translocations to prior exposure to topoisomerase II inhibitors. 11 figs. 3 figs

  4. Nuclear toxicology file: cell response to the steady or radioactive chemical elements exposure

    International Nuclear Information System (INIS)

    The cellular response to an exposure in a toxic element is made at different levels. The first level is the agent detoxication by its elimination or its neutralization. The second level is the repair of the damages caused by this agent (for example the DNA repair). The third level is the control of the cellular death programmed to eliminate the irreparably damaged cells.Finally, the hurt cell can inform the nearby cells by producing molecular effectors inducing an abscopal or bystander effect. (N.C.)

  5. Application of industrial hygiene techniques for work-place exposure assessment protocols related to petro-chemical exploration and production field activities

    International Nuclear Information System (INIS)

    Standard industrial hygiene techniques for recognition, evaluation, and control can be directly applied to development of technical protocols for workplace exposure assessment activities for a variety of field site locations. Categories of occupational hazards include chemical and physical agents. Examples of these types of hazards directly related to oil and gas exploration and production workplaces include hydrocarbons, benzene, oil mist, hydrogen sulfide, Naturally Occurring Radioactive Materials (NORM), asbestos-containing materials, and noise. Specific components of well process chemicals include potential hazardous chemical substances such as methanol, acrolein, chlorine dioxide, and hydrochloric acid. Other types of exposure hazards may result from non-routine conduct of sandblasting and painting operations

  6. Integrated risk analysis for acute and chronic exposure to toxic chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Gurjar, B.R.; Mohan, Manju

    2003-10-01

    The traditional practice to assess and evaluate different types of risk in isolation to each other are liable to give erroneous results. Integrated risk assessment is an answer to overcome this problem. This paper presents the cumulative or integrated assessment of acute risk posed by accidental release of hazardous chemical (e.g. chlorine) and chronic risk induced by toxic chemicals (e.g. cadmium, chromium and nickel) present in the ambient environment. The present study has been carried out in a most simplified way to demonstrate and appreciate the broader context of integrated risk analysis (IRA). It has been observed that the inclusion of background risk factors (BRF) in individual risk factors (IRF) related to an industry may significantly alter the siting and planning strategies of that industry.

  7. International issues on human health effects of exposure to chemical mixtures.

    OpenAIRE

    Feron, Victor J; Cassee, Flemming R; Groten, John P.; van Vliet, Petronella W; van Zorge, Job A

    2002-01-01

    In this article, we highlight new developments and recent studies concerning adverse human health effects related to chemical mixtures. One group of activities comprises the development of a new computer program for analyzing mixture studies and a mathematical model as a basis for combination rules that predict the toxicity of mixtures. Other new activities in the area of experimental studies are the application of gene expression technologies in mixture research, and pattern recognition as a...

  8. Chemicals in textiles : A potential source for human exposure and environmental pollution

    OpenAIRE

    Luongo, Giovanna

    2015-01-01

    The wide use of chemicals in textile production is common knowledge, whilst very little has been done to disclose the potentially harmful compounds hiding in our closet. The initial part of this work focused on explorative screening of textile materials in common clothing. Non-targeted analysis of a set of sixty garments revealed the presence of thousands of compounds, among which over a hundred were tentatively identified. Depending on the frequency of occurrence in textile, skin penetrating...

  9. Comparison of Chest HRCT in Inspiration and Expiration of patients with Chemical Gas Exposure

    OpenAIRE

    Kh. Bakhtavar

    2005-01-01

    Background/Objectives: Chemical weapon agents (CWA) including Sulfur Mustard (SM), were com-monly used in the Iran-Iraq war and pulmonary complications are known to occur in over half of the exposed patients. Previous studies showed that HRCT in inspiration was normal in most of the patients. In this study comparison between the HRCT findings in deep inspiration and full expiration was carried out. Materials and Method: HRCT in deep inspiration and full expiration in 473 patients with history...

  10. Chemical Process R&D for Pharmaceutical Industry in the New Millennium, Challenges and Opportunities

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tony Yantao; BINGHAM Alphus

    2001-01-01

    @@ The genomic revolution has offered scientists in the world with unprecedented number of targets and opportunities to eradicate human diseases. High throughput screening technology using enzymatic and receptor binding assays has shifted the bottleneck in drug discovery to the laboratories of chemistry. Recent upsurge of interest in combinatorial chemistry is a testimony to the urgency of increasing the efficiency of how drug-like molecules are made. What the implication of all these on chemical process research? If the Internet has revolutionized the distribution and of data, information, and knowledge, how can this powerful tool be utilized to harness the collective intellect of chemists all across the world? If the effort of a few thousands people was able to send men to the moon, can the cross-pollination of ideas from chemists all over the world, each of them thinking in his or her unique way, produce the most cost effective way of making a particular molecule, reduce pollution of a current process, or deliver a cure for cancer? We will examine the brief history of modern organic chemistry and provide some personal musings on different course one can take in the area of chemical process R&D.

  11. Chemical Process R&D for Pharmaceutical Industry in the New Millennium, Challenges and Opportunities

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Tony; Yantao

    2001-01-01

    The genomic revolution has offered scientists in the world with unprecedented number of targets and opportunities to eradicate human diseases. High throughput screening technology using enzymatic and receptor binding assays has shifted the bottleneck in drug discovery to the laboratories of chemistry. Recent upsurge of interest in combinatorial chemistry is a testimony to the urgency of increasing the efficiency of how drug-like molecules are made. What the implication of all these on chemical process research? If the Internet has revolutionized the distribution and of data, information, and knowledge, how can this powerful tool be utilized to harness the collective intellect of chemists all across the world? If the effort of a few thousands people was able to send men to the moon, can the cross-pollination of ideas from chemists all over the world, each of them thinking in his or her unique way, produce the most cost effective way of making a particular molecule, reduce pollution of a current process, or deliver a cure for cancer? We will examine the brief history of modern organic chemistry and provide some personal musings on different course one can take in the area of chemical process R&D.  ……

  12. Chronic radionuclide low dose exposure for non-human biota: challenges in establishing links between speciation in the exposure sources, bioaccumulation and biological effects. Uranium in aquatic ecosystems: A case-study

    International Nuclear Information System (INIS)

    In the field of environmental radioprotection, the knowledge gaps concern situations leading to chronic exposure at the lower doses typical of the living conditions of organisms influenced by radioactive releases. For any radionuclide and ecosystem, the specificities of these situations are as followed: (i) various chemical forms occur in the environment as a function of the physico-chemical conditions of the medium; (ii) each transfer from one component to another can lead to a modification of these forms with a 'chemical form-specific' mobility and bioavailability; (iii) different categories of non-radioactive toxicants are simultaneously present. In this multipollution context, the biological effects of ionising radiation may be exacerbated or reduced with the potential for action or interaction of all the pollutants present simultaneously. These situations of chronic exposure at low levels are likely to cause toxic responses distinct from those observed after acute exposure at high doses since long-term accumulation mechanisms in cells and tissues may lead to microlocalised accumulation in some target cells or subcellular components. The assessment of these mechanisms is primordial with regard to internal exposure to radionuclides since they increase locally both the radionuclide concentration and the delivered dose, coupling radiological and chemical toxicity. This is the main purpose of the ENVIRHOM research programme, recently launched at IRSN. After a global overview of the experimental strategy and of the first results obtained for phytoplankton and uranium, this paper scans the state of art for uranium within freshwaters and underlines inconsistency encountered when one wants to carry out an Ecological Risk Assessment (ERA) on the chemical or on the radiological standpoint. This example argues for future research needs in order to establish well-defined relationship between chemo-toxicity and radiotoxicity for internal contamination. The operational aim

  13. Alterations in the infrared spectral signature of avian feathers reflect potential chemical exposure: a pilot study comparing two sites in Pakistan.

    Science.gov (United States)

    Llabjani, Valon; Malik, Riffat N; Trevisan, Júlio; Hoti, Valmira; Ukpebor, Justina; Shinwari, Zabta K; Moeckel, Claudia; Jones, Kevin C; Shore, Richard F; Martin, Francis L

    2012-11-01

    Chemical contamination of ecosystems is a global issue with evidence that pollutants impact on living organisms in a harmful fashion. Developing sensor approaches that would allow the derivation of biomarkers or signatures of effect in target sentinel organisms and monitor environmental chemical contamination in a high throughput manner is of utmost importance. As biomolecules absorb infrared (IR), signature vibrational spectra related to structure and function can be derived. In light of this, we tested the notion that IR spectra of bird feathers might reflect environmental chemical contaminant exposure patterns. Feathers were collected from monospecific heronries of cattle egret based in two independent locations (Trimu vs. Mailsi) in the Punjab province of Pakistan; these sites were found to differ in their chemical contamination patterns. Feather samples were chemically analyzed for polychlorinated biphenyls, polybrominated diphenyl ethers, organochlorines and heavy metals. Attenuated total reflection Fourier-transform IR (ATR-FTIR) spectroscopy was employed to derive a spectral signature of individual feathers. Resultant IR spectra were then subjected to canonical correspondence analysis (CAA) to determine whether feather spectral signatures correlate to chemical exposure. Additionally, we explored if principal component analysis (PCA) and linear discriminant analysis (LDA) could be applied to distinguish site-specific differences; linear discriminant function (LDF) was also applied to classify sites. The sampled feathers varied in their chemical exposure patterns depending on whether they were sourced from one site associated with heavy metal exposure or the other which suggested high organic pollutant exposures. CCA of chemical and spectral data showed a correlation between spectral signatures and chemical exposure. PCA-LDA readily distinguished feathers from the two different sites. Discriminating alterations were identified and these were associated with

  14. Ventilatory responses during and following exposure to a hypoxic challenge in conscious mice deficient or null in S-nitrosoglutathione reductase

    OpenAIRE

    Palmer, Lisa A.; May, Walter J.; deRonde, Kimberly; Brown-Steinke, Kathleen; Bates, James N; Gaston, Benjamin; Lewis, Stephen J.

    2012-01-01

    Exposure to a hypoxic challenge increases ventilation in wild-type (WT) mice that diminish during the challenge (roll-off) whereas return to room air causes an increase in ventilation (short-term facilitation, STF). Since plasma and tissue levels of ventilatory excitant S-nitrosothiols such as S-nitrosoglutathione (GSNO) increase during hypoxia, this study examined whether (1) the initial increase in ventilation is due to generation of GSNO, (2) roll-off is due to increased activity of the GS...

  15. Exposure Assessment to Environmental Chemicals in Children from Ciudad Juarez, Chihuahua, Mexico.

    Science.gov (United States)

    Ochoa-Martinez, Angeles C; Orta-Garcia, Sandra T; Rico-Escobar, Edna M; Carrizales-Yañez, Leticia; Del Campo, Jorge D Martin; Pruneda-Alvarez, Lucia G; Ruiz-Vera, Tania; Gonzalez-Palomo, Ana K; Piña-Lopez, Iris G; Torres-Dosal, Arturo; Pérez-Maldonado, Ivan N

    2016-05-01

    It has been demonstrated that the human biomonitoring of susceptible populations is a valuable method for the identification of critical contaminants. Therefore, the purpose of this study was to assess the exposure profile for arsenic (As), lead (Pb), mercury (Hg), 1-hydroxypyrene (1-OHP), 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in children living in Ciudad Juarez, Chihuahua, Mexico (a major manufacturing center in Mexico). In 2012, we evaluated a total of 135 healthy children living in Ciudad Juarez since birth. The total PBDEs levels ranged from nondetectable (Ciudad Juarez is necessary. PMID:26987540

  16. Reproductive and carcinogenic health risks to hospital personnel from chemical exposure--a literature review.

    Science.gov (United States)

    Babich, H

    1985-01-01

    Hospital personnel, both those involved directly (surgeons, anesthesiologists, operating room nurses) and indirectly (pharmacists, laboratory technicians) with promoting the well-being of patients, and those involved in maintaining the proper functioning of the hospital (housekeeping personnel, painters, machinists), may be exposed to chemicals that are potential reproductive and carcinogenic hazards. Waste anesthetic gases, sterilants, such as ethylene oxide and formaldehyde, antineoplastic drugs, methylmethacrylate, asbestos, and various organic reagents and solvents may induce genetic damage, cancer, congenital malformation, still-birth, and spontaneous abortion. PMID:10274220

  17. Chemical Form Matters: Differential Accumulation of Mercury Following Inorganic and Organic Mercury Exposures in Zebrafish Larvae

    Energy Technology Data Exchange (ETDEWEB)

    Korbas, Malgorzata; MacDonald, Tracy C.; Pickering, Ingrid J.; George, Graham N.; Krone, Patrick H. (Saskatchewan)

    2013-04-08

    Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versus L-cysteine). For inorganic mercury species, in absence of L-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with L-cysteine present in the treatment solution, mercuric bis-L-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

  18. Analysis and prognosis of radiation exposure following the accident at the Siberian chemical combine Tomsk-7

    International Nuclear Information System (INIS)

    On the basis of the work (ground investigations and gamma aerial surveys) carried out jointly by the Rosgidromet organizations and Berezovgeologiya, data on the radiation exposure in Russia were obtained shortly after the accident of April 6, 1993 already. These data were transmitted to interested institutions. The measurements performed on April 11 and 12, 1993 indicated that within the isolines of 10 μR/h a contaminated area of up to 25 km in length and up to 6 km in width extended towards the northeastern direction. Thus, the contaminated area outside of the premises of the combine covered about 100 km2. The total amount of radioactive substances in this area was 530 - 590 Ci. Isotope composition of the radioactive trace was determined by ruthenium-103 (1%), ruthenium-106 (31%), zirconium-95 (22%), niobium-95 (45%) and plutonium-239 (0.02%). Contamination heterogeneity is caused by the existence of 'hot' particles with an activity of up to 10-11 Ci/particle. In the contaminated area the gamma exposure rate varied between 14 and 42 μR/h at 1 m height, yielding the maximum external radiation dose 100 mrem/year for the population of Georgievka. The Pu-239 inhalation dose of the population of Georgievka when passing the radioactive cloud did not exceed 1.5 mrem. A prognosis was made with regard to water contamination of the rivers Samuska and Tom during the flood in spring. Furthermore, contamination of the air layer adjacent to the ground resulting from the wind transport of radionuclides in the summer months at Georgievka was predicted. The values were far below the limits fixed according to the valid radiation protection regulations. However, that radionuclide concentration of the snow water may exceed the limits specified for drinking water. According to the data measured by the meteorological stations, the radioactive products were not entrained beyond the borders of the country. Source estimation was successfully obtained using RIMPUFF, the Risoe on

  19. Neurobehavioral deficits, diseases, and associated costs of exposure to endocrine-disrupting chemicals in the European union

    DEFF Research Database (Denmark)

    Bellanger, Martine; Demeneix, Barbara; Grandjean, Philippe;

    2015-01-01

    CONTEXT: Epidemiological studies and animal models demonstrate that endocrine-disrupting chemicals (EDCs) contribute to cognitive deficits and neurodevelopmental disabilities. OBJECTIVE: The objective was to estimate neurodevelopmental disability and associated costs that can be reasonably...... peer-reviewed studies to represent European exposure and approximate burden of disease. Cost estimation as of 2010 utilized lifetime economic productivity estimates, lifetime cost estimates for autism spectrum disorder, and annual costs for attention-deficit hyperactivity disorder. Setting, Patients.......8 billion to €194 billion). Autism spectrum disorder causation by multiple EDCs was assigned a 20-39% probability, with 316 (sensitivity analysis, 126-631) attributable cases at a cost of €199 million (sensitivity analysis, €79.7 million to €399 million). Attention-deficit hyperactivity disorder causation...

  20. Influence of UF4 physico-chemical properties on the assessment of the chronic exposure to this compound

    International Nuclear Information System (INIS)

    A method was developed in order to assess uranium exposure hazards at work stations based on the industrial experience acquired by Comurhex Malvesi at Narbonne. Applied to uranium tetrafluoride (UF4) the method involves 4 steps: 1. characterization of the industrial compound, including its physico-chemical properties (density, surface area, X-ray spectrum and uranium enrichment); 2. assessment of work station concentrations and particle size distribution (AMAD); 3. In vitro biological solubility with different synthetic fluids such as Gamble solutions with different gases or compounds added (oxygen or superoxide ions O2-) in order to determine the solubility class D, W or Y; 4. workers' monitoring by routine measurements of urinary excretion completed, if necessary, by fecal excretion and γ-spectrometry. Results and present data on UF4 are presented. 3 tabs., 4 figs

  1. Occupational hazards in hospitals: accidents, radiation, exposure to noxious chemicals, drug addiction and psychic problems, and assault

    International Nuclear Information System (INIS)

    Except for infectious diseases all the main occupational hazards affecting health workers are reviewed: accidents (explosions, fires, electrical accidents, and other sources of injury); radiation (stochastic and non-stochastic effects, protective measures, and personnel most at risk); exposure to noxious chemicals, whose effects may be either local (allergic eczema) or generalised (cancer, mutations), particular attention being paid to the hazards presented by formol, ethylene oxide, cytostatics, and anaesthetic gases; drug addiction (which is more common among health workers than the general population) and psychic problems associated with promotion, shift work, and emotional stress; and assault (various types of assault suffered by health workers, its causes, and the characterisation of the most aggressive patients). (author)

  2. One and Two-individual Movements of Fish after Chemical Exposure

    CERN Document Server

    Quach, Quang Kha; Van Nguyen, Tuyen; Chon, Tae-Soo

    2013-01-01

    Movement behavior of an indicator species, zebrafish (Danio rerio), was analyzed with one- and two-individual groups before and after treatment with a toxic chemical, formaldehyde, at a low concentration (1 ppm). After the boundary area had been determined based on experimental data, intermittency was defined as the probability distributions of the shadowing time during which data were above a pre-determined threshold and were obtained from experimental time-series data on forces and the inter-distances for one and two individuals. Overall intermittencies were similar in the boundary and central areas. However, the intermittencies were remarkably different between the one- and the two-individual groups: the single line was used to fit the data for the one-individual group whereas two phases were observed with breakpoints (approximately 10 seconds in logarithm) in the exponential fitting curves for the two-individual group. A difference in the probability distributions of shadowing time was observed "before" a...

  3. Exposure scenarios for workers

    NARCIS (Netherlands)

    Marquart, H.; Northage, C.; Money, C.

    2007-01-01

    The new European chemicals legislation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) requires the development of Exposure Scenarios describing the conditions and risk management measures needed for the safe use of chemicals. Such Exposure Scenarios should integrate con

  4. Exposure to widespread environmental endocrine disrupting chemicals and human sperm sex ratio.

    Science.gov (United States)

    Jurewicz, Joanna; Radwan, Michał; Sobala, Wojciech; Radwan, Paweł; Jakubowski, Lucjusz; Wielgomas, Bartosz; Ligocka, Danuta; Brzeźnicki, Sławomir; Hanke, Wojciech

    2016-06-01

    In recent years, a trend toward a declining proportion of male births has been noted in several, but not all, industrialized countries. The underlying reason for the drop in the sex ratio is unclear, but one theory states that widespread environmental endocrine disrupting chemicals affecting the male reproductive system in a negative manner could be part of the explanation. The present study was designed to investigate whether the urinary phthalate, pyrethroids and polycyclic aromatic hydrocarbons metabolites concentrations were associated with sperm Y:X ratio. The study population consisted of 194 men aged under 45 years of age who attended infertility clinic in Lodz, Poland for diagnostic purposes with normal semen concentration of 20-300 mln/ml or with slight oligozoospermia (semen concentration of 15-20 mln/ml) (WHO, 1999). The Y:X ratio was assessed by fluorescent in situ hybridization. Urinary concentrations of 1-hydroxypyrene were measured by high performance liquid chromatography, phthalate metabolites were analyzed using a procedure based on the LC-MS/MS methods and metabolites of synthetic pyrethroids were assessed by gas chromatography ion-tap mass spectrometry method. After adjustment for potential confounders (past diseases, age, abstinence, smoking, alcohol consumption, sperm concentration, motility, morphology) 5OH MEHP, CDCCA to TDCCA and 1-OHP was negatively related to Y:X sperm chromosome ratio (p = 0.033, p < 0.001, p = 0.047 respectively). As this is the first study to elucidate the association between the level of metabolites of widespread environmental endocrine disrupting chemicals (phthalates, synthetic pyrethroids, polycyclic aromatic hydrocarbons) on sex chromosome ratio in sperm therefore, these findings require further replication in other populations. PMID:27031570

  5. Impact of Occupational Exposure to Chemicals in Life Cycle Assessment: A Novel Characterization Model Based on Measured Concentrations and Labor Hours.

    Science.gov (United States)

    Kijko, Gaël; Margni, Manuele; Partovi-Nia, Vahid; Doudrich, Greg; Jolliet, Olivier

    2015-07-21

    According to Lim et al., based on World Health Organization (WHO) data, hazardous chemicals in the workplace are responsible for over 370,000 premature deaths annually. Despite these high figures, life cycle impact assessment (LCIA) does not yet include a fully operational method to consider occupational impacts in its scope over the entire supply chain. This paper describes a novel approach to account for occupational exposure to chemicals by inhalation in LCA. It combines labor statistics and measured occupational concentrations of chemicals from the OSHA database to calculate operational LCIA characterization factors (i.e., intakes per hour worked and impact intensities for 19,069 organic chemical/sector combinations with confidence intervals across the entire U.S. manufacturing industry). For the seven chemicals that most contribute to the global impact, measured workplace concentrations range between 5 × 10(-4) and 3 × 10(3) mg/m(3). Carcinogenic impacts range over 4 orders of magnitude, from 1.3 × 10(-8) and up to 3.4 × 10(-4) DALY per blue-collar worker labor hour. The innovative approach set out in this paper assesses health impacts from occupational exposure to chemicals with population exposure to outdoor emissions, making it possible to integrate occupational exposure within LCIA. It broadens the LCIA scope to analyze hotspots and avoid impact shifting. PMID:26079305

  6. Demining Dogs in Colombia - A Review of Operational Challenges, Chemical Perspectives, and Practical Implications.

    Science.gov (United States)

    Prada, Paola A; Chávez Rodríguez, Mario

    2016-07-01

    Within the framework of an internal armed conflict in Colombia, the use of antipersonnel mines by revolutionary armed forces represents a strategic factor for these groups. Antipersonnel mines are used by these revolutionary forces as a mean to hinder the advancement of the national armed forces in the recovery of territory and to protect tactical natural resources and illegal economies within a given area. These antipersonnel mines and improvised explosive devices (IEDs) are not of industrial manufacturing, and have a variety of activating mechanisms as well as non-metal materials which make them difficult for successful detection. The Colombian experience strongly represents the current need for advanced research and development of effective field operations within its affected territory. Current efforts are focused on a more operational demining perspective in coca cultivation sites in charge of mobile squadrons of eradication (EMCAR) from the National Police of Colombia working towards a future humanitarian demining upon an eventual peace process. The objectives of this review are not only to highlight already existing mine detection methods, but present a special emphasis on the role of mine detection canine teams in the context of this humanitarian issue in Colombia. This review seeks to bring together a description of chemical interactions of the environment with respect to landmine odor signatures, as well as mine detection dog operational perspectives for this specific detection task. The aim is to highlight that given the limited knowledge on the subject, there is a research gap that needs to be attended in order to efficiently establish optimal operating conditions for the reliable performance of mine detection dogs in Colombian demining field applications. PMID:27320400

  7. Growth of large size diamond single crystals by plasma assisted chemical vapour deposition: Recent achievements and remaining challenges

    Science.gov (United States)

    Tallaire, Alexandre; Achard, Jocelyn; Silva, François; Brinza, Ovidiu; Gicquel, Alix

    2013-02-01

    Diamond is a material with outstanding properties making it particularly suited for high added-value applications such as optical windows, power electronics, radiation detection, quantum information, bio-sensing and many others. Tremendous progresses in its synthesis by microwave plasma assisted chemical vapour deposition have allowed obtaining single crystal optical-grade material with thicknesses of up to a few millimetres. However the requirements in terms of size, purity and crystalline quality are getting more and more difficult to achieve with respect to the forecasted applications, thus pushing the synthesis method to its scientific and technological limits. In this paper, after a short description of the operating principles of the growth technique, the challenges of increasing crystal dimensions both laterally and vertically, decreasing and controlling point and extended defects as well as modulating crystal conductivity by an efficient doping will be detailed before offering some insights into ways to overcome them.

  8. Do Nanoparticle Physico-Chemical Properties and Developmental Exposure Window Influence Nano ZnO Embryotoxicity in Xenopus laevis?

    Directory of Open Access Journals (Sweden)

    Patrizia Bonfanti

    2015-07-01

    Full Text Available The growing global production of zinc oxide nanoparticles (ZnONPs suggests a realistic increase in the environmental exposure to such a nanomaterial, making the knowledge of its biological reactivity and its safe-by-design synthesis mandatory. In this study, the embryotoxicity of ZnONPs (1–100 mg/L specifically synthesized for industrial purposes with different sizes, shapes (round, rod and surface coatings (PEG, PVP was tested using the frog embryo teratogenesis assay-Xenopus (FETAX to identify potential target tissues and the most sensitive developmental stages. The ZnONPs did not cause embryolethality, but induced a high incidence of malformations, in particular misfolded gut and abdominal edema. Smaller, round NPs were more effective than the bigger, rod ones, and PEGylation determined a reduction in embryotoxicity. Ingestion appeared to be the most relevant exposure route. Only the embryos exposed from the stomodeum opening showed anatomical and histological lesions to the intestine, mainly referable to a swelling of paracellular spaces among enterocytes. In conclusion, ZnONPs differing in shape and surface coating displayed similar toxicity in X. laevis embryos and shared the same target organ. Nevertheless, we cannot exclude that the physico-chemical characteristics may influence the severity of such effects. Further research efforts are mandatory to ensure the synthesis of safer nano-ZnO-containing products.

