Evaluation of the acute toxicity of refined petroleum products against ...

African Journals Online (AJOL)

Static and static-renewal evaluation of the acute toxicity of three refined petroleum products — petrol, kerosene and diesel — against two freshwater animals, the mollusc Pila ovata and the fish Poecilia reticulata, was conducted in the laboratory. Petrol, kerosene and diesel were found to be moderately toxic to the test ...

Amount, disposal and relative toxicity of long-lived fission products and actinides in the radioactive wastes of the nuclear fuel cycles

International Nuclear Information System (INIS)

Haug, H.O.

1975-11-01

A review is presented on the magnitude of the long-term problems of radioactive wastes from the nuclear power industry of the FRG (and Western Europe). The production of long-lived fission products and actinides has been calculated for several fuel types of the uranium-plutonium and thorium-uranium fuel cycles and related to a prediction of the development and share of LWR, FBR and HTGR. The quantities and concentrations of actinides, the radioactivity and relative toxicity index of the wastes of reprocessing (and fuel refabrication) and their changes by radioactive decay are presented. The radiotoxicity of the nuclide inventory of the solidified high-level wastes have been compared with naturally occuring uranium ores. On the long term (>10 3 years) the radiotoxicity level of the total area of the final repository in deep geological formation does not result in a significantly higher radiotoxicity level than an uranium ore deposit of low uranium content. Also discussed have been the chemical separation of the actinides from high-level wastes and recycling in fission reactors. (orig.) [de

Heart Toxicity Related to Herbs and Dietary Supplements: Online Table of Case Reports. Part 4 of 5.

Science.gov (United States)

Brown, Amy C

2017-10-05

The purpose of this review was to create an online research summary table of heart toxicity case reports related to dietary supplements (DS; includes herbs). Documented PubMed case reports of DS appearing to contribute to heart-related problems were used to create a "Toxic Table" that summarized the research (1966 to April, 2016, and cross-referencing). Keywords included "herb," "dietary supplement," and cardiac terms. Case reports were excluded if they were herb combinations (some exceptions), Chinese herb mixtures, teas of mixed herb contents, mushrooms, poisonous plants, self-harm (e.g. suicide), excess dose (except vitamins/minerals), drugs or illegal drugs, drug-herbal interactions, and confounders of drugs or diseases. The spectrum of heart toxicities included hypertension, hypotension, hypokalemia, bradycardia, tachycardia, arrhythmia, ventricular fibrillation, heart attack, cardiac arrest, heart failure, and death. Heart related problems were associated with approximately seven herbs: Four traditional Chinese medicine herbs - Don quai (Angelica sinensis), Jin bu huan (Lycopodium serratum), Thundergod vine or lei gong teng (Tripterygium wilfordii Hook F), and Ting kung teng (Erycibe henryi prain); one an Ayruvedic herb - Aswagandha, (Withania somnifera); and two North American herbs - blue cohosh (Caulophyllum thalictroides), and Yohimbe (Pausinystalia johimbe). Aconitum and Ephedra species are no longer sold in the United States. The DS included, but are not limited to five DS - bitter orange, caffeine, certain energy drinks, nitric oxide products, and a calming product. Six additional DS are no longer sold. Licorice was the food related to heart problems. The online "Toxic Table" forewarns clinicians, consumers and the DS industry by listing DS with case reports related to heart toxicity. It may also contribute to Phase IV post marketing surveillance to diminish adverse events that Government officials use to regulate DS.

Toxic element contamination of natural health products and pharmaceutical preparations.

Directory of Open Access Journals (Sweden)

Stephen J Genuis

Full Text Available BACKGROUND: Concern has recently emerged regarding the safety of natural health products (NHPs-therapies that are increasingly recommended by various health providers, including conventional physicians. Recognizing that most individuals in the Western world now consume vitamins and many take herbal agents, this study endeavored to determine levels of toxic element contamination within a range of NHPs. METHODS: Toxic element testing was performed on 121 NHPs (including Ayurvedic, traditional Chinese, and various marine-source products as well as 49 routinely prescribed pharmaceutical preparations. Testing was also performed on several batches of one prenatal supplement, with multiple samples tested within each batch. Results were compared to existing toxicant regulatory limits. RESULTS: Toxic element contamination was found in many supplements and pharmaceuticals; levels exceeding established limits were only found in a small percentage of the NHPs tested and none of the drugs tested. Some NHPs demonstrated contamination levels above preferred daily endpoints for mercury, cadmium, lead, arsenic or aluminum. NHPs manufactured in China generally had higher levels of mercury and aluminum. CONCLUSIONS: Exposure to toxic elements is occurring regularly as a result of some contaminated NHPs. Best practices for quality control-developed and implemented by the NHP industry with government oversight-is recommended to guard the safety of unsuspecting consumers.

Shape-Related Toxicity of Titanium Dioxide Nanofibres

Science.gov (United States)

Allegri, Manfredi; Bianchi, Massimiliano G.; Chiu, Martina; Varet, Julia; Costa, Anna L.; Ortelli, Simona; Blosi, Magda; Bussolati, Ovidio; Poland, Craig A.; Bergamaschi, Enrico

2016-01-01

Titanium dioxide (TiO2) nanofibres are a novel fibrous nanomaterial with increasing applications in a variety of fields. While the biological effects of TiO2 nanoparticles have been extensively studied, the toxicological characterization of TiO2 nanofibres is far from being complete. In this study, we evaluated the toxicity of commercially available anatase TiO2 nanofibres using TiO2 nanoparticles (NP) and crocidolite asbestos as non-fibrous or fibrous benchmark materials. The evaluated endpoints were cell viability, haemolysis, macrophage activation, trans-epithelial electrical resistance (an indicator of the epithelial barrier competence), ROS production and oxidative stress as well as the morphology of exposed cells. The results showed that TiO2 nanofibres caused a cell-specific, dose-dependent decrease of cell viability, with larger effects on alveolar epithelial cells than on macrophages. The observed effects were comparable to those of crocidolite, while TiO2 NP did not decrease cell viability. TiO2 nanofibres were also found endowed with a marked haemolytic activity, at levels significantly higher than those observed with TiO2 nanoparticles or crocidolite. Moreover, TiO2 nanofibres and crocidolite, but not TiO2 nanoparticles, caused a significant decrease of the trans-epithelial electrical resistance of airway cell monolayers. SEM images demonstrated that the interaction with nanofibres and crocidolite caused cell shape perturbation with the longest fibres incompletely or not phagocytosed. The expression of several pro-inflammatory markers, such as NO production and the induction of Nos2 and Ptgs2, was significantly increased by TiO2 nanofibres, as well as by TiO2 nanoparticles and crocidolite. This study indicates that TiO2 nanofibres had significant toxic effects and, for most endpoints with the exception of pro-inflammatory changes, are more bio-active than TiO2 nanoparticles, showing the relevance of shape in determining the toxicity of nanomaterials

Safety assessment of VHTR hydrogen production system against fire, explosion and acute toxicity

International Nuclear Information System (INIS)

Murakami, Tomoyuki; Nishihara, Tetsuo; Kunitomi, Kazuhiko

2008-01-01

The Japan Atomic Energy Agency has been developing a nuclear hydrogen production system by using heat from the Very High Temperature Reactor (VHTR). This system will handle a large amount of combustible gas and toxic gas. The risk from fire, explosion and acute toxic exposure caused by an accident involving chemical material release in a hydrogen production system is assessed. It is important to ensure the safety of the nuclear plant, and the risks for public health should be sufficiently small. This report provides the basic policy for the safety evaluation in cases of accident involving fire, explosion and toxic material release in a hydrogen production system. Preliminary safety analysis of a commercial-sized VHTR hydrogen production system, GTHTR300C, is performed. This analysis provides us with useful information on the separation distance between a nuclear plant and a hydrogen production system and a prospect that an accident in a hydrogen production system does not significantly increase the risks of the public. (author)

Oxaliplatin-Related Ocular Toxicity

Directory of Open Access Journals (Sweden)

Marina Mesquida

2010-11-01

Full Text Available We report the case of a 52-year-old woman with advanced colorectal cancer who was treated with oxaliplatin on a FOLFOX schedule. After 3 cycles of chemotherapy, she started to complain of visual loss, altered color vision and neurological symptoms. Due to the suspicion of ocular and neurological toxicity, antineoplastic treatment was stopped. Her visual field showed a concentric bilateral scotoma and the electrooculogram test revealed severe impairment of the retinal pigment epithelium. Visual acuity, color vision and visual field recovered completely 8 months later, although electrooculogram remained abnormal. Ocular toxicity has been reported as an infrequent adverse event of oxaliplatin. Findings in this case indicate toxicity of this chemotherapeutic agent on the retinal pigment epithelium, which has not been reported before. This damage could be permanent, and it thus differs from previously described oxaliplatin-induced ocular toxicities, which are usually transient and reversible. With increasing use of oxaliplatin as first-line treatment in advanced colorectal cancer, we have to be aware of this possible toxicity.

Evaluation on biosafety in long-term administration, teratogenicity and local toxicity of developed product

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung-Ho; Kim, Jong-Chun; Kim, Se-Ra; Lee, Hae-Jun; Lee, Jin-Hee [Chonnam Nat. Univ., Gwangju (Korea, Republic of)

2006-01-15

We performed this study to determine biosafety of developed product in long-term administration and teratogenicity and local toxicity (skin and eye) of developed product (HemoHIM and HemoTonic). It is suggested that long-term administration with the developed products may not exert considerable side effects. It is concluded that the administration of HemoHIM or HemoTonic does not inflict any adverse effect on fetuses of pregnant mice. HemoHIM and HemoTonic could be considered as a no irritating materials to the skin and eye of the test animals. These results indicated that HemoHIM and HemoTonic might be a useful functional food, especially since it is a relatively nontoxic natural product.

Evaluation on biosafety in long-term administration, teratogenicity and local toxicity of developed product

International Nuclear Information System (INIS)

Kim, Sung-Ho; Kim, Jong-Chun; Kim, Se-Ra; Lee, Hae-Jun; Lee, Jin-Hee

2006-01-01

We performed this study to determine biosafety of developed product in long-term administration and teratogenicity and local toxicity (skin and eye) of developed product (HemoHIM and HemoTonic). It is suggested that long-term administration with the developed products may not exert considerable side effects. It is concluded that the administration of HemoHIM or HemoTonic does not inflict any adverse effect on fetuses of pregnant mice. HemoHIM and HemoTonic could be considered as a no irritating materials to the skin and eye of the test animals. These results indicated that HemoHIM and HemoTonic might be a useful functional food, especially since it is a relatively nontoxic natural product

Radioletic degradation of monocrotophos and toxicity of breakdown products

International Nuclear Information System (INIS)

Ghanem, I.; Shamma, M.; Al-Arfi, M.; Abu-Alnaser, A.

2015-03-01

Among sources of environmental pollution, pesticides contamination is wide spread and has become a source of concern. The organophosphorus pesticide, monocrotophos, is highly toxic compound and inhibits cholinesterase. It is very dangerous by all ways of exposure. Monocrotophos is used widely in Syria to control a variety of boring, chewing and sucking insects on various fruit and veditable crops. It is even, ellegally used to protect grapes in grape orchards from birds which is potentially hazaradous to both birds and the consumers of rthis crop. Monocrotophos is imported to Syria, and this is done according to a yearly plan to assess the amount needed of each pesticide. Such planning combined with variation in the incidence of pest infestation may lead to accummulation of pesticides from year to another, they become obsolete . Getting rid of such pesticides in the developing world is a problem, and Syria is no exception. There are various method of getting rid of obsolete pesticides ranging from containment to chemical methods of breaking down the pesticide. The present study aimed at assesing the feasiblity of using gamma radiation as a means to break down high concentrations of technical grade monocrotophos Several concentrations, 50, 200, and 400 mg/ml of technical grade monocrotophos were exposed to several doses of gamma radiation, namely, 0, 15, 45, 75, and 105 kGy. For each concentration tested percentages of monocrotophos breakdown increased with the increase of applied gamma radiation dose. However, the effect of gamma radiation dose was inversely related to monocrotophos concentration. The highest percentage of moncrotophos degradation was 60% and it was achieved by exposing 50 mg/ml of monocrotophos to 105 kGy of gamma radiation Breakdown products were identified using gas chromatography coupled with mass spectrometry GC-MS. Some identified products were dimethyl methyl phosphonate, phosphoric acid trimethyl and phosphoric acid dimethyl 1-methyl ethyl

Medicinal plants and natural products in amelioration of arsenic toxicity: a short review.

Science.gov (United States)

Bhattacharya, Sanjib

2017-12-01

Chronic arsenic toxicity (arsenicosis) is considered a serious public health menace worldwide, as there is no specific, safe, and efficacious therapeutic management of arsenicosis. To collate the studies on medicinal plants and natural products with arsenic toxicity ameliorative effect, active pre-clinically and/or clinically. Literature survey was carried out by using Google, Scholar Google and Pub-Med. Only the scientific journal articles found on the internet for last two decades were considered. Minerals and semi-synthetic or synthetic analogs of natural products were excluded. Literature study revealed that 34 medicinal plants and 14 natural products exhibited significant protection from arsenic toxicity, mostly in preclinical trials and a few in clinical studies. This research could lead to development of a potentially useful agent in clinical management of arsenicosis in humans.

Biochars made from agro-industrial by-products remove chlorine and lower water toxicity

Science.gov (United States)

Tzachristas, Andreas; Xirou, Maria; Manariotis, Ioannis D.; Dailianis, Stefanos; Karapanagioti, Hrissi K.

2016-04-01

Chlorination is the most common disinfection process for water and treated wastewater. For the industrial use of water in food production, chlorine can add undesired taste and odor to the final product. For this reason, dechlorination is desired for food industries that use municipal tap water. For treated wastewater discharge or reuse, chlorine can be toxic to the receiving aqueous systems and to the irrigated plants. In both the above cases, dechlorination is also required. Traditionally activated carbon has been used as the ideal material for the removal of chlorine. The main mechanisms that describe the interaction between activated carbon and HOCl or OCl- are described by the following equations (AWWA, 1990): HOCl + C* → C*O + H+ + Cl- (1), OCl- + C* → C*O + Cl- (2) Where C* and C*O represent the activated carbon surface and a surface oxide, respectively. The present study proposes the use of agro-industrial by-products for the production of biochars that will be used for dechlorination of tap-water used for food-industry production. Different raw materials such as malt spent rootlets, coffee residue, olive and grape seeds, etc. are used for the production of biochar. Various temperatures and air-to-solid ratios are tested for optimizing biochar production. Batch tests as well as a column test are employed to study the dechlorination efficiency and kinetics of the different raw and biochar materials as well as those of commercial activated carbons. As chlorine concentration increases the removal also increases linearily. After 1 and 24 hours of contact the chlorine relative removal efficiencies for the biochar made from olive seeds are 50 and 77 ± 4%, respectively. It seems that the removal kinetics are faster during the first hour; then, removal continues but with a slower rate. Most of the biochars tested (with 3 mg of solid in 20 mL of chlorine solution at initial concentration Co=1.5 mg/L) demonstrated removal efficiencies with an average of 9.4 ± 0

Oxidation of danofloxacin by free chlorine-kinetic study, structural identification of by-products by LC-MS/MS and potential toxicity of by-products using in silico test.

Science.gov (United States)

Yassine, Montaha; Rifai, Ahmad; Doumyati, Samah; Trivella, Aurélien; Mazellier, Patrick; Budzinski, Hélène; Al Iskandarani, Mohamad

2017-03-01

In this study, we aimed to investigate the kinetics and the mechanism of reaction of the fluoroquinolone antibacterial danofloxacin (DANO) by free available chlorine (FAC) during water chlorination process. Kinetic study was thus performed at pH 7.2, 20 °C in the presence of an excess of total chlorine. Under these experimental conditions, a second-order reaction rate constant (first-order relative to DANO concentration and first-order relative to FAC concentration) was evaluated to k~1446 M -1  s -1 . Five degradation products were identified at different reaction times. Their structures were investigated by using fragmentations obtained at different CID collision energies in MS/MS experiments. Moreover, the toxicity of the proposed structures was predicted by using T.E.S.T. The results indicated that all by-products may have a developmental toxicity. The oral rat LD 50 concentration was predicted to be lower than that of DANO. Furthermore, two degradation compounds presented a concentration level for fathead minnow LC 50 (96 h) lower than that of DANO and presented toxicity for the marine animals.

Stereoselective potencies and relative toxicities of coniine enantiomers.

Science.gov (United States)

Lee, Stephen T; Green, Benedict T; Welch, Kevin D; Pfister, James A; Panter, Kip E

2008-10-01

Coniine, one of the major toxic alkaloids present in poison hemlock ( Conium maculatum), occurs in two optically active forms. A comparison of the relative potencies of (+)- and (-)-coniine enantiomers has not been previously reported. In this study, we separated the enantiomers of coniine and determined the biological activity of each enantiomer in vitro and in vivo. The relative potencies of these enantiomers on TE-671 cells expressing human fetal nicotinic neuromuscular receptors had the rank order of (-)-coniine > (+/-)-coniine > (+)-coniine. A mouse bioassay was used to determine the relative lethalities of (-)-, (+/-)-, and (+)-coniine in vivo. The LD 50 values of the coniine enantiomers were 7.0, 7.7, and 12.1 mg/kg for the (-)-, (+/-)-, and (+)- forms of coniine, respectively. The results from this study demonstrate that there is a stereoselective difference in the in vitro potencies of the enantiomers of coniine that directly correlates with the relative toxicities of the enantiomers in vivo.

A novel two-dimensional liquid chromatographic system for the online toxicity prediction of pharmaceuticals and related substances

Energy Technology Data Exchange (ETDEWEB)

Li, Jian; Xu, Li [Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030 (China); Shi, Zhi-guo, E-mail: shizg@whu.edu.cn [Department of Chemistry, Wuhan University, Wuhan 430072 (China); Hu, Min [Hubei Instrument for Food and Drug Control, Wuhan (China)

2015-08-15

Highlights: • A novel two-dimensional liquid chromatographic system was developed. • The 1st dimension was ODS to separate components in the sample. • The 2nd dimension was biopartitioning micellar chromatography to predict toxicity. • The system was used to screen toxicity of pharmaceuticals and related substances. • It was promising for fast online toxicity screening of complex sample in one step. - Abstract: In this study, a novel two-dimensional liquid chromatographic (2D-LC) system was developed for simultaneous separation and toxicity prediction of pharmaceutical and its related substances. A conventional ODS column was used on the 1st-D to separate the sample; while, bio-partitioning micellar chromatography served as the 2nd-D to predict toxicity of the components. The established system was tested for the toxicity of ibuprofen and its impurities with known toxicity. With only one injection, ibuprofen and its impurities were separated on the 1st-D; and LC50 values of individual impurity were obtained based on the quantitative retention–activity relationships, which agreed well with the reported data. Furthermore, LC50 values of photolysis transformation products (TPs) of carprofen, ketoprofen and diclofenac acid (as unknown compounds) were screened in this 2D-LC system, which could be an indicator of the toxicity of these TPs and was meaningful for the environmental monitoring and drinking water treatment. The established 2D-LC system was cost-effective, time-saving and reliable, and was promising for fast online screening of toxicity of known and unknown analytes in the complex sample in a single step. It may find applications in environment, pharmaceutical and food, etc.

A novel two-dimensional liquid chromatographic system for the online toxicity prediction of pharmaceuticals and related substances

International Nuclear Information System (INIS)

Li, Jian; Xu, Li; Shi, Zhi-guo; Hu, Min

2015-01-01

Highlights: • A novel two-dimensional liquid chromatographic system was developed. • The 1st dimension was ODS to separate components in the sample. • The 2nd dimension was biopartitioning micellar chromatography to predict toxicity. • The system was used to screen toxicity of pharmaceuticals and related substances. • It was promising for fast online toxicity screening of complex sample in one step. - Abstract: In this study, a novel two-dimensional liquid chromatographic (2D-LC) system was developed for simultaneous separation and toxicity prediction of pharmaceutical and its related substances. A conventional ODS column was used on the 1st-D to separate the sample; while, bio-partitioning micellar chromatography served as the 2nd-D to predict toxicity of the components. The established system was tested for the toxicity of ibuprofen and its impurities with known toxicity. With only one injection, ibuprofen and its impurities were separated on the 1st-D; and LC50 values of individual impurity were obtained based on the quantitative retention–activity relationships, which agreed well with the reported data. Furthermore, LC50 values of photolysis transformation products (TPs) of carprofen, ketoprofen and diclofenac acid (as unknown compounds) were screened in this 2D-LC system, which could be an indicator of the toxicity of these TPs and was meaningful for the environmental monitoring and drinking water treatment. The established 2D-LC system was cost-effective, time-saving and reliable, and was promising for fast online screening of toxicity of known and unknown analytes in the complex sample in a single step. It may find applications in environment, pharmaceutical and food, etc

About neutralization of the toxic waste of galvanic production

International Nuclear Information System (INIS)

Akhmetzhanova, Z.Kh.; Samatov, I.B.

1996-01-01

The nature of heavy metals ions migration to environment from the galvanic production is considered in the article. The method of toxic precipitations transformation to non-toxic ones is proposed. The essence of stabilization method of heavy metals hydroxides precipitations consists in transformation of galvanic precipitations mixture to same metals ferrites mixture. The reaction has followed in oxygen medium under heating of galvanic precipitations from 70 up 90 deg C. Before heating the precipitation have acid medium, after temperature treatment the medium turn to the neutral one. These compounds are presented as ferrite class and can be serve as base for various pigments. (author)

Degradation study of pesticides by direct photolysis - Structural characterization and potential toxicity of photo products

International Nuclear Information System (INIS)

Rifai, A.

2013-01-01

Pesticides belong to the large family of organic pollutants. In general, they are intended to fight against crop pests. Distribution of pesticides in nature creates pollution in DIFFERENT compartments of the biosphere (water, soil and air) and can induce acute toxic effects on human beings of the terrestrial and aquatic living biomass. It is now shown that some pesticides are endocrine disruptors and are particularly carcinogenic and mutagenic effects in humans. Pesticides can undergo various processes of transformation in the natural life cycle (biodegradation, volatilization, solar radiation ...) or following applied in the sectors of natural water purification and treatment stations sewage treatment. The presence of degradation products of pesticides in our environment is even more alarming that their structures and potential toxicities generally unknown. Molecules belonging to two families of pesticides were selected for this study: herbicides, represented by metolachlor, and fungicides represented by procymidone, pyrimethanil and boscalid. The first part of the thesis focused on the development of an analytical strategy to characterize the structures of compounds from degradation by photolysis of pesticides. The second part focused on estimating the toxicity of degradation products using a test database in silico. Identification of degradation products was achieved through two complementary analysis techniques: the gas chromatography coupled to a mass spectrometer ''multi-stage'' (GC-MSn) and liquid chromatography coupled to a tandem mass spectrometer (LC-MS/MS). The estimation of the toxicity of the degradation products was performed using the TEST program QSAR recently developed to try to predict the toxicity of molecules. The strategy of the structural elucidation of degradation products of pesticides studied is based on studying of the mechanisms of fragmentation of parent molecules of the degradation products. The molar mass of parent

The impact of iodinated X-ray contrast agents on formation and toxicity of disinfection by-products in drinking water.

Science.gov (United States)

Jeong, Clara H; Machek, Edward J; Shakeri, Morteza; Duirk, Stephen E; Ternes, Thomas A; Richardson, Susan D; Wagner, Elizabeth D; Plewa, Michael J

2017-08-01

The presence of iodinated X-ray contrast media (ICM) in source waters is of high concern to public health because of their potential to generate highly toxic disinfection by-products (DBPs). The objective of this study was to determine the impact of ICM in source waters and the type of disinfectant on the overall toxicity of DBP mixtures and to determine which ICM and reaction conditions give rise to toxic by-products. Source waters collected from Akron, OH were treated with five different ICMs, including iopamidol, iopromide, iohexol, diatrizoate and iomeprol, with or without chlorine or chloramine disinfection. The reaction product mixtures were concentrated with XAD resins and the mammalian cell cytotoxicity and genotoxicity of the reaction mixture concentrates was measured. Water containing iopamidol generated an enhanced level of mammalian cell cytotoxicity and genotoxicity after disinfection. While chlorine disinfection with iopamidol resulted in the highest cytotoxicity overall, the relative iopamidol-mediated increase in toxicity was greater when chloramine was used as the disinfectant compared with chlorine. Four other ICMs (iopromide, iohexol, diatrizoate, and iomeprol) expressed some cytotoxicity over the control without any disinfection, and induced higher cytotoxicity when chlorinated. Only iohexol enhanced genotoxicity compared to the chlorinated source water. Copyright © 2017. Published by Elsevier B.V.

"The fairer the better?" Use of potentially toxic skin bleaching products.

Science.gov (United States)

Darj, Elisabeth; Infanti, Jennifer J; Ahlberg, Beth Maina; Okumu, Jecinta

2015-12-01

Skin bleaching is a widespread phenomenon in spite of their potentially toxic health effects. This study aimed to determine if such products are used in Sweden in particular by pregnant women, furthermore to explore immigrant women's view skin bleaching. 455 pregnant women completed a questionnaire, which were statistically analysed. Focus groups and individual interviews were conducted with immigrant women, content analysis was used to assess the data. Skin bleaching products were used by 2.6% of pregnant women, significantlly more by women born in non-European countries. Motivating factors were associated with the concept of beauty together with social and economic advantages. The women had low awareness of the potential health risks of the products. Regulations on the trade of skin bleaching products have not effectively reduced the availability of the products in Sweden nor the popularity of skin bleaching. There is need for further research especially among pregnant women and possible effects on newborns. Products should be tested for toxicity. Public health information should be developed and health care providers educated and aware of this practice, due to their potential negative health implications.

Metabolism related toxicity of diclofenac in yeast as model system

NARCIS (Netherlands)

van Leeuwen, J.S.; Vredenburg, G.; Dragovic, S.; Tjong, T.F.; Vos, J.C.; Vermeulen, N.P.E.

2010-01-01

Diclofenac is a widely used drug that can cause serious hepatotoxicity, which has been linked to metabolism by cytochrome P450s (P450). To investigate the role of oxidative metabolites in diclofenac toxicity, a model for P450-related toxicity was set up in Saccharomyces cerevisiae. We expressed a

Relative toxicity and residual activity of insecticides used in blueberry pest management: mortality of natural enemies.

Science.gov (United States)

Roubos, Craig R; Rodriguez-Saona, Cesar; Holdcraft, Robert; Mason, Keith S; Isaacs, Rufus

2014-02-01

A series of bioassays were conducted to determine the relative toxicities and residual activities of insecticides labeled for use in blueberry (Vaccinium corymbosum L.) on natural enemies, to identify products with low toxicity or short duration effects on biological control agents. In total, 14 insecticides were evaluated using treated petri dishes and four commercially available natural enemies (Aphidius colemani Viereck, Orius insidiosus [Say], Chrysoperla rufilabris [Burmeister], and Hippodamia convergens [Guérin-Menéville]). Dishes were aged under greenhouse conditions for 0, 3, 7, or 14 d before introducing insects to test residual activity. Acute effects (combined mortality and knockdown) varied by insecticide, residue age, and natural enemy species. Broad-spectrum insecticides caused high mortality to all biocontrol agents, whereas products approved for use in organic agriculture had little effect. The reduced-risk insecticide acetamiprid consistently caused significant acute effects, even after aging for 14 d. Methoxyfenozide, novaluron, and chlorantraniliprole, which also are classified as reduced-risk insecticides, had low toxicity, and along with the organic products could be compatible with biological control. This study provides information to guide blueberry growers in their selection of insecticides. Further research will be needed to determine whether adoption of a pest management program based on the use of more selective insecticides will result in higher levels of biological control in blueberry.

Analysis of toxic metals in branded Pakistani herbal products

International Nuclear Information System (INIS)

Saeed, M.; Muhammad, N.; Khan, H.

2010-01-01

The present study was designed to estimate the concentration of heavy toxic metals in Pakistani herbal products frequently used for the treatment of various ailments. For this purpose, twenty five herbal products of well reputed herbal manufacturers were selected. The results of our investigation revealed that the concentrations of lead, cadmium, nickel and chromium were far beyond the permissible limits proposed by the International Regulatory Authorities for herbal drugs. Therefore, this study conveys a strong message to the ministry of health to establish proper rules and regulations for the validation of herbal products on scientific grounds in order to protect the general public from the harmful effects of these heavy metals in herbal products. (author)

Investigation of the potential influence of production treatment chemicals on produced water toxicity

International Nuclear Information System (INIS)

Stine, E.R.; Gala, W.R.; Henry, L.R.

1993-01-01

Production treatment chemicals represent a diverse collection of chemical classes, added at various points from the wellhead to the final flotation cell, to prevent operational upsets and enhance the separation of oil from water. Information in the literature indicates that while many treatment chemicals are thought to partition into oil and not into the produced water, there are cases where a sufficiently water soluble treatment chemical is added at high enough concentrations to suggest that the treatment chemical may add to the aquatic toxicity of the produced water. A study was conducted to evaluate the potential effect of production treatment chemicals on the toxicity of produced waters using the US EPA Seven-day Mysidopsis bahia Survival, Growth and Fecundity Test. Samples of produced water were collected and tested for toxicity from three platforms under normal operating conditions, followed by repeated sampling and testing after a 72-hour period in which treatment chemical usage was discontinued, to the degree possible. Significant reductions in produced water toxicity were observed for two of the three platforms tested following either cessation of treatment chemical usage, or by comparing the toxicity of samples collected upstream and downstream of the point of treatment chemical addition

Screening of foods and related products for toxic elements with a portable X-ray tube analyzer

International Nuclear Information System (INIS)

Anderson, D.L.

2009-01-01

Capabilities of a portable X-ray tube-based analyzer were evaluated for screening foods, thin films, and ceramic glazes for toxic elements. A beverage spiked with Cr, Cu, and As and cocoa powder spiked with As and Pb could easily be distinguished from unadulterated products when analyzed through their original container walls. With calibration, results for thin films and ceramic glazes yielded accurate Pb results. Limits of detection (LODs) were 0.2-15 and 15 μg cm -2 , respectively, for Pb and Cd in thin films and about 2 μg cm -2 for Pb in glazes. With analysis times of 0.5-1 min, sensitivities and LODs were superior to those obtained with radioisotopic X-ray fluorescence analysis. (author)

Toxicity of magnesium alloy biodegradation products in experiment

Directory of Open Access Journals (Sweden)

Yu. M. Neryanov

2013-08-01

Full Text Available The article presents information on the study of possible toxic effects of biodegradation products of original magnesium-based alloy on laboratory rats. The used laboratory methods of investigation are described. Author has examined biochemical parameters of plasma on the base of which endogenous intoxication in rats was studied. It was found out that products of alloy biological resorption don’t cause toxic effects on tissues and don’t enhance cell destruction, that is evidenced by the absence of signs of endogenous intoxication and oxidative damage of functional macromolecules. Materials and methods. We used white mongrel male rats weighing 220-270 g (n = 20. Fixator consisting of a modified magnesium alloy ML-10 was implanted into the femur muscle mass of the animals of the experimental group (n = 14. The control group consisted of white mongrel male rats weighing 230-250 g (n = 6, which were not subjected to surgery (intact group. The degree of oxidative damage to proteins, the content of the average molecular weight, nucleic acids and the stable metabolites of nitric oxide were evaluated in plasma. Results and discussion. The studies revealed the reliable (relative to the intact group increase in the content of all fractions of middle molecules in the plasma of the experimental group of rats, the increase shows only that the immune system of animals with magnesium implants is in a reactive state and responds with minor release of biologically active substances into the bloodstream. At this rate of endogenous intoxication this exponent usually increases tenfold, but we have not seen that. Levels of stable metabolites of nitric oxide increase insignificantly(1,4 times, that likely indicates more on the start of adaptive signaling processes than a pathological condition. The experimental data concerning the content of nucleic acids in the plasma of animals with magnesium implants testifies in support of this hypothesis. There were no

Corrosion protection products as a source of bisphenol A and toxicity to the aquatic environment.

Science.gov (United States)

Vermeirssen, Etiënne L M; Dietschweiler, Conrad; Werner, Inge; Burkhardt, Michael

2017-10-15

Steel components are typically treated with anti-corrosion coatings like epoxy or polyurethane resins to protect the integrity and functioning of steel. Such resins may contain substances, such as bisphenol A (BPA), that have caused concern in a human and environmental toxicological context. We investigated the release of toxicity from four anti-corrosion coatings used in hydraulic and civil engineering. Resins were applied onto glass plates and leachate samples produced by horizontally shaking the plates in water for 7 days. Two experiments were conducted, one with a 1 day and one with a 7 day curing period. Using a suite of bioassays, we tested samples for: agonistic and antagonistic effects on various mammalian nuclear receptors; inhibition of photosynthesis and growth in algae; inhibition of bacterial bioluminescence; and inhibition of water flea reproduction. Concentrations of BPA, bisphenol F and various BPA transformation products were determined by chemical analysis (LC-MS/MS). Bioassay results were evaluated using a scheme developed by DIBt (Centre of Competence for Construction, Berlin, Germany). Three products induced responses in one or more of the measured endpoints and toxicity profiles varied markedly in intensity across products. One product released high amounts of BPA which was associated with effects on nuclear receptor transactivation, requiring a more than 700-fold dilution for effect induction to fall below 20%. The same product was also the most toxic to water flea reproduction, requiring ca. 70-fold dilution for effects to fall below 20%. Another product was highly toxic in terms of bacterial bioluminescence, particularly after a shorter curing time, requiring a ca. 1'300-fold dilution for effects to fall below 20%. The third product required a 22-fold dilution for inhibition of water flea reproduction to drop below 20%. Results show that anti-corrosion coatings based on epoxy resins can be a source of toxicity to the aquatic environment

Effects of ZnO nanoparticles and Zn"2"+ on fluvial biofilms and the related toxicity mechanisms

International Nuclear Information System (INIS)

Xu, Yi; Wang, Chao; Hou, Jun; Dai, Shanshan; Wang, Peifang; Miao, Lingzhan; Lv, Bowen; Yang, Yangyang; You, Guoxiang

2016-01-01

Zinc oxide nanoparticles (ZnO NPs) used in consumer products are largely released into the environment through the wastewater stream. The health hazard of ZnO NPs and the contribution of dissolved Zn"2"+ in toxicity of ZnO NPs has attracted extensive worldwide attention. In this study, the toxic effects of ZnO nanoparticles (ZnO NPs) and the effects of dissolved Zn"2"+ on fluvial biofilms were investigated. At the end of the exposure time (21 days), scanning electron microscopy (SEM) images and bioaccumulation experiments revealed that large quantities of ZnO NPs were adsorbed on the biofilm. The algal biomasses were significantly decreased by six- and eleven-fold compared with the control (1.43 μg/L) by exposure to concentrations of 100 mg/L ZnO NPs and 7.85 mg/L Zn"2"+, respectively. Moreover, under the same exposure conditions, the quantum yields presented contents of 53.33 and 33.33% relative to the control, and a shift in the community composition that manifested as a strong reduction in diatoms was observed from 7 days and reached 15.63 and 6.25% of the control after 21 days of exposure, respectively. The reductions in bacteria viability and reactive oxygen species (ROS) production were noticeably enhanced following exposure to 100 mg/L ZnO NPs and 7.85 mg/L Zn"2"+, respectively. Additionally, the acute and rapid toxicity of Zn"2"+ and the increasing toxicity of the ZnO NPs with increased bioaccumulation were noted in the exposure experiment. - Highlights: • Fluvial biofilm was exposed to ZnO NPs and the dissolved Zn"2"+. • Chl-a and Φ_M decreased at high doses (100 and 7.85 mg/L of ZnO NPs and Zn"2"+). • A shift in the algae community composition was observed at high dosage levels. • The enhanced production of ROS declined the bacteria viability. • Zn"2"+ was more toxic than that of the ZnO-NPs.

Steroselective Potencies and Relative Toxicities of Coniine Enantiomers

Science.gov (United States)

Coniine, one of the major toxic alkaloids present in poison hemlock (Conium maculatum), occurs in two optically active forms. A comparison of the relative potencies of (+)- and (-)-coniine enantiomers has not been previously reported. In this study, we separated the enantiomers of coniine and dete...

Testing of CFC replacement fluids for arc-induced toxic by-products

Energy Technology Data Exchange (ETDEWEB)

Cravey, W.R.; Goerz, D.A.; Hawley-Fedder, R.A.

1993-06-01

The authors have developed a unique test-stand for quantifying the generation of perfluoroisobutylene (PFIB) in chlorofluorocarbon (CFC) replacement fluids when they are subjected to high electrical stress/breakdown environments. PFIB is an extremely toxic gas with a threshold limit value of 10 ppbv as set by the American Conference of Governmental Industrial Hygienists. They have tested several new fluids from various manufacturers for their potential to generate PFIB. Their goal is to determine breakdown characteristics and quantify toxic by-products of these replacement fluids to determine a safe, usable alternative for present CFC`s.

Levofloxacin oxidation by ozone and hydroxyl radicals: kinetic study, transformation products and toxicity.

Science.gov (United States)

Hamdi El Najjar, Nasma; Touffet, Arnaud; Deborde, Marie; Journel, Romain; Leitner, Nathalie Karpel Vel

2013-10-01

This work was carried out to investigate the fate of the antibiotic levofloxacin upon oxidation with ozone and hydroxyl radicals. A kinetic study was conducted at 20 °C for each oxidant. Ozonation experiments were performed using a competitive kinetic method with carbamazepin as competitor. Significant levofloxacin removal was observed during ozonation and a rate constant value of 6.0×10(4) M(-1) s(-1) was obtained at pH 7.2. An H2O2/UV system was used for the formation of hydroxyl radicals HO. The rate constant of HO was determined in the presence of a high H2O2 concentration. The kinetic expressions yielded a [Formula: see text] value of 4.5×10(9) M(-1) s(-1) at pH 6.0 and 5.2×10(9) M(-1) s(-1) at pH 7.2. These results were used to develop a model to predict the efficacy of the ozonation process and pharmaceutical removal was estimated under different ozonation conditions (i.e. oxidant concentrations and contact times). The results showed that levofloxacin was completely degraded by molecular ozone during ozonation of water and that hydroxyl radicals had no effect in real waters conditions. Moreover, LC/MS/MS and toxicity assays using Lumistox test were performed to identify ozonation transformation products. Under these conditions, four transformation products were observed and their chemical structures were proposed. The results showed an increase in toxicity during ozonation, even after degradation of all of the observed transformation products. The formation of other transformation products not identified under our experimental conditions could be responsible for the observed toxicity. These products might be ozone-resistant and more toxic to Vibrio fisheri than levofloxacin. Copyright © 2013 Elsevier Ltd. All rights reserved.

Motor vehicle-related air toxics study. Final report

International Nuclear Information System (INIS)

1993-04-01

Section 202 (1)(1) of the Clean Air Act (CAA), as amended (Section 206 of the Clean Air Act Amendments) (CAAA) of 1990 added paragraph (1) to Section 202 of the (CAA), directs the Environmental Protection Agency (EPA) to complete a study by May 15, 1992 of the need for, and feasibility of, controlling emissions of toxic air pollutants which are unregulated under the Act and associated with motor vehicles and motor vehicle fuels. The report has been prepared in response to Section 202 (1)(1). Specific pollutants or pollutant categories which are discussed in the report include benezene, formaldehyde, 1,3-butadiene, acetaldehyde, diesel particulate matter, gasoline particulate matter, and gasoline vapors as well as certain of the metals and motor vehicle-related pollutants identified in Section 112 of the Clean Air Act. The focus of the report is on carcinogenic risk. The study attempts to summarize what is known about motor vehicle-related air toxics and to present all significant scientific opinion on each issue

Influence of the Vaginal Microbiota on Toxic Shock Syndrome Toxin 1 Production by Staphylococcus aureus

OpenAIRE

MacPhee, Roderick A.; Miller, Wayne L.; Gloor, Gregory B.; McCormick, John K.; Hammond, Jo-Anne; Burton, Jeremy P.; Reid, Gregor

2013-01-01

Menstrual toxic shock syndrome (TSS) is a serious illness that afflicts women of premenopausal age worldwide and arises from vaginal infection by Staphylococcus aureus and concurrent production of toxic shock syndrome toxin-1 (TSST-1). Studies have illustrated the capacity of lactobacilli to reduce S. aureus virulence, including the capacity to suppress TSST-1. We hypothesized that an aberrant microbiota characteristic of pathogenic bacteria would induce the increased production of TSST-1 and...

Flavoring Compounds Dominate Toxic Aldehyde Production during E-Cigarette Vaping.

Science.gov (United States)

Khlystov, Andrey; Samburova, Vera

2016-12-06

The growing popularity of electronic cigarettes (e-cigarettes) raises concerns about the possibility of adverse health effects to primary users and people exposed to e-cigarette vapors. E-Cigarettes offer a very wide variety of flavors, which is one of the main factors that attract new, especially young, users. How flavoring compounds in e-cigarette liquids affect the chemical composition and toxicity of e-cigarette vapors is practically unknown. Although e-cigarettes are marketed as safer alternatives to traditional cigarettes, several studies have demonstrated formation of toxic aldehydes in e-cigarette vapors during vaping. So far, aldehyde formation has been attributed to thermal decomposition of the main components of e-cigarette e-liquids (propylene glycol and glycerol), while the role of flavoring compounds has been ignored. In this study, we have measured several toxic aldehydes produced by three popular brands of e-cigarettes with flavored and unflavored e-liquids. We show that, within the tested e-cigarette brands, thermal decomposition of flavoring compounds dominates formation of aldehydes during vaping, producing levels that exceed occupational safety standards. Production of aldehydes was found to be exponentially dependent on concentration of flavoring compounds. These findings stress the need for a further, thorough investigation of the effect of flavoring compounds on the toxicity of e-cigarettes.

Comparative acute toxicity of leachates from plastic products made of polypropylene, polyethylene, PVC, acrylonitrile-butadiene-styrene, and epoxy to Daphnia magna.

Science.gov (United States)

Lithner, Delilah; Nordensvan, Ildikó; Dave, Göran

2012-06-01

The large global production of plastics and their presence everywhere in the society and the environment create a need for assessing chemical hazards and risks associated with plastic products. The aims of this study were to determine and compare the toxicity of leachates from plastic products made of five plastics types and to identify the class of compounds that is causing the toxicity. Selected plastic types were those with the largest global annual production, that is, polypropylene, polyethylene, and polyvinyl chloride (PVC), or those composed of hazardous monomers (e.g., PVC, acrylonitrile-butadiene-styrene [ABS], and epoxy). Altogether 26 plastic products were leached in deionized water (3 days at 50°C), and the water phases were tested for acute toxicity to Daphnia magna. Initial Toxicity Identification Evaluations (C18 filtration and EDTA addition) were performed on six leachates. For eleven leachates (42%) 48-h EC50s (i.e the concentration that causes effect in 50 percent of the test organisms) were below the highest test concentration, 250 g plastic/L. All leachates from plasticized PVC (5/5) and epoxy (5/5) products were toxic (48-h EC50s ranging from 2 to 235 g plastic/L). None of the leachates from polypropylene (5/5), ABS (5/5), and rigid PVC (1/1) products showed toxicity, but one of the five tested HDPE leachates was toxic (48-h EC50 17-24 g plastic/L). Toxicity Identification Evaluations indicated that mainly hydrophobic organics were causing the toxicity and that metals were the main cause for one leachate (metal release was also confirmed by chemical analysis). Toxic chemicals leached even during the short-term leaching in water, mainly from plasticized PVC and epoxy products.

Effects of ZnO nanoparticles and Zn{sup 2+} on fluvial biofilms and the related toxicity mechanisms

Energy Technology Data Exchange (ETDEWEB)

Xu, Yi; Wang, Chao [Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098 (China); College of Environment, Hohai University, Nanjing 210098 (China); Hou, Jun, E-mail: hhuhjyhj@126.com [Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098 (China); College of Environment, Hohai University, Nanjing 210098 (China); Dai, Shanshan [Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098 (China); College of Environment, Hohai University, Nanjing 210098 (China); Wang, Peifang, E-mail: pfwang2005@hhu.edu.cn [Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098 (China); College of Environment, Hohai University, Nanjing 210098 (China); Miao, Lingzhan; Lv, Bowen; Yang, Yangyang; You, Guoxiang [Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098 (China); College of Environment, Hohai University, Nanjing 210098 (China)

2016-02-15

Zinc oxide nanoparticles (ZnO NPs) used in consumer products are largely released into the environment through the wastewater stream. The health hazard of ZnO NPs and the contribution of dissolved Zn{sup 2+} in toxicity of ZnO NPs has attracted extensive worldwide attention. In this study, the toxic effects of ZnO nanoparticles (ZnO NPs) and the effects of dissolved Zn{sup 2+} on fluvial biofilms were investigated. At the end of the exposure time (21 days), scanning electron microscopy (SEM) images and bioaccumulation experiments revealed that large quantities of ZnO NPs were adsorbed on the biofilm. The algal biomasses were significantly decreased by six- and eleven-fold compared with the control (1.43 μg/L) by exposure to concentrations of 100 mg/L ZnO NPs and 7.85 mg/L Zn{sup 2+}, respectively. Moreover, under the same exposure conditions, the quantum yields presented contents of 53.33 and 33.33% relative to the control, and a shift in the community composition that manifested as a strong reduction in diatoms was observed from 7 days and reached 15.63 and 6.25% of the control after 21 days of exposure, respectively. The reductions in bacteria viability and reactive oxygen species (ROS) production were noticeably enhanced following exposure to 100 mg/L ZnO NPs and 7.85 mg/L Zn{sup 2+}, respectively. Additionally, the acute and rapid toxicity of Zn{sup 2+} and the increasing toxicity of the ZnO NPs with increased bioaccumulation were noted in the exposure experiment. - Highlights: • Fluvial biofilm was exposed to ZnO NPs and the dissolved Zn{sup 2+}. • Chl-a and Φ{sub M} decreased at high doses (100 and 7.85 mg/L of ZnO NPs and Zn{sup 2+}). • A shift in the algae community composition was observed at high dosage levels. • The enhanced production of ROS declined the bacteria viability. • Zn{sup 2+} was more toxic than that of the ZnO-NPs.

Aluminium localization and toxicity symptoms related to root growth ...

Indian Academy of Sciences (India)

2012-10-26

Oct 26, 2012 ... Aluminium localization and toxicity symptoms related to root growth inhibition in rice (Oryza sativa ... growth of this cultivar when submitted to Al3+ stress. Moreover ..... Caiapó. Previous work has shown the IAC cultivar to be.

Recovery of anaerobic digestion after exposure to toxicants. Final report

Energy Technology Data Exchange (ETDEWEB)

Yang, J.; Parkin, G.F.; Speece, R.E.

1979-12-01

The concept that methane fermentation cannot tolerate chronic or slug doses of toxicants has almost totally precluded methane fermentation as a viable contender for the treatment of industrial wastewaters. This study assayed a wide variety of toxicants, heavy metals, inorganic salts, organic chemicals, solvents, and antibiotics which are used in industrial processes and, therefore, appear in the industrial wastewaters therefrom. Toxicity was related to the reduction in methane production of a control containing no toxicant. The response of methane fermentation after exposure to a toxicant was assayed with unacclimated cultures as well as cultures which had been acclimated to increasing concentrations of the toxicant over long periods of time. The reversible nature of the toxicants was assayed by adding slug doses to plug flow anaerobic filters and recording gas production prior to, during, and after toxicant addition.

Toxicоlogical evaluation of the plant products using Brine Shrimp (Artemia salina L. model

Directory of Open Access Journals (Sweden)

Меntor R. Hamidi

2014-04-01

Full Text Available Many natural products could serve as the starting point in the development of modern medicines because of their numerous biological and pharmacological activities. However, some of them are known to carry toxicological properties as well. In order to achieve a safe treatment with plant products, numerous research studies have recently been focused on both pharmacology and toxicity of medicinal plants. Moreover, these studies employed efforts for alternative biological assays. Brine Shrimp Lethality Assay is the most convenient system for monitoring biological activities of various plant species. This method is very useful for preliminary assessment of toxicity of the plant extracts. Rapidness, simplicity and low requirements are several advantages of this assay. However, several conditions need to be completed, especially in the means of standardized experimental conditions (temperature, pH of the medium, salinity, aeration and light. The toxicity of herbal extracts using this assay has been determined in a concentration range of 10, 100 and 1000 µg/ml of the examined herbal extract. Most toxicity studies which use the Brine Shrimp Lethality Assay determine the toxicity after 24 hours of exposure to the tested sample. The median lethal concentration (LC50 of the test samples is obtained by a plot of percentage of the dead shrimps against the logarithm of the sample concentration. LC50 values are estimated using a probit regression analysis and compared with either Meyer’s or Clarkson’s toxicity criteria. Furthermore, the positive correlation between Meyer’s toxicity scale for Artemia salina and Gosselin, Smith and Hodge’s toxicity scale for higher animal models confirmed that the Brine Shrimp Lethality Assay is an excellent predictive tool for the toxic potential of plant extracts in humans.

Investigation of the performance of fermentation processes using a mathematical model including effects of metabolic bottleneck and toxic product on cells.

Science.gov (United States)

Sriyudthsak, Kansuporn; Shiraishi, Fumihide

2010-11-01

A number of recent research studies have focused on theoretical and experimental investigation of a bottleneck in a metabolic reaction network. However, there is no study on how the bottleneck affects the performance of a fermentation process when a product is highly toxic and remarkably influences the growth and death of cells. The present work therefore studies the effect of bottleneck on product concentrations under different product toxicity conditions. A generalized bottleneck model in a fed-batch fermentation is constructed including both the bottleneck and the product influences on cell growth and death. The simulation result reveals that when the toxic product strongly influences the cell growth and death, the final product concentration is hardly changed even if the bottleneck is removed, whereas it is markedly changed by the degree of product toxicity. The performance of an ethanol fermentation process is also discussed as a case example to validate this result. In conclusion, when the product is highly toxic, one cannot expect a significant increase in the final product concentration even if removing the bottleneck; rather, it may be more effective to somehow protect the cells so that they can continuously produce the product. Copyright © 2010 Elsevier Inc. All rights reserved.

Carcinogenic Air Toxics Exposure and Their Cancer-Related Health Impacts in the United States.

Science.gov (United States)

Zhou, Ying; Li, Chaoyang; Huijbregts, Mark A J; Mumtaz, M Moiz

2015-01-01

Public health protection from air pollution can be achieved more effectively by shifting from a single-pollutant approach to a multi-pollutant approach. To develop such multi-pollutant approaches, identifying which air pollutants are present most frequently is essential. This study aims to determine the frequently found carcinogenic air toxics or hazardous air pollutants (HAPs) combinations across the United States as well as to analyze the health impacts of developing cancer due to exposure to these HAPs. To identify the most commonly found carcinogenic air toxics combinations, we first identified HAPs with cancer risk greater than one in a million in more than 5% of the census tracts across the United States, based on the National-Scale Air Toxics Assessment (NATA) by the U.S. EPA for year 2005. We then calculated the frequencies of their two-component (binary), and three-component (ternary) combinations. To quantify the cancer-related health impacts, we focused on the 10 most frequently found HAPs with national average cancer risk greater than one in a million. Their cancer-related health impacts were calculated by converting lifetime cancer risk reported in NATA 2005 to years of healthy life lost or Disability-Adjusted Life Years (DALYs). We found that the most frequently found air toxics with cancer risk greater than one in a million are formaldehyde, carbon tetrachloride, acetaldehyde, and benzene. The most frequently occurring binary pairs and ternary mixtures are the various combinations of these four air toxics. Analysis of urban and rural HAPs did not reveal significant differences in the top combinations of these chemicals. The cumulative annual cancer-related health impacts of inhaling the top 10 carcinogenic air toxics included was about 1,600 DALYs in the United States or 0.6 DALYs per 100,000 people. Formaldehyde and benzene together contribute nearly 60 percent of the total cancer-related health impacts. Our study shows that although there are many

Carcinogenic Air Toxics Exposure and Their Cancer-Related Health Impacts in the United States.

Directory of Open Access Journals (Sweden)

Ying Zhou

Full Text Available Public health protection from air pollution can be achieved more effectively by shifting from a single-pollutant approach to a multi-pollutant approach. To develop such multi-pollutant approaches, identifying which air pollutants are present most frequently is essential. This study aims to determine the frequently found carcinogenic air toxics or hazardous air pollutants (HAPs combinations across the United States as well as to analyze the health impacts of developing cancer due to exposure to these HAPs. To identify the most commonly found carcinogenic air toxics combinations, we first identified HAPs with cancer risk greater than one in a million in more than 5% of the census tracts across the United States, based on the National-Scale Air Toxics Assessment (NATA by the U.S. EPA for year 2005. We then calculated the frequencies of their two-component (binary, and three-component (ternary combinations. To quantify the cancer-related health impacts, we focused on the 10 most frequently found HAPs with national average cancer risk greater than one in a million. Their cancer-related health impacts were calculated by converting lifetime cancer risk reported in NATA 2005 to years of healthy life lost or Disability-Adjusted Life Years (DALYs. We found that the most frequently found air toxics with cancer risk greater than one in a million are formaldehyde, carbon tetrachloride, acetaldehyde, and benzene. The most frequently occurring binary pairs and ternary mixtures are the various combinations of these four air toxics. Analysis of urban and rural HAPs did not reveal significant differences in the top combinations of these chemicals. The cumulative annual cancer-related health impacts of inhaling the top 10 carcinogenic air toxics included was about 1,600 DALYs in the United States or 0.6 DALYs per 100,000 people. Formaldehyde and benzene together contribute nearly 60 percent of the total cancer-related health impacts. Our study shows that although

Structure elucidation and toxicity analyses of the radiolytic products of aflatoxin B{sub 1} in methanol-water solution

Energy Technology Data Exchange (ETDEWEB)

Wang, Feng [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Graduate School of Chinese Academy of Agricultural Sciences, 12th Zhongguancun South Road, Hai Dian District, Beijing 100081 (China); Xie, Fang [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Xue, Xiaofeng [Bee Research Institute of Chinese Academy of Agricultural Sciences, 1st Xiangshan North Ditch, Hai Dian District, Beijing 100093 (China); Wang, Zhidong; Fan, Bei [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Ha, Yiming, E-mail: wxfay2011@hotmail.com [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China)

2011-09-15

Highlights: {yields} Radiolytic products of aflatoxin B{sub 1} were produced under gamma irradiation. {yields} Seven key radiolytic products were structure-elucidated. {yields} Free-radical species in radiolytic solution resulted in the formation of products. {yields} Based on the structure-activity relationship analysis, the toxicity of radiolytic products was significantly reduced compared with that of AFB{sub 1}. {yields} The addition reaction on furan ring double bond was the reason for the reduced toxicity. - Abstract: The identification of the radiolytic products of mycotoxins is a key issue in the feasibility study of gamma ray radiation detoxification. Methanol-water solution (60:40, v/v) spiked with aflatoxin B{sub 1} (AFB{sub 1}; 20 mg L{sup -1}) was irradiated with Co{sup 60} gamma ray to generate radiolytic products. Liquid chromatography-quadruple time-of-flight mass spectrometry was applied to identify the radiolytic products of AFB{sub 1}. Accurate mass and proposed molecular formulas with a high-matching property of more than 20 radiolytic products were obtained. Seven key radiolytic products were proposed based on the molecular formulas and tandem mass spectrometry spectra. The analyses of toxicity and formation pathways were proposed based on the structure of the radiolytic products. The addition reaction caused by the free-radical species in the methanol-water solution resulted in the formation of most radiolytic products. Based on the structure-activity relationship analysis, the toxicity of radiolytic products was significantly reduced compared with that of AFB{sub 1} because of the addition reaction that occurred on the double bond in the terminal furan ring. For this reason, gamma irradiation is deemed an effective tool for the detoxification of AFB{sub 1}.

Ammonia production, excretion, toxicity, and defense in fish: A Review

Directory of Open Access Journals (Sweden)

Alex Y K Ip

2010-10-01

Full Text Available Many fishes are ammonotelic but some species can detoxify ammonia to glutamine or urea. Certain fish species can accumulate high levels of ammonia in the brain or defense against ammonia toxicity by enhancing the effectiveness of ammonia excretion through active NH4+ transport, manipulation of ambient pH, or reduction in ammonia permeability through the branchial and cutaneous epithelia. Recent reports on ammonia toxicity in mammalian brain reveal the importance of permeation of ammonia through the blood-brain barrier and passages of ammonia and water through transporters in the plasmalemma of brain cells. Additionally, brain ammonia toxicity could be related to the passage of glutamine through the mitochondrial membranes into the mitochondrial matrix. On the other hand, recent reports on ammonia excretion in fish confirm the involvement of Rhesus glycoproteins in the branchial and cutaneous epithelia. Therefore, this review focuses on both the earlier literature and the up-to-date information on the problems and mechanisms concerning the permeation of ammonia, as NH3, NH4+ or proton-neutral nitrogenous compounds, across mitochondrial membranes, the blood-brain barrier, the plasmalemma of neurons, and the branchial and cutaneous epithelia of fish. It also addresses how certain fishes with high ammonia tolerance defend against ammonia toxicity through the regulation of the permeation of ammonia and related nitrogenous compounds through various types of membranes. It is hoped that this review would revive the interests in investigations on the passage of ammonia through the mitochondrial membranes and the blood-brain barrier of ammonotelic fishes and fishes with high brain ammonia-tolerance, respectively.

A tacrolimus-related immunosuppressant with reduced toxicity.

Science.gov (United States)

Dumont, F J; Koprak, S; Staruch, M J; Talento, A; Koo, G; DaSilva, C; Sinclair, P J; Wong, F; Woods, J; Barker, J; Pivnichny, J; Singer, I; Sigal, N H; Williamson, A R; Parsons, W H; Wyvratt, M

1998-01-15

Tacrolimus (FK506) has potent immunosuppressive properties reflecting its ability to block the transcription of lymphokine genes in activated T cells through formation of a complex with FK506 binding protein-12, which inhibits the phosphatase activity of calcineurin. The clinical usefulness of tacrolimus is limited, however, by severe adverse effects, including neurotoxicity and nephrotoxicity. Although this toxicity, like immunosuppression, appears mechanistically related to the calcineurin inhibitory action of the drug, a large chemistry effort has been devoted to search for tacrolimus analogs with reduced toxicity but preserved immunosuppressive activity that might have enhanced therapeutic utility. Here, we report on the identification of such an analog, which was synthetically derived from ascomycin (ASC), the C21 ethyl analog of tacrolimus, by introducing an indole group at the C32 position. The profile of biological activity of indolyl-ASC was characterized in rodent models of immunosuppression and toxicity. Indolyl-ASC was found to exhibit an immunosuppressive potency equivalent to that of tacrolimus in T-cell activation in vitro and in murine transplant models, even though indolyl-ASC bound about 10 times less to intracellular FK506 binding protein-12 than tacrolimus or ASC. Further evaluation of indolyl-ASC revealed that it is threefold less potent than tacrolimus in inducing hypothermia, a response that may reflect neurotoxicity, and in causing gastrointestinal transit alterations in mice. Moreover, indolyl-ASC was at least twofold less nephrotoxic than tacrolimus upon 3-week oral treatment in rats. Altogether, these data indicate a modest but definite improvement in the therapeutic index for indolyl-ASC compared with tacrolimus in rodent models.

Toxicity of systems for energy generation and storage

International Nuclear Information System (INIS)

Bhattacharyya, M.H.

1979-01-01

This section contains summaries of research on assessment of health and environmental effects of electric storage systems, and the metabolism and toxicity of metal compounds associated with energy production and storage. The first project relates to the production and use of electric storage battery systems. The second project deals with the effects of pregnancy and lactation on the gastrointestinal absorption, tissue distribution, and toxic effects of metals (Cd). Also included in this study is work on the absorption of actinides ( 239 Pu)

The severity of toxic reactions to ephedra: comparisons to other botanical products and national trends from 1993-2002.

Science.gov (United States)

Woolf, Alan D; Watson, William A; Smolinske, Susan; Litovitz, Toby

2005-01-01

Ephedra is a botanical product widely used to enhance alertness, as a weight loss aide, and as a decongestant. Its reported adverse effects led the Food and Drug Administration (FDA) to ban ephedra-containing products in the United States in 2004. This study's purpose was to compare toxicity from botanical products containing ephedra to nonephedra products. The Toxic Exposure Surveillance System (TESS), a national poison center database, was utilized to determine the number and outcomes of cases involving botanical products reported from 1993-2002. Cases listing both a botanical product and any other drugs or chemicals were excluded a priori. Ten-year hazard rates (moderate outcomes + major outcomes + deaths per 1000 exposures) were used to compare botanical product categories. There were 21,533 toxic exposures with definitive medical outcomes reported over the 10 yrs where a botanical product was the only substance involved. Of these, 4306 (19.9%) had moderate or major medical outcomes and there were two deaths, for an overall hazard score of 200 per 1000 exposures. The number of ephedra reports to poison centers increased 150-fold over the 10-yr period. The hazard rate for products that contained only ephedra was 250 per 1000 exposures and 267 per 1000 exposures for products that contained ephedra and additional ingredients; whereas the hazard score for only nonephedra botanical products was 96 per 1000 exposures. The rate ratios for multibotanical products with ephedra (RR 1.33; 95% C.I. 1.27-1.40) and for single-ingredient ephedra products (RR 1.25; 95% C.I. 1.11-1.40) were both two to six times higher than those of other common botanical products. Yohimbe-containing products had the highest hazard score (417) and rate ratio (2.08; 95% C.I. 1.59-2.80). Ephedra-containing botanical products accounted for a significant number of toxic exposures with severe medical outcomes reported to poison centers. Hazard rate analysis suggests poison center-reported events

Organophosphorus insecticides: Toxic effects and bioanalytical tests for evaluating toxicity during degradation processes

Directory of Open Access Journals (Sweden)

Čolović Mirjana B.

2013-01-01

Full Text Available Organophosphorus insecticides have been the most applied group of insecticides for the last two decades. Their main toxic effects are related to irreversible inactivation of acetylcholinesterase (AChE. Actually, they covalently bind to serine OH group in the enzyme active site forming phosphorylated enzyme that cannot hydrolyze acetylcholine. Organophosphorus insecticides in the environment undergo the natural degradation pathway including mainly homogeneous and heterogeneous hydrolysis (especially at high pH generating non-inhibiting products. Additionally, thio organophosphates are easily oxidized by naturally present oxidants and UV light, forming more toxic and stable oxons. Thus, oxidative degradation procedures, generally referred as advanced oxidation processes (AOP, have been applied for their efficient removal from contaminated waters. The most applied bioassays to monitor the organophosphate toxicity i.e. the detoxification degree during AOP are Vibrio fischeri and AChE bioassays. Vibrio fischeri toxicity test exploits bioluminescence as the measure of luciferase activity of this marine bacterium, whereas AChE bioassay is based on AChE activity inhibition. Both bioanalytical techniques are rapid (several minutes, simple, sensitive and reproducible. Vibrio fischeri test seems to be a versatile indicator of toxic compounds generated in AOP for organophosphorus insecticides degradation. However, detection of neurotoxic AChE inhibitors, which can be formed in AOP of some organophosphates, requires AChE bioassays. Therefore, AChE toxicity test is more appropriate for monitoring the degradation processes of thio organophosphates, because more toxic oxo organophosphates might be formed and overlooked by Vibrio fischeri bioluminescence inhibition. In addition, during organophosphates removal by AOP, compounds with strong genotoxic potential may be formed, which cannot be detected by standard toxicity tests. For this reason, determination of

Relative developmental toxicity of short-chain chlorinated paraffins in Zebrafish (Danio rerio) embryos.

Science.gov (United States)

Liu, Lihua; Li, Yifan; Coelhan, Mehmet; Chan, Hing Man; Ma, Wanli; Liu, Liyan

2016-12-01

Short-chain chlorinated paraffins (SCCPs) are ubiquitous in the environment and might cause adverse environmental and human health effects. Little is known about the relative toxicity of different SCCP compounds especially during development. The objective of this study was to characterize and compare effects of seven SCCP groups at environmentally relevant levels, using a zebrafish (Danio rerio) model. Observations on malformation, survival rates at 96 h post fertilization (hpf), and hatching rates at 72 hpf indicated that the C 10- groups (C 10 H 18 Cl 4 , 1,2,5,6,9,10-C 10 H 16 Cl 6 and C 10 H 15 Cl 7 ) were more toxic than the C 12- groups (C 12 H 22 Cl 4 , C 12 H 19 Cl 7 and 1,1,1,3,10,12,12,12-C 12 H 18 Cl 8 ) and Cereclor 63L. The C 10- groups were also more potent than C 12- groups and Cereclor 63L in decreasing thyroid hormone levels. Among the three compounds within the C 10- group, the compounds with less chlorine content had stronger effects on sub-lethal malformations but less effects on triiodothyronine (T3) and tetraiodothyronine (T4). Only C 10 H 18 Cl 4 significantly decreased the mRNA expression of tyr, ttr, dio2 and dio3 at a dose-dependent manner suggesting that the specific mode of actions differ with different congeners. The mechanisms of disruption of thyroid status by different SCCPs could be different. C 10 H 18 Cl 4 might inhibit T3 production through the inhibition effect on dio2. These results indicate that SCCP exposure could alter gene expression in the hypothalamic-pituitary-thyroid (HPT) axis and thyroid hormone levels. The mechanisms of disruption of thyroid status by different SCCPs could be different. Our results on the relative developmental toxicities of SCCPs will be useful to reach a better understanding of SCCP toxicity supporting environmental risk evaluation and regulation and used as a guidance for environmental monitoring of SCCPs in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

REPRODUCTIVE TOXICITY OF PHTHALATE ESTERS

Science.gov (United States)

Phthalate esters display several modes of toxicity in mammalian species. In the rat, in utero exposure at relatively low dosage levels disrupts development of the reproductive system of the male rat by altering fetal testis hormone production. This presentation is a review of t...

Determination of Toxic Metals in Indian Smokeless Tobacco Products

Directory of Open Access Journals (Sweden)

Dhanashri Dhaware

2009-01-01

Full Text Available This study targets the lesser-known ingredients of smokeless tobacco products, i.e., the toxic metals, in Indian brands. The metals selected in the study included lead (Pb, cadmium (Cd, arsenic (As, copper (Cu, mercury (Hg, and selenium (Se. The differential pulse anodic stripping voltammetry (DPASV technique was used for estimating the metals Pb, Cd, and Cu; square wave voltammetry for As; and the cold vapor atomic absorption technique for Hg. The resulting levels of the metals were compared to the daily consumption of the smokeless tobacco products. It was observed that almost 30% of gutkha brand samples exceeded the permissible levels of metals Pb and Cu, when compared to the provisional tolerable intake limits determined by the FAO/WHO. The reliability of data was assured by analyzing standard reference materials.

Is the OECD acute worm toxicity test environmentally relevant? The effect of mineral form on calculated lead toxicity

International Nuclear Information System (INIS)

Davies, N.A.Nicola A.; Hodson, M.E.Mark E.; Black, S.Stuart

2003-01-01

The current OECD acute worm toxicity test does not relate well to ambient conditions. - In a series of experiments the toxicity of lead to worms in soil was determined following the draft OECD earthworm reproduction toxicity protocol except that lead was added as solid lead nitrate, carbonate and sulphide rather than as lead nitrate solution as would normally be the case. The compounds were added to the test soil to give lead concentrations of 625-12500 μg Pb g -1 of soil. Calculated toxicities of the lead decreased in the order nitrate>carbonate>sulphide, the same order as the decrease in the solubility of the metal compounds used. The 7-day LC 50 (lethal concentration when 50% of the population is killed) for the nitrate was 5321±275 μg Pb g -1 of soil and this did not change with time. The LC 50 values for carbonate and sulphide could not be determined at the concentration ranges used. The only parameter sensitive enough to distinguish the toxicities of the three compounds was cocoon (egg) production. The EC 50 s for cocoon production (the concentration to produce a 50% reduction in cocoon production) were 993, 8604 and 10246 μg Pb g -1 of soil for lead nitrate, carbonate and sulphide, respectively. Standard toxicity tests need to take into account the form in which the contaminant is present in the soil to be of environmental relevance

Associations between gastrointestinal toxicity, micro RNA and cytokine production in patients undergoing myeloablative allogeneic stem cell transplantation

DEFF Research Database (Denmark)

Pontoppidan, Peter Erik Lotko; Jordan, Karina Kwi Im; Carlsen, Anting Liu

2015-01-01

with significantly elevated miRNA-155 and decreased miRNA-146a levels, from day 0 to day +28 compared with pre-conditioning levels. Citrulline levels below the median at day +7 were associated with higher spontaneous production of IL-6 and TNF-α as well as higher in vitro stimulated production of IL-17A at day +21......, lactulose-mannitol test and plasma citrulline, as a measure of the enterocyte population. Nadir of citrulline and maximum of oral toxicity scores, intestinal permeability, CRP and plasma levels of IL-6 and IL-10 was seen at day +7 post-HSCT. miRNA-155 and mi-RNA-146a showed an inverse relation...

Chemotherapy related toxicity in locally advanced non-small cell lung cancer

Directory of Open Access Journals (Sweden)

Bahl Amit

2006-01-01

Full Text Available Background: For inoperable non-small cell lung cancer combined chemotherapy and radiotherapy plays an important role as a therapeutic modality. The aim of the present study was to analyze neoadjuvant chemotherapy related acute toxicity in locally advanced lung cancer (stage IIIA and IIIB in Indian patients using Cisplatin and Etoposide combination chemotherapy. Material and methods: Forty patients of locally advanced Non small cell lung cancer received three cycles neoadjuvant chemotherapy using Injection Cisplatin and Etoposide. The patients were taken for Radical radiotherapy to a dose of 60 Gray over 30 fractions in conventional fractionation after completing chemotherapy. Chemotherapy associated toxicity was assessed using common toxicity criteria (CTC v2.0 Results: Forty patients were available for final evaluation. Median age of presentation of patients was fifty-six years. Thirteen patients had Non small cell lung cancer stage IIIA while twenty-seven patients had Stage IIIB disease. Anemia was the most common hematological toxicity observed (seen in 81% of patients. Nausea and vomiting were the most common non -hematological toxicity seen. Sensory neuropathy was seen in 38%of patients. 88% patients developed alopecia. Seven patients developed febrile neutropenias. Conclusion: Neo-adjuvant chemotherapy using Cisplatin and Etoposide continues to be a basic regimen in the Indian set up despite availability of higher molecules, since it is cost effective, well tolerated and therapeutically effective. Blood transfusions, growth factors and supportive care can be used effectively to over come toxicity associated with this regimen.

Impact of CHO Metabolism on Cell Growth and Protein Production: An Overview of Toxic and Inhibiting Metabolites and Nutrients

DEFF Research Database (Denmark)

Pereira, Sara; Kildegaard, Helene F.; Andersen, Mikael R.

2018-01-01

and process optimization and monitoring to perform efficiently. One of the main reasons for this is the production and accumulation of toxic and growth-inhibiting metabolites during culture. Lactate and ammonium are the most known, but many more have been identified. In this review, we present an overview...... of metabolites that deplete and accumulate throughout the course of cultivations with toxic and growth inhibitory effects to the cells. We further provide an overview of the CHO metabolism with emphasis to metabolic pathways of amino acids, glutathione (GSH), and related compounds which have growth...... of resources that describe the cellular mechanisms of CHO and are available on-line. Finally, we discuss the application of this knowledge for bioprocess and medium development and cell line engineering....

Molecular toxicity mechanism of nanosilver

Directory of Open Access Journals (Sweden)

Danielle McShan

2014-03-01

Full Text Available Silver is an ancient antibiotic that has found many new uses due to its unique properties on the nanoscale. Due to its presence in many consumer products, the toxicity of nanosilver has become a hot topic. This review summarizes recent advances, particularly the molecular mechanism of nanosilver toxicity. The surface of nanosilver can easily be oxidized by O2 and other molecules in the environmental and biological systems leading to the release of Ag+, a known toxic ion. Therefore, nanosilver toxicity is closely related to the release of Ag+. In fact, it is difficult to determine what portion of the toxicity is from the nano-form and what is from the ionic form. The surface oxidation rate is closely related to the nanosilver surface coating, coexisting molecules, especially thiol-containing compounds, lighting conditions, and the interaction of nanosilver with nucleic acids, lipid molecules, and proteins in a biological system. Nanosilver has been shown to penetrate the cell and become internalized. Thus, nanosilver often acts as a source of Ag+ inside the cell. One of the main mechanisms of toxicity is that it causes oxidative stress through the generation of reactive oxygen species and causes damage to cellular components including DNA damage, activation of antioxidant enzymes, depletion of antioxidant molecules (e.g., glutathione, binding and disabling of proteins, and damage to the cell membrane. Several major questions remain to be answered: (1 the toxic contribution from the ionic form versus the nano-form; (2 key enzymes and signaling pathways responsible for the toxicity; and (3 effect of coexisting molecules on the toxicity and its relationship to surface coating.

Pharmacogenetic Predictors of Treatment-Related Toxicity Among Children With Acute Lymphoblastic Leukemia.

Science.gov (United States)

Maxwell, Rochelle R; Cole, Peter D

2017-06-01

The aim of this review is to summarize the most recent and most robust pharmacogenetic predictors of treatment-related toxicity (TRT) in childhood acute lymphoblastic leukemia (ALL). Multiple studies have examined the toxicities of the primary chemotherapeutic agents used to treat childhood ALL in relation to host genetic factors. However, few results have been replicated independently, largely due to cohort differences in ancestry, chemotherapy treatment protocols, and definitions of toxicities. To date, there is only one widely accepted clinical guideline for dose modification based on gene status: thiopurine dosing based on TPMT genotype. Based on recent data, it is likely that this guideline will be modified to incorporate other gene variants, such as NUDT15. We highlight genetic variants that have been consistently associated with TRT across treatment groups, as well as those that best illustrate the underlying pathophysiology of TRT. In the coming decade, we expect that survivorship care will routinely specify screening recommendations based on genetics. Furthermore, clinical trials testing protective interventions may modify inclusion criteria based on genetically determined risk of specific TRTs.

Solar driven production of toxic halogenated and nitroaromatic compounds in natural seawater

Energy Technology Data Exchange (ETDEWEB)

Calza, Paola [Dipartimento di Chimica Analitica, Universita di Torino, via P. Giuria 5, 10125 Torino (Italy)], E-mail: paola.calza@unito.it; Massolino, Cristina; Pelizzetti, Ezio; Minero, Claudio [Dipartimento di Chimica Analitica, Universita di Torino, via P. Giuria 5, 10125 Torino (Italy)

2008-07-15

Natural seawater (NSW) sampled in March and June 2007 in the Gulf of Trieste, Italy, has been spiked with phenol and irradiated in a device simulating solar light spectrum and intensity. Opposite to the case of artificial seawater, for which phenol is slightly degraded by direct photolysis, in NSW the phenol degradation mediated by natural photosensitizers occurs, forming several secondary pollutants, including hydroxyderivatives (1,4-benzoquinone, resorcinol), three chlorophenol isomers, 2,3-dichlorophenol, 2- and 4-bromophenol, 2- and 4-nitrophenol, and several condensed products (2 and 4-phenoxyphenol, 2,2'-, 4,4'- and 2,4-bisphenol). These compounds are toxic to bacteria and other living organisms. Ecotoxicologic effect has been evaluated by using the Vibrio Fischeri luminescent bacteria assay. This technique uses marine organisms, and it is therefore well suited for the study on marine samples. A correlation exists between the intermediates evolution and the toxicity profile, as the largest toxicity is observed when compounds with the lower EC50 (halophenols, phenoxyphenols) are formed at higher concentration.

Solar driven production of toxic halogenated and nitroaromatic compounds in natural seawater

International Nuclear Information System (INIS)

Calza, Paola; Massolino, Cristina; Pelizzetti, Ezio; Minero, Claudio

2008-01-01

Natural seawater (NSW) sampled in March and June 2007 in the Gulf of Trieste, Italy, has been spiked with phenol and irradiated in a device simulating solar light spectrum and intensity. Opposite to the case of artificial seawater, for which phenol is slightly degraded by direct photolysis, in NSW the phenol degradation mediated by natural photosensitizers occurs, forming several secondary pollutants, including hydroxyderivatives (1,4-benzoquinone, resorcinol), three chlorophenol isomers, 2,3-dichlorophenol, 2- and 4-bromophenol, 2- and 4-nitrophenol, and several condensed products (2 and 4-phenoxyphenol, 2,2'-, 4,4'- and 2,4-bisphenol). These compounds are toxic to bacteria and other living organisms. Ecotoxicologic effect has been evaluated by using the Vibrio Fischeri luminescent bacteria assay. This technique uses marine organisms, and it is therefore well suited for the study on marine samples. A correlation exists between the intermediates evolution and the toxicity profile, as the largest toxicity is observed when compounds with the lower EC50 (halophenols, phenoxyphenols) are formed at higher concentration

The toxicity of sulfolane and DIPA from sour gas plants to aquatic species

International Nuclear Information System (INIS)

Lintott, D.R.; Goudey, J.S.; Wilson, J.; Swanson, S.; Drury, C.

1997-01-01

The ecological effects of sulfolane and diisopropanolamine (DIPA), which are used to remove sulfur compounds from natural gas, were studied to establish risk-based cleanup criteria and to evaluate effective remedial measures. Toxicity tests were conducted on both the parent compounds and the thermal and biological degradation products. Toxicity testing focused on aquatic species because surface outlets, such as creeks, were found to be the major pathways for the water soluble DIPA and sulfolane chemicals. Sulfolane proved to be relatively non-toxic to aquatic species, with the exception of bacteria. DIPA was relatively toxic to algae at pH found in ground and surface waters. Aqueous and methanol reclaimer bottom extracts from five different gas plant sites were also tested using modified acute toxicity screening tests with different species. The reclaimer bottoms were found to be highly toxic to all species tested. DIPA and sulfolane did not entirely account for the toxicity of the reclaimer bottoms. Inorganic salts and metals present in reclaimer bottoms were found not to contribute to toxicity directly. The same was true for DIPA and sulfolane degradation products. 3 refs., 7 tabs., 8 figs

The toxicity of sulfolane and DIPA from sour gas plants to aquatic species

Energy Technology Data Exchange (ETDEWEB)

Lintott, D.R.; Goudey, J.S. [HydroQual Consultants, Inc., Calgary, AB (Canada); Wilson, J.; Swanson, S. [Golder Associates, Calgary, AB (Canada); Drury, C. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre

1997-12-31

The ecological effects of sulfolane and diisopropanolamine (DIPA), which are used to remove sulfur compounds from natural gas, were studied to establish risk-based cleanup criteria and to evaluate effective remedial measures. Toxicity tests were conducted on both the parent compounds and the thermal and biological degradation products. Toxicity testing focused on aquatic species because surface outlets, such as creeks, were found to be the major pathways for the water soluble DIPA and sulfolane chemicals. Sulfolane proved to be relatively non-toxic to aquatic species, with the exception of bacteria. DIPA was relatively toxic to algae at pH found in ground and surface waters. Aqueous and methanol reclaimer bottom extracts from five different gas plant sites were also tested using modified acute toxicity screening tests with different species. The reclaimer bottoms were found to be highly toxic to all species tested. DIPA and sulfolane did not entirely account for the toxicity of the reclaimer bottoms. Inorganic salts and metals present in reclaimer bottoms were found not to contribute to toxicity directly. The same was true for DIPA and sulfolane degradation products. 3 refs., 7 tabs., 8 figs.

Rapid and Simultaneous Determination of Acetylsalicylic Acid, Paracetamol, and Their Degradation and Toxic Impurity Products by HPLC in Pharmaceutical Dosage Forms

OpenAIRE

AKAY, Cemal

2008-01-01

Aims: Determinations of drug impurity and drug degradation products are very important from both pharmacological and toxicological perspectives. Establishment of monitoring methods for impurities and degradation products during pharmaceutical development is necessary because of their potential toxicity. The aim of this study was to develop a rapid and simultaneous determination method for paracetamol and acetylsalicylic acid (ACA) and their degradation and toxic impurity products by high perf...

Transformation of benzophenone-type UV filters by chlorine: Kinetics, products identification and toxicity assessments

International Nuclear Information System (INIS)

Li, Jian; Ma, Li-yun; Xu, Li

2016-01-01

Highlights: • Chlorination kinetics of three benzophenone-type UV filters (BPs) was studied. • Chlorination of BPs followed second-order reaction. • The transformation products (TPs) of six BPs were identified. • Several transformation pathways were proposed. • Mostly enhanced toxicity of TPs after chlorination was observed. - Abstract: The present study focused on the kinetics, transformation pathways and toxicity of several benzophenone-type ultraviolet filters (BPs) during the water chlorination disinfection process. The transformation kinetics of the studied three BPs was found to be second-order reaction, which was dependent on the concentration of BPs and chlorine. The second-order rate constants increased from 86.7 to 975 M"−"1 s"−"1 for oxybenzone, 49.6–261.7 M"−"1 s"−"1 for 4-hydroxybenzophenone and 51.7–540 M"−"1 s"−"1 for 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid with the increasing pH value from 6 to 8 of the chlorination disinfection condition. Then the transformation products (TPs) of these BPs were identified by HPLC-QTof analysis. Several transformation pathways, including electrophilic substitution, methoxyl substitution, ketone groups oxidation, hydrolysis, decarboxylation and ring cleavage reaction, were speculated to participate in the chlorination transformation process. Finally, according to the toxicity experiment on luminescent bacteria, Photobacterium phosphoreum, enhanced toxicity was observed for almost all the TPs of the studied BPs except for 2,2′-dihydroxy-4,4′-dimethoxybenzophenone; it suggested the formation of TPs with more toxic than the parent compounds during the chlorination process. The present study provided a foundation to understand the transformation of BPs during chlorination disinfection process, and was of great significance to the drinking water safety.

Transformation of benzophenone-type UV filters by chlorine: Kinetics, products identification and toxicity assessments

Energy Technology Data Exchange (ETDEWEB)

Li, Jian; Ma, Li-yun; Xu, Li, E-mail: xulpharm@mails.tjmu.edu.cn

2016-07-05

Highlights: • Chlorination kinetics of three benzophenone-type UV filters (BPs) was studied. • Chlorination of BPs followed second-order reaction. • The transformation products (TPs) of six BPs were identified. • Several transformation pathways were proposed. • Mostly enhanced toxicity of TPs after chlorination was observed. - Abstract: The present study focused on the kinetics, transformation pathways and toxicity of several benzophenone-type ultraviolet filters (BPs) during the water chlorination disinfection process. The transformation kinetics of the studied three BPs was found to be second-order reaction, which was dependent on the concentration of BPs and chlorine. The second-order rate constants increased from 86.7 to 975 M{sup −1} s{sup −1} for oxybenzone, 49.6–261.7 M{sup −1} s{sup −1} for 4-hydroxybenzophenone and 51.7–540 M{sup −1} s{sup −1} for 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid with the increasing pH value from 6 to 8 of the chlorination disinfection condition. Then the transformation products (TPs) of these BPs were identified by HPLC-QTof analysis. Several transformation pathways, including electrophilic substitution, methoxyl substitution, ketone groups oxidation, hydrolysis, decarboxylation and ring cleavage reaction, were speculated to participate in the chlorination transformation process. Finally, according to the toxicity experiment on luminescent bacteria, Photobacterium phosphoreum, enhanced toxicity was observed for almost all the TPs of the studied BPs except for 2,2′-dihydroxy-4,4′-dimethoxybenzophenone; it suggested the formation of TPs with more toxic than the parent compounds during the chlorination process. The present study provided a foundation to understand the transformation of BPs during chlorination disinfection process, and was of great significance to the drinking water safety.

Radionuclide toxicity

International Nuclear Information System (INIS)

Galle, P.

1982-01-01

The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

Acute inhalation toxicity of carbonyl sulfide

Energy Technology Data Exchange (ETDEWEB)

Benson, J.M.; Hahn, F.F.; Barr, E.B. [and others

1995-12-01

Carbonyl sulfide (COS), a colorless gas, is a side product of industrial procedures sure as coal hydrogenation and gasification. It is structurally related to and is a metabolite of carbon disulfide. COS is metabolized in the body by carbonic anhydrase to hydrogen sulfide (H{sub 2}S), which is thought to be responsible for COS toxicity. No threshold limit value for COS has been established. Results of these studies indicate COS (with an LC{sub 50} of 590 ppm) is slightly less acutely toxic than H{sub 2}S (LC{sub 50} of 440 ppm).

Toxicity and physical properties of atrazine and its degradation products: A literature survey

Energy Technology Data Exchange (ETDEWEB)

Pugh, K.C.

1994-10-01

The Tennessee Valley Authority`s Environmental Research Center has been developing a means of detoxifying atrazine waste waters using TiO{sub 2} photocatalysis. The toxicity and physical properties of atrazine and its degradation products will probably be required information in obtaining permits from the United States Environmental Protection Agency for the demonstration of any photocatalytic treatment of atrazine waste waters. The following report is a literature survey of the toxicological and physical properties of atrazine and its degradation products.

ToxicDocs (www.ToxicDocs.org): from history buried in stacks of paper to open, searchable archives online.

Science.gov (United States)

Rosner, David; Markowitz, Gerald; Chowkwanyun, Merlin

2018-02-01

As a result of a legal mechanism called discovery, the authors accumulated millions of internal corporate and trade association documents related to the introduction of new products and chemicals into workplaces and commerce. What did these private entities discuss among themselves and with their experts? The plethora of documents, both a blessing and a curse, opened new sources and interesting questions about corporate and regulatory histories. But they also posed an almost insurmountable challenge to historians. Thus emerged ToxicDocs, possible only with a technological innovation known as "Big Data." That refers to the sheer volume of new digital data and to the computational power to analyze them. Users will be able to identify what firms knew (or did not know) about the dangers of toxic substances in their products-and when. The database opens many areas to inquiry including environmental studies, business history, government regulation, and public policy. ToxicDocs will remain a resource free and open to all, anywhere in the world.