  9. Prevention of unnecessary pregnancy terminations by counselling women on drug, chemical, and radiation exposure during the first trimester

    International Nuclear Information System (INIS)

    As part of a new approach to counselling pregnant women concerned about antenatal exposure to drugs, chemicals, or radiation, we measured their tendency to terminate their pregnancy by using a visual analogue scale (VAS). Analysis of 78 cases where women had less than 50% tendency to continue pregnancy before they were advised by us reveals that 61 decided to continue their pregnancy after the consultation (57 normal, healthy infants, four miscarriages) and 17 terminated. Women who continued their pregnancy significantly changed their tendency after we discussed relevant information with them (from 34.3 +/- 2.5% to 84.5 +/- 3.3%, P less than 0.00001), whereas most of those who eventually terminated pregnancy did not change their tendency to continue pregnancy beyond the 50% mark (from 24.8 +/- 5.4% to 45.1 +/- 9.8%) (P greater than 0.1). Only two of the women who terminated their pregnancy were exposed to teratogenic drugs; however, in most other cases, other obvious reasons, unrelated to the exposure in question, were identified by the women as leading reasons for termination. An appropriate intervention in early pregnancy can prevent unnecessary pregnancy terminations by correcting misinformation and thereby decreasing the unrealistically high perception of risk by women exposed to nonteratogens

  10. Novel photoacid generators for chemically amplified resists with g-line, i-line, and DUV exposure

    Science.gov (United States)

    Asakura, Toshikage; Yamato, Hitoshi; Matsumoto, Akira; Ohwa, Masaki

    2001-08-01

    A new class of compounds, (5-alkylsulfonyloxyimino-5H-thiophen-2-ylidene)-2-methylphen yl-acetonitriles, characterized as non-ionic and halogen-free photoacid generators (PAG's) was developed. The compounds generate various kinds of sulfonic acids, such as methane, n-propane and camphor sulfonic acid under the g-line (436nm), i-line (365 nm) and Deep UV (DUV, 248 nm or shorter) exposure and are applicable for chemically amplified (CA) photoresists. The application-relevant properties of the compounds such as solubility in propylene glycol monomethyl ether acetate (PGMEA), UV absorption, thermal stability with or without poly(4-hydroxystyrene), storage stability in a neat form, sensitivity in some model resist formulations and dissolution inhibition efficiency during development process were evaluated. The compounds exhibit enough solubility in PGMEA, red-shifted UV absorption ($lamdamax: 405 nm), good thermal stability up to 140 C in a phenolic matrix, effective acid generation in terms of quantum yield in an acetonitrile solution and high sensitivity in negative tone and positive tone CA resist formulations, such as tert-butyl ester type and t-BOC type formulations, with g-line, i-line and DUV exposure. The photochemical decomposition reaction of the compound was also studied. Additionally a scanning electron microscope (SEM) photography as an application example of microlithography by the CA negative tone resist with the PAG is presented.

  11. Effects of Exposure to Four Endocrine Disrupting-Chemicals on Fertilization and Embryonic Development of Barbel Chub (Squaliobarbus curriculus)

    Institute of Scientific and Technical Information of China (English)

    NIU Cuijuan; WANG Wei; GAO Ying; LI Li

    2013-01-01

    The toxicities of 4 common endocrine-disrupting chemicals (EDCs),17β-estradiol (E2),p,p'-dichlorodiphenyldichloro-ethylene (DDE),4-nonylphenol (NP) and tributyltin (TBT),to sperm motility,fertilization rate,hatching rate and embryonic development of Barbel chub (Squaliobarbus curriculus) were investigated in this study.The duration of sperm motility was significantly shortened by exposure to the EDCs at the threshold concentrations of 10ngL-1 for E2 and TBT,1 μgL-1 for NP and 100μgL-1 for DDE,respectively.The fertilization rate was substantially reduced by the EDCs at the lowest observable effect concentrations (LOECs) of 10ng L-1 for E2 and TBT and 10 lg L-1 for DDE and NP,respectively.Of the tested properties of S.curriculus,larval deformity rate was most sensitive to EDC exposure and was significantly increased by DDE at the lowest experimental level of 0.1 μgL-1.Other EDCs increased the larval deformity rate at the LOECs of 1 ngL-1 for E2,10ngL-1 for TBT and 1 μgL-1 for NP,respectively.Despite their decreases with the increasing EDC concentrations,the hatching rate and larval survival rate ofS.curriculus were not significantly affected by the exposure to EDCs.The results indicated that all the 4 EDCs affected significantly and negatively the early life stages of the freshwater fish S.curriculus.Overall,E2 and TBT were more toxic than NP and DDE,while DDE might be more toxic to larval deformity rate than to other measured parameters.Thus,the 4 EDCs showed potential negative influences on natural population dynamics of S.curriculus.Our findings provided valuable basic data for the ecological risk assessment of E2,DDE,NP and TBT.

  12. Effects of exposure to four endocrine disrupting-chemicals on fertilization and embryonic development of Barbel chub ( Squaliobarbus curriculus)

    Science.gov (United States)

    Niu, Cuijuan; Wang, Wei; Gao, Ying; Li, Li

    2013-09-01

    The toxicities of 4 common endocrine-disrupting chemicals (EDCs), 17β-estradiol (E2), p,p'-dichlorodiphenyldichloro-ethylene (DDE), 4-nonylphenol (NP) and tributyltin (TBT), to sperm motility, fertilization rate, hatching rate and embryonic development of Barbel chub ( Squaliobarbus curriculus) were investigated in this study. The duration of sperm motility was significantly shortened by exposure to the EDCs at the threshold concentrations of 10 ng L-1 for E2 and TBT, 1 μg L-1 for NP and 100 μg L-1 for DDE, respectively. The fertilization rate was substantially reduced by the EDCs at the lowest observable effect concentrations (LOECs) of 10 ng L-1 for E2 and TBT and 10 μg L-1 for DDE and NP, respectively. Of the tested properties of S. curriculus, larval deformity rate was most sensitive to EDC exposure and was significantly increased by DDE at the lowest experimental level of 0.1 μg L-1. Other EDCs increased the larval deformity rate at the LOECs of 1 ng L-1 for E2, 10 ng L-1 for TBT and 1 μg L-1 for NP, respectively. Despite their decreases with the increasing EDC concentrations, the hatching rate and larval survival rate of S. curriculus were not significantly affected by the exposure to EDCs. The results indicated that all the 4 EDCs affected significantly and negatively the early life stages of the freshwater fish S. curriculus. Overall, E2 and TBT were more toxic than NP and DDE, while DDE might be more toxic to larval deformity rate than to other measured parameters. Thus, the 4 EDCs showed potential negative influences on natural population dynamics of S. curriculus. Our findings provided valuable basic data for the ecological risk assessment of E2, DDE, NP and TBT.

  13. Childhood exposure to DEHP, DBP and BBP under existing chemical management systems: A comparative study of sources of childhood exposure in Korea and in Denmark

    DEFF Research Database (Denmark)

    Lee, Jihyun; Lee, Jong-Hyeon; Kim, Chan-Kook;

    2014-01-01

    an exposure scenario approach. Then, the scenario based exposure level was compared with back-calculated exposure levels based on biomonitored urinary phthalate metabolite concentrations. The result verifies the existence of varying territorial human background exposure levels and the gap between......, while Korea produces more than 0.4 million tons of the three above-mentioned phthalates each year. First, a comparative review of the existing phthalate regulations in the two countries was performed. Next, the level of childhood phthalate exposure from environmental and food sources was estimated using...... exposure estimations based on exposure modeling and biomonitoring data. Cumulative childhood risk levels in Denmark were lower than in Korea. For both countries, risk levels from back calculation were higher than those from scenario estimation. The median cumulative risk levels from scenario estimation and...

  14. Chemical structure changes of thermal-insulating polymers by exposures to high-energy ions

    International Nuclear Information System (INIS)

    The space machines on the low altitude orbits of the earth fly in the dilute atmospheric plasma formed by solar ultraviolet ray. Recently it has become a problem that to the insulators on spaceship surfaces that are charged negatively, the metallic parts attached to high voltage solar cell panels and their peripheral insulators, high energy ions collide, and deteriorate those materials. In this research, high energy ion beam irradiation test was carried out on the heat-resistant polymers for space use, and the change in their chemical structure was examined by XPS, thus the deterioration mechanism was presumed. The ECR ion source was used for ion acceleration, the kinds of generated ions were oxygen and nitrogen, and the irradiated ion energy was up to about 5 keV. The structures of three kinds of the polymers used for this research are shown. In this experiment, after the irradiation of ion beam, the samples were held for one hour in argon gas, and analyzed by XPS in the atmosphere. The XPS spectra of polyimide, PEEK and PFA are shown. It was presumed that by the irradiation of ion beam, on the surfaces of samples, both formation and dropping-off of functional groups occur. According to the energy and dose of irradiated ions, either effect becomes dominant, and the increase or decrease of functional groups occurs. By this change of structure, the lowering of heat resistance is expected. (K.I.)

  15. Using Biologic Markers in Blood to Assess Exposure to Multiple Environmental Chemicals for Inner-City Children 3–6 Years of Age

    OpenAIRE

    Sexton, Ken; Adgate, John L.; Fredrickson, Ann L; Ryan, Andrew D.; Needham, Larry L.; Ashley, David L.

    2005-01-01

    Biomarkers of exposure & early effects: field studiesBiomarker: 50 environmental chemicalsExposure/effect represented:detection of 11 VOCs, 2 heavy metals, 11organochlorine pesticides, 30 PCB congenersStudy design: cross-sectionalStudy size: 43 ethnically diverse childrenAnalytical technique: GC/MSTissue/biological material/sample size: bloodIntra-individual variation: for 6 VOCs (1,4 dichlorobenzene, ethylbenzene, m-l-p-xylene, o-xylene, styrene, tetrachloroethylene) and PCB 66, 105, 110, 18...

  16. In-situ Real-Time Monitoring of Volatile Organic Compound Exposure and Heart Rate Variability for Patients with Multiple Chemical Sensitivity

    OpenAIRE

    Atsushi Mizukoshi; Kazukiyo Kumagai; Naomichi Yamamoto; Miyuki Noguchi; Kazuhiro Yoshiuchi; Hiroaki Kumano; Kou Sakabe; Yukio Yanagisawa

    2015-01-01

    In-situ real-time monitoring of volatile organic compound (VOC) exposure and heart rate variability (HRV) were conducted for eight multiple chemical sensitivity (MCS) patients using a VOC monitor, a Holter monitor, and a time-activity questionnaire for 24 h to identify the relationship between VOC exposure, biological effects, and subjective symptoms in actual life. The results revealed no significantly different parameters for averaged values such as VOC concentration, HF (high frequency), a...

  17. Analytical methods for the assessment of endocrine disrupting chemical exposure during human fetal and lactation stages: a review.

    Science.gov (United States)

    Jiménez-Díaz, I; Vela-Soria, F; Rodríguez-Gómez, R; Zafra-Gómez, A; Ballesteros, O; Navalón, A

    2015-09-10

    In the present work, a review of the analytical methods developed in the last 15 years for the determination of endocrine disrupting chemicals (EDCs) in human samples related with children, including placenta, cord blood, amniotic fluid, maternal blood, maternal urine and breast milk, is proposed. Children are highly vulnerable to toxic chemicals in the environment. Among these environmental contaminants to which children are at risk of exposure are EDCs -substances able to alter the normal hormone function of wildlife and humans-. The work focuses mainly on sample preparation and instrumental techniques used for the detection and quantification of the analytes. The sample preparation techniques include, not only liquid-liquid extraction (LLE) and solid-phase extraction (SPE), but also modern microextraction techniques such as extraction with molecular imprinted polymers (MIPs), stir-bar sorptive extraction (SBSE), hollow-fiber liquid-phase microextraction (HF-LPME), dispersive liquid-liquid microextraction (DLLME), matrix solid phase dispersion (MSPD) or ultrasound-assisted extraction (UAE), which are becoming alternatives in the analysis of human samples. Most studies focus on minimizing the number of steps and using the lowest solvent amounts in the sample treatment. The usual instrumental techniques employed include liquid chromatography (LC), gas chromatography (GC) mainly coupled to tandem mass spectrometry. Multiresidue methods are being developed for the determination of several families of EDCs with one extraction step and limited sample preparation. PMID:26388473

  18. Engineering propionibacteria as versatile cell factories for the production of industrially important chemicals: advances, challenges, and prospects.

    Science.gov (United States)

    Guan, Ningzi; Zhuge, Xin; Li, Jianghua; Shin, Hyun-Dong; Wu, Jing; Shi, Zhongping; Liu, Long

    2015-01-01

    Propionibacteria are actinobacteria consisting of two principal groups: cutaneous and dairy. Cutaneous propionibacteria are considered primary pathogens to humans, whereas dairy propionibacteria are widely used in the food and pharmaceutical industries. Increasing attention has been focused on improving the performance of dairy propionibacteria for the production of industrially important chemicals, and significant advances have been made through strain engineering and process optimization in the production of flavor compounds, nutraceuticals, and antimicrobial compounds. In addition, genome sequencing of several propionibacteria species has been completed, deepening understanding of the metabolic and physiological features of these organisms. However, the metabolic engineering of propionibacteria still faces several challenges owing to the lack of efficient genome manipulation tools and the existence of various types of strong restriction-modification systems. The emergence of systems and synthetic biology provides new opportunities to overcome these bottlenecks. In this review, we first introduce the major species of propionibacteria and their properties and provide an overview of their functions and applications. We then discuss advances in the genome sequencing and metabolic engineering of these bacteria. Finally, we discuss systems and synthetic biology approaches for engineering propionibacteria as efficient and robust cell factories for the production of industrially important chemicals. PMID:25431012

  19. Imaging challenges: a U.S. perspective on controlling exposure to ionizing radiation in children with cancer

    OpenAIRE

    Kaste, Sue C.

    2008-01-01

    Issues pertaining to control of radiation dose exposures in pediatric imaging are on the forefront of patient care worldwide. Certain factors contribute to appropriate – or inappropriate – use of ionizing radiation in pediatric medical imaging. Such issues include naiveté regarding cancer risk and the role of medical imaging in its development, misinformation about exposure to ionizing radiation, resource availability, staffing, scheduling “snags,” costs, limited evidence-based imaging practi...

  20. Study sensitivity: Evaluating the ability to detect effects in systematic reviews of chemical exposures.

    Science.gov (United States)

    Cooper, Glinda S; Lunn, Ruth M; Ågerstrand, Marlene; Glenn, Barbara S; Kraft, Andrew D; Luke, April M; Ratcliffe, Jennifer M

    2016-01-01

    A critical step in systematic reviews of potential health hazards is the structured evaluation of the strengths and weaknesses of the included studies; risk of bias is a term often used to represent this process, specifically with respect to the evaluation of systematic errors that can lead to inaccurate (biased) results (i.e. focusing on internal validity). Systematic review methods developed in the clinical medicine arena have been adapted for use in evaluating environmental health hazards; this expansion raises questions about the scope of risk of bias tools and the extent to which they capture the elements that can affect the interpretation of results from environmental and occupational epidemiology studies and in vivo animal toxicology studies, (the studies typically available for assessment of risk of chemicals). One such element, described here as "sensitivity", is a measure of the ability of a study to detect a true effect or hazard. This concept is similar to the concept of the sensitivity of an assay; an insensitive study may fail to show a difference that truly exists, leading to a false conclusion of no effect. Factors relating to study sensitivity should be evaluated in a systematic manner with the same rigor as the evaluation of other elements within a risk of bias framework. We discuss the importance of this component for the interpretation of individual studies, examine approaches proposed or in use to address it, and describe how it relates to other evaluation components. The evaluation domains contained within a risk of bias tool can include, or can be modified to include, some features relating to study sensitivity; the explicit inclusion of these sensitivity criteria with the same rigor and at the same stage of study evaluation as other bias-related criteria can improve the evaluation process. In some cases, these and other features may be better addressed through a separate sensitivity domain. The combined evaluation of risk of bias and

  1. Chemical contaminants in water and sediment near fish nesting sites in the Potomac River basin: determining potential exposures to smallmouth bass (Micropterus dolomieu)

    Science.gov (United States)

    Kolpin, Dana W.; Blazer, Vicki; Gray, James L.; Focazio, Michael J.; Young, John A.; Alvarez, David A.; Iwanowicz, Luke R.; Foreman, William T.; Furlong, Edward T.; Speiran, Gary K.; Zaugg, Steven D.; Hubbard, Laura E.; Meyer, Michael T.; Sandstrom, Mark W.; Barber, Larry B.

    2013-01-01

    The Potomac River basin is an area where a high prevalence of abnormalities such as testicular oocytes (TO), skin lesions, and mortality has been observed in smallmouth bass (SMB, Micropterus dolomieu). Previous research documented a variety of chemicals in regional streams, implicating chemical exposure as one plausible explanation for these biological effects. Six stream sites in the Potomac basin (and one out-of-basin reference site) were sampled to provide an assessment of chemicals in these streams. Potential early life-stage exposure to chemicals detected was assessed by collecting samples in and around SMB nesting areas. Target chemicals included those known to be associated with important agricultural and municipal wastewater sources in the Potomac basin. The prevalence and severity of TO in SMB were also measured to determine potential relations between chemistry and biological effects. A total of 39 chemicals were detected at least once in the discrete-water samples, with atrazine, caffeine, deethylatrazine, simazine, and iso-chlorotetracycline being most frequently detected. Of the most frequently detected chemicals, only caffeine was detected in water from the reference site. No biogenic hormones/sterols were detected in the discrete-water samples. In contrast, 100 chemicals (including six biogenic hormones/sterols) were found in a least one passive-water sample, with 25 being detected at all such samples. In addition, 46 chemicals (including seven biogenic hormones/sterols) were found in the bed-sediment samples, with caffeine, cholesterol, indole, para-cresol, and sitosterol detected in all such samples. The number of herbicides detected in discrete-water samples per site had a significant positive relation to TOrank (a nonparametric indicator of TO), with significant positive relations between TOrank and atrazine concentrations in discrete-water samples and to total hormone/sterol concentration in bed-sediment samples. Such significant correlations

  2. Evaluation of the protection elicited by direct and indirect exposure to live attenuated infectious laryngotracheitis virus vaccines against a recent challenge strain from the United States.

    Science.gov (United States)

    Rodríguez-Avila, Andrés; Oldoni, Ivomar; Riblet, Sylva; Garcia, Maricarmen

    2008-06-01

    In a recent study (Oldoni & García, 2007), some field strains of infectious laryngotracheitis viruses (ILTV) were characterized as genotypically different (group VI) from ILT vaccine strains. The objective of this study was to evaluate the protection elicited by one chicken embryo origin (CEO) and one tissue culture origin (TCO) vaccine against a field isolate from group VI after direct and indirect exposure to ILTV live attenuated vaccines. In phase 1 of the experiment, non-vaccinated chickens were placed into contact with the eye drop vaccinates for a period of four weeks after vaccination. Transmission of the vaccine virus to these in-contact birds was demonstrated by real time PCR and antibody production, although the in-contact birds did not become protected against disease when subsequently challenged in phase 2 of the experiment. This emphasized the importance of uniform vaccination to obtain adequate protection, both to avoid the occurrence of susceptible chickens, and to minimize the potential for reversion to virulence of live-attenuated vaccines. In phase 2, protection against challenge with a group VI field virus was assessed four weeks after vaccination by scoring clinical signs and mortality, and quantifying weight gain. Sentinel birds were added to the groups one day after challenge to assess shedding of challenge virus, using real time PCR and virus isolation, during the period 2 to 12 days post challenge. The results showed that the CEO and TCO eye drop-vaccinated chickens were protected against challenge with the group VI virus, even though it was genetically different from the vaccine strains, and that challenge virus was not transmitted from these protected birds to the sentinels. PMID:18568655

  3. Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead

    Czech Academy of Sciences Publication Activity Database

    Goodson, W.H.; Vondráček, Jan

    2015-01-01

    Roč. 36, JUN 2015 (2015), s. 254-296. ISSN 0143-3334 R&D Projects: GA ČR(CZ) GA13-07711S Keywords : BREAST - CANCER CELLS * ESTROGEN-RECEPTOR-ALPHA * EPITHELIAL-MESENCHYMAL TRANSITION Subject RIV: BO - Biophysics Impact factor: 5.334, year: 2014

  4. A workflow to investigate exposure and pharmacokinetic influences on high-throughput in vitro chemical screening based on adverse outcome pathways, OpenTox USA 2015 Poster

    Science.gov (United States)

    Adverse outcome pathways (AOP) link known population outcomes to a molecular initiating event (MIE) that can be quantified using high-throughput in vitro methods. Practical application of AOPs in chemical-specific risk assessment requires consideration of exposure and absorption,...

  5. The MOBI-Kids study protocol: challenges in assessing childhood and adolescent exposure to electromagnetic fields from wireless telecommunication technologies and possible association with brain tumor risk

    Directory of Open Access Journals (Sweden)

    Siegal eSadetzki

    2014-09-01

    Full Text Available The rapid increase in mobile phone use in young people has generated concern about possible health effects of exposure to radiofrequency (RF, extremely low frequency (ELF electromagnetic fields (EMF. MOBI-Kids, a multinational case-control study, investigates the potential effects of childhood and adolescent exposure to EMF from mobile communications technologies on brain tumor risk in 14 countries. The study, which aims to include approximately 1,000 brain tumor cases aged 10-24 years and two individually matched controls for each case, follows a common protocol and builds upon the methodological experience of the INTERPHONE study. The design and conduct of a study on EMF exposure and brain tumor risk in young people in a large number of countries is complex and poses methodological challenges. This manuscript discusses the design of MOBI-Kids and describes the challenges and approaches chosen to address them, including: 1 the choice of controls operated for suspected appendicitis, to reduce potential selection bias related to low response rates among population controls; 2 investigating a young study population spanning a relatively wide age-range. 3 conducting a large, multinational epidemiological study, while adhering to increasingly stricter ethics requirements; 4 investigating a rare and potentially fatal disease; and 5 assessing exposure to EMF from communication technologies. Our experience thus far developing and implementing the study protocol indicates that MOBI-Kids is feasible and will generate results that will contribute to the understanding of potential brain tumor risks associated with use of mobile phones and other wireless communications technologies among young people.

  6. The MOBI-Kids Study Protocol: Challenges in Assessing Childhood and Adolescent Exposure to Electromagnetic Fields from Wireless Telecommunication Technologies and Possible Association with Brain Tumor Risk

    Science.gov (United States)

    Sadetzki, Siegal; Langer, Chelsea Eastman; Bruchim, Revital; Kundi, Michael; Merletti, Franco; Vermeulen, Roel; Kromhout, Hans; Lee, Ae-Kyoung; Maslanyj, Myron; Sim, Malcolm R.; Taki, Masao; Wiart, Joe; Armstrong, Bruce; Milne, Elizabeth; Benke, Geza; Schattner, Rosa; Hutter, Hans-Peter; Woehrer, Adelheid; Krewski, Daniel; Mohipp, Charmaine; Momoli, Franco; Ritvo, Paul; Spinelli, John; Lacour, Brigitte; Delmas, Dominique; Remen, Thomas; Radon, Katja; Weinmann, Tobias; Klostermann, Swaantje; Heinrich, Sabine; Petridou, Eleni; Bouka, Evdoxia; Panagopoulou, Paraskevi; Dikshit, Rajesh; Nagrani, Rajini; Even-Nir, Hadas; Chetrit, Angela; Maule, Milena; Migliore, Enrica; Filippini, Graziella; Miligi, Lucia; Mattioli, Stefano; Yamaguchi, Naohito; Kojimahara, Noriko; Ha, Mina; Choi, Kyung-Hwa; Mannetje, Andrea ’t; Eng, Amanda; Woodward, Alistair; Carretero, Gema; Alguacil, Juan; Aragones, Nuria; Suare-Varela, Maria Morales; Goedhart, Geertje; Schouten-van Meeteren, A. Antoinette Y. N.; Reedijk, A. Ardine M. J.; Cardis, Elisabeth

    2014-01-01

    The rapid increase in mobile phone use in young people has generated concern about possible health effects of exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF). MOBI-Kids, a multinational case–control study, investigates the potential effects of childhood and adolescent exposure to EMF from mobile communications technologies on brain tumor risk in 14 countries. The study, which aims to include approximately 1,000 brain tumor cases aged 10–24 years and two individually matched controls for each case, follows a common protocol and builds upon the methodological experience of the INTERPHONE study. The design and conduct of a study on EMF exposure and brain tumor risk in young people in a large number of countries is complex and poses methodological challenges. This manuscript discusses the design of MOBI-Kids and describes the challenges and approaches chosen to address them, including: (1) the choice of controls operated for suspected appendicitis, to reduce potential selection bias related to low response rates among population controls; (2) investigating a young study population spanning a relatively wide age range; (3) conducting a large, multinational epidemiological study, while adhering to increasingly stricter ethics requirements; (4) investigating a rare and potentially fatal disease; and (5) assessing exposure to EMF from communication technologies. Our experience in thus far developing and implementing the study protocol indicates that MOBI-Kids is feasible and will generate results that will contribute to the understanding of potential brain tumor risks associated with use of mobile phones and other wireless communications technologies among young people. PMID:25295243

  7. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  8. Paternal Occupational Exposure to Endocrine-Disrupting Chemicals as a Risk Factor for Leukaemia in Children: A Case-Control Study from the North of England

    Directory of Open Access Journals (Sweden)

    Mark S. Pearce

    2014-01-01

    Full Text Available Occupations with exposures to a variety of chemicals, including those thought to be potential endocrine disruptors, have been associated with an increased risk of leukaemia in offspring. We investigated whether an association exists between paternal occupations at birth involving such exposures and risk of leukaemia in offspring. Cases (n=958 were matched, on sex and year of birth, to controls from two independent sources, one other cancers, one cancer-free live births. Paternal occupations at birth were classified, using an occupational exposure matrix, as having “very unlikely,” “possible,” or “likely” exposure to six groups of potential endocrine-disrupting chemicals. There was a significantly increased risk of acute nonlymphocytic leukaemia (ANLL for polychlorinated organic compounds (OR 1.95, 95% CI 1.08–3.54 only in comparison with cancer-free controls, and for phthalates (OR 1.61, 95% CI 1.00–2.61 only with registry controls. A number of other, including inverse, associations were seen, but limited to one control group only. No associations were seen with likely paternal exposure to heavy metals. The associations identified in this study require further investigation, with better exposure and potential confounding (for example maternal variables information, to evaluate the likelihood of true associations to assess whether they are real or due to chance.

  9. Endocrine disrupting chemicals-Linking internal exposure to vitellogenin levels and ovotestis in Abramis brama from Dutch surface waters.

    Science.gov (United States)

    Reinen, Jelle; Suter, Marc J-F; Vögeli, A Christiane; Fernandez, Mariana F; Kiviranta, Hannu; Eggen, Rik I L; Vermeulen, Nico P E

    2010-11-01

    The exposure of male bream from three Dutch freshwater locations to endocrine disrupting compounds (EDCs) and corresponding effects are described in this study. Fish specimen displaying reproductive disorders associated with high levels of plasma vitellogenin (VTG) concentrations and occurrence of ovotestis (OT) were investigated. To provide information on the full spectrum of EDCs in fish tissue, adipose tissue samples of individual fish were analyzed for nearly 130 chemicals targeting different compound classes (bisphenols, alkylphenols, pesticides, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), hydroxylated polychlorinated biphenyls (OH-PCBs), polybrominated diphenyl ethers (PBDEs) and biphenyls (PBBs)) and steroid hormones. To establish whether tissue from specimen with reproductive disorders shows a spectrum of EDCs that is qualitatively and quantitatively different from that of controls free of symptoms, bioassay-directed fractionation was performed using the recombinant yeast estrogen screen (YES), the E-Screen bioassay, the human sulfotransferase 1E1 (SULT1E1) inhibition assay, and the coumestrol-based estrogen receptor α (ERα) high resolution screening (HRS) assay. No differences in estrogenicity could be observed between the cases and controls and steroidal estrogens accounted for the majority of estrogenicity found in the complex mixtures. In this study, the combination of the different assays employed to measure total estrogenicity and the SULT1E1 inhibition does not predict the outcome of unwanted physiological effects, however, it can be used to determine the presence of EDCs in fish samples and their estrogenic effects. PMID:21787654

  10. Assessment of Semi-Quantitative Health Risks of Exposure to Harmful Chemical Agents in the Context of Carcinogenesis in the Latex Glove Manufacturing Industry.

    Science.gov (United States)

    Yari, Saeed; Fallah Asadi, Ayda; Varmazyar, Sakineh

    2016-01-01

    Excessive exposure to chemicals in the workplace can cause poisoning and various diseases. Thus, for the protection of labor, it is necessary to examine the exposure of people to chemicals and risks from these materials. The purpose of this study is to evaluate semi-quantitative health risks of exposure to harmful chemical agents in the context of carcinogenesis in a latex glove manufacturing industry. In this cross-sectional study, semi-quantitative risk assessment methods provided by the Department of Occupational Health of Singapore were used and index of LD50, carcinogenesis (ACGIH and IARC) and corrosion capacity were applied to calculate the hazard rate and the biggest index was placed as the basis of risk. To calculate the exposure rate, two exposure index methods and the actual level of exposure were employed. After identifying risks, group H (high) and E (very high) classified as high-risk were considered. Of the total of 271 only 39 (15%) were at a high risk level and 3% were very high (E). These risks only was relevant to 7 materials with only sulfuric acid placed in group E and 6 other materials in group H, including nitric acid (48.3%), chromic acid (6.9%), hydrochloric acid (10.3%), ammonia (3.4%), potassium hydroxide (20.7%) and chlorine (10.3%). Overall, the average hazard rate level was estimated to be 4 and average exposure rate to be 3.5. Health risks identified in this study showed that the manufacturing industry for latex gloves has a high level of risk because of carcinogens, acids and strong alkalisand dangerous drugs. Also according to the average level of risk impact, it is better that the safety design strategy for latex gloves production industry be placed on the agenda. PMID:27165227

  11. Virus-Like Particle Vaccination Protects Nonhuman Primates from Lethal Aerosol Exposure with Marburgvirus (VLP Vaccination Protects Macaques against Aerosol Challenges

    Directory of Open Access Journals (Sweden)

    John M. Dye

    2016-04-01

    Full Text Available Marburg virus (MARV was the first filovirus to be identified following an outbreak of viral hemorrhagic fever disease in Marburg, Germany in 1967. Due to several factors inherent to filoviruses, they are considered a potential bioweapon that could be disseminated via an aerosol route. Previous studies demonstrated that MARV virus-like particles (VLPs containing the glycoprotein (GP, matrix protein VP40 and nucleoprotein (NP generated using a baculovirus/insect cell expression system could protect macaques from subcutaneous (SQ challenge with multiple species of marburgviruses. In the current study, the protective efficacy of the MARV VLPs in conjunction with two different adjuvants: QS-21, a saponin derivative, and poly I:C against homologous aerosol challenge was assessed in cynomolgus macaques. Antibody responses against the GP antigen were equivalent in all groups receiving MARV VLPs irrespective of the adjuvant; adjuvant only-vaccinated macaques did not demonstrate appreciable antibody responses. All macaques were subsequently challenged with lethal doses of MARV via aerosol or SQ as a positive control. All MARV VLP-vaccinated macaques survived either aerosol or SQ challenge while animals administered adjuvant only exhibited clinical signs and lesions consistent with MARV disease and were euthanized after meeting the predetermined criteria. Therefore, MARV VLPs induce IgG antibodies recognizing MARV GP and VP40 and protect cynomolgus macaques from an otherwise lethal aerosol exposure with MARV.

  12. Public health activities for mitigation of radiation exposures and risk communication challenges after the Fukushima nuclear accident.

    Science.gov (United States)

    Shimura, Tsutomu; Yamaguchi, Ichiro; Terada, Hiroshi; Robert Svendsen, Erik; Kunugita, Naoki

    2015-05-01

    Herein we summarize the public health actions taken to mitigate exposure of the public to radiation after the Fukushima accident that occurred on 11 March 2011 in order to record valuable lessons learned for disaster preparedness. Evacuations from the radiation-affected areas and control of the distribution of various food products contributed to the reduction of external and internal radiation exposure resulting from the Fukushima incident. However, risk communication is also an important issue during the emergency response effort and subsequent phases of dealiing with a nuclear disaster. To assist with their healing process, sound, reliable scientific information should continue to be disseminated to the radiation-affected communities via two-way communication. We will describe the essential public health actions following a nuclear disaster for the early, intermediate and late phases that will be useful for radiological preparedness planning in response to other nuclear or radiological disasters. PMID:25862700

  13. Public health activities for mitigation of radiation exposures and risk communication challenges after the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Herein we summarize the public health actions taken to mitigate exposure of the public to radiation after the Fukushima accident that occurred on 11 March 2011 in order to record valuable lessons learned for disaster preparedness. Evacuations from the radiation-affected areas and control of the distribution of various food products contributed to the reduction of external and internal radiation exposure resulting from the Fukushima incident. However, risk communication is also an important issue during the emergency response effort and subsequent phases of dealing with a nuclear disaster. To assist with their healing process, sound, reliable scientific information should continue to be disseminated to the radiation-affected communities via two-way communication. We will describe the essential public health actions following a nuclear disaster for the early, intermediate and late phases that will be useful for radiological preparedness planning in response to other nuclear or radiological disasters. (author)

  14. A framework incorporating the impact of exposure scenarios and application conditions on risk assessment of chemicals applied to skin

    OpenAIRE

    Dancik, Yuri; Troutman, John A; Jaworska, Joanna

    2013-01-01

    Purpose 1. To develop a framework for exposure calculation via the dermal route to meet the needs of 21st century toxicity testing and refine current approaches; 2. To demonstrate the impact of exposure scenario and application conditions on the plasma concentration following dermal exposure. Method A workflow connecting a dynamic skin penetration model with a generic whole-body physiologically-based pharmacokinetic (PBPK) model was developed. The impact of modifying exposure scenarios and ap...

  15. Retos futuros de la exposición personal a contaminantes en aire Future challenges regarding personal exposure to air pollutants

    Directory of Open Access Journals (Sweden)

    Pascual Pérez Ballesta

    2005-12-01

    Full Text Available El concepto de exposición de la población como un indicador directo del impacto de la contaminación sobre la salud pública es una consecuencia lógica del hecho de definir como objetivo primordial de las medidas de calidad del aire la protección de la salud del individuo. En este artículo se presenta la exposición a contaminantes en aire en diversos ámbitos como: la higiene industrial, la contaminación de ambientes interiores y su repercusión sobre la legislación de calidad del aire. La disminución del riesgo de salud de la población a la exposición de contaminantes en aire abre numerosos retos a la hora de definir indicadores de exposición, estrategias de control y evaluaciones efectivas de la exposición de la población.The concept of population exposure as a direct indicator of the impact of pollution on public health is a consequence of the fact that the final aim of air quality measurements is the protection of the individuals' health. This article presents a picture of the exposure to air pollutants in different environments: industrial hygiene, indoor pollution and air quality legislation. The reduction of the health risk of the population to air pollution exposure opens new challenges when defining exposure indicators, control strategies and an effective assessment human exposure.

  16. The applied indicators of water quality may underestimate the risk of chemical exposure to human population in reservoirs utilized for human supply-Southern Brazil.

    Science.gov (United States)

    Dos Santos, Debora Regina; Yamamoto, Flávia Yoshie; Filipak Neto, Francisco; Randi, Marco Antônio Ferreira; Garcia, Juan Esquivel; Costa, Daniele Dietrich Moura; Liebel, Samuel; Campos, Sandro Xavier; Voigt, Carmen Lúcia; de Oliveira Ribeiro, Ciro Alberto

    2016-05-01

    The knowledge concerning associations between chronic chemical exposure and many disorders with complex etiology involving gene-environment interactions is increasing, and new methods must be developed to improve water quality monitoring. The complexity of chemical mixtures in polluted aquatic environments makes the evaluation of toxic potential in those sites difficult, but the use of biomarkers and bioindicators has been recognized as a reliable tool to assess risk of exposure to biota and also the human population. In order to evaluate the use of fish and biomarkers to assess toxic potential and bioavailability of chemicals in human-related hydric resources, an in situ experiment was accomplished in two water reservoirs designated for human supply, which were previously evaluated by the local environmental regulatory agency through a set of physical, chemical, and classical biological parameters. Molecular, biochemical, and morphological biomarkers were performed in caged Oreochromis niloticus kept for 6 months in the studied reservoirs to assess potentially useful biomarkers to evaluate the quality of water for human supply. Chemical analysis of toxic metals in liver and muscle and polycyclic aromatic hydrocarbons (PAHs) in bile was considered to assess the bioavailability of pollutants and highlight human activity impact. The reservoir previously classified by a governmental agency as less impacted presented more risk of exposure to biota. These results were supported by chemical analysis, vitellogenin expression, histopathological findings (gonads, liver, and gills), as well as indicators of neurotoxic effects and oxidative stress in liver. The inclusion of some biomarkers as parameters in regulatory monitoring programs in reservoirs designated for human supply is strongly suggested to evaluate the risks of exposure to the human population. Thus, a revision of the traditional biological and physicochemical analysis utilized to establish the conditions of

  17. Carboniferous (namurian) deformation in the Blanskě les Massif, southern Bohemia:U-Pb zircon evidence. In: MAEG - 10 Challenges to Chemical Geology. Abstracts

    Czech Academy of Sciences Publication Activity Database

    Svojtka, Martin; Košler, J.; Vokurka, K.; Novák, M. (ed.); Janoušek, V. (ed.); Košler, J. (ed.)

    Česká geologická společnost. Roč. 42, č. 3 (1997), s. 25. ISSN 1210-8197. [Meeting Association of European Geological Societies /10./ Challenges to Chemical Geology. 01.09.1997-05.09.1997, Karlovy Vary] R&D Projects: GA ČR GA205/97/0244

  18. Subchronic Arsenic Exposure Induces Anxiety-Like Behaviors in Normal Mice and Enhances Depression-Like Behaviors in the Chemically Induced Mouse Model of Depression

    Directory of Open Access Journals (Sweden)

    Chia-Yu Chang

    2015-01-01

    Full Text Available Accumulating evidence implicates that subchronic arsenic exposure causes cerebral neurodegeneration leading to behavioral disturbances relevant to psychiatric disorders. However, there is still little information regarding the influence of subchronic exposure to arsenic-contaminated drinking water on mood disorders and its underlying mechanisms in the cerebral prefrontal cortex. The aim of this study is to assess the effects of subchronic arsenic exposure (10 mg/LAs2O3 in drinking water on the anxiety- and depression-like behaviors in normal mice and in the chemically induced mouse model of depression by reserpine pretreatment. Our findings demonstrated that 4 weeks of arsenic exposure enhance anxiety-like behaviors on elevated plus maze (EPM and open field test (OFT in normal mice, and 8 weeks of arsenic exposure augment depression-like behaviors on tail suspension test (TST and forced swimming test (FST in the reserpine pretreated mice. In summary, in this present study, we demonstrated that subchronic arsenic exposure induces only the anxiety-like behaviors in normal mice and enhances the depression-like behaviors in the reserpine induced mouse model of depression, in which the cerebral prefrontal cortex BDNF-TrkB signaling pathway is involved. We also found that eight weeks of subchronic arsenic exposure are needed to enhance the depression-like behaviors in the mouse model of depression. These findings imply that arsenic could be an enhancer of depressive symptoms for those patients who already had the attribute of depression.

  19. Effects of physico-chemical properties of actinide oxides on tumour induction after inhalation exposure in rats

    Energy Technology Data Exchange (ETDEWEB)

    Fritsch, P.; Dudoignon, N.; Ramounet, B.; Guezingar-Liebard, F.; Matton, S.; Lizon, C.; Massiot, P. [CEA, DSV/DRR/SRCA/LRT, Bruyeres le Chatel (France). Laboratoire de Radiotoxicologie

    2000-07-01

    This review described results obtained with new methods in authors' laboratory to measure dissolution parameters of inhaled actinide oxides and the distribution of {alpha}-delivered dose within lungs in relation to their tumor induction in rats. The oxides were industrial PuO{sub 2} (>50% of {alpha}, due to {sup 238}Pu), {sup 237}NpO{sub 2} and 2 different (U, Pu)O{sub 2} containing about 5% industrial Pu. The aerodynamic median activity diameter of their aerosols with authors' specific device measured with a cascade impactor were similar to each other (1.7-3.6 {mu}m {sigma}g). Their chemical composition was characterized using scanning transmission electron microscopy by energy dispersive X-ray spectrometry on alveolar macrophages which had phagocytosed them. Measurements of dissolution parameters after inhalation exposure in the rat and after in vitro incubation respectively revealed that the f{sub r} values were in the range of 2 x 10{sup -2}-1 x 10{sup -4}, indicating oxides behaved as a type S compound, and that the values were quite different from those above, suggesting S{sub s} should be considered as a variable for dose calculation, depending on time after inhalation. An autoradiographic method using solid tract detector and lung frozen sections revealed that aggeregations involving interstitial macrophages were often associated with fibrosis and/or preneoplastic lesions, which was explainable of a threshold in the dose-effect relationship for lung cancer occurrence. Results showed that, on inhalation of the oxides, risk assessment for lung tumor induction at low doses can not be extrapolated from that at high doses. (K.H.)

  20. Malignant lymphoma and exposure to chemicals, especially organic solvents, chlorophenols and phenoxy acids: a case-control study.

    OpenAIRE

    Hardell, L; Eriksson, M.; Lenner, P; Lundgren, E.

    1981-01-01

    A number of men with malignant lymphoma of the histiocytic type and previous exposure to phenoxy acids or chlorophenols were observed and reported in 1979. A matched case-control study has therefore been performed with cases of malignant lymphoma (Hodgkin's disease and non-Hodgkin lymphoma). This study included 169 cases and 338 controls. The results indicate that exposure to phenoxy acids, chlorophenols, and organic solvents may be a causative factor in malignant lymphoma. Combined exposure ...

  1. Environmental exposure measurement in cancer epidemiology

    OpenAIRE

    Wild, Christopher P.

    2008-01-01

    Environmental exposures, used in the broadest sense of lifestyle, infections, radiation, natural and man-made chemicals and occupation, are a major cause of human cancer. However, the precise contribution of specific risk factors and their interaction, both with each other and with genotype, continues to be difficult to elucidate. This is partially due to limitations in accurately measuring exposure with the subsequent risk of misclassification. One of the primary challenges of molecular canc...

  2. HELLE: Health Effects of Low Level Exposures/ Gezondheidseffecten van lage blootstellingniveaus [International workshop: Influence of low level exposures to chemicals and radiation on human and ecological health

    Energy Technology Data Exchange (ETDEWEB)

    Schoten, Eert

    1998-11-26

    The Health Council is closely involved in establishing the scientific foundation of exposure limits for substances and radiation in order to protect public health. Through the years, the Council has contributed to the formulation of principles and procedures, both for carcinogenic and for noncarcinogenic agents. As a rule, the discussion with regard to the derivation of health-based recommended exposure limits centers around the appropriateness of extrapolation methods (What can be inferred from data on high exposure levels and on experimental animals?). Generally speaking, there is a lack of direct information on the health effects of low levels of exposure. Effects at these levels cannot usually be detected by means of traditional animal experiments or epidemiological research. The capacity of these analytical instruments to distinguish between ''signal'' and ''noise'' is inadequate in most cases. Annex B of this report contains a brief outline of the difficulties and the established methods for tackling this problem. In spite of this, the hope exists that the posited weak signals, if they are indeed present, can be detected by other means. The search will have to take place on a deeper level. In other words, effort must be made to discover what occurs at underlying levels of biological organization when organisms are exposed to low doses of radiation or substances. Molecular and cell biology provide various methods and techniques which give an insight into the processes within the cell. This results in an increase in the knowledge about the molecular and cellular effects of exposure to agents, or stated differently, the working mechanisms which form the basis of the health effects. Last year, the Health Council considered that the time was ripe to take stock of the state of knowledge in this field. To this end, an international working conference was held from 19 to 21 October 1997, entitled ''Health Effects of

  3. Chronic exposure to odorous chemicals in residential areas and effects on human psychosocial health: dose-response relationships.

    Science.gov (United States)

    Blanes-Vidal, Victoria; Bælum, Jesper; Nadimi, Esmaeil S; Løfstrøm, Per; Christensen, Lars P

    2014-08-15

    Perceived air pollution, including environmental odor pollution, is known to be an environmental stressor that affects individuals' psychosocial health and well-being. However, very few studies have been able to quantify exposure-response associations based on individual-specific residential exposures to a proxy gas and to examine the mechanisms underlying these associations. In this study, individual-specific exposures in non-urban residential environments during 2005-2010 on a gas released from animal biodegradable wastes (ammonia, NH3) were calculated by the Danish Eulerian long-range transport model and the local-scale transport deposition model. We used binomial and multinomial logistic regression and mediation analyses to examine the associations between average exposures and questionnaire-based data on psychosocial responses, after controlling for person-specific covariates. About 45% of the respondents were annoyed by residential odor pollution. Exposures were associated with annoyance (adjusted odds ratio [ORadj]=3.54, 95% confidence interval [CI]=2.33-5.39), health risk perception (ORadj=4.94; 95% CI=1.95-12.5) and behavioral interference (ORadj=3.28; 95% CI=1.77-6.11), for each unit increase in loge(NH3 exposure). Annoyance was a strong mediator in exposure-behavior interference and exposure-health risk perception relationships (81% and 44% mediation, respectively). Health risk perception did not play a mediating role in exposure-annoyance or exposure-behavioral interference relationships. This is the first study to provide a quantitative estimation of the dose-response associations between ambient NH3 exposures and psychosocial effects caused by odor pollution in non-urban residential outdoor environments. It further shows that these effects are both direct and mediated by other psychosocial responses. The results support the use of NH3 as a proxy gas of air pollution from animal biodegradable wastes in epidemiologic studies. PMID:24880544

  4. Cell-mediated and humoral immune responses in pigs following primary and challenge-exposure to Lawsonia intracellularis

    DEFF Research Database (Denmark)

    Hvass, Henriette Cordes; Riber, Ulla; Jensen, Tim Kåre; Jungersen, Gregers

    2012-01-01

    To investigate immune responses upon re-infection with Lawsonia intracellularis, local and peripheral humoral and cell-mediated immune responses to primary and challenge inoculations were studied in 22 pigs. Pigs were orally inoculated with virulent L. intracellularis at the age of 5-6 weeks...... not boosted by the re-inoculation, since identical intestinal IgA responses developed in response to the inoculation in both the susceptible CC pigs and the protected RE pigs. A memory recall cell-mediated immune response developed in RE pigs which was significantly stronger compared to the primary......-mediated immune responses are likely mediators of protective immunity against L. intracellularis, with CD8+ effector cells and CD4+CD8+ double positive memory T cells as main contributors to the antigen-specific IFN-γ production....

  5. Too many chemicals, too little time: Rapid in silico methods to characterize and predict ADME properties for chemical toxicity and exposure potential

    Science.gov (United States)

    Evaluating proposed alternative chemical structures to support the design of safer chemicals and products is an important component of EPA's Green Chemistry and Design for the Environment (DfE) Programs. As such, science-based alternatives assessment is essential to support EPA's...

  6. Evaluation of the co-genotoxic effects of 1800 MHz GSM radiofrequency exposure and a chemical mutagen in cultured human cells

    Science.gov (United States)

    Perrin, Anne; Freire, Maëlle; Bachelet, Christine; Collin, Alice; Levêque, Philippe; Pla, Simon; Debouzy, Jean-Claude

    2010-11-01

    We investigated the effect of a 1800 MHz radiofrequency GSM signal combined with a known chemical mutagen (4-nitroquinoline-N-oxide: 4NQO) on human THP1 cells. Comet and γ-H2AX assays were used to assess DNA damage. No heating of the cell cultures was noted during exposure (2 h). The exposure of cells to electromagnetic fields with SARs of 2 to 16 W/kg did not increase the DNA damage induced by 4NQO, whereas the number of DNA strand breaks increased with a temperature increase of at least 4 °C. In conclusion, no co-genotoxic effect of radiofrequency was found at levels of exposure that did not induce heating.

  7. Effects of oil sands related aquatic reclamation on yellow perch (Perca flavescens). 2. Chemical and biochemical indicators of exposure to oil sands related waters

    International Nuclear Information System (INIS)

    The impact that oil sands related waters may have on aquatic ecosystems and fish was examined. Regardless of the oil sands tailing reclamation method, the quality of surface waters will be affected by elevated salinity and organic acids as well as by increased concentrations of polycyclic aromatic hydrocarbons (PAHs). The study determined that since surface waters will eventually impact on fish, it would be useful to have a suite of biochemical and chemical indicators of exposure to families of compounds associated with oil sands related waters. Two indicators, mixed-function oxygenase (MFO) activity and bile PAH equivalent concentration are frequently used to quantify exposure of fishes to petroleum hydrocarbons. Adult yellow perch were stocked into experimental ponds containing oil sands related waters. After 5 and 11 months, the usefulness of MFO enzymes, conjugation enzymes, bile PAH metabolite concentrations and plasma steroid hormones in yellow perch were examined. The potential of these biochemical and chemical endpoints as predictive indicators of physiological and population-level impacts was examined. It was shown that MFO activity and bile PAH equivalents were good indicators of exposure to oil sands related waters, but they were not predictive of physiological endpoints. This suggests that physiological endpoints were influenced by ecological and not chemical factors. 28 refs., 1 tab., 4 figs

  8. Epigenetic regulation of neurodevelopmental genes in response to in utero exposure to phthalate plastic chemicals: How can we delineate causal effects?

    Science.gov (United States)

    Ponsonby, Anne-Louise; Symeonides, Christos; Vuillermin, Peter; Mueller, Jochen; Sly, Peter D; Saffery, Richard

    2016-07-01

    Accumulating evidence, from animal models and human observational studies, implicates the in utero (and early postnatal) environment in the 'programming' of risk for a variety of adverse outcomes and health trajectories. The modern environment is replete with man-made compounds such as plastic product chemicals (PPC), including phenols and phthalates. Evidence from several human cohorts implicates exposure to these chemicals in adverse offspring neurodevelopment, though a direct causal relationship has not been firmly established. In this review we consider a potential causal pathway that encompasses epigenetic human variation, and how we might test this mechanistic hypothesis in human studies. In the first part of this report we outline how PPCs induce epigenetic change, focusing on the brain derived neurotrophic factor (BDNF) gene, a key regulator of neurodevelopment. Further, we discuss the role of the epigenetics of BDNF and other genes in neurodevelopment and the emerging human evidence of an association between phthalate exposure and adverse offspring neurodevelopment. We discuss aspects of epidemiological and molecular study design and analysis that could be employed to strengthen the level of human evidence to infer causality. We undertake this using an exemplar recent research example: maternal prenatal smoking, linked to methylation change at the aryl hydrocarbon receptor repressor (AHRR) gene at birth, now shown to mediate some of the effects of maternal smoking on birth weight. Characterizing the relationship between the modern environment and the human molecular pathways underpinning its impact on early development is paramount to understanding the public health significance of modern day chemical exposures. PMID:27208563

  9. Comparative assessment of the environmental hazards of and exposure to perfluoroalkyl phosphonic and phosphinic acids (PFPAs and PFPiAs): Current knowledge, gaps, challenges and research needs.