Toxicity of oils and petroleum hydrocarbons to estuarine crustaceans

Energy Technology Data Exchange (ETDEWEB)

Tatem, H.E. (Army Engineer Waterways Experiment Station, Vicksburg, MS); Cox, B.A.; Anderson, J.W.

1978-04-01

Bioassay experiments with various life stages of three estuarine shrimp and soluble petroleum hydrocarbons (PH) revealed residual Bunker C oil and refined No. 2 fuel oil to be more toxic than two crude oils tested. Larvae of Palaemonetes pugio were slightly more sensitive to the PH than adults, while young penaeid shrimp were shown to be more resistant than older, larger individuals. Shrimp exposed to PH in conjunction with temperature and salinity changes were more susceptible to the PH. Some common aromatic and diaromatic PH, including three naphthalene compounds, were utilized in bioassays. Naphthalenes were highly toxic. The toxicity of petroleum products is closely related to aromatic hydrocarbon content, especially the naphthalenes and related hydrocarbons.

Stereoselective potencies and relative toxicities of γ-coniceine and N-methylconiine enantiomers.

Science.gov (United States)

Lee, Stephen T; Green, Benedict T; Welch, Kevin D; Jordan, Glenn T; Zhang, Qian; Panter, Kip E; Hughes, David; Chang, Cheng-Wei Tom; Pfister, James A; Gardner, Dale R

2013-04-15

γ-Coniceine, coniine, and N-methylconiine are toxic alkaloids present in poison hemlock (Conium maculatum). We previously reported the comparison of the relative potencies of (+)- and (-)-coniine enantiomers. In this study, we synthesized γ-coniceine and the enantiomers of N-methylconiine and determined the biological activity of γ-coniceine and each of the N-methylconiine enantiomers in vitro and in vivo. The relative potencies of these piperidine alkaloids on cells expressing human fetal muscle-type nicotinic acetylcholine receptors had the rank order of γ-coniceine > (-)-N-methylconiine > (±)-N-methylconiine > (+)-N-methylconiine. The relative lethalities of γ-coniceine and (-)-, (±)-, and (+)-N-methylconiine in vivo using a mouse bioassay were 4.4, 16.1, 17.8, and 19.2 mg/kg, respectively. The results from this study suggest γ-coniceine is a more potent agonist than the enantiomers of N-methylconiine and that there is a stereoselective difference in the in vitro potencies of the enantiomers of N-methylconiine that correlates with the relative toxicities of the enantiomers in vivo.

Influence of the vaginal microbiota on toxic shock syndrome toxin 1 production by Staphylococcus aureus.

Science.gov (United States)

MacPhee, Roderick A; Miller, Wayne L; Gloor, Gregory B; McCormick, John K; Hammond, Jo-Anne; Burton, Jeremy P; Reid, Gregor

2013-03-01

Menstrual toxic shock syndrome (TSS) is a serious illness that afflicts women of premenopausal age worldwide and arises from vaginal infection by Staphylococcus aureus and concurrent production of toxic shock syndrome toxin-1 (TSST-1). Studies have illustrated the capacity of lactobacilli to reduce S. aureus virulence, including the capacity to suppress TSST-1. We hypothesized that an aberrant microbiota characteristic of pathogenic bacteria would induce the increased production of TSST-1 and that this might represent a risk factor for the development of TSS. A S. aureus TSST-1 reporter strain was grown in the presence of vaginal swab contents collected from women with a clinically healthy vaginal status, women with an intermediate status, and those diagnosed with bacterial vaginosis (BV). Bacterial supernatant challenge assays were also performed to test the effects of aerobic vaginitis (AV)-associated pathogens toward TSST-1 production. While clinical samples from healthy and BV women suppressed toxin production, in vitro studies demonstrated that Streptococcus agalactiae and Enterococcus spp. significantly induced TSST-1 production, while some Lactobacillus spp. suppressed it. The findings suggest that women colonized by S. aureus and with AV, but not BV, may be more susceptible to menstrual TSS and would most benefit from prophylactic treatment.

Mapping the extent and relative toxicity of sediments, Winter Quarters Bay, Antarctica

International Nuclear Information System (INIS)

Crockett, A.; White, G.; Huynh, H.

1995-01-01

McMurdo Station was established in the mid 1950s and is the largest research station in Antarctica. In earlier days, wastes were dumped on the steep shores of Winter Quarters Bay, dosed with up to 19,000 L of diesel or jet fuel and ignited. Along with periodic fuel spills, and the discharge of raw sewage the Bay became littered with trash and contaminated with elevated levels of metals, PCBs and petroleum hydrocarbons. The original benthic community was essentially totally replaced with more opportunistic species. In 1993, a study was initiated to map the distribution of PCB and hydrocarbon contamination as well as determine sediment pore water toxicity. Sediments were collected from over forty locations with an Ekman dredge after drilling through about 210 cm of ice. Maps of sediment particle size distribution, percent organic carbon, total PCBs, total petroleum hydrocarbons, etc. were developed. Potential toxicity was mapped by normalizing the data to 1 percent organic carbon and comparing the data with various sediment quality criteria. While onsite sediment pore water toxicity tests showed essentially no impacts, the new Microtox trademark chronic bioassay on both pore water and solvent extra showed considerable toxic effects. This paper compares the relative levels of contamination, with sediment quality criteria and toxicity as determined by a chronic microbial bioassays

Authorization and Toxicity of Veterinary Drugs and Plant Protection Products: Residues of the Active Ingredients in Food and Feed and Toxicity Problems Related to Adjuvants.

Science.gov (United States)

Klátyik, Szandra; Bohus, Péter; Darvas, Béla; Székács, András

2017-01-01

active ingredients and their additives in formulated products; moreover, toxicity has been evidenced for various additives. Therefore, toxicological evaluation of surfactants and other additives is essential for proper environmental risk assessment of formulations used in agriculture including animal husbandry and plant protection.

Authorization and Toxicity of Veterinary Drugs and Plant Protection Products: Residues of the Active Ingredients in Food and Feed and Toxicity Problems Related to Adjuvants

Directory of Open Access Journals (Sweden)

Szandra Klátyik

2017-09-01

between the active ingredients and their additives in formulated products; moreover, toxicity has been evidenced for various additives. Therefore, toxicological evaluation of surfactants and other additives is essential for proper environmental risk assessment of formulations used in agriculture including animal husbandry and plant protection.

Financial disclosure and toxic products: encouraging wall street to anticipate product risk and exercise precaution.

Science.gov (United States)

Lewis, Sanford; Byrne, Margaret

2009-01-01

Amidst discussion by policymakers about how regulators' failure to ensure disclosure of risks contributed to the current financial crisis, we assess how emerging product toxicity risks are addressed in companies' financial reports. Will corporations blindside investors with "the next asbestos?" Existing disclosures are found lacking in the specificity needed to forewarn of liabilities and reputational damage from the use of potentially harmful materials-from nanotechnologies, to asthmagens, to perfluorinated compounds. Improved standards could protect investors while also enhancing corporate incentives to use safer materials. Reforms by the Securities and Exchange Commission and the Financial Accounting Standards Board are recommended.

Classification of baseline toxicants for QSAR predictions to replace fish acute toxicity studies.

Science.gov (United States)

Nendza, Monika; Müller, Martin; Wenzel, Andrea

2017-03-22

Fish acute toxicity studies are required for environmental hazard and risk assessment of chemicals by national and international legislations such as REACH, the regulations of plant protection products and biocidal products, or the GHS (globally harmonised system) for classification and labelling of chemicals. Alternative methods like QSARs (quantitative structure-activity relationships) can replace many ecotoxicity tests. However, complete substitution of in vivo animal tests by in silico methods may not be realistic. For the so-called baseline toxicants, it is possible to predict the fish acute toxicity with sufficient accuracy from log K ow and, hence, valid QSARs can replace in vivo testing. In contrast, excess toxicants and chemicals not reliably classified as baseline toxicants require further in silico, in vitro or in vivo assessments. Thus, the critical task is to discriminate between baseline and excess toxicants. For fish acute toxicity, we derived a scheme based on structural alerts and physicochemical property thresholds to classify chemicals as either baseline toxicants (=predictable by QSARs) or as potential excess toxicants (=not predictable by baseline QSARs). The step-wise approach identifies baseline toxicants (true negatives) in a precautionary way to avoid false negative predictions. Therefore, a certain fraction of false positives can be tolerated, i.e. baseline toxicants without specific effects that may be tested instead of predicted. Application of the classification scheme to a new heterogeneous dataset for diverse fish species results in 40% baseline toxicants, 24% excess toxicants and 36% compounds not classified. Thus, we can conclude that replacing about half of the fish acute toxicity tests by QSAR predictions is realistic to be achieved in the short-term. The long-term goals are classification criteria also for further groups of toxicants and to replace as many in vivo fish acute toxicity tests as possible with valid QSAR

Toxic effect of volatile products of thermooxidizing decomposition of conveyor belts

Energy Technology Data Exchange (ETDEWEB)

Faff, J.; Dudkiewicz, J.; Kauczak, M.; Waniewski, E.; Tokarzewski, E.

1985-01-01

Toxic effects of thermo-oxidizing decomposition products of conveying belts made of PVC and rubber have been tested. The resultant smokes were passed through a protective absorber. During 14-days' post-exposure observation, an increased activity of asparagine, aminotransferase and in some animal alanine aminotransferase was found. Moderately increased pathomorphological changes were found in lungs (emphysema, oedema interstitial and bronchogenic inflammations), along with slight degenerative changes in the liver and kidneys. In the peripheral blood, increased amounts of erythrocytes and leukocytes were found.

Stereoselective potencies and relative toxicities of y-Coniceine and N-Methylconiine enantiomers

Science.gov (United States)

'-Coniceine, coniine, and N-methylconiine are toxic alkaloids present in poison hemlock (Conium maculatum). We previously reported the comparison of the relative potencies of (+)- and (-)-coniine enantiomers. In this study, we synthesized '-coniceine and the enantiomers of N-methylconiine and dete...

ASSESSMENT OF TOXICITY OF INDUSTRIAL WASTES USING CROP PLANT ASSAYS

Directory of Open Access Journals (Sweden)

Carmen Alice Teacă

2008-11-01

Full Text Available Environmental pollution has a harmful action on bioresources, including agricultural crops. It is generated through many industrial activities such as mining, coal burning, chemical technology, cement production, pulp and paper industry, etc. The toxicity of different industrial wastes and heavy metals excess was evaluated using crop plant assays (germination and hydroponics seedlings growth tests. Experimental data regarding the germination process of wheat (from two cultivars and rye seeds in the presence of industrial wastes (thermal power station ash, effluents from a pre-bleaching stage performed on a Kraft cellulose – chlorinated lignin products or chlorolignin, along with use of an excess of some heavy metals (Zn and Cu are presented here. Relative seed germination, relative root elongation, and germination index (a factor of relative seed germination and relative root elongation were determined. Relative root elongation and germination index were more sensitive indicators of toxicity than seed germination. The toxic effects were also evaluated in hydroponics experiments, the sensitivity of three crop plant species, namely Triticum aestivum L. (wheat, Secale cereale (rye, and Zea mays (corn being compared. Physiological aspects, evidenced both by visual observation and biometric measurements (mean root, aerial part and plant length, as well as the cellulose and lignin content were examined.

Choose Your Weaponry: Selective Storage of a Single Toxic Compound, Latrunculin A, by Closely Related Nudibranch Molluscs.

Directory of Open Access Journals (Sweden)

Karen L Cheney

Full Text Available Natural products play an invaluable role as a starting point in the drug discovery process, and plants and animals use many interesting biologically active natural products as a chemical defense mechanism against predators. Among marine organisms, many nudibranch gastropods are known to derive defensive metabolites from the sponges they eat. Here we investigated the putative sequestration of the toxic compound latrunculin A--a 16-membered macrolide that prevents actin polymerization within cellular processes--which has been identified from sponge sources, by five closely related nudibranch molluscs of the genus Chromodoris. Only latrunculin A was present in the rim of the mantle of these species, where storage reservoirs containing secondary metabolites are located, whilst a variety of secondary metabolites were found in their viscera. The species studied thus selectively accumulate latrunculin A in the part of the mantle that is more exposed to potential predators. This study also demonstrates that latrunculin-containing sponges are not their sole food source. Latrunculin A was found to be several times more potent than other compounds present in these species of nudibranchs when tested by in vitro and in vivo toxicity assays. Anti-feedant assays also indicated that latrunculin A was unpalatable to rock pool shrimps, in a dose-dependent manner. These findings led us to propose that this group of nudibranchs has evolved means both to protect themselves from the toxicity of latrunculin A, and to accumulate this compound in the mantle rim for defensive purposes. The precise mechanism by which the nudibranchs sequester such a potent compound from sponges without disrupting their own key physiological processes is unclear, but this work paves the way for future studies in this direction. Finally, the possible occurrence of both visual and chemosensory Müllerian mimicry in the studied species is discussed.

Determination of leachate toxicity through acute toxicity using Daphnia pulex and anaerobic toxicity assays

OpenAIRE

Carabalí-Rivera, Y. S; Barba-Ho, L. E; Torres-Lozada, P

2017-01-01

ABSTRACT The municipal solid waste (MSW) of large cities, in particular the ones of developing countries, is mainly disposed in landfills (LFs), whose inadequate management generates the emission of greenhouse gases and the production of leachates with high concentrations of organic and inorganic matter and, occasionally heavy metals. In this study, the toxicity of the leachates from an intermediate-age municipal landfill was evaluated by ecotoxicity and anaerobic toxicity tests. The acute to...

Evaluation of four commercial natural products for repellency and toxicity against the lone star tick, Amblyomma americanum (Acari: Ixodidae).

Science.gov (United States)

Machtinger, Erika T; Li, Andrew Y

2017-12-01

Lone star ticks are aggressive ectoparasites of domestic and wild animals, as well as humans. These ticks can transmit many pathogens that cause disease including Erhlichia and tularemia. Common compounds used for personal protection and area sprays are N-diethyl-3-methyl benzamide (DEET) and permethrin, but public concern over personal and environmental safety require the development of new, safer products. In the current study, four commercially available products (Wondercide, Essentria IC 3 , Vet's Best, and Mosquito Barrier) were tested for both repellent and toxic effects against lone star tick nymphs and adults. Overall, all four products were more effective against nymphs than against adults. Wondercide and Essentria IC 3 were as toxic to nymphs as permethrin at concentrations of 3.13% and higher, and as repellent as DEET at all concentrations. Nymphs were also repelled by Mosquito Barrier and Vet's Best, but these products had about half or less of the repellent effects of Wondercide and Essentria IC 3 at most of the concentrations. Adult ticks were repelled similarly by all products at all tested concentrations, but at lower levels than nymphs. Toxicity of the four tested products on adults was similar at concentrations of 12.5% and below, less than half of what was observed with permethrin with declining effectiveness as concentrations decreased. Overall, these four products may offer a natural way to repel lone star ticks, but further field testing is needed to determine rates of application and residual activity.

Reactions of clofibric acid with oxidative and reductive radicals—Products, mechanisms, efficiency and toxic effects

International Nuclear Information System (INIS)

Csay, Tamás; Rácz, Gergely; Salik, Ádám; Takács, Erzsébet; Wojnárovits, László

2014-01-01

The degradation of clofibric acid induced by hydroxyl radical, hydrated electron and O 2 −∙ /HO 2 ∙ reactive species was studied in aqueous solutions. Clofibric acid was decomposed more effectively by hydroxyl radical than by hydrated electron or O 2 −∙ /HO 2 ∙ . Various hydroxylated, dechlorinated and fragmentation products have been identified and quantified. A new LC–MS method was developed based on 18 O isotope labeling to follow the formation of hydroxylated derivatives of clofibric acid. Possible degradation pathways have been proposed. The overall degradation was monitored by determination of sum parameters like COD, TOC and AOX. It was found that the organic chlorine degrades very effectively prior to complete mineralization. After the treatment no toxic effect was found according to Vibrio fischeri tests. However, at early stages some of the reaction products were more harmful than clofibric acid. - Highlights: • Clofibric acid is effectively degraded by OH radical. • Main primary and secondary products are hydroxylated and dihydroxylated phenyl type derivatives of clofibric acid. • In air saturated aqueous solutions O 2 plays an important role in decomposition of the aromatic structure. • A new LC–MS method with 18 O-labeling was developed. • Early stage reaction products are more toxic to bacteria Vibrio fischeri than clofibric acid

Toxicity Assessment of Atrazine and Related Triazine Compounds in the Microtox Assay, and Computational Modeling for Their Structure-Activity Relationship

Directory of Open Access Journals (Sweden)

Jerzy Leszczynski

2000-10-01

Full Text Available The triazines are a group of chemically similar herbicides including atrazine, cyanazine, and propazine, primarily used to control broadleaf weeds. About 64 to 80 million lbs of atrazine alone are used each year in the United States, making it one of the two most widely used pesticides in the country. All triazines are somewhat persistent in water and mobile in soil. They are among the most frequently detected pesticides in groundwater. They are considered as possible human carcinogens (Group C based on an increase in mammary gland tumors in female laboratory animals. In this research, we performed the Microtox Assay to investigate the acute toxicity of a significant number of triazines including atrazine, atraton, ametryne, bladex, prometryne, and propazine, and some of their degradation products including atrazine desethyl, atrazine deisopropyl, and didealkyled triazine. Tests were carried out as described by Azur Environmental [1]. The procedure measured the relative acute toxicity of triazines, producing data for the calculation of triazine concentrations effecting 50% reduction in bioluminescence (EC50s. Quantitative structure-activity relationships (QSAR were examined based on the molecular properties obtained from quantum mechanical predictions performed for each compound. Toxicity tests yielded EC50 values of 39.87, 273.20, 226.80, 36.96, 81.86, 82.68, 12.74, 11.80, and 78.50 mg/L for atrazine, propazine, prometryne, atraton, atrazine desethyl, atrazine deisopropyl, didealkylated triazine, ametryne, and bladex, respectively; indicating that ametryne was the most toxic chemical while propazine was the least toxic. QSAR evaluation resulted in a coefficient of determination (r2 of 0.86, indicating a good value of toxicity prediction based on the chemical structures/properties of tested triazines.

Toxicity Tests Applied to the Biocidal Products

OpenAIRE

Karabay Yavaşoğlu, N.Ülkü

2015-01-01

Biocides are defined as chemical substances used to suppress, destroy, deter, render harmless, or exert a controlling effect on any harmful organism to human or animal health, or that cause damage to natural or manufactured materials. Biocidal products (BPs) containing biocides are disinfectants, products related to human and veterinary hygiene, products used for pests such as insects, rodents etc., repellents and industrial chemicals like anti-fouling paints for ship and material preservativ...

Assessment of potential toxicity of a smokeless tobacco product (naswar) available on the Pakistani market.

Science.gov (United States)

Zakiullah; Saeed, Muhammad; Muhammad, Naveed; Khan, Saeed Ahmad; Gul, Farah; Khuda, Fazli; Humayun, Muhammad; Khan, Hamayun

2012-07-01

'Naswar' is a smokeless tobacco product (STP) widely used in Pakistan. It has been correlated with oral and oesophageal cancer in recent clinical studies. The toxic effects associated with STPs have been associated with trace level contaminants present in these products. The toxin levels of Pakistani naswar are reported for the first time in this study. A total of 30 Pakistani brands of naswar were tested for a variety of toxic constituents and carcinogens such as cadmium, arsenic, lead and other carcinogenic metals, nitrite and nitrate, and nicotine and pH. The average values of all the toxins studied were well above their allowable limits, making the product a health risk for consumers. Calculated lifetime cancer risk from cadmium and lead was 1 lac (100,000) to 10 lac (1,000,000) times higher than the minimum 10E-4 (0.00001) to 10E-6 (0.000001), which is the 'target range' for potentially hazardous substances, according to the US Environmental Protection Agency. Similarly, the level of arsenic was in the range of 0.15 to 14.04 μg/g, the average being 1.25 μg/g. The estimated average bioavailable concentration of arsenic is 0.125-0.25 μg/g, which is higher than the allowable standard of 0.01 μg/g. Similarly, the average minimum daily intake of chromium and nickel was 126.97 μg and 122.01 μg, as compared to allowable 30-35 μg and 35 μg, respectively; a 4-5 times higher exposure. However, beryllium was not detected in any of the brands studied. The pH was highly basic, averaging 8.56, which favours the formation of tobacco specific amines thus making the product potentially toxic. This study validates clinical studies correlating incidence of cancer with naswar use in Pakistan. This study shows that the production, packaging, sale and consumption of naswar should be regulated so as to protect the public from the health hazards associated with its consumption.

Copper transfer from Cu-Aβ to human serum albumin inhibits aggregation, radical production and reduces Aβ toxicity

DEFF Research Database (Denmark)

Perrone, Lorena; Mothes, Emmanuelle; Vignes, Maeva

2010-01-01

the catalytic HO· production in vitro and ROS production in neuroblastoma cells generated by Cu-Aβ and ascorbate, 4) HSA and DAHK were able to rescue these cells from the toxicity of Cu-Aβ with ascorbate, 5) DAHK was more potent in ROS suppression and restoration of neuroblastoma cell viability than HSA...

Prediction of acute inhalation toxicity using in vitro lung surfactant inhibition.

Science.gov (United States)

Sørli, Jorid B; Huang, Yishi; Da Silva, Emilie; Hansen, Jitka S; Zuo, Yi Y; Frederiksen, Marie; Nørgaard, Asger W; Ebbehøj, Niels E; Larsen, Søren T; Hougaard, Karin S

2018-01-01

Private consumers and professionals may experience acute inhalation toxicity after inhaling aerosolized impregnation products. The distinction between toxic and non-toxic products is difficult to make for producers and product users alike, as there is no clearly described relationship between the chemical composition of the products and induction of toxicity. The currently accepted method for determination of acute inhalation toxicity is based on experiments on animals; it is time-consuming, expensive and causes stress for the animals. Impregnation products are present on the market in large numbers and amounts and exhibit great variety. Therefore, an alternative method to screen for acute inhalation toxicity is needed. The aim of our study was to determine if inhibition of lung surfactant by impregnation products in vitro could accurately predict toxicity in vivo in mice. We tested 21 impregnation products using the constant flow through set-up of the constrained drop surfactometer to determine if the products inhibited surfactant function or not. The same products were tested in a mouse inhalation bioassay to determine their toxicity in vivo. The sensitivity was 100%, i.e., the in vitro method predicted all the products that were toxic for mice to inhale. The specificity of the in vitro test was 63%, i.e., the in vitro method found three false positives in the 21 tested products. Six of the products had been involved in accidental human inhalation where they caused acute inhalation toxicity. All of these six products inhibited lung surfactant function in vitro and were toxic to mice.

Development of standardized bioassay protocols for the toxicity assessment of waste, manufactured products, and effluents in Latin America: Venezuela, a Case Study

International Nuclear Information System (INIS)

Rodriquez-Grau, J.

1993-01-01

The present status of the toxicity assessment of industrial products in Latin America is well below North America/EC standards. As an example, most of Latin America regulatory laws regarding effluent discharge are still based upon concentration limits of certain major pollutants, and BOD/COD measurements; no reference is made to the necessity of aquatic bioassay toxicity data. Aware of this imperative need, the Venezuelan Petroleum Industry (PDVSA), through its R ampersand D Corporative branch (INTEVEP) gave priority to the development of standardized acute/sublethal toxicity test protocols as sound means of evaluating their products and wastes. Throughout this presentation, the Venezuelan case will be studied, showing strategies undertaken to accelerate protocol development. Results will show the assessment of 14 different protocols encompassing a variety of species of aquatic/terrestrial organisms, and a series of toxicity test endpoints including mortality, reproductive, biological and immunological measurements, most of which are currently in use or being developed. These protocols have already yielded useful results in numerous cases where toxicity assessment was required, including evaluations of effluent, oil dispersants, drilling fluids, toxic wastes, fossil fuels and newly developed products. The Venezuelan case demonstrates that the integration of Industry, Academia and Government, which is an essential part of SETAC's philosophy, is absolutely necessary for the successful advancement of environmental scientific/regulatory issues

Multi-factor analysis on events related to hematological toxicity in 153Sm-EDTMP palliative therapy for skeletal metastases

International Nuclear Information System (INIS)

Zhan Hongwei; Yu Xiaoling; Ye Xiaojuan; Bao Chengkan; Sun Da; He Gangqiang

2006-01-01

Objective: To investigate the clinical factors related to hematological toxicity induced by intravenous samarium-153 ethylenediaminetetramethylene phosphonic acid ( 153 Sm-EDTMP) treatment. Methods A total of 206 patients with bony metastases treated with 153 Sm-EDTMP were retrospectively analyzed. Logistic regression (SPSS 10.0 for Windows) and correlation analysis were used to evaluate the factors concerned. Results: Age of the patient, number of bone metastatic lesion, chemotherapy before 153 Sm-EDTMP therapy, concurrent radiotherapy and repeat-times of 153 Sm-EDTMP treatments were found the individual factors related to hematological toxicity. Chemotherapy before 153 Sm-EDTMP, concurrent radiotherapy, medication for normal blood counting and repeat-times of 153 Sm-EDTMP treatments were the hematological toxicity factors in multi-factor analysis. Conclusion: In 153 Sm-EDTMP therapy, several factors were found related to hematological toxicity suggesting more attention be paid to the change of blood cell counting after the palliative therapy. (authors)

Oxygen toxicity

Directory of Open Access Journals (Sweden)

C. A. van der Westhuizen

1990-07-01

Full Text Available Oxygen has been discovered about 200 years ago. Since then the vital physiological involvement of oxygen in various biologi­cal processes, mainly energy production, has been established. However, in the body molecular oxygen can be converted to toxic oxygen metabolites such as superoxide anion, hydrogen peroxide, the hydroxyl radical and singlet oxygen. These toxic metabolites are produced mainly in the mitochondria, plasma membranes and endoplasmic reticulum.

Study of the relative toxicity of anions, with Polycelis nigra as test animal

Energy Technology Data Exchange (ETDEWEB)

Jones, J R.E.

1942-01-01

A brief review is given of existing knowledge regarding the physiological effects of anions, and literature dealing with their relative toxicity. The degree of toxicity of twenty-seven anions to Polycelis nigra (Mueller) has been assessed, by determining in each case the molar concentration the animal survives for 48 hr. at 15-18/sup 0/C. On this basis their order of increasing toxicity is as follows; commas separate ions of similar degree of toxicity: Cltoxic than cations. Even the most toxic anion (OH) is far less toxic than ionic copper, silver, or gold. The respiration rate of Polycelis is heavily depressed by cyanide, but the survival time is three days or longer, as long as the respiration rate is not less than about 16% of the normal value. With further depression the survival time shortens rapidly, and at 9% normal is under 4 hr. The normal respiration rate of Polycelis nigra is 0.165 cc O/sub 2//g./hr. This is not very much less than that of the trout. Polycelis is considerably the more resistant to cyanide. This is probably connected with its capability of surviving very many hours in water containing a very reduced supply of oxygen. 34 references, 6 figures, 1 table.

Toxic organic compounds from energy production

Energy Technology Data Exchange (ETDEWEB)

Hites, R.A.

1991-09-20

The US Department of Energy's Office of Health and Environmental Research (OHER) has supported work in our laboratory since 1977. The general theme of this program has been the identification of potentially toxic organic compounds associated with various combustion effluents, following the fates of these compounds in the environment, and improving the analytical methodology for making these measurements. The projects currently investigation include: an improved sampler for semi-volatile compounds in the atmosphere; the wet and dry deposition of dioxins and furans from the atmosphere; the photodegradation and mobile sources of dioxins and furans; and the bioaccumulation of PAH by tree bark. These projects are all responsive to OHER's interest in the pathways and mechanisms by which energy-related agents move through and are modified by the atmosphere''. The projects on gas chromatographic and liquid chromatographic tandem mass spectrometry are both responsive to OHER's interest in new and more sensitive technologies for chemical measurements''. 35 refs., 9 figs.

Electronic Cigarette Toxicity.

Science.gov (United States)

Payne, J Drew; Michaels, David; Orellana-Barrios, Menfil; Nugent, Kenneth

2017-04-01

Electronic cigarettes (e-cigarettes) are often advertised as a healthier product when compared with traditional cigarettes. Currently, there are limited data to support this and only a threat of federal regulation from the US Food and Drug Administration. Calls to poison control centers about e-cigarette toxicity, especially in children, and case reports of toxic exposures have increased over the past 3 years. This research letter reports the frequency of hazardous exposures to e-cigarettes and characterizes the reported adverse health effects associated with e-cigarette toxicity.

Degradation of fluoroquinolone antibiotics during ionizing radiation treatment and assessment of antibacterial activity, toxicity and biodegradability of the products

Science.gov (United States)

Tegze, Anna; Sági, Gyuri; Kovács, Krisztina; Homlok, Renáta; Tóth, Tünde; Mohácsi-Farkas, Csilla; Wojnárovits, László; Takács, Erzsébet

2018-06-01

This work aimed at investigating the ionizing radiation induced degradation of two fluoroquinolone antibiotics: norfloxacin and ciprofloxacin. At 0.1 mmol dm-3 concentration a low dose, 2 kGy was sufficient to degrade the initial molecules. However, despite of the high removal efficiency the degrees of both the mineralization and the oxidation were low, ∼10% and ∼25%, respectively. (The difference between the results obtained in norfloxacin and ciprofloxacin solutions was not statistically significant.) Broth microdilution tests carried out on Staphylococcus aureus evidenced removal of antibacterial activity in samples irradiated with 2 kGy. Acute toxicity determined on Vibrio fischeri bacteria showed increased toxicity at low doses indicating that the early degradation products were more toxic than the initial molecules. The results of biodegradation experiments performed in activated sludge have shown that the degradation products have become available to the metabolic processes of the microorganisms.

Determination of the toxicity level of the fluoropolymers production wastes by reaction of soil microflora and cyanobacteria Nostoc paludosum Kütz

Directory of Open Access Journals (Sweden)

Elkina Tatyana

2014-03-01

Full Text Available The environment is constantly receiving the substances that are artificially synthesized by human, hence, not inherent in nature, that are circulating in it. One of the most common wastes of fluoroelastomer SKF-26 production is the mother solution entering the environment together with the wastewater of chemical enterprises. Until now limits of allowable concentrations of these compounds have not been established, as they are considered practically safe. By determining the toxicity level of the waste of fluoropolymers production conducted by reaction of soil algae , cyanobacteria and micromycetes it was showed that the waste of fluorine rubber SKF-26 production are not safe or neutral for these groups of microorganisms. The toxicity of high concentrations of the mother solution SKF-26 was particularly evident in the damaging effects to the of the test organism Nostoc paludosum in aqueous medium. Field experiments confirmed that not only mother solutions, but also the possible products of their transformations are toxic. This fact clearly illustrates the change in the structure of mikocenoses where a progressive increase in populations with melanized mycelium takes place.

Generation of toxic degradation products by sonication of Pluronic® dispersants: implications for nanotoxicity testing.

Science.gov (United States)

Wang, Ruhung; Hughes, Tyler; Beck, Simon; Vakil, Samee; Li, Synyoung; Pantano, Paul; Draper, Rockford K

2013-11-01

Poloxamers (known by the trade name Pluronic®) are triblock copolymer surfactants that contain two polyethylene glycol blocks and one polypropylene glycol block of various sizes. Poloxamers are widely used as nanoparticle dispersants for nanotoxicity studies wherein nanoparticles are sonicated with a dispersant to prepare suspensions. It is known that poloxamers can be degraded during sonication and that reactive oxygen species contribute to the degradation process. However, the possibility that poloxamer degradation products are toxic to mammalian cells has not been well studied. We report here that aqueous solutions of poloxamer 188 (Pluronic® F-68) and poloxamer 407 (Pluronic® F-127) sonicated in the presence or absence of multi-walled carbon nanotubes (MWNTs) can became highly toxic to cultured cells. Moreover, toxicity correlated with the sonolytic degradation of the polymers. These findings suggest that caution should be used in interpreting the results of nanotoxicity studies where the potential sonolytic degradation of dispersants was not controlled.

Assessment of the relative toxicity of Cu2+ by measuring structural changes of supercoiled DNA

International Nuclear Information System (INIS)

Pan Gang; Chang Guohua; Chen Hao; Giusti, Lorenzo

2007-01-01

A method for the measurement of the relative toxicity of Cu 2+ in aquatic environments is proposed. It is based on the quantitative measurement on the shape change of the supercoiled DNA after it is contacted with different levels of Cu 2+ for various time intervals. In the absence of any redox reagents, all supercoiled DNA degraded into other forms of DNA after 24 h incubation in the presence of 5.13 x 10 -3 , 5.08 x 10 -4 and 5.35 x 10 -5 mol/L Cu 2+ . At a lower Cu 2+ concentration (10 -6 mol/L), 44% of supercoiled DNA retained its original supercoiled form after 24 h, and 29% after 48 h. The concentration of RC 50 , i.e. concentration of pollutants at which 50% of the supercoiled DNA was relaxed compared to control samples, can be obtained from the does-response curves at different exposure time, which may provide a rapid and convenient approach to assess the relative toxicity of environmental pollutants. - RC 50 values (concentration at which 50% of the supercoiled DNA relaxed) can be used to reflect the relative toxicity of Cu in aquatic environment

Ground and surface water developmental toxicity at a municipal landfill--Description and weather-related variation

Science.gov (United States)

Bruner, M.A.; Rao, M.; Dumont, J.N.; Hull, M.; Jones, T.; Bantle, J.A.

1998-01-01

Contaminated groundwater poses a significant health hazard and may also impact wildlife such as amphibians when it surfaces. Using FETAX (Frog Embryo Teratogenesis Assay-Xenopus), the developmental toxicity of ground and surface water samples near a closed municipal landfill at Norman, OK, were evaluated. The groundwater samples were taken from a network of wells in a shallow, unconfined aquifer downgradient from the landfill. Surface water samples were obtained from a pond and small stream adjacent to the landfill. Surface water samples from a reference site in similar habitat were also analyzed. Groundwater samples were highly toxic in the area near the landfill, indicating a plume of toxicants. Surface water samples from the landfill site demonstrated elevated developmental toxicity. This toxicity was temporally variable and was significantly correlated with weather conditions during the 3 days prior to sampling. Mortality was negatively correlated with cumulative rain and relative humidity. Mortality was positively correlated with solar radiation and net radiation. No significant correlations were observed between mortality and weather parameters for days 4–7 preceding sampling.

A review of reproductive toxicity of microcystins

International Nuclear Information System (INIS)

Chen, Liang; Chen, Jun; Zhang, Xuezhen; Xie, Ping

2016-01-01

Highlights: • Reproductive toxicity of MCs on mammals, fishes, amphibians, and birds is reviewed. • PP1/2A inhibition and oxidative stress are important toxic mechanisms of MCs. • Reproductive toxicity of MCs may be closely related to endocrine-disrupting effects. • The trans-generational toxicity of microcystins is a matter of concern. • Data concerning female reproductive and sex-specific effects of MCs are lacking. - Abstract: Animal studies provide strong evidence of positive associations between microcystins (MCs) exposure and reproductive toxicity, representing a threat to human reproductive health and the biodiversity of wild life. This paper reviews current knowledge of the reproductive toxicity of MCs, with regard to mammals, fishes, amphibians, and birds, mostly in males. Toxicity of MCs is primarily governed by the inhibition of protein phosphatases 1 and 2A (PP1 and PP2A) and disturbance of cellular phosphorylation balance. MCs exposure is related to excessive production of reactive oxygen species (ROS) and oxidative stress, leading to cytoskeleton disruption, mitochondria dysfunction, endoplasmic reticulum (ER) stress, and DNA damage. MCs induce cell apoptosis mediated by the mitochondrial and ROS and ER pathways. Through PP1/2A inhibition and oxidative stress, MCs lead to differential expression/activity of transcriptional factors and proteins involved in the pathways of cellular differentiation, proliferation, and tumor promotion. MC-induced DNA damage is also involved in carcinogenicity. Apart from a direct effect on testes and ovaries, MCs indirectly affect sex hormones by damaging the hypothalamic-pituitary-gonad (HPG) axis and liver. Parental exposure to MCs may result in hepatotoxicity and neurotoxicity of offspring. We also summarize the current research gaps which should be addressed by further studies.

A review of reproductive toxicity of microcystins

Energy Technology Data Exchange (ETDEWEB)

Chen, Liang, E-mail: chan91@yeah.net [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Jun, E-mail: chenjun@ihb.ac.cn [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Zhang, Xuezhen, E-mail: xuezhen@mail.hzau.edu.cn [College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Xie, Ping, E-mail: xieping@ihb.ac.cn [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)

2016-01-15

Highlights: • Reproductive toxicity of MCs on mammals, fishes, amphibians, and birds is reviewed. • PP1/2A inhibition and oxidative stress are important toxic mechanisms of MCs. • Reproductive toxicity of MCs may be closely related to endocrine-disrupting effects. • The trans-generational toxicity of microcystins is a matter of concern. • Data concerning female reproductive and sex-specific effects of MCs are lacking. - Abstract: Animal studies provide strong evidence of positive associations between microcystins (MCs) exposure and reproductive toxicity, representing a threat to human reproductive health and the biodiversity of wild life. This paper reviews current knowledge of the reproductive toxicity of MCs, with regard to mammals, fishes, amphibians, and birds, mostly in males. Toxicity of MCs is primarily governed by the inhibition of protein phosphatases 1 and 2A (PP1 and PP2A) and disturbance of cellular phosphorylation balance. MCs exposure is related to excessive production of reactive oxygen species (ROS) and oxidative stress, leading to cytoskeleton disruption, mitochondria dysfunction, endoplasmic reticulum (ER) stress, and DNA damage. MCs induce cell apoptosis mediated by the mitochondrial and ROS and ER pathways. Through PP1/2A inhibition and oxidative stress, MCs lead to differential expression/activity of transcriptional factors and proteins involved in the pathways of cellular differentiation, proliferation, and tumor promotion. MC-induced DNA damage is also involved in carcinogenicity. Apart from a direct effect on testes and ovaries, MCs indirectly affect sex hormones by damaging the hypothalamic-pituitary-gonad (HPG) axis and liver. Parental exposure to MCs may result in hepatotoxicity and neurotoxicity of offspring. We also summarize the current research gaps which should be addressed by further studies.

Sediment porewater toxicity assessment studies in the vicinity of offshore oil and gas production in the Gulf of Mexico

International Nuclear Information System (INIS)

Carr, R. S.; Chapman, D. C.; Presley, B. J.; Biedenbach, J. M.; Robertson, L.

1996-01-01

Sediment chemical analyses and porewater toxicity tests were conducted in the vicinity of five offshore oil and gas platforms in the Gulf of Mexico to determine the potential long-term environmental impacts of offshore oil and gas exploration and production. Evidence of toxicity was obtained from four of the five platforms from data on sea urchin fertilization and embryonic development. The majority of toxic samples were collected within 150 m of the platform. Sediment concentrations of several metals were well in excess of sediment quality assessment guidelines at a number of stations. Porewater metal concentrations were found to be high enough to account for the observed toxicity. The general conclusion reached from these toxicity tests was that the contaminant-induced impacts from the offshore platforms were confined to a limited area in the immediate vicinity of the platform. 23 refs., 8 tabs., 2 figs

Utilization of biodiesel by-product as substrate for high-production of β-farnesene via relatively balanced mevalonate pathway in Escherichia coli.

Science.gov (United States)

You, Shengping; Yin, Qingdian; Zhang, Jianye; Zhang, Chengyu; Qi, Wei; Gao, Lan; Tao, Zhiping; Su, Rongxin; He, Zhimin

2017-11-01

Farnesene has been identified as suitable jet fuel substitutes and metabolic engineering for microbial production of farnesene is an alternative and attractive route. In this study, due to accumulation of toxic intermediate isopentenyl pyrophosphate (IPP), an engineered Escherichia coli strain harboring heterologous mevalonate pathway produced only 4.11mg/L β-farnesene. Through higher-level expression of isopentenyl diphosphate isomerase and farnesyl diphosphate synthase to minimize the accumulated IPP, another engineered strain with relatively balanced mevalonate pathway was constructed and had the highest production of β-farnesene to date (8.74g/L) by Escherichia coli in a lab bioreactor. Furthermore, this is the first report on utilization of biodiesel by-product (simple purification) as substrate for high-production of β-farnesene by the engineered strain optimized and β-farnesene concentration reached 2.83g/L in a lab bioreactor. Therefore, the engineered strain optimized could be used as a platform host for high-production of other terpenoids using biodiesel by-product as substrate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Toxicity of a plant based mosquito repellent/killer

Science.gov (United States)

Singh, Prakash Raj; Mohanty, Manoj Kumar

2012-01-01

The mission to make humans less attractive to mosquitoes has fuelled decades of scientific research on mosquito behaviour and control. The search for the perfect topical insect repellent/killer continues. This analysis was conducted to review and explore the scientific information on toxicity produced by the ingredients/contents of a herbal product. In this process of systemic review the following methodology was applied. By doing a MEDLINE search with key words of selected plants, plant based insect repellents/killers pertinent articles published in journals and authentic books were reviewed. The World Wide Web and the Extension Toxicity Network database (IPCS-ITOX) were also searched for toxicology data and other pertinent information. Repellents do not all share a single mode of action and surprisingly little is known about how repellents act on their target insects. Moreover, different mosquito species may react differently to the same repellent. After analysis of available data and information on the ingredient, of the product in relation to medicinal uses, acute and chronic toxicity of the selected medicinal plants, it can be concluded that the ingredients included in the herbal product can be used as active agents against mosquitoes. If the product which contains the powder of the above said plants is applied with care and safety, it is suitable fo use as a mosquito repellent/killer. PMID:23554562

Toxicity identification evaluation of cosmetics industry wastewater.

Science.gov (United States)

de Melo, Elisa Dias; Mounteer, Ann H; Leão, Lucas Henrique de Souza; Bahia, Renata Cibele Barros; Campos, Izabella Maria Ferreira

2013-01-15

The cosmetics industry has shown steady growth in many developing countries over the past several years, yet little research exists on toxicity of wastewaters it generates. This study describes a toxicity identification evaluation conducted on wastewater from a small Brazilian hair care products manufacturing plant. Physicochemical and ecotoxicological analyses of three wastewater treatment plant inlet and outlet samples collected over a six month period revealed inefficient operation of the treatment system and thus treated wastewater organic matter, suspended solids and surfactants contents consistently exceeded discharge limits. Treated wastewater also presented high acute toxicity to Daphnia similis and chronic toxicity to Ceriodaphnia dubia and Pseudokirchneriella subcapitata. This toxicity was associated with suspended solids, volatile or sublatable and non-polar to moderately polar organic compounds that could be recovered in filtration and aeration residues. Seven surfactants used in the largest quantities in the production process were highly toxic to P. subcapitata and D. similis. These results indicated that surfactants, important production raw materials, are a probable source of toxicity, although other possible sources, such as fragrances, should not be discarded. Improved treatment plant operational control may reduce toxicity and lower impact of wastewater discharge to receiving waters. Copyright © 2012 Elsevier B.V. All rights reserved.

Modeling Aquatic Toxicity through Chromatographic Systems.

Science.gov (United States)

Fernández-Pumarega, Alejandro; Amézqueta, Susana; Farré, Sandra; Muñoz-Pascual, Laura; Abraham, Michael H; Fuguet, Elisabet; Rosés, Martí

2017-08-01

Environmental risk assessment requires information about the toxicity of the growing number of chemical products coming from different origins that can contaminate water and become toxicants to aquatic species or other living beings via the trophic chain. Direct toxicity measurements using sensitive aquatic species can be carried out but they may become expensive and ethically questionable. Literature refers to the use of chromatographic measurements that correlate to the toxic effect of a compound over a specific aquatic species as an alternative to get toxicity information. In this work, we have studied the similarity in the response of the toxicity to different species and we have selected eight representative aquatic species (including tadpoles, fish, water fleas, protozoan, and bacteria) with known nonspecific toxicity to chemical substances. Next, we have selected four chromatographic systems offering good perspectives for surrogation of the eight selected aquatic systems, and thus prediction of toxicity from the chromatographic measurement. Then toxicity has been correlated to the chromatographic retention factor. Satisfactory correlation results have been obtained to emulate toxicity in five of the selected aquatic species through some of the chromatographic systems. Other aquatic species with similar characteristics to these five representative ones could also be emulated by using the same chromatographic systems. The final aim of this study is to model chemical products toxicity to aquatic species by means of chromatographic systems to reduce in vivo testing.

Practices in management of cancer treatment-related cardiovascular toxicity: A cardio-oncology survey.

Science.gov (United States)

Jovenaux, Ludovic; Cautela, Jennifer; Resseguier, Noemie; Pibarot, Michele; Taouqi, Myriam; Orabona, Morgane; Pinto, Johan; Peyrol, Michael; Barraud, Jeremie; Laine, Marc; Bonello, Laurent; Paganelli, Franck; Barlesi, Fabrice; Thuny, Franck

2017-08-15

Cardiovascular toxicity has become a challenging issue during cancer therapy. Nonetheless, there is a lack of consensual guidelines for their management. We aimed to determine the current practices of oncologists regarding cardiovascular toxicity related to anthracyclines, trastuzumab and angiogenic inhibitors and to gather their opinions on the development of cardio-oncology programs. A cross-sectional declarative study was submitted to French oncologists in the form of an individual, structured questionnaire. A total of 303 oncologists responded to the survey. Ninety-nine percent of oncologists prescribed cardiotoxic therapies, including anthracyclines (83%), trastuzumab (51%) and other angiogenic inhibitors (64%). The method adopted for managing cardiovascular toxicity was based on guidelines from expert oncology societies for only 35% of oncologists. None was aware of recommendations from expert cardiology societies. Prescription of pre-, peri- and post-therapy cardiovascular assessment was inconsistent and significantly less frequent for all classes of angiogenic inhibitors than for anthracyclines and trastuzumab (Poncology programs development. Practices of oncologists are disparate in the field of cardiovascular toxicity. This finding underlines the complexity of managing many different situations and the need for distribution of formal guidelines from oncology and cardiology expert societies. The development of personalized cardio-oncology programs seems essential. Copyright © 2017 Elsevier B.V. All rights reserved.

Acute toxicity of ingested fluoride.

Science.gov (United States)

Whitford, Gary Milton

2011-01-01

This chapter discusses the characteristics and treatment of acute fluoride toxicity as well as the most common sources of overexposure, the doses that cause acute toxicity, and factors that can influence the clinical outcome. Cases of serious systemic toxicity and fatalities due to acute exposures are now rare, but overexposures causing toxic signs and symptoms are not. The clinical course of systemic toxicity from ingested fluoride begins with gastric signs and symptoms, and can develop with alarming rapidity. Treatment involves minimizing absorption by administering a solution containing calcium, monitoring and managing plasma calcium and potassium concentrations, acid-base status, and supporting vital functions. Approximately 30,000 calls to US poison control centers concerning acute exposures in children are made each year, most of which involve temporary gastrointestinal effects, but others require medical treatment. The most common sources of acute overexposures today are dental products - particularly dentifrices because of their relatively high fluoride concentrations, pleasant flavors, and their presence in non-secure locations in most homes. For example, ingestion of only 1.8 ounces of a standard fluoridated dentifrice (900-1,100 mg/kg) by a 10-kg child delivers enough fluoride to reach the 'probably toxic dose' (5 mg/kg body weight). Factors that may influence the clinical course of an overexposure include the chemical compound (e.g. NaF, MFP, etc.), the age and acid-base status of the individual, and the elapsed time between exposure and the initiation of treatment. While fluoride has well-established beneficial dental effects and cases of serious toxicity are now rare, the potential for toxicity requires that fluoride-containing materials be handled and stored with the respect they deserve. Copyright © 2011 S. Karger AG, Basel.

The Deployment of Product-Related Environmental Legislation into Product Requirements

Directory of Open Access Journals (Sweden)

Daniela C. A. Pigosso

2016-04-01

Full Text Available Environmental legislation is increasingly changing its focus from manufacturing-oriented to product-oriented instruments. Compliance with product-related environmental legislation is achieved by the incorporation of environmental requirements into the early phases of the product development process (PDP. Nevertheless, the deployment of product-related environmental legislation into product requirements is still a challenge. This study followed an inductive approach to propose a guideline to support the identification, analysis and deployment of product requirements based on product-related environmental legislation. The guideline is composed of nine steps, clustered into three groups according to their main objective: (A identification of environmental product-related legislation; (B identification of legislative topics to be considered for the deployment of requirements; and (C creation and validation of product requirements. The product requirements deployed are to be considered during the PDP. The guideline was evaluated in an expert consultation in a large manufacturing company, suggesting that it can be used to support the systematization and deployment of product-related environmental requirements.

Reproductive toxicity of a mixture of regulated drinking-water disinfection by-products in a multigenerational rat bioassay

Science.gov (United States)

BACKGROUND:Trihalomethanes (THMs) and haloaretic acids (HAAs) are regulated disinfection by-products (DBPs); their joint reproductive toxicity in drinking water is unknown.OBJECTIVE: We aimed to evaluate a drinking water mixture of the four regulated THMs and five regulated HAAs ...

Personal care product preservatives: risk assessment and mixture toxicities with an industrial wastewater.

Science.gov (United States)

Carbajo, Jose B; Perdigón-Melón, Jose A; Petre, Alice L; Rosal, Roberto; Letón, Pedro; García-Calvo, Eloy

2015-04-01

The aquatic toxicity of eight preservatives frequently used in personal care products (PCPs) (iodopropynyl butylcarbamate, bronopol, diazolidinyl urea, benzalkonium chloride, zinc pyrithione, propylparaben, triclosan and a mixture of methylchloroisothiazolinone and methylisothiazolinone) was assessed by means of two different approaches: a battery of bioassays composed of single species tests of bacteria (Vibrio fischeri and Pseudomonas putida) and protozoa (Tetrahymena thermophila), and a whole biological community resazurin-based assay using activated sludge. The tested preservatives showed considerable toxicity in the studied bioassays, but with a marked difference in potency. In fact, all biocides except propylparaben and diazolidinyl urea had EC50 values lower than 1 mg L(-1) in at least one assay. Risk quotients for zinc pyrithione, benzalkonium chloride, iodopropynyl butylcarbamate and triclosan as well as the mixture of the studied preservatives exceeded 1, indicating a potential risk for the process performance and efficiency of municipal sewage treatment plants (STPs). These four single biocides explained more than 95% of the preservative mixture risk in all bioassays. Each individual preservative was also tested in combination with an industrial wastewater (IWW) from a cosmetics manufacturing facility. The toxicity assessment was performed on binary mixtures (preservative + IWW) and carried out using the median-effect principle, which is a special case of the concept of Concentration Addition (CA). Almost 70% of all experiments resulted in EC50 values within a factor of 2 of the values predicted by the median-effect principle (CI values between 0.5 and 2). The rest of the mixtures whose toxicity was mispredicted by CA were assessed with the alternative concept of Independent Action (IA), which showed higher predictive power for the biological community assay. Therefore, the concept used to accurately predict the toxicity of mixtures of a preservative

Toxic substances handbook

Science.gov (United States)

Junod, T. L.

1979-01-01

Handbook, published in conjunction with Toxic Substances Alert Program at NASA Lewis Research Center, profiles 187 toxic chemicals in their relatively pure states and include 27 known or suspected carcinogens.

A review of acrylamide toxicity and its mechanism

Directory of Open Access Journals (Sweden)

Ehsan Zamani

2017-05-01

Full Text Available Acrylamide (AA is an important industrial chemical agent that is mainly used in the production of polymers and copolymers. Recently it has been attention because of its production in the diet at high-temperature (>120 ºC processes such as cooking, frying, toasting, roasting or baking of high carbohydrate foods. According to high exposure to acrylamide, recognition of its toxic effect is necessary. Neurotoxicity, reproductive toxicity and immunotoxicity of AA were observed in several studies. There isn’t a clear mechanism that justifies this toxicity. In this study we reviewed the mechanisms of AA toxicity especially oxidative stress and apoptosis. AA can cause neurotoxicity, reproductive toxicity and genotoxicity on animal models. It showed neurotoxicity in human. We suggested the oxidative stress is the main factor for inducing of acrylamide toxicities. We advised that modifying of food processing methods can be as a good way for decreasing of AA production in foods.

Revision of the ICH guideline on detection of toxicity to reproduction for medicinal products: SWOT analysis.

Science.gov (United States)

Barrow, Paul

2016-09-01

SWOT analysis was used to gain insights and perspectives into the revision of the ICH S5(R2) guideline on detection of toxicity to reproduction for medicinal products. The current ICH guideline was rapidly adopted worldwide and has an excellent safety record for more than 20 years. The revised guideline should aim to further improve reproductive and developmental (DART) safety testing for new drugs. Alternative methods to animal experiments should be used whenever possible. Modern technology should be used to obtain high quality data from fewer animals. Additions to the guideline should include considerations on the following: limit dose setting, maternal toxicity, biopharmaceuticals, vaccines, testing strategies by indication, developmental immunotoxicity, and male-mediated developmental toxicity. Emerging issues, such as epigenetics and the microbiome, will most likely pose challenges to DART testing in the future. It is hoped that the new guideline will be adopted even outside the ICH regions. Copyright © 2016 Elsevier Inc. All rights reserved.

Memory deficits associated with sublethal cyanide poisoning relative to cyanate toxicity in rodents.

Science.gov (United States)

Kimani, S; Sinei, K; Bukachi, F; Tshala-Katumbay, D; Maitai, C

2014-03-01

Food (cassava) linamarin is metabolized into neurotoxicants cyanide and cyanate, metabolites of which we sought to elucidate the differential toxicity effects on memory. Young 6-8 weeks old male rats were treated intraperitoneally with either 2.5 mg/kg body weight (bw) cyanide (NaCN), or 50 mg/kg bw cyanate (NaOCN), or 1 μl/g bw saline, daily for 6 weeks. Short-term and long-term memories were assessed using a radial arm maze (RAM) testing paradigm. Toxic exposures had an influence on short-term working memory with fewer correct arm entries (F(2, 19) = 4.57 p memory errors (WME) (F(2, 19) = 5.09, p RAM navigation time (F(2, 19) = 3.91, p memory was significantly impaired by cyanide with fewer correct arm entries (F(2, 19) = 7.45, p memory errors (F(2, 19) = 9.35 p memory was not affected by either cyanide or cyanate. Our study findings provide an experimental evidence for the biological plausibility that cassava cyanogens may induce cognition deficits. Differential patterns of memory deficits may reflect the differences in toxicity mechanisms of NaOCN relative to NaCN. Cognition deficits associated with cassava cyanogenesis may reflect a dual toxicity effect of cyanide and cyanate.

Reducing ZnO nanoparticles toxicity through silica coating

Directory of Open Access Journals (Sweden)

Sing Ling Chia

2016-10-01

Full Text Available ZnO NPs have good antimicrobial activity that can be utilized as agents to prevent harmful microorganism growth in food. However, the use of ZnO NPs as food additive is limited by the perceived high toxicity of ZnO NPs in many earlier toxicity studies. In this study, surface modification by silica coating was used to reduce the toxicity of ZnO NPs by significantly reducing the dissolution of the core ZnO NPs. To more accurately recapitulate the scenario of ingested ZnO NPs, we tested our as synthesized ZnO NPs in ingestion fluids (synthetic saliva and synthetic gastric juice to determine the possible forms of ZnO NPs in digestive system before exposing the products to colorectal cell lines. The results showed that silica coating is highly effective in reducing toxicity of ZnO NPs through prevention of the dissociation of ZnO NPs to zinc ions in both neutral and acidic condition. The silica coating however did not alter the desired antimicrobial activity of ZnO NPs to E. coli and S. aureus. Thus, silica coating offered a potential solution to improve the biocompatibility of ZnO NPs for applications such as antimicrobial agent in foods or food related products like food packaging. Nevertheless, caution remains that high concentration of silica coated ZnO NPs can still induce undesirable cytotoxicity to mammalian gut cells. This study indicated that upstream safer-by-design philosophy in nanotechnology can be very helpful in a product development.

Toxic Combustion Product Yields as a Function of Equivalence Ratio and Flame Retardants in Under-Ventilated Fires: Bench-Large-Scale Comparisons

Directory of Open Access Journals (Sweden)

David A. Purser

2016-09-01

Full Text Available In large-scale compartment fires; combustion product yields vary with combustion conditions mainly in relation to the fuel:air equivalence ratio (Φ and the effects of gas-phase flame retardants. Yields of products of inefficient combustion; including the major toxic products CO; HCN and organic irritants; increase considerably as combustion changes from well-ventilated (Φ < 1 to under-ventilated (Φ = 1–3. It is therefore essential that bench-scale toxicity tests reproduce this behaviour across the Φ range. Yield data from repeat compartment fire tests for any specific fuel show some variation on either side of a best-fit curve for CO yield as a function of Φ. In order to quantify the extent to which data from the steady state tube furnace (SSTF [1]; ISO TS19700 [2] represents compartment fire yields; the range and average deviations of SSTF data for CO yields from the compartment fire best-fit curve were compared to those for direct compartment fire measurements for six different polymeric fuels with textile and non-textile applications and for generic post-flashover fire CO yield data. The average yields; range and standard deviations of the SSTF data around the best-fit compartment fire curves were found to be close to those for the compartment fire data. It is concluded that SSTF data are as good a predictor of compartment fire yields as are repeat compartment fire test data.

Metal and proton toxicity to lake zooplankton: A chemical speciation based modelling approach

International Nuclear Information System (INIS)

Stockdale, Anthony; Tipping, Edward; Lofts, Stephen; Fott, Jan; Garmo, Øyvind A.; Hruska, Jakub; Keller, Bill; Löfgren, Stefan; Maberly, Stephen C.; Majer, Vladimir; Nierzwicki-Bauer, Sandra A.; Persson, Gunnar; Schartau, Ann-Kristin; Thackeray, Stephen J.

2014-01-01

The WHAM-F TOX model quantifies the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (F TOX ), a linear combination of the products of organism-bound cation and a toxic potency coefficient for each cation. We describe the application of the model to predict an observable ecological field variable, species richness of pelagic lake crustacean zooplankton, studied with respect to either acidification or the impacts of metals from smelters. The fitted results give toxic potencies increasing in the order H + TOX to relate combined toxic effects of protons and metal cations towards lake crustacean zooplankton. • The fitted results give toxic potencies increasing in the order H + TOX model has been applied to field data for pelagic lake crustacean zooplankton. The fitted results give metal toxic potencies increasing in the order H + < Al < Cu < Zn < Ni

Predicting the formation and the dispersion of toxic combustion products from the fires of dangerous substances

Science.gov (United States)

Nevrlý, V.; Bitala, P.; Danihelka, P.; Dobeš, P.; Dlabka, J.; Hejzlar, T.; Baudišová, B.; Míček, D.; Zelinger, Z.

2012-04-01

Natural events, such as wildfires, lightning or earthquakes represent a frequent trigger of industrial fires involving dangerous substances. Dispersion of smoke plume from such fires and the effects of toxic combustion products are one of the reference scenarios expected in the framework of major accident prevention. Nowadays, tools for impact assessment of these events are rather missing. Detailed knowledge of burning material composition, atmospheric conditions, and other factors are required in order to describe quantitatively the source term of toxic fire products and to evaluate the parameters of smoke plume. Nevertheless, an assessment of toxic emissions from large scale fires involves a high degree of uncertainty, because of the complex character of physical and chemical processes in the harsh environment of uncontrolled flame. Among the others, soot particle formation can be mentioned as still being one of the unresolved problems in combustion chemistry, as well as decomposition pathways of chemical substances. Therefore, simplified approach for estimating the emission factors from outdoor fires of dangerous chemicals, utilizable for major accident prevention and preparedness, was developed and the case study illustrating the application of the proposed method was performed. ALOFT-FT software tool based on large eddy simulation of buoyant fire plumes was employed for predicting the local toxic contamination in the down-wind vicinity of the fire. The database of model input parameters can be effectively modified enabling the simulation of the smoke plume from pool fires or jet fires of arbitrary flammable (or combustible) gas, liquid or solid. This work was supported by the Ministry of Education, Youth and Sports of the Czech Republic via the project LD11012 (in the frame of the COST CM0901 Action) and the Ministry of Environment of the Czech Republic (project no. SPII 1a10 45/70).

Aluminium Toxicity Targets in Plants

Directory of Open Access Journals (Sweden)

Sónia Silva

2012-01-01

Full Text Available Aluminium (Al is the third most abundant metallic element in soil but becomes available to plants only when the soil pH drops below 5.5. At those conditions, plants present several signals of Al toxicity. As reported by literature, major consequences of Al exposure are the decrease of plant production and the inhibition of root growth. The root growth inhibition may be directly/indirectly responsible for the loss of plant production. In this paper the most remarkable symptoms of Al toxicity in plants and the latest findings in this area are addressed. Root growth inhibition, ROS production, alterations on root cell wall and plasma membrane, nutrient unbalances, callose accumulation, and disturbance of cytoplasmic Ca2+ homeostasis, among other signals of Al toxicity are discussed, and, when possible, the behavior of Al-tolerant versus Al-sensitive genotypes under Al is compared.

Aquatic toxicity testing for hazard identification of engineered nanoparticles

DEFF Research Database (Denmark)

Sørensen, Sara Nørgaard

the traditionally applied, and determination of different exposure fractions such as the concentration of dissolved ions from ENPs and body burdens. Although these approaches are scientifically exploratory by nature, the aim is to generate data applicable for regulatory hazard identification of ENPs. The focus has......Within the last few decades, major advances in the field of nanotechnology have enabled production of engineered nanoparticles (ENPs) for various applications and consumer products already available on the market. ENPs may exhibit unique and novel properties compared to their bulk counterparts...... and the response axes. The actual exposure experienced by organisms may not be reflected by the ENPconcentration in medium, commonly applied as the exposure metric, and the responses of organisms may result from various toxic and non-toxic mechanisms occurring simultaneously. In this thesis, the challenges related...

Acute And Toxicity Effect of The Aqueous Extract

African Journals Online (AJOL)

Administrator

antidiarrhoeal, antimalarial and antitrypanosomal activities of plants-based products support this ... Experimental design for Acute toxicity Study: The acute toxicity study was .... Lorke, D. (1983). A new approach to practical acute toxicity testing.

Beyond the polymerase-γ theory: Production of ROS as a mode of NRTI-induced mitochondrial toxicity.

Directory of Open Access Journals (Sweden)

Reuben L Smith

Full Text Available Use of some HIV-1 nucleoside reverse transcriptase inhibitors (NRTI is associated with severe adverse events. However, the exact mechanisms behind their toxicity has not been fully understood. Mitochondrial dysfunction after chronic exposure to specific NRTIs has predominantly been assigned to mitochondrial polymerase-γ inhibition by NRTIs. However, an increasing amount of data suggests that this is not the sole mechanism. Many NRTI induced adverse events have been linked to the incurrence of oxidative stress, although the causality of events leading to reactive oxygen species (ROS production and their role in toxicity is unclear. In this study we show that short-term effects of first generation NRTIs, which are rarely discussed in the literature, include inhibition of oxygen consumption, decreased ATP levels and increased ROS production. Collectively these events affect fitness and longevity of C. elegans through mitohormetic signalling events. Furthermore, we demonstrate that these effects can be normalized by addition of the anti-oxidant N-acetylcysteine (NAC, which suggests that ROS likely influence the onset and severity of adverse events upon drug exposure.

Antidotes for poisoning by alcohols that form toxic metabolites.

Science.gov (United States)

McMartin, Kenneth; Jacobsen, Dag; Hovda, Knut Erik

2016-03-01

The alcohols, methanol, ethylene glycol and diethylene glycol, have many features in common, the most important of which is the fact that the compounds themselves are relatively non-toxic but are metabolized, initially by alcohol dehydrogenase, to various toxic intermediates. These compounds are readily available worldwide in commercial products as well as in homemade alcoholic beverages, both of which lead to most of the poisoning cases, from either unintentional or intentional ingestion. Although relatively infrequent in overall occurrence, poisonings by metabolically-toxic alcohols do unfortunately occur in outbreaks and can result in severe morbidity and mortality. These poisonings have traditionally been treated with ethanol since it competes for the active site of alcohol dehydrogenase and decreases the formation of toxic metabolites. Although ethanol can be effective in these poisonings, there are substantial practical problems with its use and so fomepizole, a potent competitive inhibitor of alcohol dehydrogenase, was developed for a hopefully better treatment for metabolically-toxic alcohol poisonings. Fomepizole has few side effects and is easy to use in practice and it may obviate the need for haemodialysis in some, but not all, patients. Hence, fomepizole has largely replaced ethanol as the toxic alcohol antidote in many countries. Nevertheless, ethanol remains an important alternative because access to fomepizole can be limited, the cost may appear excessive, or the physician may prefer ethanol due to experience. © 2015 The British Pharmacological Society.

NO3-/NH4+ ratios affect nutritional homeostasis and production of Tanzania guinea grass under Cu toxicity.

Science.gov (United States)

de Souza Junior, João Cardoso; Nogueirol, Roberta Corrêa; Monteiro, Francisco Antonio

2018-05-01

Nitrogen (N) can alleviate metal toxicity. However, as of yet, there have been no studies showing the efficacy of NO 3 - /NH 4 + in mitigating Cu toxicity. The objective of this study was to evaluate the Cu toxicity on the nutritional and productive attributes of Panicum maximum cv. Tanzania as well as the role of NO 3 - and NH 4 + ratios in nutritional homeostasis. The experiment was conducted using 3 × 4 factorial treatments arranged in a randomized complete block design with three replicates. The treatments were three NO 3 - /NH 4 + ratios (100/0, 70/30, and 50/50) and four Cu rates (0.3, 250, 500, and 1000 μmol L -1 ) in nutrient solution. Copper concentrations in the diagnostic leaves (DL) were highest in plants grown under 70/30 NO 3 - /NH 4 + ratios and a Cu rate of 1000 μmol L -1 . In this combination, it was observed that DL had higher concentrations of NH 4 + , greater glutamine synthetase activity, lower chlorophyll concentration (SPAD value), and lower shoot dry mass, suggesting high disorders of nutritional homeostasis. Plants receiving N in the form of NO 3 - and 1000 Cu μmol L -1 showed that DL had lower concentrations of Cu, higher concentration of chlorophyll, higher NO 3 - concentration, higher nitrate reductase activity, and higher NO 3 - accumulation in the roots, suggesting a reduction in disorders of nutritional homeostasis. The disorders on mineral uptake, N assimilation, and biomass production caused by Cu toxicity are shown to be affected by NO 3 - /NH 4 + ratios, and N supply via NO 3 - allowed for better homeostasis of the forage grass.

FLUORIDE TOXICITY – A HARSH REALITY

OpenAIRE

Bandlapalli Pavani; Mandava Ragini; David Banji; Otilia J F Banji; N Gouri Pratusha

2011-01-01

There are many incidents of fluoride toxicity whether it is acute or chronic. Fluoride toxicity is an environmental hazard which arises from the upper layers of geological crust and is dissolved in water. Prolonged drinking of such water causes chronic fluoride toxicity. Use of fluoride containing compounds for various purposes such as dental products, metal, glass, refrigerator and chemical industries act as a source of fluoride poisoning and increase the risk of toxicity. This review reflec...

Solar photo-Fenton treatment of microcystin-LR in aqueous environment: Transformation products and toxicity in different water matrices

Science.gov (United States)

Transformation products and toxicity patterns of microcystin-LR (MC-LR), a common cyanotoxin in freshwaters, during degradation by solar photo-Fenton process were studied in the absence and presence of two major water components, namely fulvic acid and alkalinity. The transformat...

Metabolomics Analysis of the Toxic Effects of the Production of Lycopene and Its Precursors

Directory of Open Access Journals (Sweden)

April M. Miguez

2018-05-01

Full Text Available Using cells as microbial factories enables highly specific production of chemicals with many advantages over chemical syntheses. A number of exciting new applications of this approach are in the area of precision metabolic engineering, which focuses on improving the specificity of target production. In recent work, we have used precision metabolic engineering to design lycopene-producing Escherichia coli for use as a low-cost diagnostic biosensor. To increase precursor availability and thus the rate of lycopene production, we heterologously expressed the mevalonate pathway. We found that simultaneous induction of these pathways increases lycopene production, but induction of the mevalonate pathway before induction of the lycopene pathway decreases both lycopene production and growth rate. Here, we aim to characterize the metabolic changes the cells may be undergoing during expression of either or both of these heterologous pathways. After establishing an improved method for quenching E. coli for metabolomics analysis, we used two-dimensional gas chromatography coupled to mass spectrometry (GCxGC-MS to characterize the metabolomic profile of our lycopene-producing strains in growth conditions characteristic of our biosensor application. We found that the metabolic impacts of producing low, non-toxic levels of lycopene are of much smaller magnitude than the typical metabolic changes inherent to batch growth. We then used metabolomics to study differences in metabolism caused by the time of mevalonate pathway induction and the presence of the lycopene biosynthesis genes. We found that overnight induction of the mevalonate pathway was toxic to cells, but that the cells could recover if the lycopene pathway was not also heterologously expressed. The two pathways appeared to have an antagonistic metabolic effect that was clearly reflected in the cells’ metabolic profiles. The metabolites homocysteine and homoserine exhibited particularly interesting

Application of Neutron Activation Analysis to the determination of essential and toxic elements in agroindustrial by-products employed in animal feeding

International Nuclear Information System (INIS)

Teruya, Carla Mitie

1999-01-01

In the present work the concentrations of essential elements Ca (calcium), CI (chlorine), K (potassium), Mg (magnesium), Na (sodium), Co (cobalt), Cr (chromium), Cu (copper), Fe (iron), Mn (manganese). Mo (molybdenum), Se (selenium), V (vanadium) and Zn (zinc), the toxic elements As (arsenic), Cd (cadmium) and Hg (mercury) and the elements without defined functions to the animal metabolism, such as Br (bromine), Eu (europium). La (lanthanum), Rb (rubidium), Sb (antinomies), Sc (scandium), Ta (tantalum), Th (thorium) and U (uranium) were determined in agroindustrial by-products employed in animal feeding by instrumental neutron activation analysis (INAA). Forty samples of agroindustrial by-products were analyzed, six of which are from animal origin and the others are from vegetable origin. All these materials are widely used in bovine feeding, mainly in dry season, when the forage become scarce. The precision and accuracy of the method were evaluated by means of analysis of the following certified reference materials: Rice Flour NIES-CRM-10C, Pig Kidney BCR-CRM, Oyster Tissue NIST-SRM-1566a e Buffalo River Sediment NIST-SRM-2704. The results, in general, are lower than 10 %. The results for the most of essential minerals were lower than the toxic limit for animals, and they reached the minimum requirements for domestic animals, although some agroindustrial by-products showed concentrations lower than the requirement. For all samples, the concentrations of toxic minerals were lower than the toxic limit (author)

Multiwall carbon nanotubes modulate paraquat toxicity in Arabidopsis thaliana.

Science.gov (United States)

Fan, Xiaoji; Xu, Jiahui; Lavoie, Michel; Peijnenburg, W J G M; Zhu, Youchao; Lu, Tao; Fu, Zhengwei; Zhu, Tingheng; Qian, Haifeng

2018-02-01

Carbon nanotubes can be either toxic or beneficial to plant growth and can also modulate toxicity of organic contaminants through surface sorption. The complex interacting toxic effects of carbon nanotubes and organic contaminants in plants have received little attention in the literature to date. In this study, the toxicity of multiwall carbon nanotubes (MWCNT, 50 mg/L) and paraquat (MV, 0.82 mg/L), separately or in combination, were evaluated at the physiological and the proteomic level in Arabidopsis thaliana for 7-14 days. The results revealed that the exposure to MWCNT had no inhibitory effect on the growth of shoots and leaves. Rather, MWCNT stimulated the relative electron transport rate and the effective photochemical quantum yield of PSII value as compared to the control by around 12% and lateral root production up to nearly 4-fold as compared to the control. The protective effect of MWCNT on MV toxicity on the root surface area could be quantitatively explained by the extent of MV adsorption on MWCNT and was related to stimulation of photosynthesis, antioxidant protection and number and area of lateral roots which in turn helped nutrient assimilation. The influence of MWCNT and MV on photosynthesis and oxidative stress at the physiological level was consistent with the proteomics analysis, with various over-expressed photosynthesis-related proteins (by more than 2 folds) and various under-expressed oxidative stress related proteins (by about 2-3 folds). This study brings new insights into the interactive effects of two xenobiotics (MWCNT and MV) on the physiology of a model plant. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fluoroacetate-mediated toxicity of fluorinated ethanes.

Science.gov (United States)

Keller, D A; Roe, D C; Lieder, P H

1996-04-01

A series of 1-(di)halo-2-fluoroethanes reported in the literature to be nontoxic or of low toxicity were found to be highly toxic by the inhalation route. Experiments were performed that showed the compounds, 1,2-difluoroethane, 1-chloro-2-fluoroethane, 1-chloro-1,2-difluoroethane, and 1-bromo-2-fluoroethane to be highly toxic to rats upon inhalation for 4 hr. All four compounds had 4-hr approximate lethal concentrations of difluoroethane (commonly referred to as HFC-152a) has very low acute toxicity with a 4-hr LC50 of > 400,000 ppm in rats. Rats exposed to the selected toxic fluoroethanes showed clinical signs of fluoroacetate toxicity (lethargy, hunched posture, convulsions). 1,2-Difluoroethane, 1-chloro-2-fluoroethane, 1-chloro-1,2-difluoroethane, and 1-bromo-2-fluoroethane were shown to increase concentrations of citrate in serum and heart tissue, a hallmark of fluoroacetate intoxication. 19F NMR analysis confirmed that fluoroacetate was present in the urine of rats exposed to each toxic compound. Fluorocitrate, a condensation product of fluoroacetate and oxaloacetate, was identified in the kidney of rats exposed to 1,2-difluoroethane. There was a concentration-related elevation of serum and heart citrate in rats exposed to 0-1000 ppm 1,2-fluoroethane. Serum citrate was increased up to 5-fold and heart citrate was increased up to 11-fold over control citrate levels. Metabolism of 1,2-difluoroethane by cytochrome P450 (most likely CYP2E1) is suspected because pretreatment of rats or mice with SKF-525F, disulfiram, or dimethyl sulfoxide prevented or delayed the toxicity observed in rats not pretreated. Experimental evidence indicates that the metabolism of the toxic fluoroethanes is initiated at the carbon-hydrogen bond, with metabolism to fluoroacetate via an aldehyde or an acyl fluoride. The results of these studies show that 1-(di)halo-2-fluoroethanes are highly toxic to rats and should be considered a hazard to humans unless demonstrated otherwise.

Modeling physiological processes that relate toxicant exposure and bacterial population dynamics.

Directory of Open Access Journals (Sweden)

Tin Klanjscek

Full Text Available Quantifying effects of toxicant exposure on metabolic processes is crucial to predicting microbial growth patterns in different environments. Mechanistic models, such as those based on Dynamic Energy Budget (DEB theory, can link physiological processes to microbial growth.Here we expand the DEB framework to include explicit consideration of the role of reactive oxygen species (ROS. Extensions considered are: (i additional terms in the equation for the "hazard rate" that quantifies mortality risk; (ii a variable representing environmental degradation; (iii a mechanistic description of toxic effects linked to increase in ROS production and aging acceleration, and to non-competitive inhibition of transport channels; (iv a new representation of the "lag time" based on energy required for acclimation. We estimate model parameters using calibrated Pseudomonas aeruginosa optical density growth data for seven levels of cadmium exposure. The model reproduces growth patterns for all treatments with a single common parameter set, and bacterial growth for treatments of up to 150 mg(Cd/L can be predicted reasonably well using parameters estimated from cadmium treatments of 20 mg(Cd/L and lower. Our approach is an important step towards connecting levels of biological organization in ecotoxicology. The presented model reveals possible connections between processes that are not obvious from purely empirical considerations, enables validation and hypothesis testing by creating testable predictions, and identifies research required to further develop the theory.

The toxic effects of chlorophenols and associated mechanisms in fish

International Nuclear Information System (INIS)

Ge, Tingting; Han, Jiangyuan; Qi, Yongmei; Gu, Xueyan; Ma, Lin; Zhang, Chen; Naeem, Sajid; Huang, Dejun

2017-01-01

Highlights: • We review the toxic effects of chlorophenols (CPs) and underlying mechanisms in fish. • CPs induce lethal effects, oxidative stress, endocrine disruption, reproductive toxicity and apoptosis in fish. • CPs exhibit toxicity through multiple signaling pathways in fish and different pathways co-exist under the same conditions. • Studies on DNA methylation provide new insights into our understanding of epigenetic mechanisms of CPs-induced toxicity. • Mechanisms studies on CPs toxicity performed under environmental concentrations need more attentions. - Abstract: Chlorophenols (CPs) are ubiquitous contaminants in the environment primarily released from agricultural and industrial wastewater. These compounds are not readily degraded naturally, and easily accumulate in organs, tissues and cells via food chains, further leading to acute and chronic toxic effects on aquatic organisms. Herein, we review the available literature regarding CP toxicity in fish, with special emphasis on the potential toxic mechanisms. CPs cause oxidative stress via generation of reactive oxygen species, induction of lipid peroxidation and/or oxidative DNA damage along with inhibition of antioxidant systems. CPs affect immune system by altering the number of mature B cells and macrophages, while suppressing phagocytosis and down-regulating the expression of immune factors. CPs also disrupt endocrine function by affecting hormone levels, or inducing abnormal gene expression and interference with hormone receptors. CPs at relatively higher concentrations induce apoptosis via mitochondria-mediated pathway, cell death receptor-mediated pathway, and/or DNA damage-mediated pathway. CPs at relatively lower concentrations promote cell proliferation, and foster cancers-prone environment by increasing the rate of point mutations and oxidative DNA lesions. These toxic effects in fish are induced directly by CPs per se or indirectly by their metabolic products. In addition, recent

The toxic effects of chlorophenols and associated mechanisms in fish

Energy Technology Data Exchange (ETDEWEB)

Ge, Tingting; Han, Jiangyuan; Qi, Yongmei; Gu, Xueyan; Ma, Lin; Zhang, Chen; Naeem, Sajid; Huang, Dejun, E-mail: huangdj@lzu.edu.cn

2017-03-15

Highlights: • We review the toxic effects of chlorophenols (CPs) and underlying mechanisms in fish. • CPs induce lethal effects, oxidative stress, endocrine disruption, reproductive toxicity and apoptosis in fish. • CPs exhibit toxicity through multiple signaling pathways in fish and different pathways co-exist under the same conditions. • Studies on DNA methylation provide new insights into our understanding of epigenetic mechanisms of CPs-induced toxicity. • Mechanisms studies on CPs toxicity performed under environmental concentrations need more attentions. - Abstract: Chlorophenols (CPs) are ubiquitous contaminants in the environment primarily released from agricultural and industrial wastewater. These compounds are not readily degraded naturally, and easily accumulate in organs, tissues and cells via food chains, further leading to acute and chronic toxic effects on aquatic organisms. Herein, we review the available literature regarding CP toxicity in fish, with special emphasis on the potential toxic mechanisms. CPs cause oxidative stress via generation of reactive oxygen species, induction of lipid peroxidation and/or oxidative DNA damage along with inhibition of antioxidant systems. CPs affect immune system by altering the number of mature B cells and macrophages, while suppressing phagocytosis and down-regulating the expression of immune factors. CPs also disrupt endocrine function by affecting hormone levels, or inducing abnormal gene expression and interference with hormone receptors. CPs at relatively higher concentrations induce apoptosis via mitochondria-mediated pathway, cell death receptor-mediated pathway, and/or DNA damage-mediated pathway. CPs at relatively lower concentrations promote cell proliferation, and foster cancers-prone environment by increasing the rate of point mutations and oxidative DNA lesions. These toxic effects in fish are induced directly by CPs per se or indirectly by their metabolic products. In addition, recent

The toxicity of different lead salts to Enchytraeus crypticus in relation to bioavailability in soil.

Science.gov (United States)

Zhang, Lulu; Van Gestel, Cornelis A M

2017-08-01

The present study aimed to assess the bioavailability and toxicity of lead nitrate and lead chloride to Enchytraeus crypticus in a natural standard soil. Worms were exposed to Pb-spiked soil for 21 d, and survival and reproduction were related to total, 0.01 M CaCl 2 -extractable, and porewater Pb concentrations in the soil and internal concentrations in the surviving animals. The Pb availability for Pb(NO 3 ) 2 and PbCl 2 was similar, as confirmed by Langmuir and Freundlich isotherms. The Pb concentrations in surviving worms increased with increasing Pb concentrations in the soil and did not differ for the 2 Pb salts. Lead was toxic to E. crypticus at median lethal concentrations (LC50s) of 543 and 779 mg Pb/kg dry soil and median effect concentrations (EC50s) of 189 and 134 mg Pb/kg dry soil, for Pb(NO 3 ) 2 and PbCl 2 , respectively. Mortality of E. crypticus was related to internal Pb concentrations in the worms rather than to total or available Pb concentrations in the soil, whereas reproduction toxicity was better explained from Pb concentrations in 0.01 M CaCl 2 extracts or porewater of the test soil than from total Pb concentrations in the soil or Pb concentrations in the worms. Overall, the bioavailability and toxicity of Pb(NO 3 ) 2 and PbCl 2 to E. crypticus in LUFA 2.2 soil did not differ. Environ Toxicol Chem 2017;36:2083-2091. © 2017 SETAC. © 2017 SETAC.

Variation in shoot tolerance mechanisms not related to ion toxicity in barley

KAUST Repository

Tilbrook, Joanne

2017-09-27

Soil salinity can severely reduce crop growth and yield. Many studies have investigated salinity tolerance mechanisms in cereals using phenotypes that are relatively easy to measure. The majority of these studies measured the accumulation of shoot Na+ and the effect this has on plant growth. However, plant growth is reduced immediately after exposure to NaCl before Na+ accumulates to toxic concentrations in the shoot. In this study, nondestructive and destructive measurements are used to evaluate the responses of 24 predominately Australian barley (Hordeum vulgare L.) lines at 0, 150 and 250mMNaCl. Considerable variation for shoot tolerance mechanisms not related to ion toxicity (shoot ion-independent tolerance) was found, withsome lines being able to maintain substantial growth rates under salt stress, whereas others stopped growing. Hordeum vulgare spp. spontaneum accessions and barley landraces predominantly had the best shoot ion independent tolerance, although two commercial cultivars, Fathom and Skiff, also had high tolerance. The tolerance of cv. Fathom may be caused by a recent introgression from H. vulgare L. spp. spontaneum. This study shows that the most salt-tolerant barley lines are those that contain both shoot ion-independent tolerance and the ability to exclude Na+ from the shoot (and thus maintain high K+: Na+ ratios).

Variation in shoot tolerance mechanisms not related to ion toxicity in barley

KAUST Repository

Tilbrook, Joanne; Schilling, Rhiannon K.; Berger, Bettina; Garcia, Alexandre F.; Trittermann, Christine; Coventry, Stewart; Rabie, Huwaida; Brien, Chris; Nguyen, Martin; Tester, Mark A.; Roy, Stuart J.

2017-01-01

Soil salinity can severely reduce crop growth and yield. Many studies have investigated salinity tolerance mechanisms in cereals using phenotypes that are relatively easy to measure. The majority of these studies measured the accumulation of shoot Na+ and the effect this has on plant growth. However, plant growth is reduced immediately after exposure to NaCl before Na+ accumulates to toxic concentrations in the shoot. In this study, nondestructive and destructive measurements are used to evaluate the responses of 24 predominately Australian barley (Hordeum vulgare L.) lines at 0, 150 and 250mMNaCl. Considerable variation for shoot tolerance mechanisms not related to ion toxicity (shoot ion-independent tolerance) was found, withsome lines being able to maintain substantial growth rates under salt stress, whereas others stopped growing. Hordeum vulgare spp. spontaneum accessions and barley landraces predominantly had the best shoot ion independent tolerance, although two commercial cultivars, Fathom and Skiff, also had high tolerance. The tolerance of cv. Fathom may be caused by a recent introgression from H. vulgare L. spp. spontaneum. This study shows that the most salt-tolerant barley lines are those that contain both shoot ion-independent tolerance and the ability to exclude Na+ from the shoot (and thus maintain high K+: Na+ ratios).

Effects of protein-calorie malnutrition and refeeding on fluorouracil toxicity

Energy Technology Data Exchange (ETDEWEB)

Gamelli, R.L.; Foster, R.S. Jr.

1983-10-01

Mice were used to study the effects of protein-calorie malnutrition and its reversal on granulocyte-macrophage production and fluorouracil's toxic effect on bone marrow. An in vitro quantitative clonal culture technique for bone marrow granulocyte-macrophage progenitor cells (GM-CFC) was used. Animals on a protein-free but otherwise complete diet for ten days had a significant contraction in total marrow cellularity and GM-CFC numbers paralleling the animal's weight loss. The acute toxic effect of fluorouracil on bone marrow was not increased in protein-deprived animals. On refeeding, there was a biphasic response in the degree of toxic effect on marrow. Animals refed for one day had significantly increased fluorouracil-related marrow abnormalities. However, animals refed for four days, when marrows were repleted, were partially protected from the drug's cytotoxic effects. The increased sensitivity in mice refed for one day was related to more GM-CFC in active DNA synthesis.