    Science.gov (United States)

    Wang, Zhanyun; Cousins, Ian T; Berger, Urs; Hungerbühler, Konrad; Scheringer, Martin

    2016-01-01

    Perfluoroalkyl phosphonic and phosphinic acids (PFPAs and PFPiAs) are sub-groups of per- and polyfluoroalkyl substances (PFASs) that have been commercialized since the 1970s, particularly as defoamers in pesticide formulations and wetting agents in consumer products. Recently, C4/C4 PFPiA and its derivatives have been presented as alternatives to long-chain PFASs in certain applications. In this study, we systematically assess the publicly available information on the hazardous properties, occurrence, and exposure routes of PFPAs and PFPiAs, and make comparisons to the corresponding properties of their better-known carboxylic and sulfonic acid analogs (i.e. PFCAs and PFSAs). This comparative assessment indicates that [i] PFPAs likely have high persistence and long-range transport potential; [ii] PFPiAs may transform to PFPAs (and possibly PFCAs) in the environment and biota; [iii] certain PFPAs and PFPiAs can only be slowly eliminated from rainbow trout and rats, similarly to long-chain PFCAs and PFSAs; [iv] PFPAs and PFPiAs have modes-of-action that are both similar to, and different from, those of PFCAs and PFSAs; and [v] the measured levels of PFPAs/PFPiAs in the global environment and biota appear to be low in comparison to PFCAs and PFSAs, suggesting, for the time being, low risks from PFPAs and PFPiAs alone. Although risks from individual PFPAs/PFPiAs are currently low, their ongoing production and use and high persistence will lead to increasing exposure and risks over time. Furthermore, simultaneous exposure to PFPAs, PFPiAs and other PFASs may result in additive effects necessitating cumulative risk assessments. To facilitate effective future research, we highlight possible strategies to overcome sampling and analytical challenges. PMID:26922149

  10. Developing health-based pre-planning clearance goals for airport remediation following a chemical terrorist attack: Decision criteria for multipathway exposure routes

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Annetta Paule [ORNL; Dolislager, Frederick [University of Tennessee, Knoxville (UTK); Hall, Dr. Linda [ENVIRON International Corporation; Hauschild, Veronique [U.S. Army Center for Health Promotion and Preventive Medicine; Raber, Ellen [Lawrence Livermore National Laboratory (LLNL); Love, Dr. Adam [Johnson Wright, Inc.

    2011-01-01

    In the event of a chemical terrorist attack on a transportation hub, post-event remediation and restoration activities necessary to attain unrestricted facility re-use and re-entry could require hours to multiple days. While timeframes are dependent on numerous variables, a primary controlling factor is the level of pre-planning and decision-making completed prior to chemical release. What follows is the second of a two-part analysis identifying key considerations, critical information and decision criteria to facilitate post-attack and post-decontamination consequence management activities. Decision criteria analysis presented here provides first-time, open-literature documentation of multi-pathway, health-based remediation exposure guidelines for selected toxic industrial compounds, chemical warfare agents, and agent degradation products for pre-planning application in anticipation of a chemical terrorist attack. Guideline values are provided for inhalation and direct ocular vapor exposure routes as well as percutaneous vapor, surface contact, and ingestion. Target populations include various employees as well as transit passengers. This work has been performed as a national case study conducted in partnership with the Los Angeles International Airport and The Bradley International Terminal. All recommended guidelines have been selected for consistency with airport scenario release parameters of a one-time, short-duration, finite airborne release from a single source followed by compound-specific decontamination.

  11. Contaminant mixtures and repoductive health: Developmental toxicity effects in rats after mixed exposure to environmentally relevant endocrine disrupting chemicals, with focus on effects in females

    DEFF Research Database (Denmark)

    Jacobsen, Pernille Rosenskjold; Christiansen, Sofie; Hass, Ulla

    effects in females both early and later in life. Methods: The results, presented in this thesis, were obtained in five developmental toxicology studies. Two studies investigated mixtures of endocrine disrupting pesticides (Pestimix), two investigated mixtures of endocrine disrupting chemicals based...... on human exposures (Contamed), and one study tested a positive control for estrogenic effects, ethinyl estradiol (EE2). The project with the mixture of the five pesticides included two range-finding studies (collectively called Pestimix RF) and a dose response study (Pestimix DR). In the Contamed project...... chemicals included phthalates, pesticides, UV-filters, bisphenol A, parabens and the drug paracetamol. Together the chemicals represented several modes of action with regard to endocrine disrupting mode of action. Finally, results from a dose response study on the estrogenic drug EE2 were included. In all...

  12. Challenges and Successes in Dissemination of Evidence-Based Treatments for Posttraumatic Stress: Lessons Learned From Prolonged Exposure Therapy for PTSD.

    Science.gov (United States)

    Foa, Edna B; Gillihan, Seth J; Bryant, Richard A

    2013-05-01

    Posttraumatic stress disorder (PTSD) poses monumental public health challenges because of its contribution to mental health, physical health, and both interpersonal and social problems. Recent military engagements in Iraq and Afghanistan and the multitude of resulting cases of PTSD have highlighted the public health significance of these conditions. There are now psychological treatments that can effectively treat most individuals with PTSD, including active duty military personnel, veterans, and civilians. We begin by reviewing the effectiveness of these treatments, with a focus on prolonged exposure (PE), a cognitive-behavioral therapy (CBT) for PTSD. Many studies conducted in independent research labs have demonstrated that PE is highly efficacious in treating PTSD across a wide range of trauma types, survivor characteristics, and cultures. Furthermore, therapists without prior CBT experience can readily learn and implement the treatment successfully. Despite the existence of highly effective treatments like PE, the majority of individuals with PTSD receive treatments of unknown efficacy. Thus, it is crucial to identify the barriers and challenges that must be addressed in order to promote the widespread dissemination of effective treatments for PTSD. In this review, we first discuss some of the major challenges, such as a professional culture that often is antagonistic to evidence-based treatments (EBTs), a lack of clinician training in EBTs, limited effectiveness of commonly used dissemination techniques, and the significant cost associated with effective dissemination models. Next, we review local, national, and international efforts to disseminate PE and similar treatments and illustrate the challenges and successes involved in promoting the adoption of EBTs in mental health systems. We then consider ways in which the barriers discussed earlier can be overcome, as well as the difficulties involved in effecting sustained organizational change in mental health

  13. Medical countermeasure against respiratory toxicity and acute lung injury following inhalation exposure to chemical warfare nerve agent VX

    International Nuclear Information System (INIS)

    To develop therapeutics against lung injury and respiratory toxicity following nerve agent VX exposure, we evaluated the protective efficacy of a number of potential pulmonary therapeutics. Guinea pigs were exposed to 27.03 mg/m3 of VX or saline using a microinstillation inhalation exposure technique for 4 min and then the toxicity was assessed. Exposure to this dose of VX resulted in a 24-h survival rate of 52%. There was a significant increase in bronchoalveolar lavage (BAL) protein, total cell number, and cell death. Surprisingly, direct pulmonary treatment with surfactant, liquivent, N-acetylcysteine, dexamethasone, or anti-sense syk oligonucleotides 2 min post-exposure did not significantly increase the survival rate of VX-exposed guinea pigs. Further blocking the nostrils, airway, and bronchioles, VX-induced viscous mucous secretions were exacerbated by these aerosolized treatments. To overcome these events, we developed a strategy to protect the animals by treatment with atropine. Atropine inhibits muscarinic stimulation and markedly reduces the copious airway secretion following nerve agent exposure. Indeed, post-exposure treatment with atropine methyl bromide, which does not cross the blood-brain barrier, resulted in 100% survival of VX-exposed animals. Bronchoalveolar lavage from VX-exposed and atropine-treated animals exhibited lower protein levels, cell number, and cell death compared to VX-exposed controls, indicating less lung injury. When pulmonary therapeutics were combined with atropine, significant protection to VX-exposure was observed. These results indicate that combinations of pulmonary therapeutics with atropine or drugs that inhibit mucous secretion are important for the treatment of respiratory toxicity and lung injury following VX exposure

  14. Minimally invasive transcriptome profiling in salmon: Detection of biological response in rainbow trout caudal fin following exposure to environmental chemical contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Nik; Stevenson, Mitchel R. [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055, STN CSC, Victoria, BC V8W 3P6 (Canada); Skirrow, Rachel C. [Pacific and Yukon Laboratory for Environmental Testing, Pacific Environmental Science Centre, Environment Canada, 2645 Dollarton Highway, North Vancouver, BC V7H 1B1 (Canada); Rieberger, Kevin J. [Environmental Sustainability and Strategic Policy Division, Water Protection and Sustainability Branch, British Columbia Ministry of Environment, P.O. Box 9362 Stn Prov Govt, Victoria, BC V8W 9M2 (Canada); Aggelen, Graham van [Pacific and Yukon Laboratory for Environmental Testing, Pacific Environmental Science Centre, Environment Canada, 2645 Dollarton Highway, North Vancouver, BC V7H 1B1 (Canada); Meays, Cynthia L. [Environmental Sustainability and Strategic Policy Division, Water Protection and Sustainability Branch, British Columbia Ministry of Environment, P.O. Box 9362 Stn Prov Govt, Victoria, BC V8W 9M2 (Canada); Helbing, Caren C., E-mail: chelbing@uvic.ca [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055, STN CSC, Victoria, BC V8W 3P6 (Canada)

    2013-10-15

    Highlights: •A minimally-invasive tail fin biopsy assay was developed for use in fish. •Quantitative real time polymerase reaction provided gene expression readout. •Results were comparable to classical liver tissue responses. •The approach was used on two salmonid species and can be coupled with genomic sex determination using an additional biopsy for maximal information. -- Abstract: An increasing number of anthropogenic chemicals have demonstrated potential for disruption of biological processes critical to normal growth and development of wildlife species. Both anadromous and freshwater salmon species are at risk of exposure to environmental chemical contaminants that may affect migratory behavior, environmental fitness, and reproductive success. A sensitive metric in determination of the presence and impact of such environmental chemical contaminants is through detection of changes in the status of gene transcript levels using a targeted quantitative real-time polymerase chain reaction assay. Ideally, the wildlife assessment strategy would incorporate conservation-centered non-lethal practices. Herein, we describe the development of such an assay for rainbow trout, Oncorhynchus mykiss, following an acute 96 h exposure to increasing concentrations of either 17α-ethinyl estradiol or cadmium. The estrogenic screen included measurement of mRNA encoding estrogen receptor α and β isoforms, vitellogenin, vitelline envelope protein γ, cytochrome p450 family 19 subfamily A, aryl hydrocarbon receptor, and the stress indicator, catalase. The metal exposure screen included evaluation of the latter two mRNA transcripts along with those encoding the metallothionein A and B isoforms. Exposure-dependent transcript abundance profiles were detected in both liver and caudal fin supporting the use of the caudal fin as a non-lethally obtained tissue source. The potential for both transcriptome profiling and genotypic sex determination from fin biopsy was extended, in

  15. Minimally invasive transcriptome profiling in salmon: Detection of biological response in rainbow trout caudal fin following exposure to environmental chemical contaminants

    International Nuclear Information System (INIS)

    Highlights: •A minimally-invasive tail fin biopsy assay was developed for use in fish. •Quantitative real time polymerase reaction provided gene expression readout. •Results were comparable to classical liver tissue responses. •The approach was used on two salmonid species and can be coupled with genomic sex determination using an additional biopsy for maximal information. -- Abstract: An increasing number of anthropogenic chemicals have demonstrated potential for disruption of biological processes critical to normal growth and development of wildlife species. Both anadromous and freshwater salmon species are at risk of exposure to environmental chemical contaminants that may affect migratory behavior, environmental fitness, and reproductive success. A sensitive metric in determination of the presence and impact of such environmental chemical contaminants is through detection of changes in the status of gene transcript levels using a targeted quantitative real-time polymerase chain reaction assay. Ideally, the wildlife assessment strategy would incorporate conservation-centered non-lethal practices. Herein, we describe the development of such an assay for rainbow trout, Oncorhynchus mykiss, following an acute 96 h exposure to increasing concentrations of either 17α-ethinyl estradiol or cadmium. The estrogenic screen included measurement of mRNA encoding estrogen receptor α and β isoforms, vitellogenin, vitelline envelope protein γ, cytochrome p450 family 19 subfamily A, aryl hydrocarbon receptor, and the stress indicator, catalase. The metal exposure screen included evaluation of the latter two mRNA transcripts along with those encoding the metallothionein A and B isoforms. Exposure-dependent transcript abundance profiles were detected in both liver and caudal fin supporting the use of the caudal fin as a non-lethally obtained tissue source. The potential for both transcriptome profiling and genotypic sex determination from fin biopsy was extended, in

  16. Developmental exposure to endocrine-disrupting chemicals programs for reproductive tract alterations and obesity later in life1234

    OpenAIRE

    Newbold, Retha R.

    2011-01-01

    Many chemicals in the environment, especially those with estrogenic activity, are able to disrupt the programming of endocrine signaling pathways established during development; these chemicals are referred to as endocrine-disrupting chemicals. Altered programming can result in numerous adverse consequences in estrogen-target tissues, some of which may not be apparent until later in life. For example, a wide variety of structural, functional, and cellular effects have been identified in repro...

  17. Using PBPK guided “Body-on-a-Chip” Systems to Predict Mammalian Response to Drug and Chemical Exposure

    OpenAIRE

    Sung, Jong Hwan; Srinivasan, Balaji; Esch, Mandy Brigitte; McLamb, William T.; Bernabini, Catia; Shuler, Michael L.; Hickman, James J.

    2014-01-01

    The continued development of in vitro systems that accurately emulate human response to drugs or chemical agents will impact drug development, our understanding of chemical toxicity, and enhance our ability to respond to threats from chemical or biological agents. A promising technology is to build microscale replicas of humans that capture essential elements of physiology, pharmacology and/or toxicology (microphysiological systems). Here, we review progress on systems for microscale models o...

  18. Exposure to bacterial signals does not alter pea aphids' survival upon a second challenge or investment in production of winged offspring.

    Directory of Open Access Journals (Sweden)

    Bas ter Braak

    Full Text Available Pea aphids have an obligate nutritional symbiosis with the bacteria Buchneraaphidicola and frequently also harbor one or more facultative symbionts. Aphids are also susceptible to bacterial pathogen infections, and it has been suggested that aphids have a limited immune response towards such pathogen infections compared to other, more well-studied insects. However, aphids do possess at least some of the genes known to be involved in bacterial immune responses in other insects, and immune-competent hemocytes. One possibility is that immune priming with microbial elicitors could stimulate immune protection against subsequent bacterial infections, as has been observed in several other insect systems. To address this hypothesis we challenged aphids with bacterial immune elicitors twenty-four hours prior to live bacterial pathogen infections and then compared their survival rates to aphids that were not pre-exposed to bacterial signals. Using two aphid genotypes, we found no evidence for immune protection conferred by immune priming during infections with either Serratia marcescens or with Escherichia coli. Immune priming was not altered by the presence of facultative, beneficial symbionts in the aphids. In the absence of inducible immune protection, aphids may allocate energy towards other defense traits, including production of offspring with wings that could escape deteriorating conditions. To test this, we monitored the ratio of winged to unwinged offspring produced by adult mothers of a single clone that had been exposed to bacterial immune elicitors, to live E. coli infections or to no challenge. We found no correlation between immune challenge and winged offspring production, suggesting that this mechanism of defense, which functions upon exposure to fungal pathogens, is not central to aphid responses to bacterial infections.

  19. Endocrine disrupting chemicals and other substances of concern in food contact materials: an updated review of exposure, effect and risk assessment.

    Science.gov (United States)

    Muncke, Jane

    2011-10-01

    Food contact materials (FCM) are an underestimated source of chemical food contaminants and a potentially relevant route of human exposure to endocrine disrupting chemicals (EDCs). Quantifying the exposure of the general population to substances from FCM relies on estimates of food consumption and leaching into food. Recent studies using polycarbonate plastics show that food simulants do not always predict worst-case leaching of bisphenol A, a common FCM substance. Also, exposure of children to FCM substances is not always realistically predicted using the common conventions and thus possibly misjudged. Further, the exposure of the whole population to substances leaching into dry foods is underestimated. Consumers are exposed to low levels of substances from FCM across their entire lives. Effects of these compounds currently are assessed with a focus on mutagenicity and genotoxicity. This approach however neglects integrating recent new toxicological findings, like endocrine disruption, mixture toxicity, and developmental toxicity. According to these new toxicology paradigms women of childbearing age and during pregnancy are a new sensitive population group requiring more attention. Furthermore, in overweight and obese persons a change in the metabolism of xenobiotics is observed, possibly implying that this group of consumers is insufficiently protected by current risk assessment practice. Innovations in FCM risk assessment should therefore include routine testing for EDCs and an assessment of the whole migrate toxicity of a food packaging, taking into account all sensitive population groups. In this article I focus on recent issues of interest concerning either exposure to or effects of FCM-related substances. Further, I review the use of benzophenones and organotins, two groups of known or suspected EDCs, in FCM authorized in the US and EU. PMID:21073950

  20. Investigation of the relation between self-reported food consumption and household chemical exposures with urinary levels of selected nonpersistent pesticides.

    Science.gov (United States)

    Kieszak, Stephanie M; Naeher, Luke P; Rubin, Carol S; Needham, Larry L; Backer, Lorraine; Barr, Dana; McGeehin, Michael

    2002-11-01

    Concerns about pesticide exposure through food consumption have increased during the past several years. The main objective of our study was to determine whether we could use data from the Third National Health and Nutrition Examination Survey (NHANES III) to detect a relation between self-reported food consumption--particularly consumption of fruits, vegetables, and bread products--and urinary levels of pesticides or their metabolites in a population of 978 adults living in the US. A secondary objective was to investigate whether these urine levels differed for people who reported exposure to selected common household chemicals including bug or insect spray, weed killer, and mothballs or crystals. We used monthly food frequency data from the NHANES III, 1988-1994. Urinary pesticide/metabolite levels and information about chemical exposures were taken from the Priority Toxicant Reference Range Study (a component of the NHANES III). Six pesticides or their metabolites were detected in at least 50% of the sample, three of which--1-naphthol (86.4%), pentachlorophenol (62.5%), and 3,5,6-trichloro-2-pyridinol (82.0%)--were possibly related to food consumption. We were unable to detect a relation between self-reported food consumption and their urinary levels. This may be due more to the limitations of the datasets than to a lack of a relation between food consumption and urine pesticide/metabolite levels. We did find that people who reported recently using selected common chemicals had higher geometric mean urine pesticide/metabolite levels than did people who reported not recently using these chemicals. PMID:12415488

  1. Chemical protection against long-term effects of whole-body exposure of mice to ionizing radiation. III. The effects of fractionated exposure to C57Bl mice

    International Nuclear Information System (INIS)

    Mice of the C57Bl/Cnb strain were exposed to four fractionated doses delivered at weekly intervals (total doses from 4 x 50 to 4 x 375 R). One group of mice received a mixture of radioprotectors. The animals were followed to their natural death and investigated for histopathology. Life-shortening showed a sigmoid dependency on the dose in nonprotected and protected mice with a dose reduction factor of 2.1 at 50% life-shorteining. Thymic lymphoma was the most predominant cause of death in irradiated C57Bl mice. Radioprotectors diminished significantly the incidence of this disease but apparently did not reduce other causes of death. Reticulum cell sarcoma B also increased at the same low doses as thymic lymphoma. Both thymic lymphoma and reticulum cell sarcoma B increased in frequency after a fractionated dose compared to a single exposure with doses of 600 to 700 R and 300 to 400 R, respectively

  2. Evaluating the Value of Augmenting In Vitro Hazard Assessment with Exposure and Pharmacokinetics Considerations for Chemical Prioritization

    Science.gov (United States)

    Over time, toxicity-testing paradigms have progressed from low-throughput in vivo animal studies for limited numbers of chemicals to high-throughput (HT) in vitro screening assays for thousands of chemicals. Such HT in vitro methods, along with HT in silico predictions of popula...

  3. Toxicity challenges in environmental chemicals: Prediction of human plasma protein binding through quantitative structure-activity relationship (QSAR) models

    Science.gov (United States)

    The present study explores the merit of utilizing available pharmaceutical data to construct a quantitative structure-activity relationship (QSAR) for prediction of the fraction of a chemical unbound to plasma protein (Fub) in environmentally relevant compounds. Independent model...

  4. The LINA Study: Higher Sensitivity of Infant Compared to Maternal Eosinophil/Basophil Progenitors to Indoor Chemical Exposures

    Directory of Open Access Journals (Sweden)

    Friederike Hörnig

    2016-01-01

    Full Text Available Purpose. Enhanced eosinophil/basophil (Eo/B progenitor cell levels are known to be associated with allergic inflammation and atopy risk. The aim of the present study was to investigate the influence of different indoor exposures on the recruitment and differentiation of Eo/B progenitors in mother-child pairs. Methods. In 68 mother-child pairs of the LINA study peripheral blood mononuclear cells were used to assess Eo/B colony forming units (CFUs. Information about disease outcomes and indoor exposures was obtained from questionnaires. Indoor concentrations of volatile organic compounds (VOCs were measured by passive sampling. Results. Infant’s Eo/B CFUs were positively associated with exposure to tobacco smoke, disinfectants, or VOCs. In contrast, for maternal Eo/B CFUs, only a few associations were seen. Higher numbers of infant Eo/B CFUs were observed in children with wheezing symptoms within the second year of life. Conclusions. We demonstrate that infant’s hematopoietic cells seem to respond with more sensitivity to environmental exposure compared to maternal cells. At least in infants, an activation of these hematopoietic cells by environmental exposure could contribute to an enhanced risk for the development of respiratory outcomes.

  5. Non-Hodgkin Lymphoma and Occupational Exposure to Agricultural Pesticide Chemical Groups and Active Ingredients: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Leah Schinasi

    2014-04-01

    Full Text Available This paper describes results from a systematic review and a series of meta-analyses of nearly three decades worth of epidemiologic research on the relationship between non-Hodgkin lymphoma (NHL and occupational exposure to agricultural pesticide active ingredients and chemical groups. Estimates of associations of NHL with 21 pesticide chemical groups and 80 active ingredients were extracted from 44 papers, all of which reported results from analyses of studies conducted in high-income countries. Random effects meta-analyses showed that phenoxy herbicides, carbamate insecticides, organophosphorus insecticides and the active ingredient lindane, an organochlorine insecticide, were positively associated with NHL. In a handful of papers, associations between pesticides and NHL subtypes were reported; B cell lymphoma was positively associated with phenoxy herbicides and the organophosphorus herbicide glyphosate. Diffuse large B-cell lymphoma was positively associated with phenoxy herbicide exposure. Despite compelling evidence that NHL is associated with certain chemicals, this review indicates the need for investigations of a larger variety of pesticides in more geographic areas, especially in low- and middle-income countries, which, despite producing a large portion of the world’s agriculture, were missing in the literature that were reviewed.

  6. Canine toys and training devices as sources of exposure to phthalates and bisphenol A: quantitation of chemicals in leachate and in vitro screening for endocrine activity.

    Science.gov (United States)

    Wooten, Kimberly J; Smith, Philip N

    2013-11-01

    Chewing and mouthing behaviors exhibited by pet dogs are likely to lead to oral exposures to a variety of environmental chemicals. Products intended for chewing and mouthing uses include toys and training devices that are often made of plastics. The goal of the current study was to determine if a subset of phthalates and bisphenol A (BPA), endocrine disrupting chemicals commonly found in plastics, leach out of dog toys and training devices (bumpers) into synthetic canine saliva. In vitro assays were used to screen leachates for endocrine activity. Bumper leachates were dominated by di-2-ethylhexyl phthalate (DEHP) and BPA, with concentrations reaching low μg mL(-1) following short immersions in synthetic saliva. Simulated chewing of bumpers during immersion in synthetic saliva increased concentrations of phthalates and BPA as compared to new bumpers, while outdoor storage had variable effects on concentrations (increased DEHP; decreased BPA). Toys leached substantially lower concentrations of phthalates and BPA, with the exception of one toy which leached considerable amounts of diethyl phthalate. In vitro assays indicated anti-androgenic activity of bumper leachates, and estrogenic activity of both bumper and toy leachates. These results confirm that toys and training devices are potential sources of exposure to endocrine disrupting chemicals in pet dogs. PMID:24007620

  7. Adverse Reproductive and Developmental Health Outcomes Following Prenatal Exposure to a Hydraulic Fracturing Chemical Mixture in Female C57Bl/6 Mice.

    Science.gov (United States)

    Kassotis, Christopher D; Bromfield, John J; Klemp, Kara C; Meng, Chun-Xia; Wolfe, Andrew; Zoeller, R Thomas; Balise, Victoria D; Isiguzo, Chiamaka J; Tillitt, Donald E; Nagel, Susan C

    2016-09-01

    Unconventional oil and gas operations using hydraulic fracturing can contaminate surface and groundwater with endocrine-disrupting chemicals. We have previously shown that 23 of 24 commonly used hydraulic fracturing chemicals can activate or inhibit the estrogen, androgen, glucocorticoid, progesterone, and/or thyroid receptors in a human endometrial cancer cell reporter gene assay and that mixtures can behave synergistically, additively, or antagonistically on these receptors. In the current study, pregnant female C57Bl/6 dams were exposed to a mixture of 23 commonly used unconventional oil and gas chemicals at approximately 3, 30, 300, and 3000 μg/kg·d, flutamide at 50 mg/kg·d, or a 0.2% ethanol control vehicle via their drinking water from gestational day 11 through birth. This prenatal exposure to oil and gas operation chemicals suppressed pituitary hormone concentrations across experimental groups (prolactin, LH, FSH, and others), increased body weights, altered uterine and ovary weights, increased heart weights and collagen deposition, disrupted folliculogenesis, and other adverse health effects. This work suggests potential adverse developmental and reproductive health outcomes in humans and animals exposed to these oil and gas operation chemicals, with adverse outcomes observed even in the lowest dose group tested, equivalent to concentrations reported in drinking water sources. These endpoints suggest potential impacts on fertility, as previously observed in the male siblings, which require careful assessment in future studies. PMID:27560547

  8. Experimental Investigation Of Microbially Induced Corrosion Of Test Samples And Effect Of Self-assembled Hydrophobic Monolayers. Exposure Of Test Samples To Continuous Microbial Cultures, Chemical Analysis, And Biochemical Studies

    CERN Document Server

    Laurinavichius, K S

    1998-01-01

    Experimental Investigation Of Microbially Induced Corrosion Of Test Samples And Effect Of Self-assembled Hydrophobic Monolayers. Exposure Of Test Samples To Continuous Microbial Cultures, Chemical Analysis, And Biochemical Studies

  9. Disentangling the developmental and neurobehavioural effects of perinatal exposure to a chemical mixture found in blood of Arctic populations: differential toxicity of mixture components

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, W.; Nakai, J.; Yagminas, A.; Chu, I.; Moir, D. [Health Canada (Canada)

    2004-09-15

    The current study was designed to evaluate the neurobehavioral effects of perinatal exposure to a chemical mixture that is based on relative concentrations of persistent organic pollutants found in the blood of Canadian Arctic populations and contains 14 PCB congeners, 12 organochlorine pesticides and methyl mercury. This study compared the effects of the complete mixture with the effects of three major components of the mixture (the PCB component, the organochlorine pesticide component, and the methyl mercury component). By examining a range of neurobehavioural functions over development we also determine if specific neurobehavioural disturbances produced by the mixture can be attributed to components of the mixture and if neurobehavioural effects produced by components of the mixture are altered by concurrent exposure to other components in the mixture. Ninety-two nulliparious female Sprague-Dawley rats served as subjects.

  10. Spaces of Uneventful Disaster Tracking Emergency Housing and Domestic Chemical Exposures from New Orleans to National Crises

    OpenAIRE

    Shapiro, Nicholas E; Hsu, Elisabeth; Lezaun, Javier

    2014-01-01

    In this thesis, I examine the politics, poetics, and logics of uneventful human harm in the United States by tracking the life and afterlife of a chemically contaminated emergency housing unit. In 2005, the Federal Emergency Management Agency (FEMA) deployed 120,000 trailers to the US Gulf Coast to house those displaced by Hurricanes Katrina and Rita. Chemical testing, spurred by reports of inhabitant illness, revealed elevated levels of formaldehyde emanating from the plywood walls of the tr...

  11. Foetal Hypothalamic and Pituitary Expression of Gonadotrophin Releasing Hormone and Galanin Systems is Disturbed by Exposure to Sewage Sludge Chemicals via Maternal Ingestion

    Science.gov (United States)

    Bellingham, Michelle; Fowler, Paul A.; Amezaga, Maria R.; Whitelaw, Christine M.; Rhind, Stewart M.; Cotinot, Corinne; Mandon-Pepin, Beatrice; Sharpe, Richard M.; Evans, Neil P.

    2016-01-01

    Animals and humans are chronically exposed to endocrine disrupting chemicals (EDCs) which are ubiquitous in the environment. There are strong circumstantial links between environmental EDC exposure and both declining human/wildlife reproductive health and the increasing incidence of reproductive system abnormalities. Verification of such links, however, is difficult and requires animal models exposed to 'real life', environmentally relevant concentrations/mixtures of environmental contaminants (ECs), particularly in- utero, when sensitivity to EC exposure is high. The aim of this study was to determine whether the fetal sheep reproductive neuroendocrine axis, particularly GnRH and galaninergic systems were affected by maternal exposure to a complex mixture of chemicals, applied to pasture, in the form of sewage sludge. Sewage sludge contains high concentrations of a spectrum of EDCs and other pollutants, relative to environmental concentrations but is frequently recycled to land as a fertiliser. We found that foetuses exposed, to the EDC mixture in-utero through their mothers, had lower GnRH mRNA expression in the hypothalamus and lower GnRHR and galanin receptor (GALR) mRNA expression in the hypothalamus and pituitary gland. Strikingly, this, treatment had no significant effect on maternal GnRH or GnRHR mRNA expression although GALR mRNA expression within the maternal hypothalamus and pituitary gland was reduced. This study clearly demonstrates that the developing foetal neuroendocrine axis is sensitive to real-world mixtures of environmental chemicals. Given the important role of GnRH and GnRHR in the regulation of reproductive function, its known in-utero programming role, and the role of galanin in the regulation of many physiological/neuroendocrine systems, in-utero changes in the activity of these systems are likely to have long term consequences in adulthood and represent a novel pathway through which EC mixtures could perturb normal reproductive function

  12. Calibration of nylon organic chemical integrative samplers and sentinel samplers for quantitative measurement of pulsed aquatic exposures.

    Science.gov (United States)

    Morrison, Shane A; Belden, Jason B

    2016-06-01

    Environmental exposures often occur through short, pulsed events; therefore, the ability to accurately measure these toxicologically-relevant concentrations is important. Three different integrative passive sampler configurations were evaluated under different flow and pulsed exposure conditions for the measurement of current-use pesticides (n=19), polyaromatic hydrocarbons (n=10), and personal care products (n=5) spanning a broad range of hydrophobicities (log Kow 1.5-7.6). Two modified POCIS-style samplers were investigated using macroporous nylon mesh membranes (35μm pores) and two different sorbent materials (i.e. Oasis HLB and Dowex Optipore L-493). A recently developed design, the Sentinel Sampler (ABS Materials), utilizing Osorb media enclosed within stainless steel mesh (145μm pores), was also investigated. Relatively high sampling rates (Rs) were achieved for all sampler configurations during the short eight-day exposure (4300-27mL/d). Under flow conditions, median Rs were approximately 5-10 times higher for POCIS-style samplers and 27 times higher for Sentinel Samplers, as compared to static conditions. The ability of samplers to rapidly measure hydrophobic contaminants may be a trade off with increased flow dependence. Analyte accumulation was integrative under pulsed and continuous exposures for POCIS-style samplers with mean difference between treatments of 11% and 33%; however, accumulation into Sentinel Samplers was more variable. Collectively, results show that reducing membrane limitations allows for rapid, integrative accumulation of a broad range of analytes even under pulsed exposures. As such, these sampler designs may be suitable for monitoring environmental substances that have short aquatic half-lives. PMID:27139214

  13. Is Case-Based Learning an Effective Teaching Strategy to Challenge Students' Alternative Conceptions regarding Chemical Kinetics?

    Science.gov (United States)

    Yalcinkaya, Eylem; Tastan-Kirik, Ozgecan; Boz, Yezdan; Yildiran, Demet

    2012-01-01

    Background: Case-based learning (CBL) is simply teaching the concept to the students based on the cases. CBL involves a case, which is a scenario based on daily life, and study questions related to the case, which allows students to discuss their ideas. Chemical kinetics is one of the most difficult concepts for students in chemistry. Students…

  14. Burden of disease and costs of exposure to endocrine disrupting chemicals in the European Union: an updated analysis

    DEFF Research Database (Denmark)

    Trasande, L.; Zoeller, R. T.; Hass, Ulla;

    2016-01-01

    A previous report documented that endocrine disrupting chemicals contribute substantially to certain forms of disease and disability. In the present analysis, our main objective was to update a range of health and economic costs that can be reasonably attributed to endocrine disrupting chemical...... Group, and evaluated laboratory and animal evidence of endocrine disruption using definitions recently promulgated by the Danish Environmental Protection Agency. The Delphi method was used to make decisions on the strength of the data. Expert panels consensus was achieved for probable (>20%) endocrine...... disrupting chemical causation for IQ loss and associated intellectual disability; autism; attention deficit hyperactivity disorder; endometriosis; fibroids; childhood obesity; adult obesity; adult diabetes; cryptorchidism; male infertility, and mortality associated with reduced testosterone. Accounting...

  15. Formation of Glycidyl Fatty Acid Esters Both in Real Edible Oils during Laboratory-Scale Refining and in Chemical Model during High Temperature Exposure.

    Science.gov (United States)

    Cheng, Weiwei; Liu, Guoqin; Liu, Xinqi

    2016-07-27

    In the present study, the formation mechanisms of glycidyl fatty acid esters (GEs) were investigated both in real edible oils (soybean oil, camellia oil, and palm oil) during laboratory-scale preparation and refining and in chemical model (1,2-dipalmitin (DPG) and 1-monopalmitin (MPG)) during high temperature exposure (160-260 °C under nitrogen). The formation process of GEs in the chemical model was monitored using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. The results showed that the roasting and pressing process could produce certain amounts of GEs that were much lower than that produced in the deodorization process. GE contents in edible oils increased continuously and significantly with increasing deodorization time below 200 °C. However, when the temperature exceeded 200 °C, GE contents sharply increased in 1-2 h followed by a gradual decrease, which could verify a simultaneous formation and degradation of GEs at high temperature. In addition, it was also found that the presence of acylglycerol (DAGs and MAGs) could significantly increase the formation yield of GEs both in real edible oils and in chemical model. Compared with DAGs, moreover, MAGs displayed a higher formation capacity but substantially lower contribution to GE formation due to their low contents in edible oils. In situ ATR-FTIR spectroscopic evidence showed that cyclic acyloxonium ion intermediate was formed during GE formation derived from DPG and MPG in chemical model heated at 200 °C. PMID:27319409

  16. Chemical characterization of exhaled breath to differentiate between patients with malignant plueral mesothelioma from subjects with similar professional asbestos exposure

    Energy Technology Data Exchange (ETDEWEB)

    Gennaro, G. de; Longobardi, F.; Stallone, G.; Trizio, L.; Tutino, M. [University of Bari Aldo Moro, Department of Chemistry, Bari (Italy); Dragonieri, S. [University of Bari Aldo Moro, Department of Pulmonology, Bari (Italy); Musti, M. [University of Bari Aldo Moro, Department of Occupational Medicine, Bari (Italy)

    2010-12-15

    Malignant pleural mesothelioma (MPM) is an aggressive tumour whose main aetiology is the long-term exposure to asbestos fibres. The diagnostic procedure of MPM is difficult and often requires invasive approaches; therefore, it is clinically important to find accurate markers for MPM by new noninvasive methods that may facilitate the diagnostic process and identify patients at an earlier stage. In the present study, the exhaled breath of 13 patients with histology-established diagnosis of MPM, 13 subjects with long-term certified professional exposure to asbestos (EXP) and 13 healthy subjects without exposure to asbestos (healthy controls, HC) were analysed. An analytical procedure to determine volatile organic compounds by sampling of air on a bed of solid sorbent and thermal desorption GC-MS analysis was developed in order to identify the compounds capable of discriminating among the three groups. The application of univariate (ANOVA) and multivariate statistical treatments (PCA, DFA and CP-ANN) showed that cyclopentane and cyclohexane were the dominant variables able to discriminate among the three groups. In particular, it was found that cyclohexane is the only compound able to differentiate the MPM group from the other two; therefore, it can be a possible marker of MPM. Cyclopentane is the dominant compound in the discrimination between EXP and the other groups (MPM and HC); then, it can be considered a good indicator for long-term asbestos exposure. This result suggests the need to perform frequent and thorough investigations on people exposed to asbestos in order to constantly monitor their state of health or possibly to study the evolution of disease over time. (orig.)

  17. Transcriptomic profiling of Alexandrium fundyense during physical interaction with or exposure to chemical signals from the parasite Amoebophrya

    OpenAIRE

    Lu, Yameng; Wohlrab, Sylke; Groth, Marco; Glöckner, Gernot; Guillou, Laure; John, Uwe

    2016-01-01

    Toxic microalgae have their own pathogens, and understanding the way in which these microalgae respond to antagonistic attacks may provide information about their capacity to persist during harmful algal bloom events. Here, we compared the effects of the physical presence of the parasite Amoebophrya sp. and exposure to waterborne cues from cultures infected with this parasite, on gene expression by the toxic dinoflagellates, Alexandrium fundyense. Compared with control samples, a total of 14 ...

  18. Chemical exposure reduction: Factors impacting on South African herbicide sprayers' personal protective equipment compliance and high risk work practices.

    Science.gov (United States)

    Andrade-Rivas, Federico; Rother, Hanna-Andrea

    2015-10-01

    The high exposure risks of workers to herbicides in low- and middle-income countries is an important public health concern because of the potential resulting negative impacts on workers' health. This study investigated workers' personal protective equipment (PPE) compliance as a risk mitigation measure; particularly workers who apply herbicides for Working for Water (WfW) - a South African invasive alien vegetation control programme. The study aim was to understand workers' low PPE compliance by analysing their risk perceptions of herbicide use, working conditions and socio-cultural context. Research methods included ethnographic observations, informal interviews, visual media, questionnaires and a focus group. Study results indicated that low PPE compliance persists despite workers' awareness of herbicide exposure risks and as a result of the influence from workers' socio-cultural context (i.e. gender dynamics and social status), herbicide risk perceptions and working conditions (i.e. environmental and logistical). Interestingly, teams comprised of mostly women had the highest compliance rate. These findings highlighted that given the complexity of PPE compliance, especially in countries with several economic and social constraints, exposure reduction interventions should not rely solely on PPE use promotion. Instead, other control strategies requiring less worker input for effectiveness should be implemented, such as elimination and substitution of highly hazardous pesticides, and altering application methods. PMID:26093240

  19. Experimental paradigm for in-lab proxy aquatic studies under conditions of static, non flow through chemical exposures

    Science.gov (United States)

    Endocrine disrupting chemicals (EDCs) such as 17α ethynylestradiol (EE2), 17β estradiol (E2), estrone (E1) and para-nonylphenol (NP) have been measured in wastewater treatment plant effluents, surface waters, sediments and sludge, and have been shown to induce liver-sp...

  20. A First Exploration of Health Impact Assessment of Chemical Exposure: Assigning Weights to Subclinical Effects Based on Animal Studies

    NARCIS (Netherlands)

    Burg, W. ter; Bokkers, B.G.H.; Kroese, E.D.; Schuur, A.G.

    2015-01-01

    ABSTRACT: Health impact assessments (HIA) have become an important tool for applying evidence-based policy. Recently, the concept of HIA has been introduced in the field of chemical substances. Two main issues are encountered, i.e., the focus of risk assessment is deriving safe levels and on first s

  1. Development of databases for use in validation studies of probabilistic models of dietary exposure to food chemicals and nutrients

    NARCIS (Netherlands)

    Leclerq, C.; Arcella, D.; Armentia, A.; Boon, P.E.; Kruizinga, A.G.; Gilsenan, M.B.; Thompson, R.L.

    2003-01-01

    The data currently available in the European Union in terms of food consumption and of food chemical and nutrient concentration data present many limitations when used for estimating intake. The most refined techniques currently available were used within the European Union FP5 Monte Carlo project t

  2. Chemical Leukoderma.

    Science.gov (United States)

    Bonamonte, Domenico; Vestita, Michelangelo; Romita, Paolo; Filoni, Angela; Foti, Caterina; Angelini, Gianni

    2016-01-01

    Chemical leukoderma, often clinically mimicking idiopathic vitiligo and other congenital and acquired hypopigmentation, is an acquired form of cutaneous pigment loss caused by exposure to a variety of chemicals that act through selective melanocytotoxicity. Most of these chemicals are phenols and aromatic or aliphatic catechols derivatives. These chemicals, however, are harmful for melanocytes in individuals with an individual susceptibility. Nowadays, chemical leukoderma is fairly common, caused by common domestic products. The presence of numerous acquired confetti- or pea-sized macules is clinically characteristic of chemical leukoderma, albeit not diagnostic. Other relevant diagnostic elements are a history of repeated exposure to a known or suspected depigmenting agent at the sites of onset and a macules distribution corresponding to sites of chemical exposure. Spontaneous repigmentation has been reported when the causative agent is avoided; the repigmentation process is perifollicular and gradual, taking place for a variable period of weeks to months. PMID:27172302

  3. Analysis of determination modalities concerning the exposure and emission limits values of chemical and radioactive substances; Analyse des modalites de fixation des valeurs limites d'exposition et d'emission pour les substances chimiques et radioactives

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, C.; Schneider, T

    2002-08-01

    This document presents the generic approach adopted by various organizations for the determination of the public exposure limits values to chemical and radioactive substances and for the determination of limits values of chemical products emissions by some installations. (A.L.B.)

  4. Concentration and chemical status of arsenic in the blood of pregnant hamsters during critical embryogenesis. 1. Subchronic exposure to arsenate utilizing constant rate administration

    International Nuclear Information System (INIS)

    The concentration, availability, and chemical status of radiolabeled arsenic has been determined in the blood of pregnant hamsters at the beginning (morning of Day 8) and the end (morning of Day 9) of the critical period of embryogenesis. Hamster dams were exposed to teratogenic doses of arsenate by means of osmotic minipumps implanted on the morning of Day 6 of the gestation period. Whole blood arsenic concentrations were the same for 48 and 72 hr postimplant. The arsenic concentration of plasma equaled that of red cells. Plasma arsenic was not bound to macromolecules and had the same chemical status 48 and 72 hr postimplant. Arsenate was the dominant form (67% of the total). However, the presence of dimethylarsinic acid and arsenite indicates that the pentavalent species was metabolized. Red cell arsenic was bound to macromolecules in the cell sap. Seventy percent of red cell sap arsenic was dialyzable 48 hr postimplant, but only 56% 72 hr postimplant. Arsenate was the dominant dialyzable red cell species on Day 8 and arsenite was the major dialyzable form on Day 9. The authors findings demonstrate a relationship between the maternal blood concentration and chemical status of arsenic and the presence of malformations resulting from a constant rate exposure of pregnant hamsters to arsenate via the osmotic minipump

  5. Diversity of active microbial communities subjected to long-term exposure to chemical contaminants along a 40-year-old sediment core.

    Science.gov (United States)

    Kaci, Assia; Petit, Fabienne; Fournier, Matthieu; Cécillon, Sébastien; Boust, Dominique; Lesueur, Patrick; Berthe, Thierry

    2016-03-01

    In estuarine ecosystems, metallic and organic contaminants are mainly associated with fine grain sediments which settle on mudflats. Over time, the layers of sediment accumulate and are then transformed by diagenetic processes mainly controlled by microbial activity, recording the history of the estuary's chemical contamination. In an environment of this specific type, we investigated the evolution of the chemical contamination and the structure of both total and active microbial communities, based on PhyloChip analysis of a 4.6-m core corresponding to a 40-year sedimentary record. While the archaeal abundance remained constant along the core, a decrease by one order of magnitude in the bacterial abundance was observed with depth. Both total and active microbial communities were dominated by Proteobacteria, Actinobacteria, and Firmicutes in all sediment samples. Among Proteobacteria, alpha-Proteobacteria dominated both total (from 37 to 60 %) and metabolically active (from 19.7 to 34.6 %) communities, including the Rhizobiales, Rhodobacter, Caulobacterales, and Sphingomonadales orders. Co-inertia analysis revealed a relationship between polycyclic aromatic hydrocarbons, zinc and some polychlorobiphenyls concentrations, and the structure of total and active microbial communities in the oldest and most contaminated sediments (from 1970 to 1975), suggesting that long-term exposure to chemicals shaped the structure of the microbial community. PMID:25934230

  6. Risks assessment of environmental exposure to certain organo chemicals in male rats: the possible modulatory effect of micro nutrients

    International Nuclear Information System (INIS)

    Trichloroethylene (TCE) is a widely volatile organic compound, because of its widespread commercial use. So, TCE become a major environmental pollutant. It is the most frequently reported organic contaminant in ground water, so a considerable numbers of people are exposed to TCE via inhalation, through the skin or through drinking water and rarely through food. The main symptoms of exposure are headache, dizziness, and confusion, beyond the effects on the central nervous system, work place exposure to TCE has been associated with toxic effects in many organs including liver, kidney and testes in addition to attenuation to the immune system. The present study aims to investigate the possible modulatory effect of certain micro nutrients such as vitamin C and zinc alone and in combination on the damage of liver, kidney and testes of male rats intoxicated with trichloroethylene for 20 and 105 days. The results showed significant decrease in body and testes weight and increase in liver and kidney weights after long period of treatment with TCE. Some of the selected hematological and biochemical parameters of the rats intoxicated by TCE for short and long period significantly changed. The results revealed significant decrease in free tetraiodothyronine (thyroxine) (FT4) and significant increase in free triiodothyronine (FT3) and thyroid stimulating hormone (Thyrotropin) (TSH) in TCE-intoxicated rat groups for the two periods of treatment. Also results revealed significant decrease of total testosterone in TCE-intoxicated rat groups as compared to that of normal control. Also significant changes were detected in the level of immunoglobulins IgG and IgM.Histopathological examination of liver, kidney and testicular tissues showed significant alteration. The DNA damage was observed in both period of treatment and increased DNA damage with apoptosis was recorded after 105 days of the treatment. Withdrawal group recorded mild improvement in all changed parameters and the

  7. Current approaches and challenges for chemical characterization of inhibitory effect against cancer cell line isolated from Gokshur extract.

    Science.gov (United States)

    Bouabdallah, Salwa; Sghaier, Rabiaa-M; Selmi, Sawssen; Khlifi, Daycem; Laouini, Dhafer; Ben-Attia, Mossadok

    2016-07-15

    In the present study, the potential effect anti tumor and the chemical composition of different fractions of Gokshur was evaluated. Commonly known as puncture vine, it has been used for a long time in both the Indian and traditional Chinese medicine. It is popularly used as a remedy for fertility disorder in Ayurveda. Samples were collected during June-September 2014 in the Cap Bon (north east of the northern Tunisia). Different organs were separated and extracted by sequential process to compare and investigate their potential anti-tumor effect. For the first time, we report the antiproliferatif effect of leaves n-butannolic fraction against cancer cell lines. The better anti-tumor fraction (94.76±1.52%) has been detected and performed by RP-HPLC has shown a great peak area (5578.21Mau). Novel designed natural derivatives from Gokshur, a cyclotrisiloxane, major compound identified by GC-MS. PMID:26711680

  8. Blood plasma clinical-chemical parameters as biomarker endpoints for organohalogen contaminant exposure in Norwegian raptor nestlings

    DEFF Research Database (Denmark)

    Sonne, Christian; Bustnes, Jan O.; Herzke, Dorte;

    2012-01-01

    Raptors are exposed to biomagnifying and toxic organohalogenated compounds (OHCs) such as organochlorines, brominated flame retardants and perfluorinated compounds. To investigate how OHC exposure may affect biochemical pathways we collected blood plasma from Norwegian northern goshawk (n=56......), golden eagle (n=12) and white-tailed eagle (n=36) nestlings during three consecutive breeding seasons. We found that blood plasma concentrations of calcium, sodium, creatinine, cholesterol, albumin, total protein, urea, inorganic phosphate, protein:creatinine, urea:creatinine and uric acid...... were also negatively correlated to PCBs and PFCs, respectively. The most significant relationships were found for the highly contaminated northern goshawks and white-tailed eagles. The statistical relationships between OHCs and BCCPs indicate that biochemical pathways could be influenced while it is...

  9. Standardization of Chemical Analytical Techniques for Pyrolysis Bio-Oil: History, Challenges, and Current Status of Methods

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, Jack R., III; Olarte, Mariefel V.; Christensen, Earl D.; Padmaperuma, Asanga B.; Connatser, Raynella M.; Stankovikj, Filip; Meier, Dietrich; Paasikallio, Ville

    2016-09-01

    In this perspective, we discuss the standardization of analytical techniques for pyrolysis bio-oils, including the current status of methods, and our opinions on future directions. First, the history of past standardization efforts is summarized, and both successful and unsuccessful validation of analytical techniques highlighted. The majority of analytical standardization studies to-date has tested only physical characterization techniques. Here, we present results from an international round robin on the validation of chemical characterization techniques for bio-oils. Techniques tested included acid number, carbonyl titrations using two different methods (one at room temperature and one at 80 degrees C), 31P NMR for determination of hydroxyl groups, and a quantitative gas chromatography-mass spectrometry (GC-MS) method. Both carbonyl titration and acid number methods have yielded acceptable inter-laboratory variabilities. 31P NMR produced acceptable results for aliphatic and phenolic hydroxyl groups, but not for carboxylic hydroxyl groups. As shown in previous round robins, GC-MS results were more variable. Reliable chemical characterization of bio-oils will enable upgrading research and allow for detailed comparisons of bio-oils produced at different facilities. Reliable analytics are also needed to enable an emerging bioenergy industry, as processing facilities often have different analytical needs and capabilities than research facilities. We feel that correlations in reliable characterizations of bio-oils will help strike a balance between research and industry, and will ultimately help to determine metrics for bio-oil quality. Finally, the standardization of additional analytical methods is needed, particularly for upgraded bio-oils.