Sediment porewater toxicity assessment studies in the vicinity of offshore oil and gas production platforms in the Gulf of Mexico

Science.gov (United States)

Carr, R.S.; Chapman, D.C.; Presley, B.J.; Biedenbach, J.M.; Robertson, L.; Boothe, P.; Kilada, R.; Wade, T.; Montagna, P.

1996-01-01

As part of a multidisciplinary program to assess the potential long-term impacts of offshore oil and gas exploration and production activities in the Gulf of Mexico, sediment chemical analyses and porewater toxicity tests were conducted in the vicinity of five offshore platforms. Based on data from sea urchin fertilization and embryological development assays, toxicity was observed near four of the five platforms sampled; the majority of the toxic samples were collected within 150 m of a platform. There was excellent agreement among the results of porewater tests with three different species (sea urchin embryological development, polychaete reproduction, and copepod nauplii survival). The sediment concentrations of several metals were well in excess of sediment quality assessment guidelines at a number of stations, and good agreement was observed between predicted and observed toxicity. Porewater metal concentrations compared with EC50, LOEC, and NOEC values generated for water-only exposures indicated that the porewater concentrations for several metals were high enough to account for the observed toxicity. Results of these studies utilizing highly sensitive toxicity tests suggest that the contaminant-induced impacts from offshore platforms are limited to a localized area in the immediate vicinity of the platforms. 

Management of treatment-related toxicities in advanced medullary thyroid cancer.

Science.gov (United States)

Brose, Marcia S; Bible, Keith C; Chow, Laura Q M; Gilbert, Jill; Grande, Carolyn; Worden, Francis; Haddad, Robert

2018-04-22

Progress in the treatment of advanced medullary thyroid cancer (MTC) has resulted from the approval of 2 drugs within the past 5 years, vandetanib and cabozantinib. These multikinase inhibitors (MKIs) possess overlapping specificities for multiple kinase targets implicated in the progression of MTC. Both drugs are associated with toxicities, including hypertension, hemorrhage/perforation, diarrhea and other gastrointestinal events, several dermatologic events, and hypothyroidism. In addition, vandetanib is uniquely associated with QTc prolongation through interaction with myocardial potassium channels, and cabozantinib is uniquely associated with hand-foot skin reaction. Treatment-related toxicities occur frequently and can be severe or life-threatening, and patients undergoing long-term treatment will likely experience adverse events (AEs). Here we offer specific practical recommendations for managing AEs commonly occurring with vandetanib and cabozantinib. The recommended approach relies on early recognition and palliation of symptoms, dose interruption, and dose reduction as necessary in order for the patient to maintain the highest tolerable dose for as long as possible and optimal quality of life. Treatment guidelines do not specify a recommended sequence for treating with vandetanib and cabozantinib; however, most patients will receive both drugs during their lifetime. The choice for first-line therapy is individualized after a risk-benefit assessment and depends on physician preference and patient-related factors, such as comorbid conditions. Because most generalist practices may not be familiar with the intricacies of agents such as vandetanib and cabozantinib, we commend that patients with advanced MTC be managed and treated by a thyroid cancer specialist with coordination of care within a multidisciplinary team. Copyright © 2018. Published by Elsevier Ltd.

Effects of UV-B radiation on microcystin production of a toxic strain of Microcystis aeruginosa and its competitiveness against a non-toxic strain

International Nuclear Information System (INIS)

Yang, Zhen; Kong, Fanxiang; Shi, Xiaoli; Yu, Yang; Zhang, Min

2015-01-01

Highlights: • UV-B radiation showed higher inhibition to non-toxin producing than toxin-producing strains on growth and photosynthetic activity. • Both intracellular and extracellular MC contents decreased markedly under UV-B radiation. • Higher resistance to UV-B radiation helped toxin-producing M. aeruginosa to predominate in the competition. - Abstract: Microcystins (MCs) produced by toxic cyanobacteria pose a health hazard to humans and animals. Some environmental factors can alter the MC concentrations by affecting the abundance of toxin-producing strains in a cyanobacteria population and/or their toxin production. In this study, we designed a monoculture and competition experiment to investigate the impacts of UV-B radiation on MC production and the competition between toxin and non-toxin producing strains of Microcystis aeruginosa. UV-B radiation resulted in higher inhibition of the growth and photosynthetic activity of the non-toxin producing strain relative to that observed for the toxin-producing strain. Both intracellular and extracellular MC contents decreased markedly when the toxin-producing strain was exposed to UV-B radiation. In addition, a quantitative real-time PCR assay revealed that the ratio of toxin-producing M. aeruginosa under UV-B exposure was higher than that under PAR alone at an early stage of the experiment. However, its abundance under UV-B exposure was lower compared with the PAR alone treatment after day 12. Our study demonstrated that UV-B radiation has a great impact on the abundance of the toxin-producing strain in the Microcystis population and their toxin production, which suggests that the fluctuation of UV-B radiation affects the MC level of cyanobacteria blooms

Effects of UV-B radiation on microcystin production of a toxic strain of Microcystis aeruginosa and its competitiveness against a non-toxic strain

Energy Technology Data Exchange (ETDEWEB)

Yang, Zhen, E-mail: zhyang@niglas.ac.cn; Kong, Fanxiang, E-mail: fxkong@niglas.ac.cn; Shi, Xiaoli; Yu, Yang; Zhang, Min

2015-02-11

Highlights: • UV-B radiation showed higher inhibition to non-toxin producing than toxin-producing strains on growth and photosynthetic activity. • Both intracellular and extracellular MC contents decreased markedly under UV-B radiation. • Higher resistance to UV-B radiation helped toxin-producing M. aeruginosa to predominate in the competition. - Abstract: Microcystins (MCs) produced by toxic cyanobacteria pose a health hazard to humans and animals. Some environmental factors can alter the MC concentrations by affecting the abundance of toxin-producing strains in a cyanobacteria population and/or their toxin production. In this study, we designed a monoculture and competition experiment to investigate the impacts of UV-B radiation on MC production and the competition between toxin and non-toxin producing strains of Microcystis aeruginosa. UV-B radiation resulted in higher inhibition of the growth and photosynthetic activity of the non-toxin producing strain relative to that observed for the toxin-producing strain. Both intracellular and extracellular MC contents decreased markedly when the toxin-producing strain was exposed to UV-B radiation. In addition, a quantitative real-time PCR assay revealed that the ratio of toxin-producing M. aeruginosa under UV-B exposure was higher than that under PAR alone at an early stage of the experiment. However, its abundance under UV-B exposure was lower compared with the PAR alone treatment after day 12. Our study demonstrated that UV-B radiation has a great impact on the abundance of the toxin-producing strain in the Microcystis population and their toxin production, which suggests that the fluctuation of UV-B radiation affects the MC level of cyanobacteria blooms.

Estimating Emissions of Toxic Hydrocarbons from Natural Gas Production Sites in the Barnett Shale Region of Northern Texas.

Science.gov (United States)

Marrero, Josette E; Townsend-Small, Amy; Lyon, David R; Tsai, Tracy R; Meinardi, Simone; Blake, Donald R

2016-10-04

Oil and natural gas operations have continued to expand and move closer to densely populated areas, contributing to growing public concerns regarding exposure to hazardous air pollutants. During the Barnett Shale Coordinated Campaign in October, 2013, ground-based whole air samples collected downwind of oil and gas sites revealed enhancements in several potentially toxic volatile organic compounds (VOCs) when compared to background values. Molar emissions ratios relative to methane were determined for hexane, benzene, toluene, ethylbenzene, and xylene (BTEX compounds). Using methane leak rates measured from the Picarro mobile flux plane (MFP) system and a Barnett Shale regional methane emissions inventory, the rates of emission of these toxic gases were calculated. Benzene emissions ranged between 51 ± 4 and 60 ± 4 kg h -1 . Hexane, the most abundantly emitted pollutant, ranged from 642 ± 45 to 1070 ± 340 kg h -1 . While observed hydrocarbon enhancements fall below federal workplace standards, results may indicate a link between emissions from oil and natural gas operations and concerns about exposure to hazardous air pollutants. The larger public health risks associated with the production and distribution of natural gas are of particular importance and warrant further investigation, particularly as the use of natural gas increases in the United States and internationally.

[Source identification of toxic wastewaters in a petrochemical industrial park].

Science.gov (United States)

Yang, Qian; Yu, Yin; Zhou, Yue-Xi; Chen, Xue-Min; Fu, Xiao-Yong; Wang, Miao

2014-12-01

Petrochemical wastewaters have toxic impacts on the microorganisms in biotreatment processes, which are prone to cause deterioration of effluent quality of the wastewater treatment plants. In this study, the inhibition effects of activated sludge's oxygen consumption were tested to evaluate the toxicity of production wastewaters in a petrochemical industrial park. The evaluation covered the wastewaters from not only different production units in the park, but also different production nodes in each unit. No direct correlation was observed between the toxicity effects and the organic contents, suggesting that the toxic properties of the effluents could not be predicted by the organic contents. In view of the variation of activated sludge sensitivity among different tests, the toxicity data were standardized according to the concentration-effect relationships of the standard toxic substance 3, 5-dichlorophenol on each day, in order to improve the comparability among the toxicity data. Furthermore, the Quality Emission Load (QEL) of corresponding standard toxic substance was calculated by multiplying the corresponding 3, 5-dichlorophenol concentration and the wastewater flow quantity, to indicate the toxicity emission contribution of each wastewater to the wastewater treatment plant. According to the rank list of the toxicity contribution of wastewater from different units and nodes, the sources of toxic wastewater in the petrochemical industrial park were clearly identified. This study provides effective guidance for source control of wastewater toxicity in the large industrial park.

A review of current knowledge on toxic benthic freshwater cyanobacteria--ecology, toxin production and risk management.

Science.gov (United States)

Catherine, Quiblier; Susanna, Wood; Isidora, Echenique-Subiabre; Mark, Heath; Aurélie, Villeneuve; Jean-François, Humbert

2013-10-01

Benthic cyanobacteria are found globally in plethora of environments. Although they have received less attention than their planktonic freshwater counterparts, it is now well established that they produce toxins and reports of their involvement in animal poisonings have increased markedly during the last decade. Most of the known cyanotoxins have been identified from benthic cyanobacteria including: the hepatotoxic microcystins, nodularins and cylindrospermopsins, the neurotoxic saxitoxins, anatoxin-a and homoanatoxin-a and dermatotoxins, such as lyngbyatoxin. In most countries, observations of toxic benthic cyanobacteria are fragmented, descriptive and in response to animal toxicosis events. Only a limited number of long-term studies have aimed to understand why benthic proliferations occur, and/or how toxin production is regulated. These studies have shown that benthic cyanobacterial blooms are commonly a mixture of toxic and non-toxic genotypes and that toxin concentrations can be highly variable spatially and temporally. Physiochemical parameters responsible for benthic proliferation vary among habitat type with physical disturbance (e.g., flow regimes, wave action) and nutrients commonly identified as important. As climatic conditions change and anthropogenic pressures on waterways increase, it seems likely that the prevalence of blooms of benthic cyanobacteria will increase. In this article we review current knowledge on benthic cyanobacteria: ecology, toxin-producing species, variables that regulate toxin production and bloom formation, their impact on aquatic and terrestrial organisms and current monitoring and management strategies. We suggest research needs that will assist in filling knowledge gaps and ultimately allow more robust monitoring and management protocols to be developed. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Structure Identification and Toxicity Assessment of the Degradation Products of Aflatoxin B₁ in Peanut Oil under UV Irradiation.

Science.gov (United States)

Mao, Jin; He, Bing; Zhang, Liangxiao; Li, Peiwu; Zhang, Qi; Ding, Xiaoxia; Zhang, Wen

2016-11-12

Aflatoxins, a group of extremely hazardous compounds because of their genotoxicity and carcinogenicity to human and animals, are commonly found in many tropical and subtropical regions. Ultraviolet (UV) irradiation is proven to be an effective method to reduce or detoxify aflatoxins. However, the degradation products of aflatoxins under UV irradiation and their safety or toxicity have not been clear in practical production such as edible oil industry. In this study, the degradation products of aflatoxin B₁ (AFB₁) in peanut oil were analyzed by Ultra Performance Liquid Chromatograph-Thermo Quadrupole Exactive Focus mass spectrometry/mass spectrometry (UPLC-TQEF-MS/MS). The high-resolution mass spectra reflected that two main products were formed after the modification of a double bond in the terminal furan ring and the fracture of the lactone ring, while the small molecules especially nitrogen-containing compound may have participated in the photochemical reaction. According to the above results, the possible photodegradation pathway of AFB₁ in peanut oil is proposed. Moreover, the human embryo hepatocytes viability assay indicated that the cell toxicity of degradation products after UV irradiation was much lower than that of AFB₁, which could be attributed to the breakage of toxicological sites. These findings can provide new information for metabolic pathways and the hazard assessment of AFB₁ using UV detoxification.

Toxicity of sediment pore water associated with offshore oil and gas platforms in the Gulf of Mexico

International Nuclear Information System (INIS)

Carr, R.S.; Chapman, D.C.

1993-01-01

As a part of a multidisciplinary program to assess the long-term impacts of offshore petroleum production in the Gulf of Mexico, a series of sediment porewater toxicity tests were conducted. Sediments were samples from five petroleum production platforms along five radial transects. Pore water was extracted from the sediment using a pressure extraction device, centrifuged, and frozen for later toxicity testing and chemical analysis. The sea urchin (Arbacia punctulata) embryological development assay and fertilization assay were used to assess porewater toxicity. Significant decreases in normal development of embryos was observed at 14 stations and fertilization was reduced at three stations. All stations with reduced fertilization also showed impaired development in the embryological development assay. All but three toxic sites were within 150 m of the platform. The six most toxic stations were at one platform near the Flower Garden reef, occurring near the platform along three radii; toxicity was always greater at the first site on a radium than at the second. Toxicity is discussed in relation to metal and hydrocarbon concentrations in whole sediment and in pore water

Subacute toxicity of copper and glyphosate and their interaction to earthworm (Eisenia fetida)

International Nuclear Information System (INIS)

Zhou, Chui-Fan; Wang, Yu-Jun; Li, Cheng-Cheng; Sun, Rui-Juan; Yu, Yuan-Chun; Zhou, Dong-Mei

2013-01-01

Glyphosate (GPS) and copper (Cu) are common pollutants in soils, and commonly co-exist. Due to the chemical structure of GPS, it can form complexes of heavy metals and interface their bioavailability in soil environment. In order to explore the interactions between GPS and Cu, subacute toxicity tests of Cu and GPS on soil invertebrate earthworms (Eisenia fetida) were conducted. The relative weight loss and whole-worm metal burdens increased significantly with the increasing exposure concentration of Cu, while the toxicity of GPS was insignificant. The joint toxicity data showed that the relative weight loss and the uptake of Cu, as well as the superoxide dismutase, catalase and malondialdehyde activities, were significantly alleviated in the present of GPS, which indicated that GPS could reduce the toxicity and bioavailability of Cu in the soil because of its strong chelating effects. Highlights: •Cu markedly increased the weight loss ratio of earthworm. •Cu decreased the cocoon production of earthworm. •The toxicity of GPS on earthworm was insignificant. •The presence of GPS could reduce the toxicity of Cu on earthworm. -- The presence of glyphosate could reduce the toxicity and bioavailability of Cu in the soil because of its strong chelating effects

Prediction of acute inhalation toxicity using in vitro lung surfactant inhibition

DEFF Research Database (Denmark)

Sørli, Jorid Birkelund; Huang, Yishi; Da Silva, Emilie

2018-01-01

impregnation products using the constant flow through set-up of the constrained drop surfactometer to determine if they inhibited LS function or not. The same products were tested in a mouse inhalation bioassay to determine their toxicity in vivo. The sensitivity was 100%, i.e. the in vitro method predicted...... the chemical composition of the products and induction of toxicity. The currently accepted method for determination of acute inhalation toxicity is based on experiments on animals; it is time-consuming, expensive and causes stress for the animals. Impregnation products are present on the market in large...... numbers and amounts and exhibit great variety. Therefore, an alternative method to screen for acute inhalation toxicity is needed. The aim of our study was to determine if inhibition of lung surfactant by impregnation products in vitro could accurately predict toxicity in vivo in mice. We tested 21...

Gold leaching by organic base polythionates: new non-toxic and secure technology

OpenAIRE

Smolyaninov, Vladislav; Shekhvatova, Galina; Vainshtein, Mikhail

2014-01-01

The article present a review on own experimental and some published data which are related with the gold leaching. It is well-known that the most common and usual process of the leaching with cyanide can be dangerous, needs a great water consumption, and additional costs for remediation of the poisoned and toxic sites. The experimental data described production of poythionates which are not toxic but perspective for the prosperous gold leaching. The paper dedicated to the safe gold leaching w...

Phylogenetic diversity of bacteria associated with toxic and non-toxic ...

African Journals Online (AJOL)

Phylogenetic diversity of bacteria associated with toxic and non-toxic strains of Alexandrium minutum. L Palacios, B Reguera, J Franco, I Marín. Abstract. Marine planktonic dinoflagellates are usually associated with bacteria, some of which seem to have a symbiotic relation with the dinoflagellate cells. The role of bacteria in ...

The Surface Reactivities of Single-Walled Carbon Nanotubes and Their Related Toxicities

Science.gov (United States)

Ren, Lei

After 20 years of extensive exploration, people are more and more convinced on the great potentials of single-walled carbon nanotubes (SWCNTs) in the applications of many different areas. On the other hand, the properties and toxicities have also been closely watched for the safe utilization. In this dissertation I focus on the surface properties of SWCNTs and their related toxicities. In chapter 2, we revealed the generation of peroxyl radical by the unmodified SWCNT and the poly(ethylene glycol) functionalized SWCNT in aqueous solution with capillary electrophoresis (CE) and a reactive oxygen species (ROS) indicator, 2,7-dichlorodihydrofluorescein (H2DCF). According to the results, we identified peroxyl radical, ROO• as the major ROS in our system. Peroxyl radical could be produced from the adsorption of oxygen on the SWCNT surface. In chapter 3, we studied oxidation of several biologically relevant reducing agents in the presence of SWCNTs in aqueous solutions. H2DCF and several small antioxidants (vitamin C, Trolox, and cysteine), and a high-molecular-weight ROS scavenger (bovine serum albumin (BSA)) were selected as reductants. We revealed that the unmodified or carboxylated SWCNT played duplex roles by acting as both oxidants and catalysts in the reaction. In chapter 4, we confirmed that SWCNTs bind to horseradish peroxidase (HRP) at a site proximate to the enzyme's activity center and participating in the ET process, enhancing the activity of (HRP) in the solution-based redox reaction. The capability of SWCNT in receiving electrons and the direct attachment of HRP to the surface of SWCNT strongly affected the enzyme activity due to the direct involvement of SWCNT in ET. In chapter 5, the toxicity of SWCNTs coated with different concentrations of BSA to a human fibroblast cell line was explored. The result indicates that the toxicity of SWCNTs decrease with the higher coating degree as assumed. Then we choose mitochondrion to study the interactions between

1997 Toxic Hazards Research Annual Report

Science.gov (United States)

1998-05-01

evaluate the potential for CF 3I to produce reproductive toxicity and to provide additional information on the effect of CF 3I exposure on the...questions raised on the effects of CF 3I exposure following the recently completed acute and subchronic inhalation toxicity studies (Dodd et al., 1997a...individuals from potential toxic consequences resulting from exposure to combustion products of advanced composite materials (ACM), this laboratory has

INAA and AAS of different products from sugar cane industry in Pakistan. Toxic trace elements for nutritional safety

International Nuclear Information System (INIS)

Waheed, S.; Rahman, S.; Gill, K.P.

2009-01-01

Instrumental neutron activation analysis (INAA) have been used to determine As, Br, Hg, Sb and Se in combination with atomic absorption spectrometry (AAS) as a complementary technique for the quantification of Cd and Pb in jaggery, brown sugar, white sugar and molasses. All sugar cane products were collected from the local sugar cane industry of Pakistan. The highest concentration of these potentially toxic elements was quantified in molasses; however, molasses together with jaggery, brown sugar and white sugar contains trace amounts of all of these elements. Due to very low concentration of Cd it could only be detected in molasses. To evaluate the percentage contribution of these elements in the sugar cane products to the weekly recommended values, intakes on weekly consumption of 100 g of each item have also been calculated which follow the pattern Br>Se>Pb>Hg>As>Sb. The elevated Br contents may be attributed to the use of Br-containing chemicals for fumigation; however, these contents are well within the tolerance levels. The estimated weekly intake of all toxic elements is very low indicating that sugar cane products can be safely ingested as part of the diets. (author)

The influence of folate pathway polymorphisms on high-dose methotrexate-related toxicity and survival in children with non-Hodgkin malignant lymphoma

International Nuclear Information System (INIS)

Erculj, Nina; Kotnik, Barbara Faganel; Debeljak, Marusa; Jazbec, Janez; Dolzan, Vita

2014-01-01

We evaluated the influence of folate pathway polymorphisms on high-dose methotrexate (HD-MTX) related toxicity in paediatric patients with T-cell non-Hodgkin lymphoma (NHL). In total, 30 NHL patients were genotyped for selected folate pathway polymorphisms. Carriers of at least one MTHFR 677T allele had significantly higher MTX area under the time-concentration curve levels at third MTX cycle (P = 0.003). These patients were also at higher odds of leucopoenia (P = 0.006) or thrombocytopenia (P = 0.041) and had higher number of different HD-MTX-related toxicity (P = 0.035) compared to patients with wild-type genotype. Our results suggest an important role of MTHFR 677C>T polymorphism in the development of HD-MTX-related toxicity in children with NHL

Toxic acrolein production due to Ca(2+) influx by the NMDA receptor during stroke.

Science.gov (United States)

Nakamura, Mizuho; Uemura, Takeshi; Saiki, Ryotaro; Sakamoto, Akihiko; Park, Hyerim; Nishimura, Kazuhiro; Terui, Yusuke; Toida, Toshihiko; Kashiwagi, Keiko; Igarashi, Kazuei

2016-01-01

N-Methyl-d-aspartate (NMDA) receptors have a high permeability to Ca(2+), contributing to neuronal cell death after stroke. We recently found that acrolein produced from polyamines is a major toxic compound during stroke. Thus, it was determined whether over-accumulation of Ca(2+) increases the production of acrolein from polyamines in a photochemically-induced thrombosis mouse model of stroke and in cell culture systems. A unilateral infarction was induced in mouse brain by photoinduction after injection of Rose Bengal. The volume of the infarction was analyzed using the public domain National Institutes of Health image program. Protein-conjugated acrolein levels at the locus of infarction and in cells were measured by Western blotting. Levels of polyamines were measured by high-performance liquid chromatography. When the size of brain infarction was decreased by N(1), N(4), N(8)-tribenzylspermidine, a channel blocker of the NMDA receptors, levels of Ca(2+) and protein-conjugated acrolein (PC-Acro) were reduced, while levels of polyamines were increased at the locus of infarction. When cell growth of mouse mammary carcinoma FM3A cells and neuroblastoma Neuro2a cells was inhibited by Ca(2+), the level of polyamines decreased, while that of PC-Acro increased. It was also shown that Ca(2+) toxicity was decreased in an acrolein toxicity decreasing FM3A mutant cells recently isolated. In addition, 20-40 μM Ca(2+) caused the release of polyamines from ribosomes. The results indicate that acrolein is produced from polyamines released from ribosomes through Ca(2+) increase. The results indicate that toxicity of Ca(2+) during brain infarction is correlated with the increase of acrolein. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Comparison of the relative sensitivity of Arctic species to dispersed oil using total petroleum and PAH measures of toxicity

Science.gov (United States)

Extended periods of open water have expanded the potential opportunities for petroleum and gas exploration and production in the Arctic, increasing the focus on understanding the potential impacts of released oil on aquatic organisms. However, information regarding the toxicity o...

Acute Limonene Toxicity in Escherichia coli Is Caused by Limonene Hydroperoxide and Alleviated by a Point Mutation in Alkyl Hydroperoxidase AhpC.

Science.gov (United States)

Chubukov, Victor; Mingardon, Florence; Schackwitz, Wendy; Baidoo, Edward E K; Alonso-Gutierrez, Jorge; Hu, Qijun; Lee, Taek Soon; Keasling, Jay D; Mukhopadhyay, Aindrila

2015-07-01

Limonene, a major component of citrus peel oil, has a number of applications related to microbiology. The antimicrobial properties of limonene make it a popular disinfectant and food preservative, while its potential as a biofuel component has made it the target of renewable production efforts through microbial metabolic engineering. For both applications, an understanding of microbial sensitivity or tolerance to limonene is crucial, but the mechanism of limonene toxicity remains enigmatic. In this study, we characterized a limonene-tolerant strain of Escherichia coli and found a mutation in ahpC, encoding alkyl hydroperoxidase, which alleviated limonene toxicity. We show that the acute toxicity previously attributed to limonene is largely due to the common oxidation product limonene hydroperoxide, which forms spontaneously in aerobic environments. The mutant AhpC protein with an L-to-Q change at position 177 (AhpC(L177Q)) was able to alleviate this toxicity by reducing the hydroperoxide to a more benign compound. We show that the degree of limonene toxicity is a function of its oxidation level and that nonoxidized limonene has relatively little toxicity to wild-type E. coli cells. Our results have implications for both the renewable production of limonene and the applications of limonene as an antimicrobial. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Toxicity evaluation of boron nitride nanospheres and water-soluble boron nitride in Caenorhabditis elegans.

Science.gov (United States)

Wang, Ning; Wang, Hui; Tang, Chengchun; Lei, Shijun; Shen, Wanqing; Wang, Cong; Wang, Guobin; Wang, Zheng; Wang, Lin

2017-01-01

Boron nitride (BN) nanomaterials have been increasingly explored for potential biological applications. However, their toxicity remains poorly understood. Using Caenorhabditis elegans as a whole-animal model for toxicity analysis of two representative types of BN nanomaterials - BN nanospheres (BNNSs) and highly water-soluble BN nanomaterial (named BN-800-2) - we found that BNNSs overall toxicity was less than soluble BN-800-2 with irregular shapes. The concentration thresholds for BNNSs and BN-800-2 were 100 µg·mL -1 and 10 µg·mL -1 , respectively. Above this concentration, both delayed growth, decreased life span, reduced progeny, retarded locomotion behavior, and changed the expression of phenotype-related genes to various extents. BNNSs and BN-800-2 increased oxidative stress levels in C. elegans by promoting reactive oxygen species production. Our results further showed that oxidative stress response and MAPK signaling-related genes, such as GAS1 , SOD2 , SOD3 , MEK1 , and PMK1 , might be key factors for reactive oxygen species production and toxic responses to BNNSs and BN-800-2 exposure. Together, our results suggest that when concentrations are lower than 10 µg·mL -1 , BNNSs are more biocompatible than BN-800-2 and are potentially biocompatible material.

The gas phase reaction of ozone with 1,3-butadiene: formation yields of some toxic products

Science.gov (United States)

Kramp, Franz; Paulson, Suzanne E.

The formation yields of acrolein, 1,2-epoxy-3-butene and OH radicals have been measured from reaction of ozone with 1,3-butadiene at room temperature and atmosphere pressure. 1,3,5-Trimethyl benzene was added to scavenge OH radicals in measurements of product yields. In separate experiments, small quantities of 1,3,5-trimethyl benzene were added as a tracer for OH. Formation yields of acrolein of (52±7)%, 1,2-epoxy-3-butene of (3.1±0.5)% and OH radicals of (13±3)% were observed. In addition, the rate coefficient of the gas-phase reaction of ozone with 1,2-epoxy-3-butene was measured both directly and relative to propene, finding an average of (1.6±0.4)×10 -18 cm 3 molecule -1 s -1, respectively, at 296±2 K. The results are briefly discussed in terms of the effect of atmospheric processing on the toxicity of 1,3-butadiene.

Screening the Toxicity of Selected Personal Care Products Using Embryo Bioassays: 4-MBC, Propylparaben and Triclocarban

Directory of Open Access Journals (Sweden)

Tiago Torres

2016-10-01

Full Text Available Recently, several emerging pollutants, including Personal Care Products (PCPs, have been detected in aquatic ecosystems, in the ng/L or µg/L range. Available toxicological data is limited, and, for certain PCPs, evidence indicates a potential risk for the environment. Hence, there is an urgent need to gather ecotoxicological data on PCPs as a proxy to improve risk assessment. Here, the toxicity of three different PCPs (4-Methylbenzylidene Camphor (4-MBC, propylparaben and triclocarban was tested using embryo bioassays with Danio rerio (zebrafish and Paracentrotus lividus (sea urchin. The No Observed Effect Concentration (NOEC for triclocarban was 0.256 µg/L for sea urchin and 100 µg/L for zebrafish, whereas NOEC for 4-MBC was 0.32 µg/L for sea urchin and 50 µg/L for zebrafish. Both PCPs impacted embryo development at environmentally relevant concentrations. In comparison with triclocarban and 4-MBC, propylparaben was less toxic for both sea urchin (NOEC = 160 µg/L and zebrafish (NOEC = 1000 µg/L. Overall, this study further demonstrates the sensitivity of embryo bioassays as a high-throughput approach for testing the toxicity of emerging pollutants.

Synthesis, toxicity, biocompatibility, and biomedical applications of graphene and graphene-related materials

Directory of Open Access Journals (Sweden)

Gurunathan S

2016-05-01

Full Text Available Sangiliyandi Gurunathan, Jin-Hoi Kim Stem Cell and Regenerative Biology, Konkuk University, Seoul, Republic of Korea Abstract: Graphene is a two-dimensional atomic crystal, and since its development it has been applied in many novel ways in both research and industry. Graphene possesses unique properties, and it has been used in many applications including sensors, batteries, fuel cells, supercapacitors, transistors, components of high-strength machinery, and display screens in mobile devices. In the past decade, the biomedical applications of graphene have attracted much interest. Graphene has been reported to have antibacterial, antiplatelet, and anticancer activities. Several salient features of graphene make it a potential candidate for biological and biomedical applications. The synthesis, toxicity, biocompatibility, and biomedical applications of graphene are fundamental issues that require thorough investigation in any kind of applications related to human welfare. Therefore, this review addresses the various methods available for the synthesis of graphene, with special reference to biological synthesis, and highlights the biological applications of graphene with a focus on cancer therapy, drug delivery, bio-imaging, and tissue engineering, together with a brief discussion of the challenges and future perspectives of graphene. We hope to provide a comprehensive review of the latest progress in research on graphene, from synthesis to applications. Keywords: biomedical applications, cancer therapy, drug delivery, graphene, graphene-related materials, tissue engineering, toxicity 

Comparative In Vitro Toxicity Profile of Electronic and Tobacco Cigarettes, Smokeless Tobacco and Nicotine Replacement Therapy Products: E-Liquids, Extracts and Collected Aerosols

Directory of Open Access Journals (Sweden)

Manoj Misra

2014-10-01

Full Text Available The use of electronic cigarettes (e-cigs continues to increase worldwide in parallel with accumulating information on their potential toxicity and safety. In this study, an in vitro battery of established assays was used to examine the cytotoxicity, mutagenicity, genotoxicity and inflammatory responses of certain commercial e-cigs and compared to tobacco burning cigarettes, smokeless tobacco (SLT products and a nicotine replacement therapy (NRT product. The toxicity evaluation was performed on e-liquids and pad-collected aerosols of e-cigs, pad-collected smoke condensates of tobacco cigarettes and extracts of SLT and NRT products. In all assays, exposures with e-cig liquids and collected aerosols, at the doses tested, showed no significant activity when compared to tobacco burning cigarettes. Results for the e-cigs, with and without nicotine in two evaluated flavor variants, were very similar in all assays, indicating that the presence of nicotine and flavors, at the levels tested, did not induce any cytotoxic, genotoxic or inflammatory effects. The present findings indicate that neither the e-cig liquids and collected aerosols, nor the extracts of the SLT and NRT products produce any meaningful toxic effects in four widely-applied in vitro test systems, in which the conventional cigarette smoke preparations, at comparable exposures, are markedly cytotoxic and genotoxic.

Greening Non-Product-Related Procurement

DEFF Research Database (Denmark)

Mosgaard, Mette; Riisgaard, Henrik; Huulgaard, Rikke Dorothea

2013-01-01

link to the strategy for greening private consumption, as similarities exist and the purchasers lean on their private experiences when purchasing non-product related items; and finally, 3) Intensify the efforts in product categories in which strict normative legislation makes management more motivated....... environmental benefits of millions of procurement decisions do add up to large environmental improvement potentials. Thus, non-product-related procurement focuses on the similarities in the purchases made across different sectors. Explorative interviews with purchasers in Danish companies form the basis...

Streptococcal toxic-shock syndrome due to Streptococcus dysgalactiae subspecies equisimilis in breast cancer-related lymphedema: a case report.

Science.gov (United States)

Sumazaki, Makoto; Saito, Fumi; Ogata, Hideaki; Yoshida, Miho; Kubota, Yorichika; Magoshi, Syunsuke; Kaneko, Hironori

2017-07-14

Breast cancer-related lymphedema often causes cellulitis and is one of the most common complications after breast cancer surgery. Streptococci are the major pathogens underlying such cellulitis. Among the streptococci, the importance of the Lancefield groups C and G is underappreciated; most cases involve Streptococcus dysgalactiae subspecies equisimilis. Despite having a relatively weak toxicity compared with group A streptococci, Streptococcus dysgalactiae subspecies equisimilis is associated with a mortality rate that is as high as that of group A streptococci in cases of invasive infection because Streptococcus dysgalactiae subspecies equisimilis mainly affects elderly individuals who already have various comorbidities. An 83-year-old Japanese woman with breast cancer-related lymphedema in her left upper limb was referred to our hospital with high fever and acute pain with erythema in her left arm. She showed septic shock with disseminated intravascular coagulation. Blood culture showed positive results for Streptococcus dysgalactiae subspecies equisimilis, confirming a diagnosis of streptococcal toxic-shock syndrome. She survived after successful intensive care. To the best of our knowledge, this case represents the first report of Streptococcus dysgalactiae subspecies equisimilis-induced streptococcal toxic-shock syndrome in a patient with breast cancer-related lymphedema. Breast cancer-related lymphedema is a common problem, and we must pay attention to invasive streptococcal soft tissue infections, particularly in elderly patients with chronic disease.

Relative oral efficacy and acute toxicity of hydroxypyridin-4-one iron chelators in mice

International Nuclear Information System (INIS)

Porter, J.B.; Morgan, J.; Hoyes, K.P.; Burke, L.C.; Huehns, E.R.; Hider, R.C.

1990-01-01

The relationship between the oral efficacy and the acute toxicity of hydroxypyridin-4-one iron chelators has been investigated to clarify structure-function relationships of these compounds in vivo and to identify compounds with the maximum therapeutic safety margin. By comparing 59Fe excretion following oral or intraperitoneal administration of increasing doses of each chelator to iron-overloaded mice, the most effective compounds have been identified. These have partition coefficients (Kpart) above 0.3 in the iron-free form with a trend of increasing oral efficacy with increasing Kpart values (r = .6). However, this is achieved at a cost of increasing acute toxicity, as shown by a linear correlation between 59Fe excretion increase per unit dose and 1/LD50 (r = .83). A sharp increase in the LD50 values is observed for compounds with Kpart values above 1.0, suggesting that such compounds are unlikely to possess a sufficient therapeutic safety margin. Below a Kpart of 1.0, acute toxicity is relatively independent of lipid solubility. All the compounds are less toxic by the oral route than by the intraperitoneal route, although iron excretion is not significantly different by these two routes. At least five compounds (CP51, CP94, CP93, CP96, and CP21) are more effective orally than the same dose of intraperitoneal desferrioxamine (DFO) (P less than or equal to .02) or orally administered L1(CP20) (P less than or equal to .02)

The influence of folate pathway polymorphisms on high-dose methotrexate-related toxicity and survival in children with non-Hodgkin malignant lymphoma

Science.gov (United States)

Erculj, Nina; Kotnik, Barbara Faganel; Debeljak, Marusa; Jazbec, Janez; Dolzan, Vita

2014-01-01

Background We evaluated the influence of folate pathway polymorphisms on high-dose methotrexate (HD-MTX) related toxicity in paediatric patients with T-cell non-Hodgkin lymphoma (NHL). Patients and methods In total, 30 NHL patients were genotyped for selected folate pathway polymorphisms. Results Carriers of at least one MTHFR 677T allele had significantly higher MTX area under the time-concentration curve levels at third MTX cycle (P = 0.003). These patients were also at higher odds of leucopoenia (P = 0.006) or thrombocytopenia (P = 0.041) and had higher number of different HD-MTX-related toxicity (P = 0.035) compared to patients with wild-type genotype. Conclusions Our results suggest an important role of MTHFR 677C>T polymorphism in the development of HD-MTX-related toxicity in children with NHL. PMID:25177243

Why are Functional Amyloids Non-Toxic in Humans?

Directory of Open Access Journals (Sweden)

Matthew P. Jackson

2017-09-01

Full Text Available Amyloids were first identified in association with amyloidoses, human diseases in which proteins and peptides misfold into amyloid fibrils. Subsequent studies have identified an array of functional amyloid fibrils that perform physiological roles in humans. Given the potential for the production of toxic species in amyloid assembly reactions, it is remarkable that cells can produce these functional amyloids without suffering any obvious ill effect. Although the precise mechanisms are unclear, there are a number of ways in which amyloid toxicity may be prevented. These include regulating the level of the amyloidogenic peptides and proteins, minimising the production of prefibrillar oligomers in amyloid assembly reactions, sequestrating amyloids within membrane bound organelles, controlling amyloid assembly by other molecules, and disassembling the fibrils under physiological conditions. Crucially, a better understanding of how toxicity is avoided in the production of functional amyloids may provide insights into the prevention of amyloid toxicity in amyloidoses.

Toxicity of venoms from vipers of Pelias group to crickets Gryllus assimilis and its relation to snake entomophagy.

Science.gov (United States)

Starkov, Vladislav G; Osipov, Alexey V; Utkin, Yuri N

2007-06-01

The existing data indicate that snake venom is most toxic towards the natural vertebrate preys. Several species of snake include arthropods in their food. However, there is no available data on the toxicity of venom from entomophagous snakes towards their prey. We have studied the toxicity of venom from vipers of Pelias group towards crickets Gryllus assimilis. The Pelias group includes several closely related viper species inhabiting mainly the South European part of Russia, and they differ in their feeding preferences. Snakes from the Vipera renardi, Vipera lotievi, Vipera kaznakovi, and Vipera orlovi species feed on wide range of animals including insects, whereas snakes from Vipera berus and Vipera nikolskii species do not include insects in their diet. We have found that the venom from vipers that include insects in their diet possesses greater toxicity towards crickets. The greatest toxicity was observed for the venom from V. lotievi, which displays a preference for insects in its diet. Therefore, based on our data, we suggest that the viper entomophagy is not a result of behavior plasticity, but is probably determined at a genetic level.

Emissions of Toxic Carbonyls in an Electronic Cigarette

Directory of Open Access Journals (Sweden)

Guthery William

2016-01-01

Full Text Available Electronic cigarettes (e-cigs provide a smoke-free alternative for inhalation of nicotine without the vast array of toxic and carcinogenic combustion products produced by tobacco smoke. Elevated levels of toxic carbonyls may be generated during vaporisation; however, it is unclear whether that is indicative of a fault with the device or is due to the applied conditions of the test. A device, designed and built at this facility, was tested to determine the levels of selected toxic carbonyls. The reservoir was filled with approximately 960 mg of an e-liquid formulation containing 1.8% (w/v nicotine. Devices were puffed 200 times in blocks of 40 using a standardised regime consisting of a 55 mL puff volume; 3 s puff duration; 30 s puff interval; square wave puff profile. Confirmatory testing for nicotine and total aerosol delivery resulted in mean (n = 8 values of 10 mg (RSD 12.3% and 716 mg (RSD 11.2%, respectively. Emissions of toxic carbonyls were highly variable yet were between < 0.1% and 22.9% of expected levels from a Kentucky Reference Cigarette (K3R4F puffed 200 times under Health Canada Intense smoking conditions. It has been shown that a device built to a high specification with relatively consistent nicotine and aerosol delivery emits inconsistent levels of carbonyls. The exposure is greatly reduced when compared with lit tobacco products. However, it was observed that as the reservoirs neared depletion then emission levels were significantly higher

Testing of toxicity based methods to develop site specific clean up objectives - phase 1: Toxicity protocol screening and applicability

International Nuclear Information System (INIS)

Hamilton, H.; Kerr, D.; Thorne, W.; Taylor, B.; Zadnik, M.; Goudey, S.; Birkholz, D.

1994-03-01

A study was conducted to develop a cost-effective and practical protocol for using bio-assay based toxicity assessment methods for remediation of decommissioned oil and gas production, and processing facilities. The objective was to generate site-specific remediation criteria for contaminated sites. Most companies have used the chemical-specific approach which, however, did not meet the ultimate land use goal of agricultural production. The toxicity assessment method described in this study dealt with potential impairment to agricultural crop production and natural ecosystems. Human health concerns were not specifically addressed. It was suggested that chemical-specific methods should be used when human health concerns exist. . Results showed that toxicity tests will more directly identify ecological stress caused by site contamination than chemical-specific remediation criteria, which can be unnecessarily protective. 11 refs., 7 tabs., 6 figs

Ability of Cu2+-montmorillonite to accept an toxic pollutants

International Nuclear Information System (INIS)

Janikova, V.; Jona, E.; Janik, R.; Pavlik, V.

2015-01-01

It is global problem that toxic pollutants are in the permanent contact to people through soil and water. Nowadays, it is important to eliminate these pollutants for future generations and to keep environment in the health condition. In relation to this article, aromatic organic compounds like benzene, phenol and aniline were chosen. These are used in various branches of industry, mainly in rubber industry or for production of dyes and in addition, phenol is commonly used in cosmetics or in food industry. Montmorillonite is clay mineral consisting of 2:1 sheets (tetrahedral:octahedral) and interlayer space where exchangeable cations and water molecules are present. Due to its structure, montmorillonite is able to accept some compounds or pollutants. This is the reason why it is mainly used as the covering material of radioactive waste in order to remove toxic pollutants. For investigation of toxic pollutants removing, XRD powder diffraction, infrared spectroscopy and thermal analysis were used. Our results show that Cu 2+ -montmorillonite is able to accept toxic benzene ring-based pollutants into interlayer. This mentioned ability can be proven on the basis of the investigation results relating to difference of interlayer distance, typical frequencies of -OH group or -NH 2 group, while these results were supplemented by thermal properties. (authors)

Glutathione and its dependent enzymes' modulatory responses to toxic metals and metalloids in fish--a review.

Science.gov (United States)

Srikanth, K; Pereira, E; Duarte, A C; Ahmad, I

2013-04-01

Toxic metals and metalloid are being rapidly added from multiple pathways to aquatic ecosystem and causing severe threats to inhabiting fauna including fish. Being common in all the type of aquatic ecosystems such as freshwater, marine and brackish water fish are the first to get prone to toxic metals and metalloids. In addition to a number of physiological/biochemical alterations, toxic metals and metalloids cause enhanced generation of varied reactive oxygen species (ROS) ultimately leading to a situation called oxidative stress. However, as an important component of antioxidant defence system in fish, the tripeptide glutathione (GSH) directly or indirectly regulates the scavenging of ROS and their reaction products. Additionally, several other GSH-associated enzymes such as GSH reductase (GR, EC 1.6.4.2), GSH peroxidase (EC 1.11.1.9), and GSH sulfotransferase (glutathione-S-transferase (GST), EC 2.5.1.18) cumulatively protect fish against ROS and their reaction products accrued anomalies under toxic metals and metalloids stress conditions. The current review highlights recent research findings on the modulation of GSH, its redox couple (reduced glutathione/oxidised glutathione), and other GSH-related enzymes (GR, glutathione peroxidase, GST) involved in the detoxification of harmful ROS and their reaction products in toxic metals and metalloids-exposed fish.

Fluorescent Chemosensors for Toxic Organophosphorus Pesticides: A Review

Directory of Open Access Journals (Sweden)

Kenneth Fletcher

2010-07-01

Full Text Available Many organophosphorus (OP based compounds are highly toxic and powerful inhibitors of cholinesterases that generate serious environmental and human health concerns. Organothiophosphates with a thiophosphoryl (P=S functional group constitute a broad class of these widely used pesticides. They are related to the more reactive phosphoryl (P=O organophosphates, which include very lethal nerve agents and chemical warfare agents, such as, VX, Soman and Sarin. Unfortunately, widespread and frequent commercial use of OP-based compounds in agricultural lands has resulted in their presence as residues in crops, livestock, and poultry products and also led to their migration into aquifers. Thus, the design of new sensors with improved analyte selectivity and sensitivity is of paramount importance in this area. Herein, we review recent advances in the development of fluorescent chemosensors for toxic OP pesticides and related compounds. We also discuss challenges and progress towards the design of future chemosensors with dual modes for signal transduction.

Mechanisms of toxicity and biomarkers of flavoring and flavor enhancing chemicals in emerging tobacco and non-tobacco products.

Science.gov (United States)

Kaur, Gurjot; Muthumalage, Thivanka; Rahman, Irfan

2018-05-15

Tobacco products containing flavorings, such as electronic nicotine delivery devices (ENDS) or e-cigarettes, cigars/cigarillos, waterpipes, and heat-not-burn devices (iQOS) are continuously evolving. In addition to increasing the exposure of teenagers and adults to nicotine containing flavoring products and flavoring enhancers, chances of nicotine addiction through chronic use and abuse also increase. These flavorings are believed to be safe for ingestion, but little information is available about their effects on the lungs. In this review, we have discussed the in vitro and in vivo data on toxicity of flavoring chemicals in lung cells. We have further discussed the common flavoring agents, such as diacetyl and menthol, currently available detection methods, and the toxicological mechanisms associated with oxidative stress, inflammation, mucociliary clearance, and DNA damage in cells, mice, and humans. Finally, we present potential biomarkers that could be utilized for future risk assessment. This review provides crucial parameters important for evaluation of risk associated with flavoring agents and flavoring enhancers used in tobacco products and ENDS. Future studies can be designed to address the potential toxicity of inhaled flavorings and their biomarkers in users as well as in chronic exposure studies. Copyright © 2018 Elsevier B.V. All rights reserved.

Toxicity assessment strategies, data requirements, and risk assessment approaches to derive health based guidance values for non-relevant metabolites of plant protection products.

Science.gov (United States)

Dekant, Wolfgang; Melching-Kollmuss, Stephanie; Kalberlah, Fritz

2010-03-01

In Europe, limits for tolerable concentrations of "non-relevant metabolites" for active ingredients (AI) of plant protection products in drinking water between 0.1 and 10 microg/L are discussed depending on the toxicological information available. "Non-relevant metabolites" are degradation products of AIs, which do not or only partially retain the targeted toxicities of AIs. For "non-relevant metabolites" without genotoxicity (to be confirmed by testing in vitro), the application of the concept of "thresholds of toxicological concern" results in a health-based drinking water limit of 4.5 microg/L even for Cramer class III compounds, using the TTC threshold of 90 microg/person/day (divided by 10 and 2). Taking into account the thresholds derived from two reproduction toxicity data bases a drinking water limit of 3.0 microg/L is proposed. Therefore, for "non-relevant metabolites" whose drinking water concentration is below 3.0 microg/L, no toxicity testing is necessary. This work develops a toxicity assessment strategy as a basis to delineate health-based limits for "non-relevant metabolites" in ground and drinking water. Toxicological testing is recommended to investigate, whether the metabolites are relevant or not, based on the hazard properties of the parent AIs, as outlined in the SANCO Guidance document. Also, genotoxicity testing of the water metabolites is clearly recommended. In this publication, tiered testing strategies are proposed for non-relevant metabolites, when drinking water concentrations >3.0 microg/L will occur. Conclusions based on structure-activity relationships and the detailed toxicity database on the parent AI should be included. When testing in animals is required for risk assessment, key aspects are studies along OECD-testing guidelines with "enhanced" study designs addressing additional endpoints such as reproductive toxicity and a developmental screening test to derive health-based tolerable drinking water limits with a limited number

Degradation of carbendazim in water via photo-Fenton in Raceway Pond Reactor: assessment of acute toxicity and transformation products.

Science.gov (United States)

da Costa, Elizângela Pinheiro; Bottrel, Sue Ellen C; Starling, Maria Clara V M; Leão, Mônica M D; Amorim, Camila Costa

2018-05-08

This study aimed at investigating the degradation of fungicide carbendazim (CBZ) via photo-Fenton reactions in artificially and solar irradiated photoreactors at laboratory scale and in a semi-pilot scale Raceway Pond Reactor (RPR), respectively. Acute toxicity was monitored by assessing the sensibility of bioluminescent bacteria (Aliivibrio fischeri) to samples taken during reactions. In addition, by-products formed during solar photo-Fenton were identified by liquid chromatography coupled to mass spectrometry (UFLC-MS). For tests performed in lab-scale, two artificial irradiation sources were compared (UV λ > 254nm and UV-Vis λ > 320nm ). A complete design of experiments was performed in the semi-pilot scale RPR in order to optimize reaction conditions (Fe 2+ and H 2 O 2 concentrations, and water depth). Efficient degradation of carbendazim (> 96%) and toxicity removal were achieved via artificially irradiated photo-Fenton under both irradiation sources. Control experiments (UV photolysis and UV-Vis peroxidation) were also efficient but led to increased acute toxicity. In addition, H 2 O 2 /UV λ > 254nm required longer reaction time (60 minutes) when compared to the photo-Fenton process (less than 1 min). While Fenton's reagent achieved high CBZ and acute toxicity removal, its efficiency demands higher concentration of reagents in comparison to irradiated processes. Solar photo-Fenton removed carbendazim within 15 min of reaction (96%, 0.75 kJ L -1 ), and monocarbomethoxyguanidine, benzimidazole isocyanate, and 2-aminobenzimidazole were identified as transformation products. Results suggest that both solar photo-Fenton and artificially irradiated systems are promising routes for carbendazim degradation.

Coenzyme Q10 and alpha-tocopherol protect against amitriptyline toxicity

International Nuclear Information System (INIS)

Cordero, Mario D.; Moreno-Fernandez, Ana Maria; Gomez-Skarmeta, Jose Luis; Miguel, Manuel de; Garrido-Maraver, Juan; Oropesa-Avila, Manuel; Rodriguez-Hernandez, Angeles; Navas, Placido; Sanchez-Alcazar, Jose Antonio

2009-01-01

Since amitriptyline is a very frequently prescribed antidepressant drug, it is not surprising that amitriptyline toxicity is relatively common. Amitriptyline toxic systemic effects include cardiovascular, autonomous nervous, and central nervous systems. To understand the mechanisms of amitriptyline toxicity we studied the cytotoxic effects of amitriptyline treatment on cultured primary human fibroblasts and zebrafish embryos, and the protective role of coenzyme Q 10 and alpha-tocopherol, two membrane antioxidants. We found that amitriptyline treatment induced oxidative stress and mitochondrial dysfunction in primary human fibroblasts. Mitochondrial dysfunction in amitriptyline treatment was characterized by reduced expression levels of mitochondrial proteins and coenzyme Q 10 , decreased NADH:cytochrome c reductase activity, and a drop in mitochondrial membrane potential. Moreover, and as a consequence of these toxic effects, amitriptyline treatment induced a significant increase in apoptotic cell death activating mitochondrial permeability transition. Coenzyme Q 10 and alpha-tocopherol supplementation attenuated ROS production, lipid peroxidation, mitochondrial dysfunction, and cell death, suggesting that oxidative stress affecting cell membrane components is involved in amitriptyline cytotoxicity. Furthermore, amitriptyline-dependent toxicity and antioxidant protection were also evaluated in zebrafish embryos, a well established vertebrate model to study developmental toxicity. Amitriptyline significantly increased embryonic cell death and apoptosis rate, and both antioxidants provided a significant protection against amitriptyline embryotoxicity

Framework for product knowledge and product related knowledge which supports product modelling for mass customization

DEFF Research Database (Denmark)

Riis, Jesper; Hansen, Benjamin Loer; Hvam, Lars

2003-01-01

on experience from product modelling projects in several companies. Among them for example companies manufacturing electronic switchboards, spray dryer systems and air conditioning equipment. The framework is divided into three views: the product knowledge view, the life phase system view and the transformation...... and personalization. The framework for product knowledge and product related knowledge is based on the following theories: axiomatic design, technical systems, theory of domains, theory of structuring, theory of properties and the framework for the content of product and product related models. The framework is built......The article presents a framework for product knowledge and product related knowledge which can be used to support the product modelling process which is needed for developing IT systems. These IT systems are important tools for many companies when they aim at achieving mass customization...

Determination of toxic elements in tobacco products by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Ahmad, S.; Chaudhry, M.S.; Qureshi, I.H.

1979-01-01

The concentration of 15 elements in various brands of cigarette tobacco and cigarette wrapping paper were determined using instrumental neutron activation analysis. The paper of some of the brands contains higher concentrations of toxic elements than the tobacco. The cigarette filter and the ash were also analyzed to determine the adsorption of toxic elements on the filter and their transference in smoke. The toxic effects of some of the elements have been briefly discussed. (author)

Occular and dermal toxicity of Jatropha curcas phorbol esters.

Science.gov (United States)

Devappa, Rakshit K; Roach, Joy S; Makkar, Harinder P S; Becker, Klaus

2013-08-01

Jatropha curcas seeds are a promising feedstock for biodiesel production. However, Jatropha seed oil and other plant parts are toxic due to the presence of phorbol esters (PEs). The ever-increasing cultivation of toxic genotype of J. curcas runs the risk of increased human exposure to Jatropha products. In the present study, effects of J. curcas oil (from both toxic and nontoxic genotypes), purified PEs-rich extract and purified PEs (factors C1, C2, C(3mixture), (C4+C5)) on reconstituted human epithelium (RHE) and human corneal epithelium (HCE) were evaluated in vitro. The PEs were purified from toxic Jatropha oil. In both RHE and HCE, the topical application of PEs containing samples produced severe cellular alterations such as marked oedema, presence of less viable cell layers, necrosis and/or partial tissue disintegration in epithelium and increased inflammatory response (interleukin-1α and prostaglandin E2). When compared to toxic oil, histological alterations and inflammatory response were less evident (PJatropha PEs are toxic towards RHE and HCE models, which represents dermal and occular toxicity respectively. Data obtained from this study would aid in the development of safety procedures for Jatropha biodiesel industries. It is advised to use protective gloves and glasses when handling PEs containing Jatropha products. Copyright © 2013 Elsevier Inc. All rights reserved.

Investigating the formation and toxicity of nitrogen transformation products of diclofenac and sulfamethoxazole in wastewater treatment plants

International Nuclear Information System (INIS)

Osorio, Victoria; Sanchís, Josep; Abad, Jose Luís; Ginebreda, Antoni; Farré, Marinella; Pérez, Sandra; Barceló, Damià

2016-01-01

Highlights: • Environmental monitoring of recently discovered TPs of diclofenac in wastewater and surface water. • Quantitative determination of non-detected TPs of sulfamethoxazole in wastewater and impacted surface waters. • Toxicity assessment of diclofenac and its TPs in a panel of standard assays of aquatic organism. • Only nitro-diclofenac proved to be more toxic than the parent compound. - Abstract: Diclofenac (DCF) and sulfamethoxazole (SMX) are highly consumed pharmaceuticals and concentrated in effluents from conventional wastewater treatment plants (WWTPs) since they are not completely eliminated. Under microbial mediated nitrification/denitrification processes occurring in nitrifying activated sludge DCF biotransformed into its nitroso and nitro derivatives (NO-DCF and NO 2 -DCF, respectively). SMX was biotransformed under denitrification conditions in water/sediment batch reactors into its nitro and desamino derivatives (NO 2 -SMX and Des-SMX, respectively). Four transformation products (TPs) from DCF and SMX were analized in wastewaters (WW) and receiving surface waters (SW). Nitrifying/denitrifying-derivatives of DCF and SMX were detected for the first time in WW and SW at one order of magnitude lower than their parent compounds. Relationships observed among levels of NO-DCF, NO 2 -DCF and nitrogen-species tentatively suggested that nitrification/denitrification processes are involved in nitration and nitrosation of DCF during biological WW treatment. Acute toxicity of analytes to Daphnia magna and Vibrio fischeri was assessed individually and in mixtures with other relevant micropollutants. Individual effects showed these compounds as not harmful and not toxic. However, synergism effects observed in mixtures evidenced that contribution of these compounds to overall toxicity of complex environmental samples, should not be dismissed.

Investigating the formation and toxicity of nitrogen transformation products of diclofenac and sulfamethoxazole in wastewater treatment plants

Energy Technology Data Exchange (ETDEWEB)

Osorio, Victoria; Sanchís, Josep [Water and Soil Quality Research Group, Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain); Abad, Jose Luís [RUBAM-IIQAC-CSIC, Jordi Girona 18-26, Barcelona (Spain); Ginebreda, Antoni; Farré, Marinella [Water and Soil Quality Research Group, Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain); Pérez, Sandra, E-mail: spsqam@idaea.csic.es [Water and Soil Quality Research Group, Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain); Barceló, Damià [Water and Soil Quality Research Group, Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain); Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, Emili Grahit 101, Girona (Spain)

2016-05-15

Highlights: • Environmental monitoring of recently discovered TPs of diclofenac in wastewater and surface water. • Quantitative determination of non-detected TPs of sulfamethoxazole in wastewater and impacted surface waters. • Toxicity assessment of diclofenac and its TPs in a panel of standard assays of aquatic organism. • Only nitro-diclofenac proved to be more toxic than the parent compound. - Abstract: Diclofenac (DCF) and sulfamethoxazole (SMX) are highly consumed pharmaceuticals and concentrated in effluents from conventional wastewater treatment plants (WWTPs) since they are not completely eliminated. Under microbial mediated nitrification/denitrification processes occurring in nitrifying activated sludge DCF biotransformed into its nitroso and nitro derivatives (NO-DCF and NO{sub 2}-DCF, respectively). SMX was biotransformed under denitrification conditions in water/sediment batch reactors into its nitro and desamino derivatives (NO{sub 2}-SMX and Des-SMX, respectively). Four transformation products (TPs) from DCF and SMX were analized in wastewaters (WW) and receiving surface waters (SW). Nitrifying/denitrifying-derivatives of DCF and SMX were detected for the first time in WW and SW at one order of magnitude lower than their parent compounds. Relationships observed among levels of NO-DCF, NO{sub 2}-DCF and nitrogen-species tentatively suggested that nitrification/denitrification processes are involved in nitration and nitrosation of DCF during biological WW treatment. Acute toxicity of analytes to Daphnia magna and Vibrio fischeri was assessed individually and in mixtures with other relevant micropollutants. Individual effects showed these compounds as not harmful and not toxic. However, synergism effects observed in mixtures evidenced that contribution of these compounds to overall toxicity of complex environmental samples, should not be dismissed.

Productivity loss at work; Health-related and work-related factors

NARCIS (Netherlands)

Heuvel, S.G. van den; Geuskens, G.A.; Hooftman, W.E.; Koppes, L.L.J.; Bossche, S.N.J. van den

2010-01-01

Introduction Productivity loss is an increasing problem in an aging working population that is decreasing in numbers. The aim of this study is to identify work-related and health-related characteristics associated with productivity loss, due to either sickness absence or reduced performance at work.

Sulfur-Mediated-Alleviation of Aluminum-Toxicity in Citrus grandis Seedlings

Directory of Open Access Journals (Sweden)

Peng Guo

2017-12-01

Full Text Available Limited data are available on the sulfur (S-mediated-alleviation of aluminum (Al-toxicity in higher plants. Citrus grandis seedlings were irrigated for 18 weeks with 0.5 mM MgSO4 or 0.5 mM MgSO4 + 0.5 mM Na2SO4, and 0 (−Al or 1 mM AlCl3·6H2O (+Al, Al-toxicity. Under Al-toxicity, S decreased the level of Al in leaves; increased the relative water content (RWC of roots and leaves, the contents of phosphorus (P, calcium (Ca and magnesium (Mg per plant, the dry weights (DW of roots and shoots, the ratios of root DW/shoot DW, and the Al-induced secretion of citrate from root; and alleviated the Al-induced inhibition of photosynthesis via mitigating the Al-induced decrease of electron transport capacity resulting from the impaired photosynthetic electron transport chain. In addition to decreasing the Al-stimulated H2O2 production, the S-induced upregulation of both S metabolism-related enzymes and antioxidant enzymes also contributed to the S-mediated-alleviation of oxidative damage in Al-treated roots and leaves. Decreased transport of Al from roots to shoots and relatively little accumulation of Al in leaves, and increased leaf and root RWC and P, Ca, and Mg contents per plant might also play a role in the S-mediated-alleviation of Al-toxicity.

Sacha Inchi (Plukenetia volubilis L. powder: acute toxicity, 90 days oral toxicity study and micronucleus assay in rodents

Directory of Open Access Journals (Sweden)

Idania Rodeiro

2018-02-01

Full Text Available Context: Sacha Inchi has been consumed for years by indigenous peoples. Meanwhile, its toxicological potential has not been sufficiently studied. Aims: To assess the acute, sub-chronic toxicity and genotoxicity evaluation of Sacha Inchi powder obtained from Plukenetia volubilis L. Methods: A dose of 2000 mg/kg was orally administered to rats and mice and toxicity symptoms for 14 days were observed. In repeated dose study, the product was orally administered to Sprague Dawley rats of both sexes. Animals received 50, 250 and 500 mg/kg/day of the product for 90 days. At the end, animals were sacrificed and samples were done for hematological and biochemical analysis, organ weighs and histopathological examination. Genotoxicity potential of Sacha Inchi powder was evaluated through micronucleus test in mice. Negative controls received the vehicle (carboxymethyl cellulose, 0.5% used. Results: No morbidity or mortality at 2000 mg/kg of the product were found. Sacha Inchi powder oral administration during 90 days to rats did not lead to death, body weight gain, food consumption, or adverse events. No significant changes on hematological or biochemical parameters, organ weights or histopathological findings were observed. Induction of micronucleus formation attributable to the product was not found in mice. Conclusions: No toxicity effects after oral acute exposure of Sacha Inchi power to rats and mice were observed. Neither toxicity attributable to oral doses of the product up to 500 mg/kg during 90 days to rats were found. Results suggested Sacha Inchi powder does not have genotoxicity potential under our experimental conditions.

Pesticide Toxicity Index: a tool for assessing potential toxicity of pesticide mixtures to freshwater aquatic organisms

Science.gov (United States)

Nowell, Lisa H.; Norman, Julia E.; Moran, Patrick W.; Martin, Jeffrey D.; Stone, Wesley W.

2014-01-01

Pesticide mixtures are common in streams with agricultural or urban influence in the watershed. The Pesticide Toxicity Index (PTI) is a screening tool to assess potential aquatic toxicity of complex pesticide mixtures by combining measures of pesticide exposure and acute toxicity in an additive toxic-unit model. The PTI is determined separately for fish, cladocerans, and benthic invertebrates. This study expands the number of pesticides and degradates included in previous editions of the PTI from 124 to 492 pesticides and degradates, and includes two types of PTI for use in different applications, depending on study objectives. The Median-PTI was calculated from median toxicity values for individual pesticides, so is robust to outliers and is appropriate for comparing relative potential toxicity among samples, sites, or pesticides. The Sensitive-PTI uses the 5th percentile of available toxicity values, so is a more sensitive screening-level indicator of potential toxicity. PTI predictions of toxicity in environmental samples were tested using data aggregated from published field studies that measured pesticide concentrations and toxicity to Ceriodaphnia dubia in ambient stream water. C. dubia survival was reduced to ≤ 50% of controls in 44% of samples with Median-PTI values of 0.1–1, and to 0% in 96% of samples with Median-PTI values > 1. The PTI is a relative, but quantitative, indicator of potential toxicity that can be used to evaluate relationships between pesticide exposure and biological condition.

The toxicity of different lead salts to Enchytraeus crypticus in relation to bioavailability in soil

NARCIS (Netherlands)

Zhang, Lulu; Van Gestel, Cornelis A.M.

2017-01-01

The present study aimed to assess the bioavailability and toxicity of lead nitrate and lead chloride to Enchytraeus crypticus in a natural standard soil. Worms were exposed to Pb-spiked soil for 21 d, and survival and reproduction were related to total, 0.01 M CaCl2-extractable, and porewater Pb

The impact of gastrointestinal and genitourinary toxicity on health related quality of life among irradiated prostate cancer patients

International Nuclear Information System (INIS)

Schaake, Wouter; Wiegman, Erwin M.; Groot, Martijn de; Laan, Hans Paul van der; Schans, Cees P. van der; Bergh, Alfons C.M. van den; Langendijk, Johannes A.

2014-01-01

Purpose: To determine the impact of late radiation-induced toxicity on health-related quality of life (HRQoL) among patients with prostate cancer. Patients and methods: The study sample was composed of 227 patients, treated with external beam radiotherapy. Common Terminology Criteria for Adverse Events version 3.0 were used to grade late genitourinary and gastrointestinal toxicity. The European Organization for Research and Treatment of Cancer Quality of life Questionnaire C30 (EORTC QLQ-C30) was used to assess HRQoL at baseline, and 6, 12 and 24 months after completion of radiotherapy. Statistical analysis was performed using a multivariate analysis of variance (MANOVA). Results: Urinary incontinence and rectal discomfort significantly affected HRQoL. The impact of urinary incontinence on HRQoL was most pronounced 6 months after radiotherapy and gradually decreased over time. The impact of rectal discomfort on HRQoL was predominant at 6 months after radiotherapy, decreased at 12 months and increased again 2 years after radiotherapy. No significant impact on HRQoL was observed for any of the other toxicity endpoints, or non-toxicity related factors such as hormonal therapy, radiotherapy technique or age. Conclusion: Urinary incontinence and rectal discomfort have a significant impact on HRQoL. Prevention of these side effects may likely improve quality of life of prostate cancer patients after completion of treatment

Toxic pressure of herbicides on microalgae in Dutch estuarine and coastal waters

Science.gov (United States)

Booij, Petra; Sjollema, Sascha B.; van der Geest, Harm G.; Leonards, Pim E. G.; Lamoree, Marja H.; de Voogt, W. Pim; Admiraal, Wim; Laane, Remi W. P. M.; Vethaak, A. Dick

2015-08-01

For several decades now, there has been an increase in the sources and types of chemicals in estuarine and coastal waters as a consequence of anthropogenic activities. This has led to considerable concern about the effects of these chemicals on the marine food chain. The fact is that estuarine and coastal waters are the most productive ecosystems with high primary production by microalgae. The toxic pressure of specific phytotoxic chemicals now poses a major threat to these ecosystems. In a previous study, six herbicides (atrazine, diuron, irgarol, isoproturon, terbutryn and terbutylazine) were identified as the main contaminants affecting photosynthesis in marine microalgae. The purpose of this study is to investigate the toxic pressure of these herbicides in the Dutch estuarine and coastal waters in relation to the effective photosystem II efficiency (ΦPSII) in microalgae. Temporal and spatial variations in the concentrations of these herbicides were analyzed based on monitoring data. Additionally, a field study was carried out in which chemical analysis of water was performed and also a toxicity assessment using the Pulse Amplitude Modulation (PAM) fluorometry assay that measures ΦPSII. The toxic pressure on ΦPSII in microalgae has decreased with 55-82% from 2003 to 2012, with the Western Scheldt estuary showing the highest toxic pressure. By combining toxicity data from the PAM assay with chemical analysis of herbicide concentrations, we have identified diuron and terbutylazine as the main contributors to the toxic pressure on microalgae. Although direct effects are not expected, the toxic pressure is close to the 10% effect level in the PAM assay. A compliance check with the current environmental legislation of the European Union revealed that the quality standards are not sufficient to protect marine microalgae.

Gut as a target for cadmium toxicity.

Science.gov (United States)

Tinkov, Alexey A; Gritsenko, Viktor A; Skalnaya, Margarita G; Cherkasov, Sergey V; Aaseth, Jan; Skalny, Anatoly V

2018-04-01

The primary objective of the present study was to review the impact of Cd exposure on gut microbiota and intestinal physiology, as well as to estimate whether gut may be considered as the target for Cd toxicity. The review is based on literature search in available databases. The existing data demonstrate that the impact of Cd on gut physiology is two-sided. First, Cd exposure induces a significant alteration of bacterial populations and their relative abundance in gut (increased Bacteroidetes-to-Firmicutes ratio), accompanied by increased lipopolysaccharide (LPS) production, reflecting changed metabolic activity of the intestinal microbiome. Second, in intestinal wall Cd exposure induces inflammatory response and cell damage including disruption of tight junctions, ultimately leading to increased gut permeability. Together with increased LPS production, impaired barrier function causes endotoxinemia and systemic inflammation. Hypothetically, Cd-induced increase gut permeability may also result in increased bacterial translocation. On the one hand, bacteriolysis may be associated with aggravation of endotoxemia. At the same time, together with Cd-induced impairment of macrophage inflammatory response, increased bacterial translocation may result in increased susceptibility to infections. Such a supposition is generally in agreement with the finding of higher susceptibility of Cd-exposed mice to infections. The changed microbiome metabolic activity and LPS-induced systemic inflammation may have a significant impact on target organs. The efficiency of probiotics in at least partial prevention of the local (intestinal) and systemic toxic effects of cadmium confirms the role of altered gut physiology in Cd toxicity. Therefore, probiotic treatment may be considered as the one of the strategies for prevention of Cd toxicity in parallel with chelation, antioxidant, and anti-inflammatory therapy. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Structure Identification and Toxicity Assessment of the Degradation Products of Aflatoxin B1 in Peanut Oil under UV Irradiation

Directory of Open Access Journals (Sweden)

Jin Mao

2016-11-01

Full Text Available Aflatoxins, a group of extremely hazardous compounds because of their genotoxicity and carcinogenicity to human and animals, are commonly found in many tropical and subtropical regions. Ultraviolet (UV irradiation is proven to be an effective method to reduce or detoxify aflatoxins. However, the degradation products of aflatoxins under UV irradiation and their safety or toxicity have not been clear in practical production such as edible oil industry. In this study, the degradation products of aflatoxin B1 (AFB1 in peanut oil were analyzed by Ultra Performance Liquid Chromatograph-Thermo Quadrupole Exactive Focus mass spectrometry/mass spectrometry (UPLC-TQEF-MS/MS. The high-resolution mass spectra reflected that two main products were formed after the modification of a double bond in the terminal furan ring and the fracture of the lactone ring, while the small molecules especially nitrogen-containing compound may have participated in the photochemical reaction. According to the above results, the possible photodegradation pathway of AFB1 in peanut oil is proposed. Moreover, the human embryo hepatocytes viability assay indicated that the cell toxicity of degradation products after UV irradiation was much lower than that of AFB1, which could be attributed to the breakage of toxicological sites. These findings can provide new information for metabolic pathways and the hazard assessment of AFB1 using UV detoxification.

A Structure Identification and Toxicity Assessment of the Degradation Products of Aflatoxin B1 in Peanut Oil under UV Irradiation

Science.gov (United States)

Mao, Jin; He, Bing; Zhang, Liangxiao; Li, Peiwu; Zhang, Qi; Ding, Xiaoxia; Zhang, Wen

2016-01-01

Aflatoxins, a group of extremely hazardous compounds because of their genotoxicity and carcinogenicity to human and animals, are commonly found in many tropical and subtropical regions. Ultraviolet (UV) irradiation is proven to be an effective method to reduce or detoxify aflatoxins. However, the degradation products of aflatoxins under UV irradiation and their safety or toxicity have not been clear in practical production such as edible oil industry. In this study, the degradation products of aflatoxin B1 (AFB1) in peanut oil were analyzed by Ultra Performance Liquid Chromatograph-Thermo Quadrupole Exactive Focus mass spectrometry/mass spectrometry (UPLC-TQEF-MS/MS). The high-resolution mass spectra reflected that two main products were formed after the modification of a double bond in the terminal furan ring and the fracture of the lactone ring, while the small molecules especially nitrogen-containing compound may have participated in the photochemical reaction. According to the above results, the possible photodegradation pathway of AFB1 in peanut oil is proposed. Moreover, the human embryo hepatocytes viability assay indicated that the cell toxicity of degradation products after UV irradiation was much lower than that of AFB1, which could be attributed to the breakage of toxicological sites. These findings can provide new information for metabolic pathways and the hazard assessment of AFB1 using UV detoxification. PMID:27845743

The evolution of minor active and toxic gases in repositories

International Nuclear Information System (INIS)

Biddle, P.; Rees, J.H.; Davies, A.A.; McGahan, D.J.; Rushbrook, P.E.

1988-09-01

This study has considered a number of toxic and active gases which could potentially form in relatively small amounts in a deep repository for radioactive wastes. It has been concluded that many of these would react under repository conditions or be highly soluble in groundwater. The minor amounts of the inert and relatively insoluble gas krypton-85 would dissolve in a small volume of repository water. The wide range of organic gases and vapours that could form in trace amounts has been shortened to a list of 21 by consideration of their toxicity, volatibility and extent of formation at a landfill site for non-radioactive waste. The amounts of the inert and inactive gas helium formed from α-particles and the decay of tritium will have only a very minor effect on the overall rate of gas production. (author)

Comparative study of activities in reactive oxygen species production/defense system in mitochondria of rat brain and liver, and their susceptibility to methylmercury toxicity

Energy Technology Data Exchange (ETDEWEB)

Mori, N.; Hirayama, K. [Kumamoto University, School of Health Science, Kumamoto (Japan); Yasutake, A. [National Institute for Minamata Disease, Minamata (Japan)

2007-11-15

The involvement of oxidative stress has been suggested as a mechanism for neurotoxicity caused by methylmercury (MeHg), but the mechanism for MeHg selective toxicity in the central nervous system is still unclear. In this research, to clarify the mechanism of selective neurotoxicity caused by MeHg, the oxygen consumption levels, the reactive oxygen species (ROS) production rates and several antioxidant levels in mitochondria were compared among the cerebrum, cerebellum and liver of male Wistar rats. In addition, the alterations of these indexes were examined in MeHg-intoxicated rats (oral administration of 10 mg/kg day, for 5 days). Although the cerebrum and cerebellum in intact rats showed higher mitochondrial oxygen consumption levels and ROS production rates than the liver, glutathione peroxidase (GPX) and superoxide dismutase (SOD) activities were much lower in the cerebrum and cerebellum than in the liver. Especially, the cerebellum showed the highest oxygen consumption and ROS production rate and the lowest mitochondrial glutathione (GSH) levels among the tissues examined. In the MeHg-treated rats, decrease in the oxygen consumption and increase in the ROS generation were found only in the cerebellum mitochondria, despite a lower Hg accumulation in the mitochondrial fraction compared to the liver. Since MeHg treatment produced an enhancement of ROS generation in cerebellum mitochondria supplemented with succinate substrates, MeHg-induced oxidative stress might affect the complex II-III mediated pathway in the electron transfer chain in the cerebellum mitochondria. Our study suggested that inborn factors, high production system activity and low defense system activity of ROS in the brain, would relate to the high susceptibility of the central nervous system to MeHg toxicity. (orig.)

Sulfur dioxide : Relevance of toxic and nutritional effects for Chinese cabbage

NARCIS (Netherlands)

Yang, Liping; Stulen, Ineke; De Kok, Luit J.

2006-01-01

Shoots of Chinese cabbage formed a sink for atmospheric SO2 and there was a linear relation between the rate of uptake and the atmospheric SO2 level (0.03-1.4 mu l l(-1)). Chinese cabbage appeared to be rather susceptible to the toxic effects of SO2. Shoot biomass production was reduced upon

Investigation on by-products of bioenergy systems (anaerobic digestion and gasification) as potential crop nutrient using FTIR, XRD, SEM analysis and phyto-toxicity test.

Science.gov (United States)

Kataki, Sampriti; Hazarika, Samarendra; Baruah, D C

2017-07-01

Success and acceptability of the bio energy conversion technology to a large extent depend upon management of the inevitable by-products generated during the conversion process. By-products can be considered favourable as organic fertilizer as they retain nutrients with varying composition depending upon input biomass. However, characteristics of these heterogeneous resources with respect to feedstock and processing conditions have to be assessed to state on their agricultural and environmental benefits. Therefore, 3 types of anaerobic digestion by-products (digestate) from surplus biomass viz. cow dung, Ipomoea carnea:cow dung (60:40 dry weight basis) and rice straw:green gram stover:cow dung (30:30:40 dry weight basis) and one gasification by-product (biochar) from rice husk are considered to understand the fertilizer prospects. Considering 3 potential application options, digestate from each feedstock option was further processed as separated solid, separated liquid and ash from solid digestates. Thus, a total of 10 by-products were investigated for understanding their prospects as fertilizer using Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X ray Spectroscopy (EDX) and phyto-toxicity test to have a broad insight in terms of their organic, mineral, elemental composition, morphological feature and potential phyto-toxicity. In general, irrespective of origin of feedstock, solid digestate, ash digestate and char showed similarity in terms of composition of functional groups with some degree of variation in relative content as reflected by FTIR analysis. Dominance of organic functional groups in separated solid digestates compared to liquid fraction indicated the former as favourable organic amendments. Quartz was the prevalent mineral phase in all separated solid, ash digestate and rice husk char. Digestates in ash phase represent more concentrated plant nutrient source with

Cleaning up a toxic legacy: Environmental remediation of former uranium production sites in Central Asia

International Nuclear Information System (INIS)

Green, Andrew

2016-01-01

Nearly 60 abandoned uranium production sites dot the landscape and represent a hazard to the environment and inhabitants throughout rural Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan. Each site poses a challenge for local and national governments that lack technical expertise and resources for remediation. The sites were used to produce uranium until the 1990s. They were built before proper regulatory infrastructure was in place to ensure eventual decommissioning, so leftover residues with long-lived radioactive and highly toxic chemical contaminants still pose substantial risks to the health of the public and the environment.

Cleaning up a toxic legacy: Environmental remediation of former uranium production sites in Central Asia

International Nuclear Information System (INIS)

Green, Andrew

2016-01-01

Nearly 60 abandoned uranium production sites dot the landscape and represent a hazard to the environment and inhabitants throughout rural Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan. Each site poses a challenge for local and national governments that lack technical expertise and resources for remediation. The sites were used to produce uranium until the 1990s. They were built before proper regulatory infrastructure was in place to ensure eventual decommissioning, so leftover residues with long-lived radioactive and highly toxic chemical contaminants still pose substantial risks to the health of the public and the environment

The production of hydrotalcite from magnesite ore as non-toxic heat stabiliser for polyvinyl chloride

Directory of Open Access Journals (Sweden)

J. van der Laan

2005-09-01

Full Text Available In recent years polyvinyl chloride (PVC processors had to submit to worldwide pressure to convert to environmentally friendly stabilisers such as hydrotalcite (HT, since most of the heat stabilisers currently in use contain heavy metals such as lead, cadmium or barium – these being highly toxic. The presently used HT production process is, however, very expensive as it involves the recovering of magnesium from seawater magnesia. The purpose of this study was to prove that it is indeed possible to produce cost effective and non-toxic HT from an alternative source. During this study the costing and heat stabilising ability of the hydrotalcite produced from magnesite was compared to that of commercially available heat stabilisers. The effect of the pre-mixing process, as well as the influence of particle size distribution was also investigated. A cost comparative and stabilising efficiency study indicated the cost effectiveness of HT produced from magnesite ore, in comparison with other commercially available stabilisers. The use of HT as produced from magnesite ore would indeed assist in the worldwide changeover to environmentally friendly stabilisers.

Influence of global change-related impacts on the mercury toxicity of freshwater algal communities.

Science.gov (United States)

Val, Jonatan; Muñiz, Selene; Gomà, Joan; Navarro, Enrique

2016-01-01

The climatic-change related increase of temperatures, are expected to alter the distribution and survival of freshwater species, ecosystem functions, and also the effects of toxicants to aquatic biota. This study has thus assessed, as a first time, the modulating effect of climate-change drivers on the mercury (Hg) toxicity of freshwater algal photosynthesis. Natural benthic algal communities (periphyton) have been exposed to Hg under present and future temperature scenarios (rise of 5 °C). The modulating effect of other factors (also altered by global change), as the quality and amount of suspended and dissolved materials in the rivers, has been also assessed, exposing algae to Hg in natural river water or a synthetic medium. The EC50 values ranged from the 0.15-0.74 ppm for the most sensitive communities, to the 24-40 ppm for the most tolerant. The higher tolerance shown by communities exposed to higher Hg concentrations, as Jabarrella was in agreement with the Pollution Induced Community Tolerance concept. In other cases, the dominance of the invasive diatom Didymosphenia geminata explained the tolerance or sensitivity of the community to the Hg toxicity. Results shown that while increases in the suspended solids reduced Hg bioavailability, changes in the dissolved materials - such as organic carbon - may increase it and thus its toxic effects on biota. The impacts of the increase of temperatures on the toxicological behaviour of periphyton (combining both changes at species composition and physiological acclimation) would be certainly modulated by other effects at the land level (i.e., alterations in the amount and quality of dissolved and particulate substances arriving to the rivers). Copyright © 2015 Elsevier B.V. All rights reserved.

Toxicity of pesticides associated with potato production, including soil fumigants, to snapping turtle eggs (Chelydra serpentina).

Science.gov (United States)

de Solla, Shane Raymond; Palonen, Kimberley Elizabeth; Martin, Pamela Anne

2014-01-01

Turtles frequently oviposit in soils associated with agriculture and, thus, may be exposed to pesticides or fertilizers. The toxicity of a pesticide regime that is used for potato production in Ontario on the survivorship of snapping turtle (Chelydra serpentina) eggs was evaluated. The following treatments were applied to clean soil: 1) a mixture of the pesticides chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos, and 2) the soil fumigant metam sodium. Turtle eggs were incubated in soil in outdoor plots in which these mixtures were applied at typical and higher field application rates, where the eggs were subject to ambient temperature and weather conditions. The pesticide mixture consisting of chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos did not affect survivorship, deformities, or body size at applications up to 10 times the typical field application rates. Hatching success ranged between 87% and 100% for these treatments. Metam sodium was applied at 0.1¯ times, 0.3¯ times, 1 times, and 3 times field application rates. Eggs exposed to any application of metam sodium had 100% mortality. At typical field application rates, the chemical regime associated with potato production does not appear to have any detrimental impacts on turtle egg development, except for the use of the soil fumigant metam sodium, which is highly toxic to turtle eggs at the lowest recommended application rate. © 2013 SETAC.

Identification of phototransformation products of thalidomide and mixture toxicity assessment: an experimental and quantitative structural activity relationships (QSAR) approach.

Science.gov (United States)

Mahmoud, Waleed M M; Toolaram, Anju P; Menz, Jakob; Leder, Christoph; Schneider, Mandy; Kümmerer, Klaus

2014-02-01

The fate of thalidomide (TD) was investigated after irradiation with a medium-pressure Hg-lamp. The primary elimination of TD was monitored and structures of phototransformation products (PTPs) were assessed by LC-UV-FL-MS/MS. Environmentally relevant properties of TD and its PTPs as well as hydrolysis products (HTPs) were predicted using in silico QSAR models. Mutagenicity of TD and its PTPs was investigated in the Ames microplate format (MPF) aqua assay (Xenometrix, AG). Furthermore, a modified luminescent bacteria test (kinetic luminescent bacteria test (kinetic LBT)), using the luminescent bacteria species Vibrio fischeri, was applied for the initial screening of environmental toxicity. Additionally, toxicity of phthalimide, one of the identified PTPs, was investigated separately in the kinetic LBT. The UV irradiation eliminated TD itself without complete mineralization and led to the formation of several PTPs. TD and its PTPs did not exhibit mutagenic response in the Salmonella typhimurium strains TA 98, and TA 100 with and without metabolic activation. In contrast, QSAR analysis of PTPs and HTPs provided evidence for mutagenicity, genotoxicity and carcinogenicity using additional endpoints in silico software. QSAR analysis of different ecotoxicological endpoints, such as acute toxicity towards V. fischeri, provided positive alerts for several identified PTPs and HTPs. This was partially confirmed by the results of the kinetic LBT, in which a steady increase of acute and chronic toxicity during the UV-treatment procedure was observed for the photolytic mixtures at the highest tested concentration. Moreover, the number of PTPs within the reaction mixture that might be responsible for the toxification of TD during UV-treatment was successfully narrowed down by correlating the formation kinetics of PTPs with QSAR predictions and experimental toxicity data. Beyond that, further analysis of the commercially available PTP phthalimide indicated that transformation of

Decontamination Efficacy and Skin Toxicity of Two Decontaminants against Bacillus anthracis.

Directory of Open Access Journals (Sweden)

Chad W Stratilo

Full Text Available Decontamination of bacterial endospores such as Bacillus anthracis has traditionally required the use of harsh or caustic chemicals. The aim of this study was to evaluate the efficacy of a chlorine dioxide decontaminant in killing Bacillus anthracis spores in solution and on a human skin simulant (porcine cadaver skin, compared to that of commonly used sodium hypochlorite or soapy water decontamination procedures. In addition, the relative toxicities of these decontaminants were compared in human skin keratinocyte primary cultures. The chlorine dioxide decontaminant was similarly effective to sodium hypochlorite in reducing spore numbers of Bacillus anthracis Ames in liquid suspension after a 10 minute exposure. After five minutes, the chlorine dioxide product was significantly more efficacious. Decontamination of isolated swine skin contaminated with Bacillus anthracis Sterne with the chlorine dioxide product resulted in no viable spores sampled. The toxicity of the chlorine dioxide decontaminant was up to two orders of magnitude less than that of sodium hypochlorite in human skin keratinocyte cultures. In summary, the chlorine dioxide based decontaminant efficiently killed Bacillus anthracis spores in liquid suspension, as well as on isolated swine skin, and was less toxic than sodium hypochlorite in cultures of human skin keratinocytes.