  10. Chronic uranium exposure and growth toxicity for phytoplankton. Dose-effect relationship: first comparison of chemical and radiological toxicity

    International Nuclear Information System (INIS)

    The bioavailability of uranium for freshwater organisms, as for other dissolved metals, is closely linked to chemical speciation in solution (U aqueous speciation undergoes tremendous changes in the presence of ligands commonly found in natural waters e.g. carbonate, phosphate, hydroxide and natural organic matter). For the studied chemical domain, short-term uranium uptake experiments have already shown that the free uranyl ion concentration [UO22+] is a good predictor of uranium uptake by the green algae Chlamydomonas reinhardtii, as predicted by the Free Ion Activity Model. In agreement with these results, acidic pH and low ligands concentrations in water enhance uranium bioavailability and consequently its potential chronic effects on phytoplankton. Moreover, uranium is known to be both radio-toxic and chemo-toxic. The use of different isotopes of uranium allows to expose organisms to different radiological doses for the same molar concentration: e.g. for a given element concentration (chemical dose), replacing depleted U by U-233 obviously leads to an enhanced radiological delivered dose to organisms (x104). In this work we established relationships between uranium doses (depleted uranium and 233-U ) and effect on the growth rate of the green algae Chlamydomonas reinhardtii. Uranium bioaccumulation was also monitored. Growth rate was measured both in classical batch (0-72 hrs) and continuous (turbidostat) cultures, the latter protocol allowing medium renewal to diminish exudates accumulation and speciation changes in the medium. The differences in effects will be, if possible, related to the development of defence mechanisms against the formation of reactive oxygen species (forms of glutathione) and the production of phyto-chelatins (small peptides rich in cystein that play an important role in the homeostasis and the detoxication of metals in cells). (author)

  11. Concentration and chemical status of arsenic in the blood of pregnant hamsters during critical embryogenesis. 2. Acute exposure

    International Nuclear Information System (INIS)

    The concentration and chemical composition of arsenic has been determined in the blood of pregnant hamsters between 0.2 and 6 hr after an intraperitoneal injection of a teratogenic dose of radiolabeled sodium arsenate on the morning of the eighth day of gestation. Arsenic was present in plasma and red cells 0.20 hr postinjection. The plasma arsenic concentration reached a maximum of 220 μmole/kg blood near 0.5 hr postinjection. Plasma arsenic existed entirely as low-molecular-weight species. Both arsenite and dimethylarsinate (DMA) were present in plasma 0.20 hr postinjection, indicating that arsenate reduction and methylation of arsenic are rapidly initiated. However, the arsenite contribution remained small while the DMA contribution increased with time. Red cells arsenic included macromolecular arsenic (AsP) as well as three low-molecular-weight forms. The contribution of DMA remained small, but arsenite and AsP contributions increased with time. These findings identify the maternal blood concentration and chemical status of arsenic following the administration of a teratogenic dose of arsenate during the period of organogenesis. They could prove useful for predicting the likelihood of a teratogenic outcome in other mammalian species

  12. Effect of the laser exposure of seeds on the yield and chemical composition of sugar beet roots

    Directory of Open Access Journals (Sweden)

    U. Bojarska

    1996-06-01

    Full Text Available The purpose of the research was to characterize the effect of the pre-sowing laser biostimula-tion of sugar beet seeds on the biometric features, yielding and chemical composition of sugar beet roots. Four varieties of sugar beets were studied: Colibri, Evita, Kawetina, and Maria. Their seeds were biostimulated during free falling with divergent He-Ne laser beams (40 mW, placed one upon another. The experiments were conducted ace. to the split-plot method in 3 repetitions. Before the harvesting, 20 plants were measured biometrically for the length of leaves, weight of leaves, sticking out of roots over the surface of soil, length, weight, diameter, and circumference of roots. During the harvest, the yield of roots and leaves was specified and after the harvest the chemical analysis was made to check the plant dry mass, the content of sugar, soluble ash, alpha-amine nitrogen, P, K, Ca, Mg, Na, Fe, Zn, Mn, Cu. The results of the research showed beneficial effects of the laser pre-sowing stimulation of sugar beet seeds. In all the combinations concerning the biostimulated seeds, the yield of roots was elevated from 3,2 to 4,5 t/ha, which means an 8-10 % increase when compared to the control (non-biostimulated seeds. The sugar content was also elevated after the laser biostimulation, which caused an increase in the biological yield for about 1 t/ha independently of the variety in comparison with the control.

  13. Combined Toxic Exposures and Human Health: Biomarkers of Exposure and Effect

    Directory of Open Access Journals (Sweden)

    Johan Högberg

    2011-02-01

    Full Text Available Procedures for risk assessment of chemical mixtures, combined and cumulative exposures are under development, but the scientific database needs considerable expansion. In particular, there is a lack of knowledge on how to monitor effects of complex exposures, and there are few reviews on biomonitoring complex exposures. In this review we summarize articles in which biomonitoring techniques have been developed and used. Most examples describe techniques for biomonitoring effects which may detect early changes induced by many chemical stressors and which have the potential to accelerate data gathering. Some emphasis is put on endocrine disrupters acting via epigenetic mechanisms and on carcinogens. Solid evidence shows that these groups of chemicals can interact and even produce synergistic effects. They may act during sensitive time windows and biomonitoring their effects in epidemiological studies is a challenging task.

  14. Protective Effect of Distillate and Redistillate of Cow's Urine in Human Polymorphonuclear Leukocytes Challenged With Established Genotoxic Chemicals

    Institute of Scientific and Technical Information of China (English)

    K. KRISHNAMURTHI; DIPANWITA DUTTA; S. D. SIVANESAN; T. CHAKRABARTI

    2004-01-01

    From the ancient period cow's urine has been used as a medicine. In Veda, cow's urine was compared to the nectar. In Susrut, several medicinal properties of cow's urine have been mentioned and are known to cause weight loss, reversal of certain cardiac and kidney problems, indigestion, stomach ache, edema, etc. However, the literature and scripture did not mention the antigenotoxic properties of cow's urine. Methods In the present investigation, the antigenotoxic/ antioxidant properties of cow's urine distillate and redistillate were studied in vitro. The antioxidant status and volatile fatty acid levels were determined. Actinomycin-D (0.1 μmol/L) and hydrogen peroxide (150 μmol/L) were used for inducing DNA strand break with 0.1% DMSO as negative control. Dose for the antigenotoxic effect of cow's urine was chosen from the dose response study carried out earlier. Results Both actinomycin-D and H2O2 caused statistically significant DNA unwinding of 80% & 75% respectively (P<0.001) as revealed by fluorimetric analysis of DNA unwinding (FADU), and the damage could be protected with the redistilled cow's urine distillate (1, 50 & 100 μL) in simultaneous treatment with genotoxic chemicals. Conclusion The redistillate of cow's urine was found to possess total antioxidant status of around 2.6 mmol, contributed mainly by volatile fatty acids (1500 mg/L) as revealed by the GC-MS studies. These fatty acids and other antioxidants might cause the observed protective effects.

  15. Teacher educators and the challenge to enhance the teaching in chemical sciences in with the merger of mobile devices

    Directory of Open Access Journals (Sweden)

    Liliane da Silva Coelho Jacon

    2014-03-01

    Full Text Available Researches suggest that most teachers have not had the opportunity to qualify for the incorporation of Information and Communication Technologies (ICT in classroom practice. Many researches state that in order to incorporate ICT within a pedagogical framework that will result in real change in the teaching-learning process is essential to rethink the undergraduate syllabus, identifying and transforming practices in the preparation of future teachers. This paper presents partial results of a qualitative research that was developed as part of a doctorate and aims to promote the ongoing professional development of teacher training providers in the field of chemical science and informatics, thus providing a pedagogical practice beyond physical and formal context of traditional classroom-based. This study was an exploratory research developed through cooperation and collaboration and was especially designed by two trainers who prepared a directed study to be used with mobile devices with the goal to enhance the teaching knowledge of chemistry with mobile devices for students in their initial training course in Chemistry at Federal University of Rondonia (UNIR. The research was carried out on voluntary basis and despite of expectations to employ this technology in the educational field, it was found that just few students had access to mobile devices with compatible platform used in this research. The research showed that learning with mobile devices increases interest, motivation and most importantly, the curiosity of the students to learn in a different way. However technological and economic reasons remains a major issue.

  16. Chronic exposure to uranium compounds: medical surveillance problems related to their physico-chemical properties and their solubility: actual data and future prospects

    International Nuclear Information System (INIS)

    A method was developped to assess uranium exposure hazards at work stations based on industrial experience acquired in Comurhex Malvesi at Narbonne. Applied to uranium tetrafluoride (UF4), the method involves five steps: 1/ Characterization of the industrial compound, including physico-chemical properties (density, surface area, X-ray spectrum and uranium enrichment). 2/ In vitro biological solubility with different synthetic fluids like Gamble solution added with differents gaz or compounds (Oxygen or hydrogen peroxyde), in order to determine the solubility class D, W or Y. 3/ Assessment of work station concentration in Bq m-3 and particle size distribution (AMAD). 4/ Monitoring workers by routine urinary excretion completed, if necessary, by fecal excretion and γ spectrometry. 5/ Use of individual protection filters or masks. Results and actual data on UF4 are presented and future prospects of studies on calcinated uranates are dealed with

  17. Morphological peculiarities of chronic gastritis in children and adolescents of Belarus under conditions of low dose radiation-chemical exposure

    International Nuclear Information System (INIS)

    Following the accident at the Chernobyl nuclear power station, the unfavourable ecological situation due to chemical contamination of the environment was aggravated by the radiation effect. At present, radionuclides of caesium and lead, as well as the nitrates, are the most widely distributed ecotoxicants. Under conditions of the negative ecological effect as the result of per os penetration of the majority of xenobiotics, the gastro-intestinal tract is at particular risk. During 1990-1994, 442 children and adolescents aged 10-17 residing at the ecologically different regions of the Republic have been examined. The program of examination included morphological investigation of bioptates of the stomach mucous membrane, determination of the radiocaesium specific activity in the body and the evaluation of lead content in blood and nitrates content in urine. (author)

  18. Sub-micron period grating structures in Ta2O5 thin oxide films patterned using UV laser post-exposure chemically assisted selective etching

    International Nuclear Information System (INIS)

    A high-resolution and low-damage method for patterning relief structures in thin Ta2O5 films by chemically assisted UV laser selective etching is presented. The method is based on the initial exposure of the Ta2O5 films to pulsed UV radiation (quadrupled Nd:YAG laser at 266 nm) at fluences below the ablation threshold, for the creation of volume damage in the exposed areas. Subsequent immersion of the exposed sample in a KOH solution results in selective etching of the UV-exposed areas, developing relief structures of high quality. Interferometric exposure was used for the patterning of such gratings with periods of the order of 500 nm in films with a thickness of 100 and 500 nm. The behaviour of the patterning process is studied using diffraction efficiency measurements and AFM scans. Diffraction efficiency increases by a factor of ∼63, compared to the undeveloped structure, were obtained for gratings exposed with 1000 pulses of 30 mJ/cm2 energy density, which were developed in a KOH solution. The etching method presented is being applied to the fabrication of gratings in optical waveguides

  19. Chlorobenzylidenemalonitrile Gas Exposure from A Novelty Personal-Protection Gun

    Directory of Open Access Journals (Sweden)

    Dong, Christopher

    2007-05-01

    Full Text Available We present an unusual case of chlorobenzylidenemalonitrile (CS tear-gas exposure from the unwitting discharge of a personal-protection handgun loaded with CS gas. The gun was in a bag of toys purchased from a local thrift store and was discharged by a child. The responding paramedic presumptively identified the substance as CS based solely on personal experience. This recognition led to suboptimal field management of the incident with the paramedic failing to follow the standard operating procedures for an unknown chemical exposure. As this was a benign agent, there were no serious consequences. This case highlights the pre-hospital and emergency department challenges associated with the management of an unknown chemical exposure and the potential consequences if the chemical is a toxic substance. A methodical approach following established protocols can reduce the potential for negative outcomes. Review of the literature found no other report of CS gas exposure from such a personal-protection weapon.

  20. Heterogeneous catalysis and the challenges of powering the planet, securing chemicals for civilised life, and clean efficient utilization of renewable feedstocks.

    Science.gov (United States)

    Thomas, John Meurig

    2014-07-01

    This article reviews, first, the prospects, practices and principles of generating solar fuels. It does so with an analysis of recent progress in the light-driven emission of H2 (and other fuels) as well as O2 from water. To place this challenge in perspective, some current practices entailing the use of well-proven solid catalysts developed for fossil-based feedstocks, are described. The massive differences between proven methods of generating fuel and chemicals from non-renewable and from solar radiation are emphasized with the aid of numerous quantitative examples. Whilst it is acknowledged that a key action in reducing the liberation of greenhouse gases (GHG) is to tackle the challenge of decreasing their evolution in power generation and in the production of steel, aluminium and other bulk commodities (metals, alloys, concrete and ceramics), nevertheless much can be done to diminish the emission of CO2 (and to use it as feedstock) through the agency of new, designed solid catalysts and microalgae. Solar-thermal converters are also attractive alternatives, even though they are more likely to be used centrally rather than in small modular units like 'artificial leaves,' some of which are promising for the purposes of generating energy (and perhaps fuel) in a delocalized, modular manner. PMID:24988917

  1. Gravimetrical and chemical characterization of SiOx structures deposited on fine powders by short plasma exposure in a plasma down stream reactor

    International Nuclear Information System (INIS)

    The surface of lactose particles was modified by a plasma-enhanced chemical vapor deposition process to improve the flow behavior of the powder. For this, the particulates were treated in a plasma down stream reactor which provides a short (50 ms) and homogeneous exposure to the capacitively coupled RF discharge. The organosilicon monomer hexamethyldisiloxane (HMDSO) was used as a precursor for the formation of SiOx which is deposited on the substrate particle surface. For varying process gas mixtures (O2/Ar/HMDSO) and RF power applied, the amount of the deposited material was determined gravimetrically after dissolution of the lactose substrate particles and the chemical composition of the accumulated deposition material was investigated by means of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The concentration of the deposited SiOx relating to the substrate material was found to be in the range of 0.1 wt.%. Based on the ATR-FTIR analysis, the inorganic, i.e. oxidic SiOx fraction of the obtained deposits was shown to be controllable by varying the process parameters, whilst a relatively large amount of organic structures must be considered.

  2. Prevalence of symptoms of systemic lupus erythematosus (SLE) and of fluorescent antinuclear antibodies associated with chronic exposure to trichloroethylene and other chemicals in well water

    Energy Technology Data Exchange (ETDEWEB)

    Kilburn, K.H.; Warshaw, R.H. (Univ. of Southern California, Los Angeles (United States))

    1992-02-01

    Criteria for the recognition of systemic lupus erythematosus (SLE) were applied to 362 subjects exposed to trichloroethylene, trichloroethane, inorganic chromium, and other chemicals in water obtained from wells in an industrially contaminated aquifer in Tucson, Arizona. Their antinuclear autoantibodies were measured by fluorescence (FANA) in serum. Ten patients with clinical SLE and/or other collagen-vascular diseases were considered separately. Results were compared to an Arizona control group, to published series, and to laboratory controls. Frequencies of each of 10 ARA symptoms were higher in exposed subjects than in any comparison group except those with clinical SLE. The number of subjects with 4 or more symptoms was 2.3 times higher compared to referent women and men. FANA titers > 1:80 was approximately 2.3 times higher in women but equally frequent in men as in laboratory controls. ARA score and FANA rank were correlated with a coefficient (cc) of .1251, r{sup 2} = .0205 in women and this correlation was almost statistically significant in men cc = .1282, r{sup 2} = .0253. In control men and women neither correlation was significant. Long-term low-dose exposure to TCE and other chemicals in contaminated well water significantly increased symptoms of lupus erthematosus as perceived by the ARA score and the increased FANA titers.

  3. Gravimetrical and chemical characterization of SiO{sub x} structures deposited on fine powders by short plasma exposure in a plasma down stream reactor

    Energy Technology Data Exchange (ETDEWEB)

    Spillmann, Adrian; Sonnenfeld, Axel [Institute of Process Engineering, ETH Zurich, Zurich 8092 (Switzerland); Rohr, Philipp Rudolf von [Institute of Process Engineering, ETH Zurich, Zurich 8092 (Switzerland)], E-mail: vonrohr@ipe.mavt.ethz.ch

    2008-12-30

    The surface of lactose particles was modified by a plasma-enhanced chemical vapor deposition process to improve the flow behavior of the powder. For this, the particulates were treated in a plasma down stream reactor which provides a short (50 ms) and homogeneous exposure to the capacitively coupled RF discharge. The organosilicon monomer hexamethyldisiloxane (HMDSO) was used as a precursor for the formation of SiO{sub x} which is deposited on the substrate particle surface. For varying process gas mixtures (O{sub 2}/Ar/HMDSO) and RF power applied, the amount of the deposited material was determined gravimetrically after dissolution of the lactose substrate particles and the chemical composition of the accumulated deposition material was investigated by means of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The concentration of the deposited SiO{sub x} relating to the substrate material was found to be in the range of 0.1 wt.%. Based on the ATR-FTIR analysis, the inorganic, i.e. oxidic SiO{sub x} fraction of the obtained deposits was shown to be controllable by varying the process parameters, whilst a relatively large amount of organic structures must be considered.

  4. Quantifying Chronic Stress Exposure for Cumulative Risk Assessment: Lessons Learned from a Case Study of Allostatic Load

    Science.gov (United States)

    Although multiple methods of quantifying environmental chemical exposures have been validated for use in human health risk assessment, quantifying chronic stress exposure is more challenging. Stress is a consequence of perceiving an “exposure” (e.g., violence, poverty) as more th...

  5. Effects of Drilling Fluid Exposure to Oil and Gas Workers Presented with Major Areas of Exposure and Exposure Indicators

    Directory of Open Access Journals (Sweden)

    Eric Broni-Bediako

    2010-12-01

    Full Text Available Drilling fluid is any fluid which is circulated through a well in order to remove cuttings from a wellbore. They are used broadly in the oil and gas industry, on exploration rigs, and are critical to ensuring a safe and productive oil or gas well. During drilling, a large volume of fluids are circulated through the well and into open, partially enclosed or completely enclosed systems at elevated temperatures. When these drilling fluids are agitated during circulating process there is significant potential for chemical exposure to workers and subsequent health effects. This study seeks to identify major areas of drilling fluid exposure and health hazard associated with the use of drilling fluid. The study also presents some challenges in setting drilling fluid exposure standard which has always not been given the same attention or concern as effects and risk management of drilling fluid. Some exposure indicators are also presented.

  6. Regulation (EC) No. 1107/2009 and upcoming challenges for exposure assessment of plant protection products - Harmonisation or national modelling approaches?

    International Nuclear Information System (INIS)

    In the new European Pesticide Regulation (EC) No. 1107/2009, the harmonisation of approaches for estimation of the environmental exposure of pesticides is considered a major goal. Several member states currently require their own models for the calculation of predicted environmental concentrations (PEC) in surface water. The variety of methods makes risk evaluations rather time-consuming for both notifiers and evaluating authorities. In the present study we compare surface water concentrations of 19 compounds using EU and country-specific models and risk assessment approaches to evaluate to which extent the resulting estimated exposure concentrations differ. Our results show that EU and country specific approaches and the resulting surface water concentrations differ considerably regarding basic model assumptions and assessment methods. The results indicate that the aimed harmonisation of risk assessment approaches within the EU will be difficult based on current models. New scenarios may help to achieve a harmonisation taking country-specific features into account. - Highlights: → Currently different pesticide fate models and approaches are used in the EU. → A new regulation envisions the harmonisation of exposure assessments. → We therefore compared the models and exposure assessments within the EU. → We show differences of models, assumptions and exposure concentrations. → We discuss how harmonisation could be reached. - The results of this study show that harmonisation is hardly achievable based on the current exposure assessment approaches in the EU.

  7. Regulation (EC) No. 1107/2009 and upcoming challenges for exposure assessment of plant protection products - Harmonisation or national modelling approaches?

    Energy Technology Data Exchange (ETDEWEB)

    Erlacher, Elisabeth, E-mail: elisabeth.erlacher@rifcon.de [RIFCon GmbH, Im Neuenheimer Feld 517, 69120 Heidelberg (Germany); Wang, Magnus, E-mail: magnus.wang@rifcon.de [RIFCon GmbH, Im Neuenheimer Feld 517, 69120 Heidelberg (Germany)

    2011-12-15

    In the new European Pesticide Regulation (EC) No. 1107/2009, the harmonisation of approaches for estimation of the environmental exposure of pesticides is considered a major goal. Several member states currently require their own models for the calculation of predicted environmental concentrations (PEC) in surface water. The variety of methods makes risk evaluations rather time-consuming for both notifiers and evaluating authorities. In the present study we compare surface water concentrations of 19 compounds using EU and country-specific models and risk assessment approaches to evaluate to which extent the resulting estimated exposure concentrations differ. Our results show that EU and country specific approaches and the resulting surface water concentrations differ considerably regarding basic model assumptions and assessment methods. The results indicate that the aimed harmonisation of risk assessment approaches within the EU will be difficult based on current models. New scenarios may help to achieve a harmonisation taking country-specific features into account. - Highlights: > Currently different pesticide fate models and approaches are used in the EU. > A new regulation envisions the harmonisation of exposure assessments. > We therefore compared the models and exposure assessments within the EU. > We show differences of models, assumptions and exposure concentrations. > We discuss how harmonisation could be reached. - The results of this study show that harmonisation is hardly achievable based on the current exposure assessment approaches in the EU.

  8. Self-reported chemicals exposure, beliefs about disease causation, and risk of breast cancer in the Cape Cod Breast Cancer and Environment Study: a case-control study

    Directory of Open Access Journals (Sweden)

    Rudel Ruthann A

    2010-07-01

    that chemicals and pollutants contribute to breast cancer. Alternatively, the influence of experience on beliefs is another explanation, illustrated by the protective odds ratio for family history among women who do not believe heredity contributes "a lot." Because exposure to chemicals from household cleaning products is a biologically plausible cause of breast cancer and avoidable, associations reported here should be further examined prospectively.

  9. In situ biomonitoring of juvenile Chinook salmon (Onchorhynchus tshawytscha) using biomarkers of chemical exposures and effects in a partially remediated urbanized waterway of the Puget Sound, WA

    Energy Technology Data Exchange (ETDEWEB)

    Browne, Eva [Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way Northeast, Suite 100, Seattle, WA 98105-6099 (United States); Kelley, Matthew; Zhou, Guo-Dong; He, Ling Yu; McDonald, Thomas; Wang, Shirley [Department of Environmental and Occupational Health, Texas A and M Health Science Center, College Station, TX 77843-1266 (United States); Duncan, Bruce [US Environmental Protection Agency, Region 10, 1200 Sixth Avenue, Seattle, WA 98101 (United States); Meador, James [Ecotoxicology Division, National Marine Fisheries Service, Seattle, WA 98105 (United States); Donnelly, Kirby [Department of Environmental and Occupational Health, Texas A and M Health Science Center, College Station, TX 77843-1266 (United States); Gallagher, Evan, E-mail: evang3@u.washington.edu [Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way Northeast, Suite 100, Seattle, WA 98105-6099 (United States)

    2010-10-15

    In situ biomonitoring has been used to assess the effects of pollution on aquatic species in heavily polluted waterways. In the current study, we used in situ biomonitoring in conjunction with molecular biomarker analysis to determine the effects of pollutant exposure in salmon caged in the Duwamish waterway, a Pacific Northwest Superfund site that has been subject to remediation. The Duwamish waterway is an important migratory route for Pacific salmon and has received historic inputs of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Juvenile pre-smolt Chinook salmon (Oncorhynchus tshawytscha) caged for 8 days in the three contaminated sites in close proximity within the Duwamish were analyzed for steady state hepatic mRNA expression of 7 exposure biomarker genes encompassing several gene families and known to be responsive to pollutants, including cytochrome P4501A (CYP1A) and CYP2K1, glutathione S-transferase {pi} class (GST-{pi}), microsomal GST (mGST), glutamylcysteine ligase catalytic subunit (GCLC), UDP-glucuronyltransferase family 1 (UDPGT), and type 2 deiodinase (type 2 DI, or D2). Quantitation of gene expression was accomplished by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in assays developed specifically for Chinook salmon genes. Gill PAH-DNA adducts were assessed as a chemical effects biomarker using {sup 32}P-postlabeling. The biomarkers in the field-caged fish were analyzed with respect to caged animals maintained at the hatchery receiving flow-through water. Chemical analysis of sediment samples from three field sampling sites revealed relatively high concentrations of total PAHs in one site (site B2, 6711 ng/g dry weight) and somewhat lower concentrations of PAHs in two adjacent sites (sites B3 and B4, 1482 and 1987 ng/g, respectively). In contrast, waterborne PAHs at all of the sampling sites were relatively low (<1 ng/L). Sediment PCBs at the sites ranged from a low of 421 ng/g at site B3

  10. In situ biomonitoring of juvenile Chinook salmon (Onchorhynchus tshawytscha) using biomarkers of chemical exposures and effects in a partially remediated urbanized waterway of the Puget Sound, WA

    International Nuclear Information System (INIS)

    In situ biomonitoring has been used to assess the effects of pollution on aquatic species in heavily polluted waterways. In the current study, we used in situ biomonitoring in conjunction with molecular biomarker analysis to determine the effects of pollutant exposure in salmon caged in the Duwamish waterway, a Pacific Northwest Superfund site that has been subject to remediation. The Duwamish waterway is an important migratory route for Pacific salmon and has received historic inputs of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Juvenile pre-smolt Chinook salmon (Oncorhynchus tshawytscha) caged for 8 days in the three contaminated sites in close proximity within the Duwamish were analyzed for steady state hepatic mRNA expression of 7 exposure biomarker genes encompassing several gene families and known to be responsive to pollutants, including cytochrome P4501A (CYP1A) and CYP2K1, glutathione S-transferase π class (GST-π), microsomal GST (mGST), glutamylcysteine ligase catalytic subunit (GCLC), UDP-glucuronyltransferase family 1 (UDPGT), and type 2 deiodinase (type 2 DI, or D2). Quantitation of gene expression was accomplished by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in assays developed specifically for Chinook salmon genes. Gill PAH-DNA adducts were assessed as a chemical effects biomarker using 32P-postlabeling. The biomarkers in the field-caged fish were analyzed with respect to caged animals maintained at the hatchery receiving flow-through water. Chemical analysis of sediment samples from three field sampling sites revealed relatively high concentrations of total PAHs in one site (site B2, 6711 ng/g dry weight) and somewhat lower concentrations of PAHs in two adjacent sites (sites B3 and B4, 1482 and 1987 ng/g, respectively). In contrast, waterborne PAHs at all of the sampling sites were relatively low (<1 ng/L). Sediment PCBs at the sites ranged from a low of 421 ng/g at site B3 to 1160 ng

  11. Environmental exposure measurement in cancer epidemiology

    Science.gov (United States)

    2009-01-01

    Environmental exposures, used in the broadest sense of lifestyle, infections, radiation, natural and man-made chemicals and occupation, are a major cause of human cancer. However, the precise contribution of specific risk factors and their interaction, both with each other and with genotype, continues to be difficult to elucidate. This is partially due to limitations in accurately measuring exposure with the subsequent risk of misclassification. One of the primary challenges of molecular cancer epidemiology therefore is to improve exposure assessment. Progress has been made with biomarkers such as carcinogens and their metabolites, DNA and protein adducts and mutations measured in various tissues and body fluids. Nevertheless, much remains to be accomplished in order to establish aetiology and provide the evidence base for public health decisions. This review considers some of the principles behind the application of exposure biomarkers in cancer epidemiology. It also demonstrates how the same biomarkers can contribute both to establishing the biological plausibility of associations between exposure and disease and be valuable endpoints in intervention studies. The potential of new technologies such as transcriptomics, proteomics and metabonomics to provide a step change in environmental exposure assessment is discussed. An increasing recognition of the role of epigenetic changes in carcinogenesis presents a fresh challenge as alterations in DNA methylation, histone modification and microRNA in response to environmental exposures demand a new generation of exposure biomarker. The overall importance of this area of research is brought into sharp relief by the large prospective cohort studies (e.g. UK Biobank) which need accurate exposure measurement in order to shed light on the complex gene:environment interactions underlying common chronic disorders including cancer. It is suggested that a concerted effort is now required, with appropriate funding, to develop and

  12. Hazardous Chemicals

    Centers for Disease Control (CDC) Podcasts

    2007-04-10

    Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

  13. Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation. Comprehensive progress report, July 1991--June 1994

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, J.D.