Toxicity of 144Ce inhaled in a relatively insoluble form by aged Beagle dogs. VIII

International Nuclear Information System (INIS)

Hahn, F.F.; Muggenburg, B.A.; Boecker, B.B.; Mauderly, J.L.; McClellan, R.O.; Pickrell, J.A.

1979-01-01

The toxicity of relatively insoluble 144 Ce inhaled by 8- to 10.5-year-old dogs is being investigated to provide information on age-related differences in the response of dogs to lung burdens of this fission product. These data on aged dogs will be compared to the results of similar studies of dogs exposed at approximately 3 months or 12 to 14 months of age. Forty-two dogs were exposed, nose only, to aerosols of 144 Ce in fused aluminosilicate particles to yield initial lung burdens of 2.2 to 75 μCi/kg body weight and 12 control dogs were exposed to nonradioactive fused aluminosilicate particles. To date, 37 dogs have died or were euthanized 197 to 2375 days after inhalation of 144 Ce. The prominent findings were radiation pneumonitis in 19 dogs that died at early times with cumulative doses to lung of 20 000 to 74 000 rads and neoplastic disease in six of 14 dogs that died 943 days after exposure or later. Pulmonary tumors were found in four of these dogs. However, only one of these tumors killed the dog. No hemangiosarcomas have been observed in this study. This result is in contrast to the results with immature or young adult dogs exposed to 144 Ce. The difference may be a dose-related phenomenon since dogs which developed hemangiosarconomas had greater initial lung burdens of 144 Ce. Aged dogs with similar burdens died at earlier times with radiation pneumonitis. Observations are continuing on the five surviving 144 Ce-exposed and four control dogs

CHARACTERIZATION OF ENALAPRIL AND RANITIDINE CHLORINATION BY-PRODUCTS BY LIQUID CHROMATOGRAPHY/HIGH-RESOLUTION MASS SPECTROMETRY AND THEIR TOXICITY EVALUATION

Directory of Open Access Journals (Sweden)

Frederico Jehár Oliveira Quintão

Full Text Available Due to its low cost, its capability for disinfection and oxidation, chlorination using gaseous chlorine or hypochlorite salts, has also been commonly applied in water treatment plants for oxidation and disinfection purposes. Little is known about the identity and toxicity of by-products resulting from the chlorination of pharmaceutical micropollutants, such as enalapril (ENA and ranitidine (RAN. ENA and RAN chlorination by-products were characterized in this study by high-performance liquid chromatography coupled to high-resolution mass spectrometry (HPLC/HRMS and their toxicity were assessed by MTT assay. Chlorination experiments with ENA and RAN solutions (10 mg L-1 indicate degradation efficiencies of 100% for both compounds after only 5 min of exposure to chlorine at concentration of 9.53 mg Cl2 L-1. On the other hand mineralization rates were lower than 3%, thereby indicating there was accumulation of degradation by-products in all experiments. Mass spectrometric analysis revealed, at all times of reaction after the addition of hypochlorite, the presence of 1-(2-((4-(chlorophenyl-1-ethoxy-1-oxobutan-2-ylaminopropanoylpyrrolidine-2-carboxylic acid (enalapril by-product and N-chloro-N-(2-(((chloro-5-((dimethylaminomethylfuran-2-ylmethylsulfinylethyl-N-methyl-2-nitroethene 1,1-diamine (ranitidine by-product. Despite the formation of oxidized chlorinated by-products in all chlorination assays, the treated solutions were nontoxic to HepG2 cells by the MTT assay. It has been observed that chlorination (10 mg L-1, 5 min of ENA and RAN solutions exhibited high degradation efficiencies of the target compounds and low mineralization rates. Based on the mass spectrometry data, the routes for ENA and RAN successive oxidation by chlorine has been proposed.

Elemental Composition of Two Rice Cultivars under Potentially Toxic an Aquept and Aquent

Directory of Open Access Journals (Sweden)

Adesola Olutayo OLALEYE

2009-12-01

Full Text Available Iron toxicity is a major nutrient disorder affecting rice production of wetland rice in the irrigated and rainfed ecosystem in West Africa sub-region. Little attention has been paid to evaluating nutrient contents of rice cultivars grown on such soils and their relationship to the iron toxicity scores, grain yield and dry matter yields. A pot experiment was conducted on two potentially Fe-toxic soils (Aeric Fluvaquent and Aeric Tropaquept. The experiment was a 2 x 2 x 4 factorial experiment with three replicates in arranged in a randomized fashion. The factors were two soil types, two rice cultivars (ITA 212 and tolerant (Suakoko 8 and four Fe 2+ levels (control, 1000, 3000 and 4000 mg L-1. The result showed that for both susceptible cultivar (ITA 212 and the relatively tolerant (Suakoko 8 cultivar, little or no differences were observed in their elemental composition with regards to micro and macro-nutrients. For the susceptible cultivar, results showed that none of the tissue nutrients significantly relates to iron toxicity scores (ITS, grain yield and dry matter yield on both soil types. However, for the tolerant cultivar, ITS was observed to be significantly related to tissue K and P contents on the two soil types respectively. Tissue Ca and Mg were observed to be significantly related to the dry matter yield (DMY on Aeric Tropquept. It could be concluded that for these rice cultivars grown on two potentially Fe-toxic soils, different tissue nutrients may trigger the manifestation of bronzing or yellowing symptoms of rice cultivars.

Effectiveness of bioremediation in reducing toxicity in oiled intertidal sediments

International Nuclear Information System (INIS)

Lee, K.; Tremblay, G.H.

1995-01-01

A 123-day field study was conducted with in situ enclosures to compare the effectiveness of bioremediation strategies based in inorganic and organic fertilizer additions to accelerate the biodegradation rates and reduce the toxicity of Venture trademark condensate stranded within sand-beach sediments. Comparison of the two fertilizer formulations with identical nitrogen and phosphorus concentrations showed that the organic fertilizer stimulated bacterial productivity within the oiled sediments to the greatest extent. However, detailed chemical analysis indicated that inorganic fertilizer additions were the most effective in enhancing condensate biodegradation rates. The Microtox reg-sign Solid-Phase Test (SPT) bioassay was determined to be sensitive to Venture Condensate in laboratory tests. Subsequent application of this procedure to oiled sediment in the field showed a reduction in sediment toxicity over time. However, the Microtox reg-sign bioassay procedure did not identify significant reductions in sediment toxicity following bioremediation treatment. An observed increase in toxicity following periodic additions of the organic fertilizer was attributed to rapid biodegradation rates of the fertilizer, which resulted in the production of toxic metabolic products

Chronic toxicity of sediment-associated linear alkylbenzene sulphonates (LAS) to freshwater benthic organisms

Energy Technology Data Exchange (ETDEWEB)

Comber, S.D.W. [WRc-NSF, Henley Road, Medmenham, Marlow, Buckinghamshire, SL7 2HD (United Kingdom)]. E-mail: sean.comber@atkinsglobal.com; Conrad, A.U. [Weinberg Group, Blue Tower, Box 16, B-1050 Brussels (Belgium); Hoess, S. [ECOSSA, Thierschstrasser 43, 80538, Muenchen (Germany); Webb, S. [CEFIC, Ave E. Van Nieuwenhuyse 4, B-1160 Brussels (Belgium); Marshall, S. [Unilever Research, Environment Centre, Bebington, Wirral, Merseyside, L63 3JW (United Kingdom)

2006-11-15

The toxicity of linear alkylbenzene sulphonates (LAS), to freshwater benthic organisms was assessed during exposure to spiked sediment. Lethal and sub-lethal end-points were monitored for two organisms (oligochaete Lumbriculus variegatus and nematode Caenorhabditis elegans). Results demonstrated relatively low toxicity (LOECs >100 mg/kg dry weight). No observed effect concentrations (NOECs) of 81 mg/kg dw (Lumbriculus) and 100 mg/kg dw (Caenorhabditis) were determined. For the oligochaete, no specific endpoint was particularly sensitive to LAS. For the nematode, egg production was the most sensitive endpoint. Significant degradation was measured over the 28-day duration of the Lumbriculus study, equating to a half-life of 20 days in sediment. - This paper provides sediment toxicity data for LAS, essential for a detailed and accurate environment risk assessment.

Chronic toxicity of sediment-associated linear alkylbenzene sulphonates (LAS) to freshwater benthic organisms

International Nuclear Information System (INIS)

Comber, S.D.W.; Conrad, A.U.; Hoess, S.; Webb, S.; Marshall, S.

2006-01-01

The toxicity of linear alkylbenzene sulphonates (LAS), to freshwater benthic organisms was assessed during exposure to spiked sediment. Lethal and sub-lethal end-points were monitored for two organisms (oligochaete Lumbriculus variegatus and nematode Caenorhabditis elegans). Results demonstrated relatively low toxicity (LOECs >100 mg/kg dry weight). No observed effect concentrations (NOECs) of 81 mg/kg dw (Lumbriculus) and 100 mg/kg dw (Caenorhabditis) were determined. For the oligochaete, no specific endpoint was particularly sensitive to LAS. For the nematode, egg production was the most sensitive endpoint. Significant degradation was measured over the 28-day duration of the Lumbriculus study, equating to a half-life of 20 days in sediment. - This paper provides sediment toxicity data for LAS, essential for a detailed and accurate environment risk assessment

The Effects of Elevated Specific Conductivity on the Chronic Toxicity of Mining Influenced Streams Using Ceriodaphnia dubia.

Science.gov (United States)

Armstead, Mindy Yeager; Bitzer-Creathers, Leah; Wilson, Mandee

2016-01-01

Salinization of freshwater ecosystems as a result of human activities has markedly increased in recent years. Much attention is currently directed at evaluating the effects of increased salinity on freshwater biota. In the Central Appalachian region of the eastern United States, specific conductance from alkaline discharges associated with mountain top mining practices has been implicated in macroinvertebrate community declines in streams receiving coal mining discharges. Whole effluent toxicity testing of receiving stream water was used to test the hypothesis that mine discharges are toxic to laboratory test organisms and further, that toxicity is related to ionic concentrations as indicated by conductivity. Chronic toxicity testing using Ceriodaphnia dubia was conducted by contract laboratories at 72 sites with a total of 129 tests over a 3.5 year period. The database was evaluated to determine the ionic composition of mine effluent dominated streams and whether discharge constituents were related to toxicity in C. dubia. As expected, sulfate was found to be the dominant anion in streams receiving mining discharges with bicarbonate variable and sometimes a substantial component of the dissolved solids. Overall, the temporal variability in conductance was low at each site which would indicate fairly stable water quality conditions. Results of the toxicity tests show no relationship between conductance and survival of C. dubia in the mining influenced streams with the traditional toxicity test endpoints. However, consideration of the entire dataset revealed a significant inverse relationship between conductivity and neonate production. While conductivity explained very little of the high variability in the offspring production (r2 = 0.1304), the average numbers of offspring were consistently less than 20 neonates at the highest conductivities.

The Effects of Elevated Specific Conductivity on the Chronic Toxicity of Mining Influenced Streams Using Ceriodaphnia dubia.

Directory of Open Access Journals (Sweden)

Mindy Yeager Armstead

Full Text Available Salinization of freshwater ecosystems as a result of human activities has markedly increased in recent years. Much attention is currently directed at evaluating the effects of increased salinity on freshwater biota. In the Central Appalachian region of the eastern United States, specific conductance from alkaline discharges associated with mountain top mining practices has been implicated in macroinvertebrate community declines in streams receiving coal mining discharges. Whole effluent toxicity testing of receiving stream water was used to test the hypothesis that mine discharges are toxic to laboratory test organisms and further, that toxicity is related to ionic concentrations as indicated by conductivity. Chronic toxicity testing using Ceriodaphnia dubia was conducted by contract laboratories at 72 sites with a total of 129 tests over a 3.5 year period. The database was evaluated to determine the ionic composition of mine effluent dominated streams and whether discharge constituents were related to toxicity in C. dubia. As expected, sulfate was found to be the dominant anion in streams receiving mining discharges with bicarbonate variable and sometimes a substantial component of the dissolved solids. Overall, the temporal variability in conductance was low at each site which would indicate fairly stable water quality conditions. Results of the toxicity tests show no relationship between conductance and survival of C. dubia in the mining influenced streams with the traditional toxicity test endpoints. However, consideration of the entire dataset revealed a significant inverse relationship between conductivity and neonate production. While conductivity explained very little of the high variability in the offspring production (r2 = 0.1304, the average numbers of offspring were consistently less than 20 neonates at the highest conductivities.

Morpho-physiological analysis of tolerance to aluminum toxicity in rice varieties of North East India.

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Jay Prakash Awasthi

Full Text Available Aluminum (Al is the third most abundant metal in earth crust, whose chemical form is mainly dependent on soil pH. The most toxic form of Al with respect to plants is Al3+, which exists in soil pH <5. Acidic soil significantly limits crop production mainly due to Al3+ toxicity worldwide, impacting approximately 50% of the world's arable land (in North-Eastern India 80% soil are acidic. Al3+ toxicity in plants ensues root growth inhibition leading to less nutrient and water uptake impacting crop productivity as a whole. Rice is one of the chief grains which constitutes the staple food of two-third of the world population including India and is not untouched by Al3+ toxicity. Al contamination is a critical constraint to plant production in agricultural soils of North East India. 24 indigenous Indica rice varieties (including Badshahbhog as tolerant check and Mashuri as sensitive check were screened for Al stress tolerance in hydroponic plant growth system. Results show marked difference in growth parameters (relative growth rate, Root tolerance index, fresh and dry weight of root of rice seedlings due to Al (100 μM toxicity. Al3+ uptake and lipid peroxidation level also increased concomitantly under Al treatment. Histochemical assay were also performed to elucidate uptake of aluminum, loss of membrane integrity and lipid peroxidation, which were found to be more in sensitive genotypes at higher Al concentration. This study revealed that aluminum toxicity is a serious harmful problem for rice crop productivity in acid soil. Based on various parameters studied it's concluded that Disang is a comparatively tolerant variety whereas Joymati a sensitive variety. Western blot hybridization further strengthened the claim, as it demonstrated more accumulation of Glutathione reductase (GR protein in Disang rice variety than Joymati under stressed condition. This study also observed that the emergence of lethal toxic symptoms occurs only after 48h

Bioassay directed identification of toxicants in sludge and related reused materials from industrial wastewater treatment plants in the Yangtze River Delta.

Science.gov (United States)

Fang, Binbin; Guo, Jing; Li, Fuxing; Giesy, John P; Wang, Lianjun; Shi, Wei

2017-02-01

Industrialized development of the Yangtze River Delta, China, has resulted in larger amounts of wastes, including sludges from treatment of these wastes. Methods to manage and dispose, including reuse were urgently needed. Sludge and reused products were collected from two largest factories, KEYUAN and HENGJIA where treated sludges were turned into bricks or sludge cake to be placed in landfills, respectively. Metals and organic compounds were quantified in sludges and leachates assessed by use of toxicity characterized leaching procedure (TCLP) while acute toxicity was determined by Daphnia magna. Nine metals were detected in all raw sludges with concentrations of Cr and Ni exceeding Chinese standards. For sludge leachate, concentrations of metals were all less than Chinese standards, which changed little after being made into cake by HENGJIA, but were significantly less after being made into brick by KEYUAN. Toxicity units (TU) for all samples are greater than 1.0 indicating that they are potentially toxic to aquatic organisms. TUs changed little after being made into filter cake, but were 10-fold less after being made into bricks. Cr and Ni contributed most to the total toxicity followed by Zn and Cu. Making of sludges into K-brick 1 resulted in better inactivation of contaminants, which resulted in less toxic potencies. So that is the recommended method for handling of industrial sludges. To further assure their safe reuse, additional research on identification of key toxicants and potential hazards, based on additional endpoints, by combining bio-tests and chemical analysis should be done for reused sludges. Copyright © 2016 Elsevier Ltd. All rights reserved.

Toxicity of Urban PM10 and Relation with Tracers of Biomass Burning.

Science.gov (United States)

Van Den Heuvel, Rosette; Staelens, Jeroen; Koppen, Gudrun; Schoeters, Greet

2018-02-12

The chemical composition of particles varies with space and time and depends on emission sources, atmospheric chemistry and weather conditions. Evidence suggesting that particles differ in toxicity depending on their chemical composition is growing. This in vitro study investigated the biological effects of PM 10 in relation to PM-associated chemicals. PM 10 was sampled in ambient air at an urban traffic site (Borgerhout) and a rural background location (Houtem) in Flanders (Belgium). To characterize the toxic potential of PM 10 , airway epithelial cells (Beas-2B cells) were exposed to particles in vitro. Different endpoints were studied including cell damage and death (cell viability) and the induction of interleukin-8 (IL-8). The mutagenic capacity was assessed using the Ames II Mutagenicity Test. The endotoxin levels in the collected samples were analyzed and the oxidative potential (OP) of PM 10 particles was evaluated by electron paramagnetic resonance (EPR) spectroscopy. Chemical characteristics of PM 10 included tracers for biomass burning (levoglucosan, mannosan and galactosan), elemental and organic carbon (EC/OC) and polycyclic aromatic hydrocarbons (PAHs). Most samples displayed dose-dependent cytotoxicity and IL-8 induction. Spatial and temporal differences in PM 10 toxicity were seen. PM 10 collected at the urban site was characterized by increased pro-inflammatory and mutagenic activity as well as higher OP and elevated endotoxin levels compared to the background area. Reduced cell viability (-0.46 biomass burning, levoglucosan, mannosan and galactosan. Furthermore, direct and indirect mutagenicity were associated with tracers for biomass burning, OC, EC and PAHs. Multiple regression analyses showed levoglucosan to explain 16% and 28% of the variance in direct and indirect mutagenicity, respectively. Markers for biomass burning were associated with altered cellular responses and increased mutagenic activity. These findings may indicate a role of

Gold leaching by organic base polythionates: new non-toxic and secure technology.

Science.gov (United States)

Smolyaninov, Vladislav; Shekhvatova, Galina; Vainshtein, Mikhail

2014-01-01

The article present a review on own experimental and some published data which are related with the gold leaching. It is well-known that the most common and usual process of the leaching with cyanide can be dangerous, needs a great water consumption, and additional costs for remediation of the poisoned and toxic sites. The experimental data described production of poythionates which are not toxic but perspective for the prosperous gold leaching. The paper dedicated to the safe gold leaching with thiosulfates and organic salts of polythionic acids (organic base polythionates). The method of production of these polythionates based on the Smolyaninov reaction is described in stages and in details for the first time. Possible application of the polythionates application in the gold leaching is discussed and its advantages are compared with the gold leaching by cyanation.

Microbiological evaluation on toxicity amelioration of soil samples contaminated with petroleum-based products

International Nuclear Information System (INIS)

Khairuddin Abdul Rahim; Pauline Liew Woan Ying; Ahmad Nazrul Abd Wahid; Shamsiah Abdul Rahman; Mohd Suhaimi Hamzah; Abdul Khalik Wood; Muhamat Omar

2004-01-01

Samples of soil materials from oil sludge landfarm in Melaka and petroleum sludge ready for disposal were analysed on their potentially toxic elements and compounds and their microbial population. These were compared against uncontaminated soil samples from agricultural plots and fresh crude petroleum samples obtained from an oil refinery in Kerteh, Terengganu. Enumeration and isolation of culturable microbial populations in the above samples were conducted using standard plate counts and screening methods. Populations of microorganisms from uncontaminated soils were tested on its potential to degrade petroleum derived products on contaminated soil samples and crude petroleum samples in a laboratory experiment. Microorganisms with great potential to degrade petroleum sludge will be further screened in further bioremediation studies in the field. (Author)

Reactions of clofibric acid with oxidative and reductive radicals-Products, mechanisms, efficiency and toxic effects

Science.gov (United States)

Csay, Tamás; Rácz, Gergely; Salik, Ádám; Takács, Erzsébet; Wojnárovits, László

2014-09-01

The degradation of clofibric acid induced by hydroxyl radical, hydrated electron and O2-•/HO2• reactive species was studied in aqueous solutions. Clofibric acid was decomposed more effectively by hydroxyl radical than by hydrated electron or O2-•/HO2•. Various hydroxylated, dechlorinated and fragmentation products have been identified and quantified. A new LC-MS method was developed based on 18O isotope labeling to follow the formation of hydroxylated derivatives of clofibric acid. Possible degradation pathways have been proposed. The overall degradation was monitored by determination of sum parameters like COD, TOC and AOX. It was found that the organic chlorine degrades very effectively prior to complete mineralization. After the treatment no toxic effect was found according to Vibrio fischeri tests. However, at early stages some of the reaction products were more harmful than clofibric acid.

Radiation effects on the fluoxetine hydrochloride toxicity in the presence of domestic sewage

Energy Technology Data Exchange (ETDEWEB)

Silva, Vanessa H. Ogihara; Borrely, Sueli I., E-mail: vanessa.ogihara@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Campos, Fabio; Piveli, Roque P. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Escola Politecnica. Centro Tecnologico de Hidraulica

2013-07-01

The sanitation field is directly related to environmental quality and health. The improvements in wastewater treatment systems provide benefits to the environment and their population. It is clearly understood that the conventional wastewater treatment does not remove many micropollutants, including some medicinal products, and that these products can be toxic to living organisms. The goal of this research was the assessment of toxicity of fluoxetine hydrochloride (FH) as well as the irradiation application to remove FH from waters. The FH was irradiated in water solutions and also contained in domestic sewage. Both types of samples were irradiated at a Dynamitron® Electron Beam Accelerator (EBA). The Vibrio fischeri bacteria was applied as biological assay to the samples (water solution of FH; untreated sewage and the mixture of untreated sewage + FH). The efficiency was 1.44% to 26.21% less toxic after treatments. UV-Vis Spectrometry showed the degradation of FH by radiation. 2.5 kGy was a suitable dose that could be suggested for environmental application of Electron Beam Technology. (author)

A review of the toxicity of biomass pyrolysis liquids formed at low temperatures

Energy Technology Data Exchange (ETDEWEB)

Diebold, J P [Thermalchemie, Inc., Lakewood, CO (United States)

1997-04-01

The scaleup of biomass fast pyrolysis systems to large pilot and commercial scales will expose an increasingly large number of personnel to potential health hazards, especially during the evaluation of the commercial use of the pyrolysis condensates. Although the concept of fast pyrolysis to optimize liquid products is relatively new, low-temperature pyrolysis processes have been used over the aeons to produce charcoal and liquid by-products, e.g., smoky food flavors, food preservatives, and aerosols containing narcotics, e.g., nicotine. There are a number of studies in the historical literature that concern the hazards of acute and long-term exposure to smoke and to the historical pyrolysis liquids formed at low temperatures. The reported toxicity of smoke, smoke food flavors, and fast pyrolysis oils is reviewed. The data found for these complex mixtures suggest that the toxicity may be less than that of the individual components. It is speculated that there may be chemical reactions that take place that serve to reduce the toxicity during aging. 81 refs.

Radiation effects on the fluoxetine hydrochloride toxicity in the presence of domestic sewage

International Nuclear Information System (INIS)

Silva, Vanessa H. Ogihara; Borrely, Sueli I.; Campos, Fabio; Piveli, Roque P.

2013-01-01

The sanitation field is directly related to environmental quality and health. The improvements in wastewater treatment systems provide benefits to the environment and their population. It is clearly understood that the conventional wastewater treatment does not remove many micropollutants, including some medicinal products, and that these products can be toxic to living organisms. The goal of this research was the assessment of toxicity of fluoxetine hydrochloride (FH) as well as the irradiation application to remove FH from waters. The FH was irradiated in water solutions and also contained in domestic sewage. Both types of samples were irradiated at a Dynamitron® Electron Beam Accelerator (EBA). The Vibrio fischeri bacteria was applied as biological assay to the samples (water solution of FH; untreated sewage and the mixture of untreated sewage + FH). The efficiency was 1.44% to 26.21% less toxic after treatments. UV-Vis Spectrometry showed the degradation of FH by radiation. 2.5 kGy was a suitable dose that could be suggested for environmental application of Electron Beam Technology. (author)

Heavy metal content of selected personal care products (PCPs available in Ibadan, Nigeria and their toxic effects

Directory of Open Access Journals (Sweden)

Sunday Samuel Omenka

Full Text Available There is a growing concern on heavy metals in consumer products due to their potential human health risks and environmental effects. In this study, the levels of zinc, cadmium, lead and nickel were assessed in 3 different classes of personal care products commonly used in Ibadan, Nigeria. Samples were analysed for heavy metals using Atomic Absorption Spectrophotometer (AAS after acid digestion. Estimated daily intake (EDI of the metals and Health Risk Index (HRI were calculated to assess the human health risks associated with the use of these PCPs. The concentrations (mg/kg of zinc ranged from 3.75 to 19.3, 1.88 to 112,000 and 19.8 to 217 respectively in creams, powders and eyeliners. Cadmium ranged from ND—0.50, ND—36.3 and ND—0.50 mg/kg while lead ranged from ND—6.25, ND—468 and 3.73–27.5 mg/kg and nickel ranged from ND—6.25, 0.13–107 and 2.75–22.7 mg/kg respectively. There were high concentrations of Cd, Pb and Ni in some of the samples when compared with the available permissible limits in cosmetics (Cd: 0.3 ppm, Pb: 10 ppm and Ni: 0.6 ppm while there is no permissible limit for Zn in cosmetics currently available. Prolonged use of PCPs may pose human health and environmental risks due to toxic metal loading through dermal contact and accumulation over a period of time. Hence, the need for necessary government agencies to regulate and enforce toxic metals in consumer products including cosmetics produced and imported into Nigeria to safeguard public health and the environment, which is the final sink. Keywords: Heavy metals, Personal care products, Health effects, Dermal contact, Exposure

十溴二苯醚及其降解产物对浮游生物的毒性%Toxicity of decabromodiphenyl ether and its degradation products to plankton

Institute of Scientific and Technical Information of China (English)

韩文亮; 郑小燕

2018-01-01

十溴二苯醚(BDE-209)是我国环境中主要的多溴二苯醚(PBDEs)同系物.为研究BDE-209及其降解产物对水环境的影响,以初级消费者浮游动物大型蚤(Daphnia magna)和初级生产者浮游植物水华微囊藻(Microcystis flos-aquae)为染毒对象,研究BDE-209及其降解不同阶段产物对浮游生物的毒性.结果表明,大型蚤方面,繁殖毒性大于生长毒性,48 h半数致死浓度(48h-LC50)大小为:还原降解中间产物(0.80 mg·L-1,高毒)＞BDE-209(8.74 mg·L-1,中毒)＞还原降解终产物(15.27 mg· L-1,低毒),还原-氧化降解终产物的死亡率与溶剂空白一致,表明其基本无毒.水华微囊藻方面,染毒物质的毒性大小顺序与大型蚤一致,1 mg·L-1的BDE-209、还原中间产物、还原终产物及还原-氧化终产物对水华微囊藻的抑制率分别为15.7％、93.7％、6.6％和1.3％.BDE-209降解过程中易生成毒性较大的中间产物,彻底还原脱溴可降低其毒性,后续辅以氧化降解,可消除其环境毒性.%Decabromodiphenyl ether(BDE-209) is the primary congener of polybrominated diphenyl ethers (PBDEs) in the environment in China.In order to investigate the effects of BDE-209 and its degradation products on the aquatic environment,the zooplankton Daphnia magna (a primary consumer),and the phytoplankton Microcystisflos-aquae(a primary producer) were used to study the toxicities of BDE-209 and its degradation products of different stages.In Daphnia magna,the propagation toxicities were higher than that of growth.48h-LC50 of pollutants followed the order of intermediate reductive products(0.80 mg·L-1,high toxicity)＞ BDE-209(8.74 mg·L-1,moderate toxicity)＞ reductive final products(15.27 mg·L-1,low toxicity).The motality of the final reductive-oxidative products was comparable with that caused by the solvent,indicating that it was largely nontoxic.In Microcystis flos-aquae,the toxicity of pollutants followed the same order as in Daphnia magna

Information Search of Toxic-Free Ammunition

National Research Council Canada - National Science Library

Adelman, Stephen

1994-01-01

Task Order No. 0001, Information Search of Toxic-Free Ammunition addresses issues related to toxic and environmentally harmful effects caused by the use of some of the current small arms ammunition...

Toxicity of carbon nanotubes: A review.

Science.gov (United States)

Francis, Arul Prakash; Devasena, Thiyagarajan

2018-03-01

Carbon nanotubes (CNTs) are widely used in the aerospace, automotive, and electronics industries because of their stability, enhanced metallic, and electrical properties. CNTs are also being investigated for biomedical applications such as drug delivery systems and biosensors. However, the toxic potential of CNTs was reported in various cell lines and animal models. The toxicity depends on diverse properties of the CNTs, such as length, aspect ratio, surface area, degree of aggregation, purity, concentration, and dose. In addition, CNTs and/or associated contaminants were well known for oxidative stress, inflammation, apoptosis, pulmonary inflammation, fibrosis, and granuloma in lungs. The increased production of CNTs likely enhanced the possibility of its exposure in people. Studies on the toxicity of CNTs are mainly focused on the pulmonary effects after intratracheal administration, and only a few studies are reported about the toxicity of CNTs via other routes of exposure. So, it is essential to consider the chronic toxicity of CNTs before using them for various biomedical applications. This review focuses on the potential toxicities of CNTs.

Sanitary Assessment of Hazardous Materials Exposed To Highly Toxic Chemical Compounds

International Nuclear Information System (INIS)

Rembovskiy, V.; Ermolaeva, E.

2007-01-01

Industrial or terroristic accidents in which toxic chemicals (TC) are the main or attendant damaging factors should be regarded as a new challenge for experts, because of little knowledge on the methodology to estimating the long-term risk for humans due to contamination of the building materials and environment. In the Russian Federation, there appeared to be a kind of model systems for developing an algorithm for solving these or similar problems. Under dismantling and liquidation of the former facilities for chemical weapon production (FCWP) the building materials are regarded as potential waste products the fate of which (processing, warehousing, utilization, and destruction) is dependent on their possible hazard for human population and environment. The standard approaches for hazard assessment of waste products of the FCWP turned out to be insufficient. When conducting the present work, the following problems have been solved: 1. Selection of representative samples taking into consideration a diversity of construction materials, great quantities of potentially toxic waste materials, information on the production conditions, breakdowns in the process of production, accidents, composition of the decontaminators used, decontamination frequency, etc. 2. Analysis of TC in composite matrixes complicated by the following problems: extraction, masking effects of concomitant components during indirect analysis, lack of certified methods of direct analysis of TC, discrepancy of results of GC and direct GCMS analysis, low sensitivity of GCMS analysis, big volume of samples (more than 0.5 kg), heterogeneity of physical-chemical properties of different matrixes influencing the process of degradation of TC. 3. Hazard assessment of the wastes in toxic-and-sanitary experiment relying on non-specific signs of intoxication due to relatively low percentage of TC and masking effects of various matrix components. Application of the integral toxicity tests with soil

Glucose Toxic Effects on Granulation Tissue Productive Cells: The Diabetics’ Impaired Healing

Directory of Open Access Journals (Sweden)

Jorge Berlanga-Acosta

2013-01-01

Full Text Available Type 2 diabetes mellitus is a metabolic noncommunicable disease with an expanding pandemic magnitude. Diabetes predisposes to lower extremities ulceration and impairs the healing process leading to wound chronification. Diabetes also dismantles innate immunity favoring wound infection. Amputation is therefore acknowledged as one of the disease’s complications. Hyperglycemia is the proximal detonator of systemic and local toxic effectors including proinflammation, acute-phase proteins elevation, and spillover of reactive oxygen and nitrogen species. Insulin axis deficiency weakens wounds’ anabolism and predisposes to inflammation. The systemic accumulation of advanced glycation end-products irreversibly impairs the entire physiology from cells-to-organs. These factors in concert hamper fibroblasts and endothelial cells proliferation, migration, homing, secretion, and organization of a productive granulation tissue. Diabetic wound bed may turn chronically inflammed, procatabolic, and an additional source of circulating pro-inflammatory cytokines, establishing a self-perpetuating loop. Diabetic fibroblasts and endothelial cells may bear mitochondrial damages becoming prone to apoptosis, which impairs granulation tissue cellularity and perfusion. Endothelial progenitor cells recruitment and tubulogenesis are also impaired. Failure of wound reepithelialization remains a clinical challenge while it appears to be biologically multifactorial. Ulcer prevention by primary care surveillance, education, and attention programs is of outmost importance to reduce worldwide amputation figures.

Toxicity and bioaccumulation of chlorophenols in earthworms, in relation to bioavailability in soil

Energy Technology Data Exchange (ETDEWEB)

van Gestel, C.A.; Ma, W.C.

1988-06-01

The acute toxicity of five chlorophenols for two earthworm species was determined in two sandy soils differing in organic matter content and the results were compared with adsorption data. Adsorption increased with increasing organic matter content of the soils, but for tetra- and pentachlorophenol was also influenced by soil pH. Earthworm toxicity was significantly higher in the soil with a low level of organic matter. This difference disappeared when LC50 values were recalculated to concentrations in soil solution using adsorption data. Eisenia fetida andrei showed LC50 values lower than those of Lumbricus rubellus although bioaccumulation was generally higher in the latter species. Toxicity and bioaccumulation based on soil solution concentrations increased with increasing lipophilicity of the chlorophenols. The present results indicate that the toxicity and bioaccumulation and therefore the bioavailability of chlorophenols in soil to earthworms are dependent on the concentration in soil solution and can be predicted on the basis of adsorption data. Both the toxicity of and bioaccumulation data on chlorophenols in earthworms demonstrated surprisingly good agreement with those on chlorophenols in fish.

[Monitoring and assessment contamination of toxic elements food in Tatarstan monitoring and evaluation of contamination by toxic elements of food products in the territory of the Republic of Tatarstan].

Science.gov (United States)

Frolova, O A; Karpova, M V; Makhmutova, I P; Musin, R A

2014-01-01

Actual consumption of toxic elements in the body of an adult human in the Republic of Tatarstan (during the period of the study of the production in 2008-2012) amounts for lead: 0.68 mg/week for cadmium: 0.18 mg/day, arsenic: 0.68 mg/day, mercury: 0.21 mg/week (per 1 kg body weight) or respectively: 22.81%, 18.0%, 13.69%, 4.27% of the allowable levels of the chemical load. We have performed calculations with account of the balance of food resources per capita per year in the Republic of Tatarstan. This analysis showed that the main dietary sources of income for cadmium there are milk and dairy products (48.32%), bakery products (16.07%), meat and meat products (13.22%); for lead there are bakely products (26.85%), potatoes (24.36%), milk and dairy products (23.94%), meat and meat products (7.55%); for mercury there are milk and dairy products (53.72%), meat and meat products (16.82%), potatoes (10.92%); fish and fish products (4.74%); for arsenic there are milk and dairy products (72.51%), meat and meat products (12.8%), bakery products (3.05% ,); fish and fish products (2.23%). It is important to know not only what products are the most contaminated, but what place in the structure of the nutrition they take.

Toxicity classification and evaluation of four pharmaceuticals classes: antibiotics, antineoplastics, cardiovascular, and sex hormones

International Nuclear Information System (INIS)

Sanderson, Hans; Brain, Richard A.; Johnson, David J.; Wilson, Christian J.; Solomon, Keith R.

2004-01-01

Four different classes of environmental concern are quantitatively and qualitatively assessed for environmental hazards; antibiotics (n = 226), antineoplastics (n = 81), cardiovascular (n = 272), and sex hormones (n 92). These along with an ECOSAR scan of all pharmaceuticals (n = 2848) were then classified according to the OECD aquatic toxicity classification system. The predicted species susceptibility is: daphnid > fish > algae, and the predicted rank order of relative toxicity: sex hormones > cardiovascular antibiotics > antineoplastics (Table 1). Generally, a relatively large proportion (1/3) of all pharmaceuticals are potentially very toxic to aquatic organisms (Table 2). The qualitative risk assessment ranking relative to probability and potential severity for human and environmental health effects is: antibiotics > sex hormones > cardiovascular > antineoplastics. (Q)SARs and pharmacodynamic information should be used to prioritize and steer experimental risk assessments of pharmaceuticals, and potentially, also be used in new drug discovery optimizing efficacy and in minimising environmental hazards of new products. Nuclear receptors are relatively well conserved in evolution. Currently, antibacterial resistance represents the most significant human health hazard, and potentially the largest non-target organism hazard is sex hormones acting as endocrine modulators in wildlife. Data for the individual compounds are accessible via http://www.uoguelph.ca/~hsander/

Acute toxicity of dichloroacetonitrile (DCAN), a typical nitrogenous disinfection by-product (N-DBP), on zebrafish (Danio rerio).

Science.gov (United States)

Lin, Tao; Zhou, Dongju; Dong, Jian; Jiang, Fuchun; Chen, Wei

2016-11-01

Dichloroacetonitrile (DCAN) is a typical nitrogenous disinfection by-product (N-DBP) and its toxicity on aquatic animals is investigated for the first time. The present study was designed to investigate the potential adverse effects of DCAN on zebrafish. DCAN could induce developmental toxicity to zebrafish embryos. A significant decrease in hatchability and an increase in malformation and mortality occurred when DCAN concentration was above 100µg/L. Heart function alteration and neuronal function disturbance occurred at concentration higher than 500 and 100µg/L, respectively. Further, DCAN was easily accumulated in adult zebrafish. The rank order of declining bioconcentration factor (BCF) was liver (1240-1670)> gill (1210-1430)> muscle (644-877). DCAN caused acute metabolism damage to adult zebrafish especially at 8 days exposure, at which time the "Integrated Biomarker Response" (IBR) index value reached 798 at 1mg/L DCAN dose. Acute DNA damage was induced to adult zebrafish by DCAN even at 10µg/L dose. Copyright © 2016 Elsevier Inc. All rights reserved.

Toxic and fire hazard of flooring

Directory of Open Access Journals (Sweden)

Illarionova L. V.

2017-12-01

Full Text Available polymer materials have become widespread in the modern construction industry due to their cheapness and variety. With regard to their popularity at the present time there can appear the issues of their toxic and fire danger. The work has studied the samples of two floor synthetic building materials. The results of the determination of the fire hazard indicators of materials (combustibility, flammability, smoke ratio showed their compliance with the current certificates. The authors have studied the properties of gaseous combustion products of samples by the method of thermal analysis and FTIR analysis. The results of chloride ions analysis according the formula of Maxwell-Mohr in thermolysis products indicate the toxicity of the materials studied.

Technical manual for basic version of the Markov chain nest productivity model (MCnest)

Science.gov (United States)

The Markov Chain Nest Productivity Model (or MCnest) integrates existing toxicity information from three standardized avian toxicity tests with information on species life history and the timing of pesticide applications relative to the timing of avian breeding seasons to quantit...

User’s manual for basic version of MCnest Markov chain nest productivity model

Science.gov (United States)

The Markov Chain Nest Productivity Model (or MCnest) integrates existing toxicity information from three standardized avian toxicity tests with information on species life history and the timing of pesticide applications relative to the timing of avian breeding seasons to quantit...

Stress-related behavioral alterations accompanying cocaine toxicity: the effects of mixed opioid drugs.

Science.gov (United States)

Hayase, T; Yamamoto, Y; Yamamoto, K

2000-12-01

The present study evaluated the effects of mixed opioid drugs on the severity of cocaine (COCA) toxicity by examining stress-related behavioral alterations in mice. In order to ascertain the strength of the stress, the continuous observation of the behavioral symptoms in the cage and the forced swimming test (Porsolt test) were performed in the COCA (75 mg/kg, i.p.)-treated groups, with or without the mixed mu-kappa receptor-related opioid drugs, buprenorphine (BUP) and pentazocine (PEN). Using the high-sensitivity activity measuring instrument Supermex, both the spontaneous behaviors in the cage and the forced swimming behaviors in the water were assessed as activity counts. The behavioral alterations in the COCA-treated groups were compared with a group of mice given a 10 min immobilization stress (IM group). In the COCA-only group, a prolonged increase in the spontaneous behaviors accompanied by convulsive seizures was observed even in the surviving mice, unlike in the IM group. However, an acceleration of behavioral despair in the Porsolt test similar to that observed in the IM group was observed in the COCA group after the disappearance of the acute toxic symptoms (5 hours after the COCA treatment). Among the opioid-treated groups, the mortality rate was attenuated only in the COCA-BUP (0.25 mg/kg, i.p.) group. In the COCA-BUP group, a prolonged suppression of the morbid hyperactivity in the cage except for the convulsive seizures, and a normalization of the swimming behavior in the Porsolt test were observed in the survivors. On the other hand, in the COCA-PEN (5 mg/kg, i.p.) group, the swimming behavior in the Porsolt test was abnormally increased in addition to the prolonged morbid hyperactivity in the cage. Therefore, the COCA-induced stress-related behaviors were normalized in the group of mice treated with BUP, a group with a good prognosis.

Toxicity identification evaluations of produced-water effluents

International Nuclear Information System (INIS)

Sauer, T.C.; Costa, H.J.; Brown, J.S.; Ward, T.J.

1997-01-01

Toxicity identification evaluations (TIEs) were performed on 14 produced-water (PW) samples of various salinities from inland and offshore oil- and gas-production facilities operated by different companies in Wyoming, Texas, California, and Louisiana (USA) to evaluate the efficacy of TIE procedures in determining potential toxicants in PW effluents. The research involved acute (24- and 48-h) freshwater and marine toxicity tests on whole PW and PW fractions generated by standard US Environmental Protection Agency and PW-specific fractionation schemes. Factors influencing PW TIEs were investigated, such as the effect of salinity in selecting fractionation manipulations, the effect of toxicity test replication (i.e., reproducibility) in distinguishing changes in toxicities between whole PW and its fractions, and the suitability of different test species in PW TIEs. The results obtained and lessons learned from conducting these PW TIEs are presented in this article. Components, or fractions, contributing to toxicity differed for each PW with no specific fraction being consistently toxic. For most PW samples, toxicity attributed to any one fraction represented only part of the toxicity of the whole sample. However, no more than two fraction types were identified as potential toxicants in any sample. Potential toxicants identified during this study, besides salinity, included acidic and basic organic compound class fractions, particulates removed by filtration at pH 11, ammonia, hydrocarbons, hydrogen sulfide, material removed by pH change, and volatile compounds

Mechanisms of Phosphine Toxicity

Directory of Open Access Journals (Sweden)

Nisa S. Nath

2011-01-01

Full Text Available Fumigation with phosphine gas is by far the most widely used treatment for the protection of stored grain against insect pests. The development of high-level resistance in insects now threatens its continued use. As there is no suitable chemical to replace phosphine, it is essential to understand the mechanisms of phosphine toxicity to increase the effectiveness of resistance management. Because phosphine is such a simple molecule (PH3, the chemistry of phosphorus is central to its toxicity. The elements above and below phosphorus in the periodic table are nitrogen (N and arsenic (As, which also produce toxic hydrides, namely, NH3 and AsH3. The three hydrides cause related symptoms and similar changes to cellular and organismal physiology, including disruption of the sympathetic nervous system, suppressed energy metabolism and toxic changes to the redox state of the cell. We propose that these three effects are interdependent contributors to phosphine toxicity.