    1994-06-01

    This comprehensive progress report provides a synopsis of major research accomplishments during the years of 1991-1994, including the technical aspects of the project. The objectives and accomplishments are as follows: 1. Defining the chromosome segments associated with radiation and chemically-induced leukemogenesis (treatment-related acute myeloid leukemia, t-AML); A. Continued genetic analysis of chromosomes 5 and 7, B. Correlation of treatment with balanced and unbalanced translocations. 2. Cloning the breakpoints in balanced translocations in t-AML; A. Clone the t(9;11) and t(11;19) breakpoints, B. Clone the t(3,21)(q26,q22) breakpoint, C. Determine the relationship of these translocations to prior exposure to topoisomerase II inhibitors. 3. Compare the breakpoint junctions in patients who have the same translocations in t-AML and AML de novo. 4. Map the scaffold attachment regions in the genes that are involved in balanced translocations in t-AML. Plans for the continuation of present objectives and possible new objectives in consideration of past results are also provided.

  14. Dificultades en los métodos de estudio de exposiciones ambientales y defectos del tubo neural Methodological challenges to assess environmental exposures related to neural tube defects

    Directory of Open Access Journals (Sweden)

    Víctor Hugo Borja-Aburto

    1999-11-01

    susceptibilidad genética.Objective. To discuss the attitudes in the assessment of environmental exposures as risk factors associated with neural tube defects, and to present the main risk factors studied to date. Results. Environmental exposures have been suggested to have a roll in the genesis of birth defects. However, studies conducted in human populations have found difficulties in the design and conduction to show such an association for neural tube defects (anencephaly, espina bifida and encefalocele because of problems raised from: a the frequency measures used to compare time trends and communities, b the classification of heterogeneous malformations, c the inclusion of maternal, paternal and fetal factors as an integrated process and, d the assessment of environmental exposures. Conclusions. Hypothetically both maternal and paternal environmental exposures can produce damage before and after conception by direct action on the embryo and the fetus-placenta complex. Therefore, in the assessment of environmental exposures we need to take into account: a both paternal and maternal exposures; b the critical exposure period, three months before conception for paternal exposures and one month around the conceptional period for maternal exposures; c quantitatively evaluate environmental exposures when possible, avoiding a dichotomous classification; d the use of biological markers of exposure is highly recommended as well as markers of genetic susceptibility.

  15. Acidentes químicos ampliados: um desafio para a saúde pública The increase in chemical accidents: a challenge for public health

    Directory of Open Access Journals (Sweden)

    Carlos M. de Freitas

    1995-12-01

    Full Text Available Os acidentes envolvendo substâncias perigosas nas atividades de transporte, armazenamento e produção industrial de produtos químicos constituem um sério risco à saúde e ao meio ambiente. Objetiva-se discutir, no âmbito da saúde pública, alguns dos desafios que esses tipos de acidentes colocam, principalmente para os países de economia periférica. Através da combinação de informações quantitativas e qualitativas, foram definidos e caracterizados esses tipos de acidentes e seus diversos riscos. Esses acidentes têm se apresentado com a maior gravidade nos países de economia periférica, embora a maioria deles venha ocorrendo sem o adequado registro de informações básicas para a avaliação e vigilância, como é demonstrado no caso do Rio de Janeiro (Brasil. Além da tarefa de se avaliar as conseqüências de eventos, por vezes extremamente complexos, coloca-se também, a de formular estratégias de controle e prevenção em realidades sociais que configuram um terreno fértil para a ocorrência e agravamento dos mesmos.Chemical accidents involving explosions, large fires and leakages of hazardous substances occuring during transport, storage and industrial production of chemicals constitute a real challeng to health, environmental and industrial safety professionals. The aim of this article is to discuss the main questions that this kind of accident provokes, in terms of public helth, particularly in developing countries such as Brazil. The paper defines and characterises these accidents and the various health risk they involve excluding the leakages of hazardous substances during "normal" production in industry - through the combination of quantitative and qualitative information drawn from the international literature on the subject. From some examples of chemical accidents such as occurred in Bophal (Índia, Vila Socó (Brazil, São Paulo (México and data of the World Health Organization (WHO, the authors seek to show

  16. The challenge resulting from positive and negative effects of sunlight: how much solar UV exposure is appropriate to balance between risks of vitamin D deficiency and skin cancer?

    OpenAIRE

    Reichrath, Jörg

    2006-01-01

    KEYWORDS CLASSIFICATION: adverse effects;Animals;cancer epidemiology;deficiency;Dose-Response Relationship,Radiation;epidemiology;Environmental Exposure;Evaluation;Germany;Humans;Incidence;Internationality;lifestyle modulation of cancer & cancer biomarkers;nursing;Neoplasms,Radiation-Induced;prevention & control;Risk Assessment;Risk Factors;statistics & numerical data;Skin Neoplasms;Sunlight;therapy;Ultraviolet Therapy;Vitamin D;Vitamin D Deficiency;analysis.

  17. Estimation of human exposure to chemical substances and radiation. State of the art of the research projects of the Dutch National Institute of Public Health and Environmental Protection (RIVM)

    International Nuclear Information System (INIS)

    In 1994, the Sector Substances and Risks of RIVM decided to strengthen strategically its research into risk assessment methodology. In this report the research area of human exposure assessment at the RIVM is outlined. A representative selection of human exposure assessment models for both chemical substances and radiation is analysed with regard to aim, principle, degree of model analyses and values of default parameter. For comparison, a model to assess human exposure to micro-organisms is included as well. All models are operational or nearly so in the production of risk assessments in the Sector Substances and Risks and also in the Sectors Public Health Research and Environmental Research. The models discussed all have a defined area of application and support risk management. The research areas of exposure assessment for substances and radiation are compared and many methodological analogies are apparent. However, at the level of models and parameters an in-depth analysis of analogies and explained or unexplained differences is lacking. A detailed examination of organisation aspects and RIVM-models for human exposure assessment learns that all relevant areas of interest are covered. For all routes of exposure the reach of the actual risk and exposure assessment methodology is large. A more uniform coverage is attained for radiation than for chemical substances. For both areas the estimation and registration of emissions can be improved. The development of risk assessment systems and related harmonisation proJects have already attention for many years (e.g. CSOIL, USES, RIBRON). It is concluded that the RIVM requires a broad, up-to-date range of instruments for exposure assessment and active involvement in all kinds of national and international relevant networks. The RIVM should also remain involved in the development and evaluation of methodology and in projects aiming at harmonisation. 2 figs., 9 tabs., 64 refs

  18. Exposure of Atlantic salmon parr (Salmo salar) to a combination of resin acids and a water soluble fraction of diesel fuel oil: A model to investigate the chemical causes of pigmented salmon syndrome

    International Nuclear Information System (INIS)

    Pigmented salmon syndrome is a pollutant-induced hemolytic anemia and hyperbilirubinemia. As part of an investigation of this condition, S2 Atlantic salmon parr (Salmo salar) were exposed to a diesel fuel oil, water soluble fraction (WSF) in combination with a mixture of three resin acids (isopimaric, dehydroabietic, and abietic acids) in a continuous-flow freshwater system. The total nominal concentrations of resin acids in the exposure tanks were 10, 50, and 100 microg/L; the diesel WSF was generated in situ and provided a mean hydrocarbon concentration of 2.0 ± 0.1 mg/L (n = 12) during the 9-d exposure period. Exposure to the diesel WSF alone depressed liver bilirubin UDP-glucuronosyl transferase (UDPGT) activity and induced phenol UDPGT activity. Exposure to the diesel WSF in the absence or presence of resin acids induced liver cytochrome P4501A and increased the concentrations in the plasma of the enzymes lactate dehydrogenase, alkaline phosphatase, and glutamic oxaloacetic transaminase. The combined exposure to diesel WSF with either 50 or 100 microg/L total resin acid caused significant elevations in the concentrations of bilirubin in the plasma and many of these fish had yellow pigmentation on the ventral surface and around the gill arches. The results demonstrate that exposure to combinations of two groups of contaminants can result in the manifestation of toxic effects not apparent from exposure to either of these chemicals in isolation

  19. Exposure of Atlantic salmon parr (Salmo salar) to a combination of resin acids and a water soluble fraction of diesel fuel oil: A model to investigate the chemical causes of pigmented salmon syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Croce, B. [Scottish Office Agriculture, Environment, and Fisheries Dept., Aberdeen (United Kingdom). Marine Lab.]|[Scottish Environmental Protection Agency, Aberdeen (United Kingdom). North East River Purification Board; Stagg, R.M. [Scottish Office Agriculture, Environment, and Fisheries Dept., Aberdeen (United Kingdom). Marine Lab.

    1997-09-01

    Pigmented salmon syndrome is a pollutant-induced hemolytic anemia and hyperbilirubinemia. As part of an investigation of this condition, S2 Atlantic salmon parr (Salmo salar) were exposed to a diesel fuel oil, water soluble fraction (WSF) in combination with a mixture of three resin acids (isopimaric, dehydroabietic, and abietic acids) in a continuous-flow freshwater system. The total nominal concentrations of resin acids in the exposure tanks were 10, 50, and 100 {micro}g/L; the diesel WSF was generated in situ and provided a mean hydrocarbon concentration of 2.0 {+-} 0.1 mg/L (n = 12) during the 9-d exposure period. Exposure to the diesel WSF alone depressed liver bilirubin UDP-glucuronosyl transferase (UDPGT) activity and induced phenol UDPGT activity. Exposure to the diesel WSF in the absence or presence of resin acids induced liver cytochrome P4501A and increased the concentrations in the plasma of the enzymes lactate dehydrogenase, alkaline phosphatase, and glutamic oxaloacetic transaminase. The combined exposure to diesel WSF with either 50 or 100 {micro}g/L total resin acid caused significant elevations in the concentrations of bilirubin in the plasma and many of these fish had yellow pigmentation on the ventral surface and around the gill arches. The results demonstrate that exposure to combinations of two groups of contaminants can result in the manifestation of toxic effects not apparent from exposure to either of these chemicals in isolation.

  20. Recreational and occupational field exposure to freshwater cyanobacteria – a review of anecdotal and case reports, epidemiological studies and the challenges for epidemiologic assessment

    Directory of Open Access Journals (Sweden)

    Webb Penelope M

    2006-03-01

    Full Text Available Abstract Cyanobacteria are common inhabitants of freshwater lakes and reservoirs throughout the world. Under favourable conditions, certain cyanobacteria can dominate the phytoplankton within a waterbody and form nuisance blooms. Case reports and anecdotal references dating from 1949 describe a range of illnesses associated with recreational exposure to cyanobacteria: hay fever-like symptoms, pruritic skin rashes and gastro-intestinal symptoms are most frequently reported. Some papers give convincing descriptions of allergic reactions while others describe more serious acute illnesses, with symptoms such as severe headache, pneumonia, fever, myalgia, vertigo and blistering in the mouth. A coroner in the United States found that a teenage boy died as a result of accidentally ingesting a neurotoxic cyanotoxin from a golf course pond. This death is the first recorded human fatality attributed to recreational exposure to cyanobacteria, although uncertainties surround the forensic identification of the suspected cyanotoxin in this case. We systematically reviewed the literature on recreational exposure to freshwater cyanobacteria. Epidemiological data are limited, with six studies conducted since 1990. Statistically significant increases in symptoms were reported in individuals exposed to cyanobacteria compared to unexposed counterparts in two Australian cohort studies, though minor morbidity appeared to be the main finding. The four other small studies (three from the UK, one Australian did not report any significant association. However, the potential for serious injury or death remains, as freshwater cyanobacteria under bloom conditions are capable of producing potent toxins that cause specific and severe dysfunction to hepatic or central nervous systems. The exposure route for these toxins is oral, from ingestion of recreational water, and possibly by inhalation. A range of freshwater microbial agents may cause acute conditions that present with

  1. Stochastic modelling of human exposure to food chemicals and nutrients within the "Montecarlo" project: an exploration of the influence of brand loyalty and market share on intake estimates of intense sweeteners from sugar-free soft drinks.

    Science.gov (United States)

    Leclercq, Catherine; Arcella, Davide; Le Donne, Cinzia; Piccinelli, Raffaela; Sette, Stefania; Soggiu, Maria Eleonora

    2003-04-11

    To get a more realistic view of exposure to food chemicals, risk managers are getting more interested in stochastic modelling as an alternative to deterministic approaches based on conservative assumptions. It allows to take into account all the available information in the concentration of the chemical present in foods and in food consumption patterns. Within the EC-funded "Montecarlo" project, a comprehensive set of mathematical algorithms was developed to take into account all the necessary components for stochastic modelling of a variety of food chemicals, nutrients and ingredients. An appropriate computer software is being developed. Since the concentration of food chemicals may vary among different brands of the same product, consumer behaviour with respect to brands may have an impact on exposure assessments. Numeric experiments were carried out on different ways of incorporating indicators of market share and brand loyalty in the mathematical algorithms developed within the stochastic model of exposure to intense sweeteners from sugar-free beverages. The 95th percentiles of intake were shown to vary according to the inclusion/exclusion of these indicators. The market share should be included in the model especially if the market is not equitably distributed between brands. If brand loyalty data are not available, the model may be run under theoretical scenarios. PMID:12676493

  2. EXPOSURE ANALYSIS MODELING SYSTEM (EXAMS)

    Science.gov (United States)

    The Exposure Analysis Modeling System (EXAMS), first published in 1982 (EPA-600/3-82-023), provides interactive computer software for formulating aquatic ecosystem models and rapidly evaluating the fate, transport, and exposure concentrations of synthetic organic chemicals--pesti...

  3. Immersion exposure of rainbow trout (Oncorhynchus mykiss) fry to wildtype Flavobacterium psychrophilum induces no mortality, but protects against later intraperitoneal challenge

    DEFF Research Database (Denmark)

    Lorenzen, Ellen; Brudeseth, B.E.; Wiklund, T.;

    2010-01-01

    .e. bathing in high titres of non-attenuated isolates of F. psychrophilum, was able to induce immunity to a subsequent ip challenge. Immersion in live bacteria for 30 or 50 min caused no mortality and protected a major fraction of the fry against challenges 26 and 47 days later with RPS values of 88.2 and 60......Flavobacterium psychrophilum, the causative agent of RTFS or rainbow trout fry syndrome, causes high mortality among hatchery reared rainbow trout (Oncorhynchus mykiss) fry in Europe and the USA. Despite several attempts, no efficient vaccines have yet been developed, the main obstacle being that...... the fry have to be vaccinated very early, i.e. around 0.2–0.5 g, where RTFS usually starts to give problems in the fish farms. Consequently, only oral or bath vaccines are relevant. Immersion of fry in inactivated or attenuated bacteria has resulted in RPS values of less than 50%. However, the results...

  4. Subchronic Arsenic Exposure Induces Anxiety-Like Behaviors in Normal Mice and Enhances Depression-Like Behaviors in the Chemically Induced Mouse Model of Depression

    OpenAIRE

    Chia-Yu Chang; How-Ran Guo; Wan-Chen Tsai; Kai-Lin Yang; Li-Chuan Lin; Tain-Junn Cheng; Jiunn-Jye Chuu

    2015-01-01

    Accumulating evidence implicates that subchronic arsenic exposure causes cerebral neurodegeneration leading to behavioral disturbances relevant to psychiatric disorders. However, there is still little information regarding the influence of subchronic exposure to arsenic-contaminated drinking water on mood disorders and its underlying mechanisms in the cerebral prefrontal cortex. The aim of this study is to assess the effects of subchronic arsenic exposure (10 mg/LAs2O3 in drinking water) on t...

  5. The GREAT3 Challenge

    OpenAIRE

    Miyatake, Hironao; Mandelbaum, Rachel; collaboration, Barnaby Rowe on behalf of the GREAT3

    2014-01-01

    The GRavitational lEnsing Accuracy Testing 3 (GREAT3) challenge is an image analysis competition that aims to test algorithms to measure weak gravitational lensing from astronomical images. The challenge started in October 2013 and ends 30 April 2014. The challenge focuses on testing the impact on weak lensing measurements of realistically complex galaxy morphologies, realistic point spread function, and combination of multiple different exposures. It includes simulated ground- and space-base...

  6. USEtox human exposure and toxicity factors for comparative assessment of toxic emissions in life cycle analysis: sensitivity to key chemical properties

    DEFF Research Database (Denmark)

    Rosenbaum, Ralph K.; Huijbregts, Mark; Henderson, Andrew D.;

    2011-01-01

    USEtoxTM, primarily by extrapolating from an oral route to exposure in air (and optionally acute-to-chronic). Some exposure pathways (e.g. indoor inhalation, pesticide residues, dermal exposure) will be included in a later stage. USEtoxTM is applicable in various comparative toxicity impact assessments...... pathway considered (i.e. inhalation through air, ingestion through i) drinking water, ii) agricultural produce, iii) meat and milk, and iv) fish). The calculation of human health effect factors for cancer and non-cancer effects via ingestion and inhalation exposure respectively is described. This section...

  7. Dermal exposure assessment techniques.

    Science.gov (United States)

    Fenske, R A

    1993-12-01

    Exposure of the skin to chemical substances can contribute significantly to total dose in many workplace situations, and its relative importance will increase when airborne occupational exposure limits are reduced, unless steps to reduce skin exposure are undertaken simultaneously. Its assessment employs personal sampling techniques to measure skin loading rates, and combines these measurements with models of percutaneous absorption to estimate absorbed dose. Knowledge of dermal exposure pathways is in many cases fundamental to hazard evaluation and control. When the skin is the primary contributor to absorbed dose, dermal exposure measurements and biological monitoring play complementary roles in defining occupational exposures. Exposure normally occurs by one of three pathways: (i) immersion (direct contact with a liquid or solid chemical substance); (ii) deposition of aerosol or uptake of vapour through the skin; or (iii) surface contact (residue transfer from contaminated surfaces). Sampling methods fall into three categories: surrogate skin; chemical removal; and fluorescent tracers. Surface sampling represents a supplementary approach, providing an estimate of dermal exposure potential. Surrogate skin techniques involve placing a chemical collection medium on the skin. Whole-body garment samplers do not require assumptions relating to distribution, an inherent limitation of patch sampling. The validity of these techniques rests on the ability of the sampling medium to capture and retain chemicals in a manner similar to skin. Removal techniques include skin washing and wiping, but these measure only what can be removed from the skin, not exposure: laboratory removal efficiency studies are required for proper interpretation of data. Fluorescent tracer techniques exploit the visual properties of fluorescent compounds, and combined with video imaging make quantification of dermal exposure patterns possible, but the need to introduce a chemical substance (tracer

  8. A proposal for assessing study quality: Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument

    OpenAIRE

    Judy S. LaKind; Sobus, Jon R.; Goodman, Michael; Barr, Dana Boyd; Fürst, Peter; Albertini, Richard J.; Arbuckle, Tye E; Schoeters, Greet; Tan, Yu-Mei; Teeguarden, Justin; Tornero-Velez, Rogelio; Weisel, Clifford P.

    2014-01-01

    The quality of exposure assessment is a major determinant of the overall quality of any environmental epidemiology study. The use of biomonitoring as a tool for assessing exposure to ubiquitous chemicals with short physiologic half-lives began relatively recently. These chemicals present several challenges, including their presence in analytical laboratories and sampling equipment, difficulty in establishing temporal order in cross-sectional studies, short- and long-term variability in exposu...

  9. Chemical compounds exposure and human health: advances on the politics of chemical risk control Exposición a sustancias químicas y salud humana: avances en la política de control del riesgo químico

    OpenAIRE

    Eduardo de la Peña; Ana de la Torre; Pilar Gascó

    2002-01-01

    Advances on the politics of chemical risk control. Observed deficiencies on the management, elimination and recirculation of chemical products. Therefore, some of the main challenges for the scientific research, environmental health, nature preservation and the environmental management are closely related to the development of validation system of the impact on the environment and on health as well as prevention and elimination techniques of the pollution dumped of the aquatic and terrestrial...

  10. Room-temperature X-ray diffraction studies of cisplatin and carboplatin binding to His15 of HEWL after prolonged chemical exposure

    International Nuclear Information System (INIS)

    Binding of cisplatin to His15 in hen egg-white lysozyme in aqueous media is observed after prolonged chemical exposure for 15 months, in contrast to the lack of binding that was observed after 4 d in a previous study. Binding of carboplatin is seen in greater detail in the case of room-temperature data collection compared with cryo data collection. The anticancer complexes cisplatin and carboplatin are known to bind to both the Nδ and the N∊ atoms of His15 of hen egg-white lysozyme (HEWL) in the presence of dimethyl sulfoxide (DMSO). However, neither binds in aqueous media after 4 d of crystallization and crystal growth, suggesting that DMSO facilitates cisplatin/carboplatin binding to the N atoms of His15 by an unknown mechanism. Crystals of HEWL cocrystallized with cisplatin in both aqueous and DMSO media, of HEWL cocrystallized with carboplatin in DMSO medium and of HEWL cocrystallized with cisplatin and N-acetylglucosamine (NAG) in DMSO medium were stored for between seven and 15 months. X-ray diffraction studies of these crystals were carried out on a Bruker APEX II home-source diffractometer at room temperature. Room-temperature X-ray diffraction data collection removed the need for cryoprotectants to be used, ruling out any effect that the cryoprotectants might have had on binding to the protein. Both cisplatin and carboplatin still bind to both the Nδ and N∊ atoms of His15 in DMSO media as expected, but more detail for the cyclobutanedicarboxylate (CBDC) moiety of carboplatin was observed at the N∊ binding site. However, two molecules of cisplatin were now observed to be bound to His15 in aqueous conditions. The platinum peak positions were identified using anomalous difference electron-density maps as a cross-check with Fo − Fc OMIT electron-density maps. The occupancies of each binding site were calculated using SHELXTL. These results show that over time cisplatin binds to both N atoms of His15 of HEWL in aqueous media, whereas this binding is

  11. Biologic Monitoring of Exposure to Environmental Chemicals throughout the Life Stages: Requirements and Issues for Consideration for the National Children’s Study

    OpenAIRE

    Barr, Dana B.; Wang, Richard Y.; Needham, Larry L.

    2005-01-01

    Biomonitoring of exposure is a useful tool for assessing environmental exposures. The matrices available for analyses include blood, urine, breast milk, adipose tissue, and saliva, among others. The sampling can be staged to represent the particular time period of concern: preconceptionally from both parents, from a pregnant woman during each of the three trimesters, during and immediately after childbirth, from the mother postnatally, and from the child as it develops to 21 years of age. The...

  12. Chemical Inhibition of Nitrification: Evaluating Methods to Detect and Characterize Inhibition and the Role of Selected Stress Responses Upon Exposure to Oxidative and Hydrophobic Toxins

    OpenAIRE

    Kelly II, Richard Thomas

    2005-01-01

    This research first examined nitrification inhibition caused by different classes of industrially relevant chemicals on activated sludge and found that conventional aerobic nitrification was inhibited by single pulse inputs of every chemical tested, with 1-chloro-2,4-dinitrobenzene (oxidant) having the most severe impact, followed by alkaline pH 11, cadmium (heavy metal), cyanide, octanol (hydrophobic) and 2,4-dinitrophenol (respiratory uncoupler). Of the different chemicals tested, the oxid...

  13. Chemical Radioprotectors

    Directory of Open Access Journals (Sweden)

    S. N. Upadhyay

    2005-10-01

    Full Text Available Protection of biological systems against radiation damage is of paramount importance during accidental and unavoidable exposure to radiation. Several physico-chemical and biological factors collectively contribute to the damage caused by radiation and are, therefore, targets for developing radioprotectors. Work on the development of chemicals capable of protecting biological systemsfrom radiation damage was initiated nearly six decades ago with cysteine being the first molecule to be reported. Chemicals capable of scavenging free radicals, inducing oxygen depletion,antioxidants and modulators of immune response have been some of the radioprotectors extensively investigated with limited success. Mechanism of action of some chemical radioprotectors and their combinations have been elucidated, while further understanding is required in many instances. The present review elaborates on structure-activity relationship of some of the chemical radioprotectors, their evaluation, and assessment, limitation, and future prospects.

  14. Optical nano antennas: state of the art, scope and challenges as a biosensor along with human exposure to nano-toxicology.

    Science.gov (United States)

    Kausar, Abu Sulaiman Mohammad Zahid; Reza, Ahmed Wasif; Latef, Tarik Abdul; Ullah, Mohammad Habib; Karim, Mohammad Ershadul

    2015-01-01

    The concept of optical antennas in physical optics is still evolving. Like the antennas used in the radio frequency (RF) regime, the aspiration of optical antennas is to localize the free propagating radiation energy, and vice versa. For this purpose, optical antennas utilize the distinctive properties of metal nanostructures, which are strong plasmonic coupling elements at the optical regime. The concept of optical antennas is being advanced technologically and they are projected to be substitute devices for detection in the millimeter, infrared, and visible regimes. At present, their potential benefits in light detection, which include polarization dependency, tunability, and quick response times have been successfully demonstrated. Optical antennas also can be seen as directionally responsive elements for point detectors. This review provides an overview of the historical background of the topic, along with the basic concepts and parameters of optical antennas. One of the major parts of this review covers the use of optical antennas in biosensing, presenting biosensing applications with a broad description using different types of data. We have also mentioned the basic challenges in the path of the universal use of optical biosensors, where we have also discussed some legal matters. PMID:25884787

  15. Optical Nano Antennas: State of the Art, Scope and Challenges as a Biosensor Along with Human Exposure to Nano-Toxicology

    Directory of Open Access Journals (Sweden)

    Abu Sulaiman Mohammad Zahid Kausar

    2015-04-01

    Full Text Available The concept of optical antennas in physical optics is still evolving. Like the antennas used in the radio frequency (RF regime, the aspiration of optical antennas is to localize the free propagating radiation energy, and vice versa. For this purpose, optical antennas utilize the distinctive properties of metal nanostructures, which are strong plasmonic coupling elements at the optical regime. The concept of optical antennas is being advanced technologically and they are projected to be substitute devices for detection in the millimeter, infrared, and visible regimes. At present, their potential benefits in light detection, which include polarization dependency, tunability, and quick response times have been successfully demonstrated. Optical antennas also can be seen as directionally responsive elements for point detectors. This review provides an overview of the historical background of the topic, along with the basic concepts and parameters of optical antennas. One of the major parts of this review covers the use of optical antennas in biosensing, presenting biosensing applications with a broad description using different types of data. We have also mentioned the basic challenges in the path of the universal use of optical biosensors, where we have also discussed some legal matters.

  16. CAirTOX: A compartment model for assessing the fate of and human exposure to toxic-chemical emissions to air

    Energy Technology Data Exchange (ETDEWEB)

    McKone, T.E.

    1993-10-01

    CAirTOX has been developed as a spreadsheet model to assist in making a risk assessment of toxic air emissions. With CAirTOX, one can address how contaminants released to an air basin can lead to contamination of soil, food, surface water, and sediments. The modeling effort includes a multimedia transport and transformation model, exposure scenario models, and efforts to quantify uncertainty in multimedia, multiple-pathway exposure assessments. The multimedia transport and transformation model is a steady-state, but non-equilibrium model that can be used to assess concentrations of contaminants released continuously to air. In Part 1, the authors describe the multimedia transport and transformation model used to determine the fate of air emissions. In Part 2, they describe inputs and data needs for CAirTOX and the development of a set of landscape factors, which can be used to represent regional air basin/water-shed systems in California. In Part 3, they describe the multiple-pathway exposure scenarios and exposure algorithms. In Part 4, they compare the HRA approach and results and the CAirTOX exposure equations. In Part 5, they consider model sensitivity and uncertainty to determine how variability and uncertainty in model inputs affects the precision, accuracy, and credibility of the model output.

  17. Challenge for real-time and real-space resolved spectroscopy of surface chemical reactions. Aiming at trace of irreversible and inhomogeneous reactions

    International Nuclear Information System (INIS)

    A novel experimental technique, time-resolved wavelength-dispersive soft X-ray imaging spectroscopy, is proposed in order to achieve real-time and real-space resolved spectroscopy for the observation of irreversible and inhomogeneous surface chemical reactions. By combining the wavelength-dispersed soft X rays, in which the X-ray wavelength (photon energy) changes as a function of position on the sample, with the photoelectron emission microscope, the soft X-ray absorption spectra are separately obtained at different positions on the sample without scanning the X-ray monochromator. Therefore, the real-time resolved measurement of site-selective soft X-ray absorption spectroscopy is realized in one event without repeating the chemical reaction. It is expected that the spatial distribution of different chemical species is traced during the surface chemical reaction, which is essential to understand the reaction mechanism. (author)

  18. Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation. Progress report, January 1, 1981-December 31, 1981

    International Nuclear Information System (INIS)

    The overall aim is to determine whether there is a relationship between exposure to radiation, environmental pollutants, and/or genetic background and the development of ANLL or other hematologic malignancies. I will try to define the factors that influence the development of ANLL as a second malignancy in patients who have been exposed to large doses of radiotherapy and/or chemotherapeutic agents. Two long-term goals are (1) to identify the genes that are located at the sites of consistent translocations, and then to determine the alterations in gene function that are associated with these translocations and (2) to establish the baseline frequency of various chromosome changes (mutations) in myeloid cells and then to analyze the influence of various types of environmental exposure or medical treatment on this baseline mutation rate. Ultimately, it may be possible to determine the extent of mutagenic exposure in various populations through an analysis of the leukemic cells of that populations

  19. Effect of sunlight exposure on the release of intentionally and/or non-intentionally added substances from polyethylene terephthalate (PET) bottles into water: chemical analysis and in vitro toxicity.

    Science.gov (United States)

    Bach, Cristina; Dauchy, Xavier; Severin, Isabelle; Munoz, Jean-François; Etienne, Serge; Chagnon, Marie-Christine

    2014-11-01

    The effect of sunlight exposure on chemical migration into PET-bottled waters was investigated. Bottled waters were exposed to natural sunlight for 2, 6 and 10 days. Migration was dependent on the type of water. Formaldehyde, acetaldehyde and Sb migration increased with sunlight exposure in ultrapure water. In carbonated waters, carbon dioxide promoted migration and only formaldehyde increased slightly due to sunlight. Since no aldehydes were detected in non-carbonated waters, we conclude that sunlight exposure has no effect. Concerning Sb, its migration levels were higher in carbonated waters. No unpredictable NIAS were identified in PET-bottled water extracts. Cyto-genotoxicity (Ames and micronucleus assays) and potential endocrine disruption effects (transcriptional-reporter gene assays) were checked in bottled water extracts using bacteria (Salmonella typhimurium) and human cell lines (HepG2 and MDA-MB453-kb2). PET-bottled water extracts did not induce any toxic effects (cyto-genotoxicity, estrogenic or anti-androgenic activity) in vitro at relevant consumer-exposure levels. PMID:24874358

  20. Chemical-gene interaction networks and causal reasoning for biological effects prediction and prioritization of contaminants for environmental monitoring and surveillance

    Science.gov (United States)

    Evaluating the potential human health and ecological risks associated with exposures to complex chemical mixtures in the environment is one of the main challenges of chemical safety assessment and environmental protection. There is a need for approaches that can help to integrat...

  1. A Comparison of RIA and LC-MS/MS Methods to Quantify Steroids in Rat Serum and Urine Following Exposure to an Endocrine Disrupting Chemical

    Science.gov (United States)

    Commercially available radio immunoassays (RIM) are frequently used in toxicological studies to evaluate effects of endocrine disrupting chemicals (EDCs) on steroidogenesis in rats. Currently there are limited data comparing steroid concentrations in rats as measured by RIM to th...

  2. A Workflow to Investigate Exposure and Pharmacokinetic Influences on High-Throughput in Vitro Chemical Screening Based on Adverse Outcome Pathways

    Science.gov (United States)

    Background: Adverse outcome pathways (AOPs) link adverse effects in individuals or populations to a molecular initiating event (MIE) that can be quantified using in vitro methods. Practical application of AOPs in chemical-specific risk assessment requires incorporation of knowled...

  3. A screening method for ranking chemicals by their fate and behaviour in the environment and potential toxic effects in humans following non-occupational exposure

    OpenAIRE

    Troisi, G.; Duarte-Davidson, R.; Capelton, A

    2004-01-01

    A large number of chemicals are released intentionally or unintentionally into the environment each year. These include thousands of substances that are currently listed worldwide and several hundred new substances added annually (Mücke et al., 1986). When these compounds are used, they can reach microorganisms, plants, animals and man either in their original state or in the form of reaction and degradation products via air, water, soil or foodstuffs. Hence environmental chemicals can occur ...

  4. Comparison of secondary organic aerosol formed with an aerosol flow reactor and environmental reaction chambers: effect of oxidant concentration, exposure time and seed particles on chemical composition and yield

    Directory of Open Access Journals (Sweden)

    A. T. Lambe

    2014-12-01

    Full Text Available We performed a systematic intercomparison study of the chemistry and yields of SOA generated from OH oxidation of a common set of gas-phase precursors in a Potential Aerosol Mass (PAM continuous flow reactor and several environmental chambers. In the flow reactor, SOA precursors were oxidized using OH concentrations ranging from 2.0×108 to 2.2×1010 molec cm−3 over exposure times of 100 s. In the environmental chambers, precursors were oxidized using OH concentrations ranging from 2×106 to 2×107 molec cm−3 over exposure times of several hours. The OH concentration in the chamber experiments is close to that found in the atmosphere, but the integrated OH exposure in the flow reactor can simulate atmospheric exposure times of multiple days compared to chamber exposure times of only a day or so. A linear correlation analysis of the mass spectra (m=0.91–0.92, r2=0.93–0.94 and carbon oxidation state (m=1.1, r2=0.58 of SOA produced in the flow reactor and environmental chambers for OH exposures of approximately 1011 molec cm−3 s suggests that the composition of SOA produced in the flow reactor and chambers is the same within experimental accuracy as measured with an aerosol mass spectrometer. This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors, rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of sulfate seed particles on isoprene SOA yield measurements was examined in the flow reactor. The studies show that seed particles increase the yield of SOA produced in flow reactors by a factor of 3 to 5 and may also account in part for higher SOA yields obtained in the chambers, where seed

  5. Regulating the introduction of new chemicals under section 5 of TSCA: improving the efficiency of the process and reducing potential injury in the workplace through the use of operational MSDS and exposure limits.

    Science.gov (United States)

    Rosenthal, I; Jayjock, M A; Keener, R L; Plamondon, J E

    1991-10-01

    The Toxic Substances Control Act (TSCA) authorizes the EPA to take appropriate actions to ensure that new and existing chemicals do not pose "unreasonable risk" to health or the environment. Section 2(b)(3) of the Act directs the Agency to accomplish this objective in a manner that does "not impede unduly or create unnecessary economic barriers to technological innovation." In recent years, critics have felt that the EPA has failed to achieve these primary goals of TSCA. This paper considers some of the reasons for this criticism and advocates an alternate approach of exposure limits and operationally sufficient controls to assist in achieving these goals. An illustration of how this alternate approach might work under practical conditions is presented, using as an example a new chemical substance from the class of acrylate monomers. These concepts and risk assessments provide data for a better design of future studies according to good laboratory practice and quality assurance. PMID:1669965

  6. Predicting the accumulation of well-metabolized chemicals by fish from measured rates of in vitro intrinsic clearance: Progress made and challenges ahead

    Science.gov (United States)

    Several groups have extrapolated in vitro metabolism data for fish to the intact animal and used this information as an input to models of chemical bioconcentration. These “proof of concept” studies show that incorporating in vitro metabolism data into the models sub...

  7. Exploring the planetary boundary for chemical pollution.

    Science.gov (United States)

    Diamond, Miriam L; de Wit, Cynthia A; Molander, Sverker; Scheringer, Martin; Backhaus, Thomas; Lohmann, Rainer; Arvidsson, Rickard; Bergman, Åke; Hauschild, Michael; Holoubek, Ivan; Persson, Linn; Suzuki, Noriyuki; Vighi, Marco; Zetzsch, Cornelius

    2015-05-01

    Rockström et al. (2009a, 2009b) have warned that humanity must reduce anthropogenic impacts defined by nine planetary boundaries if "unacceptable global change" is to be avoided. Chemical pollution was identified as one of those boundaries for which continued impacts could erode the resilience of ecosystems and humanity. The central concept of the planetary boundary (or boundaries) for chemical pollution (PBCP or PBCPs) is that the Earth has a finite assimilative capacity for chemical pollution, which includes persistent, as well as readily degradable chemicals released at local to regional scales, which in aggregate threaten ecosystem and human viability. The PBCP allows humanity to explicitly address the increasingly global aspects of chemical pollution throughout a chemical's life cycle and the need for a global response of internationally coordinated control measures. We submit that sufficient evidence shows stresses on ecosystem and human health at local to global scales, suggesting that conditions are transgressing the safe operating space delimited by a PBCP. As such, current local to global pollution control measures are insufficient. However, while the PBCP is an important conceptual step forward, at this point single or multiple PBCPs are challenging to operationalize due to the extremely large number of commercial chemicals or mixtures of chemicals that cause myriad adverse effects to innumerable species and ecosystems, and the complex linkages between emissions, environmental concentrations, exposures and adverse effects. As well, the normative nature of a PBCP presents challenges of negotiating pollution limits amongst societal groups with differing viewpoints. Thus, a combination of approaches is recommended as follows: develop indicators of chemical pollution, for both control and response variables, that will aid in quantifying a PBCP(s) and gauging progress towards reducing chemical pollution; develop new technologies and technical and social

  8. Assessment of exposure to chemical agents in in fill material for artificial turf soccer pitches: development and implementation of a survey protocol

    International Nuclear Information System (INIS)

    Health concerns over the composition of the in fill material used to construct artificial turf pitches (e.g., for soccer and rugby), raised the need to develop a specific procedure to assess the risks of human exposure to pollutants that may be released by these materials. The aim of this paper was to develop and implement a survey protocol to assess exposure of artificial turf pitches users (e.g., coaches and maintenance personnel) through environmental and biological monitoring of toxic and carcinogenic substances contained in some types of in fill materials for artificial turf pitches. The exposure was assessed by personal and environmental sampling of hazardous substances - particularly of benzene, toluene, xylene (BTX), polycyclic aromatic hydrocarbons (PAHs) and heavy metals (lead, cadmium, chromium, tin and zinc) - for comparison with the occupational exposure limit values as per the Italian regulations and the lists of the American Conference of Industrial Governmental Hygienists (ACGIH). In addition, biological monitoring was performed for the quantitative and qualitative determination of the exposure bio markers of the substances of interest in potentially exposed individuals and in control group. Environmental sampling was performed on an outdoor, artificial turf soccer pitch in a sports facility in Rome characterized by recycled in fill material (rubber granules from recycled tyres, without any further processing); suction pumps were used as environmental samplers to collect the samples (located in areas of the soccer pitch deemed representative of exposure conditions) and personal samplers (in this latter case exclusively for monitoring PAHs) worn by the coaches during training sessions. For the various substances the following sampling systems were used: vials for BTX (benzene, toluene, and xylene), filters for metals and combined systems (filter plus vial) for the PAHs. The extracts were then analyzed by various instrumental techniques such as gas

  9. Risk assessment of low-level chemical exposures from consumer products under the U.S. Consumer Product Safety Commission chronic hazard guidelines.

    OpenAIRE

    Babich, M A

    1998-01-01

    The U.S. Consumer Product Safety Commission (CPSC) is an independent regulatory agency that was created in 1973. The CPSC has jurisdiction over more the 15,000 types of consumer products used in and around the home or by children, except items such as food, drugs, cosmetics, medical devices, pesticides, certain radioactive materials, products that emit radiation (e.g., microwave ovens), and automobiles. The CPSC has investigated many low-level exposures from consumer products, including forma...

  10. Self-reported occupational exposure to chemical and physical factors and risk of skin problems: a 3-year follow-up study of the general working population of Norway.

    Science.gov (United States)

    Alfonso, Jose Hernan; Thyssen, Jacob P; Tynes, Tore; Mehlum, Ingrid Sivesind; Johannessen, Håkon A

    2015-11-01

    Prospective studies on occupational dermatoses in the general working population are sparse. This study investigated prospectively the impact of self-reported occupational exposure to chemicals and physical factors on the risk of skin problems. The cohort comprised respondents drawn randomly from the general population in Norway, who were registered employed in 2006 and 2009 (n = 6,745). Indoor dry air (odds ratio (OR) 1.3; 95% confidence interval (95% CI) 1.1-1.6) was a significant baseline predictor of skin problems at follow-up, whereas exposure to cleaning products (OR 1.7; 95% CI 1.2-2.5), water (OR 1.4; 95% CI 1.1-1.9) and indoor dry air (OR 1.6; 95% CI 1.1-2.1) at both measurement time-points was significantly associated with skin problems. The population risk attributable to these factors was 16%. This study quantified the contribution of occupational exposure factors to skin problems in the general working population of Norway. PMID:25941012

  11. Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation. Comprehensive progress report, July 1991--June 1992

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, J.D.

    1992-06-01

    This project seeks to defining the chromosome segments associated with radiation induced leukemogenesis (treatment-related acute myeloid leukemia, or t-AML). Towards these goals genetic analysis of human chromosomes 5 and 7 continues to investigate correlation of treatment with balanced and unbalanced chromosomal translocations. Progress is being made in cloning the breakpoints in balanced translocations in t-AML, that is to clone the t(9;11) and t(11;19) breakpoints, to clone the t(3;21)(q26;q22) breakpoints and to determine the relationship of these translocations to prior exposure to topoisomerase II inhibitors. 11 figs. 3 figs.

  12. Effect of cluster sun exposure on chemical composition and technological properties of grapes and wine from cultivars Cabernet sauvignon and mavrud

    International Nuclear Information System (INIS)

    A study was conducted on the effect of direct solar radiation on grape clusters of cvs Cabernet sauvignon and Mavrid, formed under four different microclimatic conditions: Vo- control; V1 - clusters exposed naturally to direct sunlight; V2 - clusters formed under natural shading; V3 - clusters formed under artificial shading.The positive impact of direct solar radiation on the formation of wine structure, character and body indicated the primary role of agrotechnical practices for ensuring better sunlight exposure of clusters and microclimatic conditions to enable the production of good wine-making materials

  13. Global challenges and strategies for control, conversion and utilization of CO{sub 2} for sustainable development involving energy, catalysis, adsorption and chemical processing

    Energy Technology Data Exchange (ETDEWEB)

    Song, Chunshan [Clean Fuels and Catalysis Program, The Energy Institute, and Department of Energy and Geo-Environmental Engineering, The Pennsylvania State University 209 Academic Projects Building, University Park, PA 16802 (United States)

    2006-06-30

    Utilization of carbon dioxide (CO{sub 2}) has become an important global issue due to the significant and continuous rise in atmospheric CO{sub 2} concentrations, accelerated growth in the consumption of carbon-based energy worldwide, depletion of carbon-based energy resources, and low efficiency in current energy systems. The barriers for CO{sub 2} utilization include: (1) costs of CO{sub 2} capture, separation, purification, and transportation to user site; (2) energy requirements of CO{sub 2} chemical conversion (plus source and cost of co-reactants); (3) market size limitations, little investment-incentives and lack of industrial commitments for enhancing CO{sub 2}-based chemicals; and (4) the lack of socio-economical driving forces. The strategic objectives may include: (1) use CO{sub 2} for environmentally-benign physical and chemical processing that adds value to the process; (2) use CO{sub 2} to produce industrially useful chemicals and materials that adds value to the products; (3) use CO{sub 2} as a beneficial fluid for processing or as a medium for energy recovery and emission reduction; and (4) use CO{sub 2} recycling involving renewable sources of energy to conserve carbon resources for sustainable development. The approaches for enhancing CO{sub 2} utilization may include one or more of the following: (1) for applications that do not require pure CO{sub 2}, develop effective processes for using the CO{sub 2}-concentrated flue gas from industrial plants or CO{sub 2}-rich resources without CO{sub 2} separation; (2) for applications that need pure CO{sub 2}, develop more efficient and less-energy intensive processes for separation of CO{sub 2} selectively without the negative impacts of co-existing gases such as H{sub 2}O, O{sub 2}, and N{sub 2}; (3) replace a hazardous or less-effective substance in existing processes with CO{sub 2} as an alternate medium or solvent or co-reactant or a combination of them; (4) make use of CO{sub 2} based on the unique

  14. Early Life Exposures and Cancer

    Science.gov (United States)

    Early-life events and exposures have important consequences for cancer development later in life, however, epidemiological studies of early-life factors and cancer development later in life have had significant methodological challenges.

  15. Portuguese children exposure to multiple mycotoxins through food consumption: toward a holistic approach for multiple mycotoxins risk assessment

    OpenAIRE

    Assunção, Ricardo; Martins, Carla; Vasco, Elsa; Pinhão, M.; Loureiro, Susana; De Silva, M. J; Alvito, Paula

    2016-01-01

    Humans can be exposed to multiple chemicals at once from a variety of sources, and human risk assessment of multiple chemicals poses several challenges to scientists, risk assessors and risk managers. Ingestion of food is considered a major route of exposure to many contaminants, namely mycotoxins, especially for vulnerable population groups, as children. A lack of sufficient data regarding mycotoxins children risk assessment, could contribute to an inaccuracy of the estimated risk. Efforts m...

  16. Expression of biomarker genes of differentiation in D3 mouse embryonic stem cells after exposure to different embryotoxicant and non-embryotoxicant model chemicals

    Directory of Open Access Journals (Sweden)

    Andrea C. Romero

    2015-12-01

    Full Text Available There is a necessity to develop in vitro methods for testing embryotoxicity (Romero et al., 2015 [1]. We studied the progress of D3 mouse embryonic stem cells differentiation exposed to model embryotoxicants and non-embryotoxicants chemicals through the expression of biomarker genes. We studied a set of 16 different genes biomarkers of general cellular processes (Cdk1, Myc, Jun, Mixl, Cer and Wnt3, ectoderm formation (Nrcam, Nes, Shh and Pnpla6, mesoderm formation (Mesp1, Vegfa, Myo1e and Hdac7 and endoderm formation (Flk1 and Afp. We offer dose response in order to derive the concentration causing either 50% or 200% of expression of the biomarker gene. These records revealed to be a valuable end-point to predict in vitro the embryotoxicity of chemicals (Romero et al., 2015 [1].

  17. Self-reported chemicals exposure, beliefs about disease causation, and risk of breast cancer in the Cape Cod Breast Cancer and Environment Study: a case-control study

    OpenAIRE

    Rudel Ruthann A; Aschengrau Ann; Zota Ami R; Brody Julia

    2010-01-01

    Abstract Background Household cleaning and pesticide products may contribute to breast cancer because many contain endocrine disrupting chemicals or mammary gland carcinogens. This population-based case-control study investigated whether use of household cleaners and pesticides increases breast cancer risk. Methods Participants were 787 Cape Cod, Massachusetts, women diagnosed with breast cancer between 1988 and 1995 and 721 controls. Telephone interviews asked about product use, beliefs abou...

  18. Contaminant exposure in terrestrial vertebrates

    International Nuclear Information System (INIS)

    Here we review mechanisms and factors influencing contaminant exposure among terrestrial vertebrate wildlife. There exists a complex mixture of biotic and abiotic factors that dictate potential for contaminant exposure among terrestrial and semi-terrestrial vertebrates. Chemical fate and transport in the environment determine contaminant bioaccessibility. Species-specific natural history characteristics and behavioral traits then play significant roles in the likelihood that exposure pathways, from source to receptor, are complete. Detailed knowledge of natural history traits of receptors considered in conjunction with the knowledge of contaminant behavior and distribution on a site are critical when assessing and quantifying exposure. We review limitations in our understanding of elements of exposure and the unique aspects of exposure associated with terrestrial and semi-terrestrial taxa. We provide insight on taxa-specific traits that contribute, or limit exposure to, transport phenomenon that influence exposure throughout terrestrial systems, novel contaminants, bioavailability, exposure data analysis, and uncertainty associated with exposure in wildlife risk assessments. Lastly, we identify areas related to exposure among terrestrial and semi-terrestrial organisms that warrant additional research. - Both biotic and abiotic factors determine chemical exposure for terrestrial vertebrates

  19. Risks and Chemical Substances.

    Science.gov (United States)

    Blumberg, Avrom A.

    1994-01-01

    Examines exposure to chemicals within the home and three important ways in which hazardous substances can be identified and evaluated. Suggests a rational picture of human health risks and contains an introductory discussion of reasons for exposure, epidemiology, cancer causes and patterns, animal testing, toxins, and risk. (LZ)

  20. Chemical characterisation of scale formation of high manganese steels (Fe-Mn23-C0.6) on the sub-micrometre scale: a challenge for EPMA

    International Nuclear Information System (INIS)

    Fe-23Mn-0.6C steel oxidation in the initial state of annealing in synthetic air and an Ar / 4 % H2 / 7 % H2O atmosphere (600, 800 and 1000 °C for 20 min) was investigated. The chemical structure of the oxide scale and near-surface region of the oxidized sheet was characterized by electron probe microanalysis (EPMA). The results were correlated with the crystallographic structure of the sheet measured by electron backscatter diffraction (EBSD). Special preparations techniques i.e., focussed ion beam (FIB) milling and cross-section polishing by Ar-ions were applied to satisfy the requirements of quantitative X-ray and EBSD analyses. Moreover, carbon concentration profiles were measured on samples prepared by ion beam techniques and the conventional way with lubricants and polishing materials. Finally, a model of the near-surface region was derived by combining the results of quantitative analysis and X-ray mappings and was compared with thermodynamic calculations.