Distinct pharmacology and metabolism of K2 synthetic cannabinoids compared to Δ9-THC: Mechanism underlying greater toxicity?

Science.gov (United States)

Fantegrossi, William E.; Moran, Jeffery H.; Radominska-Pandya, Anna; Prather, Paul L.

2013-01-01

K2 or Spice products are emerging drugs of abuse that contain synthetic cannabinoids (SCBs). Although assumed by many teens and first time drug users to be a “safe” and “legal” alternative to marijuana, many recent reports indicate that SCBs present in K2 produce toxicity not associated with the primary psychoactive component of marijuana, Δ9-tetrahydrocannabinol (Δ9-THC). This mini-review will summarize recent evidence that use of K2 products poses greater health risks relative to marijuana, and suggest that distinct pharmacological properties and metabolism of SCBs relative to Δ9-THC may contribute to the observed toxicity. Studies reviewed will indicate that in contrast to partial agonist properties of Δ9-THC typically observed in vitro, SCBs in K2 products act as full cannabinoid receptor type 1 (CB1R) and type 2 (CB2R) agonists in both cellular assays and animal studies. Furthermore, unlike Δ9-THC metabolism, several SCB metabolites retain high affinity for, and exhibit a range of intrinsic activities at, CB1 and CB2Rs. Finally, several reports indicate that although quasi-legal SCBs initially evaded detection and legal consequences, these presumed “advantages” have been limited by new legislation and development of product and human testing capabilities. Collectively, evidence reported in this mini-review suggests that K2 products are neither safe nor legal alternatives to marijuana. Instead, enhanced toxicity of K2 products relative to marijuana, perhaps resulting from the combined actions of a complex mixture of different SCBs present and their active metabolites that retain high affinity for CB1 and CB2Rs, highlights the inherent danger that may accompany use of these substances. PMID:24084047

Distinct pharmacology and metabolism of K2 synthetic cannabinoids compared to Δ(9)-THC: mechanism underlying greater toxicity?

Science.gov (United States)

Fantegrossi, William E; Moran, Jeffery H; Radominska-Pandya, Anna; Prather, Paul L

2014-02-27

K2 or Spice products are emerging drugs of abuse that contain synthetic cannabinoids (SCBs). Although assumed by many teens and first time drug users to be a "safe" and "legal" alternative to marijuana, many recent reports indicate that SCBs present in K2 produce toxicity not associated with the primary psychoactive component of marijuana, ∆(9)-tetrahydrocannabinol (Δ(9)-THC). This mini-review will summarize recent evidence that use of K2 products poses greater health risks relative to marijuana, and suggest that distinct pharmacological properties and metabolism of SCBs relative to Δ(9)-THC may contribute to the observed toxicity. Studies reviewed will indicate that in contrast to partial agonist properties of Δ(9)-THC typically observed in vitro, SCBs in K2 products act as full cannabinoid receptor type 1 (CB1R) and type 2 (CB2R) agonists in both cellular assays and animal studies. Furthermore, unlike Δ(9)-THC metabolism, several SCB metabolites retain high affinity for, and exhibit a range of intrinsic activities at, CB1 and CB2Rs. Finally, several reports indicate that although quasi-legal SCBs initially evaded detection and legal consequences, these presumed "advantages" have been limited by new legislation and development of product and human testing capabilities. Collectively, evidence reported in this mini-review suggests that K2 products are neither safe nor legal alternatives to marijuana. Instead, enhanced toxicity of K2 products relative to marijuana, perhaps resulting from the combined actions of a complex mixture of different SCBs present and their active metabolites that retain high affinity for CB1 and CB2Rs, highlights the inherent danger that may accompany use of these substances. © 2013.

Human toxicity as a criterion in the environmental assessment of products

DEFF Research Database (Denmark)

Hauschild, Michael Zwicky; Olsen, Stig Irving; Wenzel, Henrik

1998-01-01

. The assessment proceeds through the steps of classification, characterization, normalization and valuation. In the classification step attention is focused on intrinsic toxicity, low biodegradability and potential for bioconcentration as properties that predicpose a substance for ecotoxicity. No concrete values...... references derived for each of these scenarios are presented as personal equivalents for citizens in the considered region. Valuation Applying the "distance to target principle to the present Danish political reduction targets for toxicity a weighting factor is derived to be used in the quantitative weighing...

Metals and cocoa products: a study on characterization of toxic and essential metals in chocolates

International Nuclear Information System (INIS)

Rahman, S.; Husnain, S.M.

2012-01-01

Metals (Pb, Cd, Ni, Fe, Cu, Zn and Mn) were assessed in 32 commonly consumed cocoa products (chocolates) prepared by different national and multinational companies. Significant differences were observed between the micro element contents of these varieties (P < 0.01). Frequent consumption of chocolates can enhance the intake of toxic metals in children. The concentration of Pb and Cd in cocoa powder is found to be highest 492 and 197 mu g/L followed by cocoa based chocolates 306 and 46.8 mu g/L, sugar based chocolates 209.8 and 40.3 mu g/L whereas it is least in milk based chocolates samples 88.3 and 33 mu g/L respectively. Weekly intake of toxic metals Pb, Cd and Ni was also calculated. Mean concentration of Pb and Cd was found below the provisional tolerable weekly intake defined by FAO/WHO. All essential elements were assessed for their weekly intake with the dietary reference intakes (DRI). Results were validated through the analysis of certified reference materials and determined metals concentrations were quite in good agreement with certified levels. Data was interpreted through cluster analysis and pattern recognition as depicted. The concentrations of Pb, Cd, Ni and Fe were found to be highest in the cocoa-based followed by milk-based and sugar-based chocolates. The daily intake of cocoa-based chocolates must be reduced as lead and cadmium intake can otherwise cross the limits set by Codex Alimentarius (FAO/WHO 2006). Raw materials should be checked before use for metal contents in order to decrease the concentrations of these metals in final chocolate products. (Orig./A.B.)

Pulmonary toxicity study in rats with PM 10 and PM 2.5: Differential responses related to scale and composition

Science.gov (United States)

Zhang, Wei; Lei, Tian; Lin, Zhi-Qing; Zhang, Hua-Shan; Yang, Dan-Feng; Xi, Zhu-Ge; Chen, Jian-Hua; Wang, Wei

2011-02-01

ObjectionTo study the pollution of atmospheric particles at winter in Beijing and compare the lung toxicity which induced by particle samples from different sampling sites. MethodWe collected samples from two sampling points during the winter for toxicity testing and chemical analysis. Wistar rats were administered with particles by intratracheal instillation. After exposure, biochemically index, esimmunity indexes, histopathology and DNA damage were detected in rat pulmonary cells. ResultThe elements with enrichment factors (EF) larger than 10 were As, Cd, Cu, Zn, S and Pb in the four experiment groups. The priority control of the total concentration of polycyclic aromatic hydrocarbons (PAHs) in PM 10 and PM 2.5 of Near-traffic source was much higher than that of Far-traffic source, it demonstrated that near the traffic source of PAHs pollution was heavier than that of Far-traffic source, as it was close to main roads Beiyuan Road, motor vehicle emissions were much higher. The pathology of lung showed that the degree of inflammation was increased with the particle diameter minished, it was the same as the detection of biochemical parameters such as lactate dehydrogenase (LDH), Total antioxidant status(T-AOC) and total protein (TP) in BALF and inflammation cytokine(interleukin-1, interleukin-6 and tumor necrosis factor-alpha) in lung homogenate. The indexes of DNA damage including the content of DNA and Olive empennage of PM 2.5 were significant higher than that of PM 10 at the same surveillance point ( P < 0.05), near-traffic particles were higher than the far-traffic particles at the same diameter, ( P < 0.05). ConclusionNear-traffic area particles had certain pollution at winter in Beijing. Meanwhile, atmospheric particulate matters on lung toxicity were related to the particles size and distance related sites which were exposed: smaller size, more toxicity; nearer from traffic, more toxicity.

New genetic associations in thiopurine-related bone marrow toxicity among inflammatory bowel disease patients.

Science.gov (United States)

Zabala, William; Cruz, Raquel; Barreiro-de Acosta, Manuel; Chaparro, María; Panes, Julián; Echarri, Ana; Esteve, Maria; Carpio, Daniel; Andreu, Montserrat; García-Planella, Esther; Domenech, Eugeni; Carracedo, Angel; Gisbert, Javier P; Barros, Francisco

2013-04-01

The toxicity related to thiopurine drug therapy for inflammatory bowel disease (IBD) varies widely among patients. Almost 15-30% of patients with IBD develop side effects during treatment, often bone marrow suppression. Several factors have been implicated in determining this toxicity, mainly individual genetic variation related to formation of active thiopurine metabolites. The aim was to identify genes involved in thiopurine-related myelosuppression. A two-stage investigation of 19,217 coding SNPs (cSNPs) was performed in a Spanish (Inflammatory Bowel Disease Group of Galicia [EIGA]) cohort of 173 IBD patients, 15 with bone marrow suppression. The top 20 cSNPs identified in the first stage with p ENEIDA) cohort (87 patients, 29 with bone marrow suppression). Several cSNPs showed a significant p-value in the allelic joint analysis (p-Cochran-Mantel-Haenszel test ≤2.55 × 10(-3)) despite no cSNP passing correction for multiple testing in the first cohort. Of note is rs3729961 in the gene IL6ST, a transducer signal chain shared by many cytokines including IL6 (p-value combined = 2.36 × 10(-4), odds ratio [95% CI]: 3.41 [1.71-6.78]). In addition, we detected association with rs3749598 in the FSTL5 gene that appears to interact with metalloproteases at the extracellular matrix level (p-value combined = 4.89 × 10(-4)), odds ratio (95% CI): 3.67 (1.68-8.01). We have identified IL6ST and FSLT5 as new bone marrow suppression susceptibility candidate genes after thiopurine treatment in IBD patients. This is the first report of variants associated with thiopurine-related myelosuppression that was identified by a genome-wide association study. Its validation awaits functional analyses and replication in additional studies. Original submitted 14 September 2012; Revision submitted 13 February 2013.

Assessment of Jatropha curcas L. biodiesel seed cake toxicity using the zebrafish (Danio rerio) embryo toxicity (ZFET) test.

Science.gov (United States)

Hallare, Arnold V; Ruiz, Paulo Lorenzo S; Cariño, J C Earl D

2014-05-01

Consequent to the growing demand for alternative sources of energy, the seeds from Jatropha curcas remain to be the favorite for biodiesel production. However, a significant volume of the residual organic mass (seed cake) is produced during the extraction process, which raises concerns on safe waste disposal. In the present study, we assessed the toxicity of J. curcas seed cake using the zebrafish (Danio rerio) embryotoxicity test. Within 1-h post-fertilization (hpf), the fertilized eggs were exposed to five mass concentrations of J. curcas seed cake and were followed through 24, 48, and 72 hpf. Toxicity was evaluated based on lethal endpoints induced on zebrafish embryos namely egg coagulation, non-formation of somites, and non-detachment of tail. The lowest concentration tested, 1 g/L, was not able to elicit toxicity on embryos whereas 100 % mortality (based also on lethal endpoints) was recorded at the highest concentration at 2.15 g/L. The computed LC50 for the J. curcas seed cake was 1.61 g/L. No further increase in mortality was observed in the succeeding time points (48 and 72 hpf) indicating that J. curcas seed cake exerted acute toxicity on zebrafish embryos. Sublethal endpoints (yolk sac and pericardial edema) were noted at 72 hpf in zebrafish embryos exposed to higher concentrations. The observed lethal endpoints induced on zebrafish embryos were discussed in relation to the active principles, notably, phorbol esters that have remained in the seed cake even after extraction.

Performance Related Pay and Labor Productivity

NARCIS (Netherlands)

Gielen, A. C.; Kerkhofs, M.J.M.; van Ours, J.C.

2006-01-01

This paper uses information from a panel of Dutch firms to investigate the labor productivity effects of performance related pay (PRP).We find that PRP increases labor productivity at the firm level with about 9%.

Performance Related Pay and Labour Productivity

OpenAIRE

Gielen, Anne; Kerkhofs, Marcel J M; van Ours, Jan C

2006-01-01

This paper uses information from a panel of Dutch firms to investigate the labour productivity effects of performance related pay (PRP). We find that PRP increases labour productivity at the firm level with about 9%.

Fingerprinting the reactive toxicity pathways of 50 drinking water disinfection by-products.

Science.gov (United States)

Stalter, Daniel; O'Malley, Elissa; von Gunten, Urs; Escher, Beate I

2016-03-15

A set of nine in vitro cellular bioassays indicative of different stages of the cellular toxicity pathway was applied to 50 disinfection by-products (DBPs) to obtain a better understanding of the commonalities and differences in the molecular mechanisms of reactive toxicity of DBPs. An Eschericia coli test battery revealed reactivity towards proteins/peptides for 64% of the compounds. 98% activated the NRf2-mediated oxidative stress response and 68% induced an adaptive stress response to genotoxic effects as indicated by the activation of the tumor suppressor protein p53. All DBPs reactive towards DNA in the E. coli assay and activating p53 also induced oxidative stress, confirming earlier studies that the latter could trigger DBP's carcinogenicity. The energy of the lowest unoccupied molecular orbital ELUMO as reactivity descriptor was linearly correlated with oxidative stress induction for trihalomethanes (r(2)=0.98) and haloacetamides (r(2)=0.58), indicating that potency of these DBPs is connected to electrophilicity. However, the descriptive power was poor for haloacetic acids (HAAs) and haloacetonitriles (r(2) (0.80, indicating that HAAs' potency is connected to both, electrophilicity and speciation. Based on the activation of oxidative stress response and the soft electrophilic character of most tested DBPs we hypothesize that indirect genotoxicity-e.g., through oxidative stress induction and/or enzyme inhibition-is more plausible than direct DNA damage for most investigated DBPs. The results provide not only a mechanistic understanding of the cellular effects of DBPs but the effect concentrations may also serve to evaluate mixture effects of DBPs in water samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genetic and rat toxicity studies of cyclodextrin glucanotransferase

Directory of Open Access Journals (Sweden)

Robert R. Maronpot

Full Text Available Introduction: Microbiologically derived cyclodextrin glucanotransferase (CGTase is used commercially as a processing agent in manufacture of food, pharmaceuticals, and cosmetics. Its toxic potential was evaluated in anticipation of use in the production of alpha-glycosyl isoquercitrin, a water-soluble form of quercetin. Methods: Following OECD guidelines, CGTase, produced by Bacillus pseudalcaliphilus DK-1139, was evaluated in a genotoxicity battery consisting of a bacterial reverse mutation assay, an in vitro micronucleus (MN assay and MN and comet assays using B6C3F1 male and female mice. These same genotoxicity assays were also conducted for sodium sulfate, a contaminant of CGTase preparation. In a 90-day Sprague Dawley rat toxicity study, CGTase was administered by gavage in water at daily doses of 0, 250, 500, and 1000 mg/kg/day. Results: CGTase did not induce mutations with or without metabolic activation in the bacterial reverse mutation assay. Formation of micronuclei was not induced in either in vitro or in vivo MN assays with or without metabolic activation. No induction of DNA damage was detected in male or female mouse liver, stomach, or duodenum in the comet assay. Sodium sulfate also tested negative in these same genotoxicity assays. In the 90-day repeated dose rat study there were no treatment-related adverse clinical or pathological findings. Conclusion: The genotoxicity assays and repeated dose toxicity study support the safe use of CGTase in production of alpha-glycosyl isoquercitrin. Keywords: Micronucleus assay, Comet assay, Enzymatically modified isoquercitrin (EMIQ, Food additive, Flavonol, Sodium sulfate

Lung inflammation caused by inhaled toxicants: a review

Directory of Open Access Journals (Sweden)

Wong J

2016-06-01

Full Text Available John Wong, Bruce E Magun, Lisa J Wood School of Nursing, MGH Institute of Health Professions, Boston, MA, USA Abstract: Exposure of the lungs to airborne toxicants from different sources in the environment may lead to acute and chronic pulmonary or even systemic inflammation. Cigarette smoke is the leading cause of chronic obstructive pulmonary disease, although wood smoke in urban areas of underdeveloped countries is now recognized as a leading cause of respiratory disease. Mycotoxins from fungal spores pose an occupational risk for respiratory illness and also present a health hazard to those living in damp buildings. Microscopic airborne particulates of asbestos and silica (from building materials and those of heavy metals (from paint are additional sources of indoor air pollution that contributes to respiratory illness and is known to cause respiratory illness in experimental animals. Ricin in aerosolized form is a potential bioweapon that is extremely toxic yet relatively easy to produce. Although the aforementioned agents belong to different classes of toxic chemicals, their pathogenicity is similar. They induce the recruitment and activation of macrophages, activation of mitogen-activated protein kinases, inhibition of protein synthesis, and production of interleukin-1 beta. Targeting either macrophages (using nanoparticles or the production of interleukin-1 beta (using inhibitors against protein kinases, NOD-like receptor protein-3, or P2X7 may potentially be employed to treat these types of lung inflammation without affecting the natural immune response to bacterial infections. Keywords: cigarette, mycotoxin, trichothecene, ricin, inflammasome, macrophage, inhibitors

Morpho-physiological analysis of tolerance to aluminum toxicity in rice varieties of North East India.

Science.gov (United States)

Awasthi, Jay Prakash; Saha, Bedabrata; Regon, Preetom; Sahoo, Smita; Chowra, Umakanta; Pradhan, Amit; Roy, Anupam; Panda, Sanjib Kumar

2017-01-01

Aluminum (Al) is the third most abundant metal in earth crust, whose chemical form is mainly dependent on soil pH. The most toxic form of Al with respect to plants is Al3+, which exists in soil pH Eastern India 80% soil are acidic). Al3+ toxicity in plants ensues root growth inhibition leading to less nutrient and water uptake impacting crop productivity as a whole. Rice is one of the chief grains which constitutes the staple food of two-third of the world population including India and is not untouched by Al3+ toxicity. Al contamination is a critical constraint to plant production in agricultural soils of North East India. 24 indigenous Indica rice varieties (including Badshahbhog as tolerant check and Mashuri as sensitive check) were screened for Al stress tolerance in hydroponic plant growth system. Results show marked difference in growth parameters (relative growth rate, Root tolerance index, fresh and dry weight of root) of rice seedlings due to Al (100 μM) toxicity. Al3+ uptake and lipid peroxidation level also increased concomitantly under Al treatment. Histochemical assay were also performed to elucidate uptake of aluminum, loss of membrane integrity and lipid peroxidation, which were found to be more in sensitive genotypes at higher Al concentration. This study revealed that aluminum toxicity is a serious harmful problem for rice crop productivity in acid soil. Based on various parameters studied it's concluded that Disang is a comparatively tolerant variety whereas Joymati a sensitive variety. Western blot hybridization further strengthened the claim, as it demonstrated more accumulation of Glutathione reductase (GR) protein in Disang rice variety than Joymati under stressed condition. This study also observed that the emergence of lethal toxic symptoms occurs only after 48h irrespective of the dose used in the study.

Relative importance of deterministic and stochastic processes in driving arbuscular mycorrhizal fungal assemblage during the spreading of a toxic plant.

Directory of Open Access Journals (Sweden)

Guoxi Shi

Full Text Available Both deterministic and stochastic processes are expected to drive the assemblages of arbuscular mycorrhizal (AM fungi, but little is known about the relative importance of these processes during the spreading of toxic plants. Here, the species composition and phylogenetic structure of AM fungal communities colonizing the roots of a toxic plant, Ligularia virgaurea, and its neighborhood plants, were analyzed in patches with different individual densities of L. virgaurea (represents the spreading degree. Community compositions of AM fungi in both root systems were changed significantly by the L. virgaurea spreading, and also these communities fitted the neutral model very well. AM fungal communities in patches with absence and presence of L. virgaurea were phylogenetically random and clustered, respectively, suggesting that the principal ecological process determining AM fungal assemblage shifted from stochastic process to environmental filtering when this toxic plant was present. Our results indicate that deterministic and stochastic processes together determine the assemblage of AM fungi, but the dominant process would be changed by the spreading of toxic plants, and suggest that the spreading of toxic plants in alpine meadow ecosystems might be involving the mycorrhizal symbionts.

Acute and subacute toxicity of 18F-FDG

International Nuclear Information System (INIS)

Dantas, Danielle Maia

2013-01-01

Before starting clinical trials of a new drug, it is necessary to perform a battery of safety tests for assessing human risk. Radiopharmaceuticals like any new drug must be tested taking into account its specificity, duration of treatment and especially the toxicity of both parties, the unlabeled molecule and its radionuclide, apart from impurities emanating from radiolysis. Regulatory agencies like the Food and Drug Administration - USA (FDA) and the European Medicine Agency (EMEA), establish guidelines for the regulation of production and research of radiopharmaceuticals. In Brazil the production of radiopharmaceuticals was not regulated until the end of 2009, when were established by the National Agency for Sanitary Surveillance (ANVISA) resolutions No. 63, which refers to the Good Manufacturing Practices of Radiopharmaceuticals and No. 64 which seeks the registration of record radiopharmaceuticals. To obtain registration of radiopharmaceuticals are necessary to prove the quality, safety, efficacy and specificity of the drug . For the safety of radiopharmaceuticals must be presented studies of acute toxicity, subacute and chronic toxicity as well as reproductive, mutagenic and carcinogenic. Nowadays IPEN-CNEN/SP produces one of the most important radiopharmaceutical of nuclear medicine, the 18 F-FDG, which is used in many clinical applications, particularly in the diagnosis and staging of tumors. The objective of this study was to evaluate the systemic toxicity (acute/ subacute) radiopharmaceutical 18 F-FDG in an in vivo test system, as recommended by the RDC No. 64, which will serve as a model for protocols toxicity of radiopharmaceuticals produced at IPEN. The following tests were performed: tests of acute and subacute toxicity, biodistribution studies of 18 F-FDG, comet assay and reproductive toxicity. In acute toxicity, healthy rats were injected . (author)

Comparative toxicity of leachates from 52 textiles to Daphnia magna.

Science.gov (United States)

Dave, Göran; Aspegren, Pia

2010-10-01

The environmental aspects of textiles are very complex and include production, processing, transport, usage, and recycling. Textiles are made from a variety of materials and can contain a large number of chemicals. Chemicals are used during production of fibres, for preservation and colouring and they are released during normal wear and during washing. The aim of this study was to investigate the release to water of toxic chemicals from various textiles. Altogether 52 samples of textiles made from cotton (21), linen (4), cotton and linen (7), cellulose (3), synthetic fibres (7), cotton and synthetic fibres (8) and wool (2). Seven were eco-labelled. All textiles were cut into squares and placed into Petri dishes with 50 ml ISO test medium in a concentration series (4-256 cm(2)/50 ml) and tested for acute toxicity to Daphnia magna. Estimated EC50s were converted into weight/volume, and 48-h EC50s ranged between 182 g/L. It was not possible to detect any difference between fibre type and toxicity (ANOVA), but a significantly higher toxicity was found for printed versus unprinted cotton and cotton/linen textiles, while the opposite was found for synthetic textiles. Eco-labelled products were evenly distributed on a toxicity scale, which means that eco-labelling in its present form does not necessarily protect users or the environment from exposure to toxic chemicals. Therefore, the results from the present study suggest that bioassays and toxicity tests should become an integrated part of textile environmental quality control programs. Copyright © 2010 Elsevier Inc. All rights reserved.

Transuranium element toxicity: dose-response relationships at low exposure levels. Summary and speculative interpretation relative to exposure limits

International Nuclear Information System (INIS)

Thompson, R.C.

1975-01-01

A summary is given of information on transuranium element toxicity and the correlation of this information with current established exposure limits. It is difficult to calculate a biologically relevant radiation dose from deposited plutonium; it is exposure that must be controlled in order to prevent biological effect, and if the relationship between exposure and effect is known, then radiation dose is of no concern. There are extensive data on the effects of plutonium in bone. Results of studies at the University of Utah indicate that plutonium in beagles may be as much as ten times more toxic than radium. It has been suggested that this toxicity ratio may be even higher in man than in the beagle dog because of differences in surface-to-volume ratios and differences in the rate of burial of surface-deposited plutonium. The present capabilities for extrapolating dose-effect relationships seem to be limited to the setting of upper limits, based on assumptions of linearity and considerations related to natural background

Chronic exposure to chlorophenol related compounds in the pesticide production workplace and lung cancer: a meta-analysis.

Science.gov (United States)

Zendehdel, Rezvan; Tayefeh-Rahimian, Raana; Kabir, Ali

2014-01-01

Chlorophenols (CPs) and related phenoxyacetic acids (PAs) are pesticide groups contaminated with highly toxic 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) during production. PAs and CPs exposure is associated with risk of cancer, but the situation regarding lung cancer has not been clearly defined. We proposed a meta-analysis of published researches to evaluate relationship between chronic exposure to PAs and CPs in pesticide production workplaces and the risk of lung cancer. After searching PubMed, Scopus, Scholar Google, Web of Sciences until August 2013, the association between chronic PAs and CPs exposure in production workplace and lung cancer was studied in 15 cohort studies. The standardized mortality rate (SMR) and 95% confidence intervals (CI) were collected from the papers. We used random or fixed-effects models, Egger test, funnel plot and meta regression in our analysis. Five papers with six reports were included in the final analysis. The standardized mortality rate for lung cancer from the random model was 1.18 (95% CI: 1.03-1.35, p=0.014) with moderate heterogeneity. Publication bias was not found for included studies in meta-analysis (p=0.9). Our findings has strengthen the evidence of lung cancer from chronic exposure to chlorophenol related compounds (PAs, CPs).

Toxicity of Urban PM10 and Relation with Tracers of Biomass Burning

Directory of Open Access Journals (Sweden)

Rosette Van Den Heuvel

2018-02-01

Full Text Available The chemical composition of particles varies with space and time and depends on emission sources, atmospheric chemistry and weather conditions. Evidence suggesting that particles differ in toxicity depending on their chemical composition is growing. This in vitro study investigated the biological effects of PM10 in relation to PM-associated chemicals. PM10 was sampled in ambient air at an urban traffic site (Borgerhout and a rural background location (Houtem in Flanders (Belgium. To characterize the toxic potential of PM10, airway epithelial cells (Beas-2B cells were exposed to particles in vitro. Different endpoints were studied including cell damage and death (cell viability and the induction of interleukin-8 (IL-8. The mutagenic capacity was assessed using the Ames II Mutagenicity Test. The endotoxin levels in the collected samples were analyzed and the oxidative potential (OP of PM10 particles was evaluated by electron paramagnetic resonance (EPR spectroscopy. Chemical characteristics of PM10 included tracers for biomass burning (levoglucosan, mannosan and galactosan, elemental and organic carbon (EC/OC and polycyclic aromatic hydrocarbons (PAHs. Most samples displayed dose-dependent cytotoxicity and IL-8 induction. Spatial and temporal differences in PM10 toxicity were seen. PM10 collected at the urban site was characterized by increased pro-inflammatory and mutagenic activity as well as higher OP and elevated endotoxin levels compared to the background area. Reduced cell viability (−0.46 < rs < −0.35, p < 0.01 and IL-8 induction (−0.62 < rs < −0.67, p < 0.01 were associated with all markers for biomass burning, levoglucosan, mannosan and galactosan. Furthermore, direct and indirect mutagenicity were associated with tracers for biomass burning, OC, EC and PAHs. Multiple regression analyses showed levoglucosan to explain 16% and 28% of the variance in direct and indirect mutagenicity, respectively. Markers for biomass burning were

DOE contractor's meeting on chemical toxicity

International Nuclear Information System (INIS)

1987-01-01

The Office of Health and Environmental Research (OHER) is required to determine the potential health and environmental effects associated with energy production and use. To ensure appropriate communication among investigators and scientific disciplines that these research studies represent, OHER has sponsored workshops. This document provides a compilation of activities at the Third Annual DOE/OHER Workshop. This year's workshop was broadened to include all OHER activities identified as within the chemical effects area. The workshop consisted of eight sessions entitled Isolation and Detection of Toxic chemicals; Adduct Formation and Repair; Chemical Toxicity (Posters); Metabolism and Genotoxicity; Inhalation Toxicology; Gene Regulation; Metals Toxicity; and Biological Mechanisms. This document contains abstracts of the information presented by session

A novel hybrid tobacco product that delivers a tobacco flavour note with vapour aerosol (Part 1): Product operation and preliminary aerosol chemistry assessment.

Science.gov (United States)

Poynton, Simon; Sutton, Joseph; Goodall, Sharon; Margham, Jennifer; Forster, Mark; Scott, Ken; Liu, Chuan; McAdam, Kevin; Murphy, James; Proctor, Christopher

2017-08-01

Vapour products have demonstrated potential to be a lower-risk alternative to cigarettes. The present study describes a novel hybrid tobacco product that combines a warm aerosol stream generated by an electronic vaporisation mechanism with tobacco top flavour from cut tobacco. During operation, the aerosol stream released from the vapour cartomiser is passed through a bed of blended cut tobacco by the puffing flow, elevating the tobacco temperature and eluting volatile tobacco flavour components. A preliminary but comprehensive analysis of the aerosol composition of the hybrid tobacco product found that emissions were dominated by the control vapour formulation. In non-targeted chemical screening, no detectable difference in GC scans was observed between the hybrid tobacco product and the control vapour product. However, a sensorially elevated tobacco flavour was confirmed by a consumer sensory panel (P products, only 26 were quantified. The novel action of tobacco heating and liquid aerosolisation produced classes and levels of toxicants that were similar to those of the control vapour product, but much lower than those of a Kentucky 3R4F reference cigarette. For nine toxicants mandated by the WHO Study Group on Tobacco Product Regulation for reduction in cigarette emissions, the levels were 91%-99% lower per puff in the hybrid tobacco product aerosol than in 3R4F smoke. Overall, the novel hybrid tobacco product provides a sensorially enhanced tobacco flavour, but maintains a toxicant profile similar to its parent vapour product with relatively low levels of known cigarette smoke toxicants. Copyright © 2017 British American Tobacco. Published by Elsevier Ltd.. All rights reserved.

Environmental, health and safety issues related to the production and use of CdTe photovoltaic modules

International Nuclear Information System (INIS)

Moskowitz, P.D.

1992-01-01

This paper examines environmental, health and safety issues associated with the production and use of CdTe photovoltaic modules. Handling of Cd and Te in photovoltaic production can present hazards to health, safety and the environment. Prior recognition of these hazards can allow device manufacturers time to implement appropriate hazard management strategies. The most important health hazards are probably related to chronic low-level exposures to Cd, especially to workers in manufacturing facilities. Because of the long latency period associated with the development of health effects arising from such exposures, and the availability of environmental and biomonitoring protocols, such hazards can be monitored and controlled. The true hazard presented by CdTe is very uncertain because characterizations of its inherent biological toxicity are based on extrapolation of data from other Cd compounds. Technical and institutional mechanisms for the recycling of spent CdTe modules may be needed to ensure public acceptance of this material option and to eliminate expensive disposal costs. (author)

Towards a more complete understanding of the occurrence and toxicities of the cylindrospermopsins

Directory of Open Access Journals (Sweden)

Ross Sadler

2015-08-01

Full Text Available The existence of a number of cylindrospermopsin analogs has been confirmed by several authors. These cylindrospermopsin analogs were formerly seen as minor constituents, with normal cylindrospermopsin always being the dominant form. However, it is now clear that the cylindrospermopsin analogs are the major species produced by certain organisms, the production being enhanced, at least in some cases, under specific physiological conditions. Presently, relatively little information is available concerning the properties, physiology of occurrence and toxicity of these molecules. The existing literature pertaining to these aspects is reviewed with respect to known cylindrospermopsin analogs.The biosynthesis of the cylindrospermopsins is discussed and the previously established pathway has been modified to take account of the production of the known cylindrospermopsin forms. The anomalies in terms of in-vivo toxicity of 7-deoxy-cylindrospermopsin are reported, along with further attempts to rationalize the situation. We also discuss reasons for the apparently similar toxicity of 7-deoxy-cylindrospermopsin and cylindrospermopsin to cell cultures in vitro. It is hypothesized that the similarity of cylindrospermopsin intoxication to nonalcoholic fatty liver disease may argue for these cyanotoxins to exert their effects via a lysosomal pathway.

Toxic chemicals: risk prevention through use reduction

National Research Council Canada - National Science Library

Higgins, Thomas E; Sachdev, Jayanti A; Engleman, Stephen A

2011-01-01

... on the actual toxicity of chemicals currently in use, discusses variables that contribute to the relative toxicity of a substance, compares alternate emphases in existing programs for reducing environmental...

VirtualToxLab — A platform for estimating the toxic potential of drugs, chemicals and natural products

International Nuclear Information System (INIS)

Vedani, Angelo; Dobler, Max; Smieško, Martin

2012-01-01

The VirtualToxLab is an in silico technology for estimating the toxic potential (endocrine and metabolic disruption, some aspects of carcinogenicity and cardiotoxicity) of drugs, chemicals and natural products. The technology is based on an automated protocol that simulates and quantifies the binding of small molecules towards a series of proteins, known or suspected to trigger adverse effects. The toxic potential, a non-linear function ranging from 0.0 (none) to 1.0 (extreme), is derived from the individual binding affinities of a compound towards currently 16 target proteins: 10 nuclear receptors (androgen, estrogen α, estrogen β, glucocorticoid, liver X, mineralocorticoid, peroxisome proliferator-activated receptor γ, progesterone, thyroid α, and thyroid β), four members of the cytochrome P450 enzyme family (1A2, 2C9, 2D6, and 3A4), a cytosolic transcription factor (aryl hydrocarbon receptor) and a potassium ion channel (hERG). The interface to the technology allows building and uploading molecular structures, viewing and downloading results and, most importantly, rationalizing any prediction at the atomic level by interactively analyzing the binding mode of a compound with its target protein(s) in real-time 3D. The VirtualToxLab has been used to predict the toxic potential for over 2500 compounds: the results are posted on (http://www.virtualtoxlab.org). The free platform — the OpenVirtualToxLab — is accessible (in client–server mode) over the Internet. It is free of charge for universities, governmental agencies, regulatory bodies and non-profit organizations. -- Highlights: ► In silico technology for estimating the toxic potential of drugs and chemicals. ► Simulation of binding towards 16 proteins suspected to trigger adverse effects. ► Mechanistic interpretation and real-time 3D visualization. ► Accessible over the Internet. ► Free of charge for universities, governmental agencies, regulatory bodies and NPOs.

VirtualToxLab — A platform for estimating the toxic potential of drugs, chemicals and natural products

Energy Technology Data Exchange (ETDEWEB)

Vedani, Angelo, E-mail: angelo.vedani@unibas.ch [Biographics Laboratory 3R, Klingelbergstrasse 50, 4056 Basel (Switzerland); Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel (Switzerland); Dobler, Max [Biographics Laboratory 3R, Klingelbergstrasse 50, 4056 Basel (Switzerland); Smieško, Martin [Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel (Switzerland)

2012-06-01

The VirtualToxLab is an in silico technology for estimating the toxic potential (endocrine and metabolic disruption, some aspects of carcinogenicity and cardiotoxicity) of drugs, chemicals and natural products. The technology is based on an automated protocol that simulates and quantifies the binding of small molecules towards a series of proteins, known or suspected to trigger adverse effects. The toxic potential, a non-linear function ranging from 0.0 (none) to 1.0 (extreme), is derived from the individual binding affinities of a compound towards currently 16 target proteins: 10 nuclear receptors (androgen, estrogen α, estrogen β, glucocorticoid, liver X, mineralocorticoid, peroxisome proliferator-activated receptor γ, progesterone, thyroid α, and thyroid β), four members of the cytochrome P450 enzyme family (1A2, 2C9, 2D6, and 3A4), a cytosolic transcription factor (aryl hydrocarbon receptor) and a potassium ion channel (hERG). The interface to the technology allows building and uploading molecular structures, viewing and downloading results and, most importantly, rationalizing any prediction at the atomic level by interactively analyzing the binding mode of a compound with its target protein(s) in real-time 3D. The VirtualToxLab has been used to predict the toxic potential for over 2500 compounds: the results are posted on (http://www.virtualtoxlab.org). The free platform — the OpenVirtualToxLab — is accessible (in client–server mode) over the Internet. It is free of charge for universities, governmental agencies, regulatory bodies and non-profit organizations. -- Highlights: ► In silico technology for estimating the toxic potential of drugs and chemicals. ► Simulation of binding towards 16 proteins suspected to trigger adverse effects. ► Mechanistic interpretation and real-time 3D visualization. ► Accessible over the Internet. ► Free of charge for universities, governmental agencies, regulatory bodies and NPOs.

The impact of gastrointestinal and genitourinary toxicity on health related quality of life among irradiated prostate cancer patients

NARCIS (Netherlands)

Schaake, Wouter; Wiegman, Erwin M.; de Groot, Martijn; van der Laan, Hans Paul; van der Schans, Cees; van den Bergh, Alfons C.M.; Langendijk, Johannes A.

2013-01-01

PURPOSE: To determine the impact of late radiation-induced toxicity on health-related quality of life (HRQoL) among patients with prostate cancer. PATIENTS AND METHODS: The study sample was composed of 227 patients, treated with external beam radiotherapy. Common Terminology Criteria for Adverse

The impact of gastrointestinal and genitourinary toxicity on health related quality of life among irradiated prostate cancer patients

NARCIS (Netherlands)

Schaake, Wouter; Wiegman, Erwin M; de Groot, Martijn; van der Laan, Hans Paul; van der Schans, Cees P.; van den Bergh, Alfons C M; Langendijk, Johannes A

PURPOSE: To determine the impact of late radiation-induced toxicity on health-related quality of life (HRQoL) among patients with prostate cancer. PATIENTS AND METHODS: The study sample was composed of 227 patients, treated with external beam radiotherapy. Common Terminology Criteria for Adverse

Aluminium localization and toxicity symptoms related to root growth ...

Indian Academy of Sciences (India)

We correlated root growth inhibition with aluminium (Al3+) localization and toxicity symptoms in rice roots using seedlings of two genotypes (tolerant and sensitive) that were exposed to different AlCl3 concentrations. Al3+ localization was evaluated by hematoxylin in primary roots and by morin in cross-sections of the root ...

Talking about Relations : Factors Influencing the Production of Relational Descriptions

NARCIS (Netherlands)

Baltaretu, Adriana-Alexandra; Krahmer, Emiel; van Wijk, Carel; Maes, Alfons

2016-01-01

In a production experiment (Experiment 1) and an acceptability rating one (Experiment 2), we assessed two factors, spatial position and salience, which may influence the production of relational descriptions (such as “the ball between the man and the drawer”). In Experiment 1, speakers were asked to

Biotransformation and induction: implications for toxicity, bioaccumulation and monitoring of environmental xenobiotics in fish

International Nuclear Information System (INIS)

Kleinow, K.M.; Melancon, M.J.; Lech, J.J.

1987-01-01

Biotransformation of xenobiotics in fish occurs by many of the same reactions as in mammals. These reactions have been shown to affect the bioaccumulation, persistence, residue dynamics, and toxicity of select chemicals in fish. P-450-dependent monooxygenase activity of fish can be induced by polycyclic aromatic hydrocarbons, but phenobarbital-type agents induce poorly, if at all. Fish monooxygenase activity exhibits ideal temperature compensation and sex-related variation. Induction of monooxygenase activity by polycyclic aromatic hydrocarbons can result in qualitative as well as quantitative changes in the metabolic profile of a chemical. Induction can also alter toxicity. In addition, multiple P-450 isozymes have been described for several fish species. The biotransformation productions of certain chemicals have been related to specific P-450 isozymes, and the formation of these products can be influenced by induction. Exposure of fish to low levels of certain environmental contaminants has resulted in induction of specific monooxygenase activities and monitoring of such activities has been suggested as a means of identifying areas of pollutant exposure in the wild

Toxic effects on and structure-toxicity relationships of phenylpropanoids, terpenes, and related compounds in Aedes aegypti larvae.

Science.gov (United States)

Santos, Sandra R L; Silva, Viviane B; Melo, Manuela A; Barbosa, Juliana D F; Santos, Roseli L C; de Sousa, Damião P; Cavalcanti, Sócrates C H

2010-12-01

In the search for toxic compounds against Aedes aegypti L. (Diptera: Culicidae) larvae, a collection of commercially available aromatic and aliphatic diversely substituted compounds were selected and evaluated. p-Cymene exhibited the highest larvicidal potency LC₅₀ = 51 ppm, whereas 1,8-cineole exhibited the lowest activity value LC₅₀ = 1419 ppm. To aid future work on the search for larvicidal compounds, the structure-toxicity relationships of this collection have been evaluated. The presence of lipophilic groups results in an overall increase in potency. In general, the presence of hydroxyl groups resulted in less potent compounds. However, methylation of such hydroxyls led to an overall increase in potency. The most potent compounds showed comparably good larvicidal activity in A. aegypti larvae as other terpenes, which we assume to be the result of the increased lipophilicity.

A non-toxic fluorogenic dye for mitochondria labeling.

Science.gov (United States)

Han, Junyan; Han, Myung Shin; Tung, Ching-Hsuan

2013-11-01

Mitochondria, powerhouses of cells, are responsible for many critical cellular functions, such as cell energy metabolism, reactive oxygen species production, and apoptosis regulation. Monitoring mitochondria morphology in live cells temporally and spatially could help with the understanding of the mechanisms of mitochondrial functional regulation and the pathogenesis of mitochondria-related diseases. A novel non-cytotoxic fluorogenic compound, AcQCy7, was developed as a mitochondria-specific dye. AcQCy7 emitted no fluorescent signal outside of cells, but it became fluorescent after intracellular hydrolysis of the acetyl group. The hydrolyzed fluorescent product was well retained in mitochondria, enabling long-lasting fluorescence imaging of mitochondria without cell washing. A 2-day culture study using AcQCy7 showed no sign of cytotoxicity, whereas a commonly used mitochondria-staining probe, Mitochondria Tracker Green, caused significant cell death even at a much lower concentration. Apoptosis-causing mitochondria fission was monitored clearly in real time by AcQCy7. A simple add-and-read mitochondria specific dye AcQCy7 has been validated in various cell models. Bright mitochondria specific fluorescent signal in treated cells lasted several days without noticeable toxicity. The probe AcQCy7 has been proofed to be a non-toxic agent for long-term mitochondria imaging. © 2013.

Percentage of toxic trace elements; Pb, Cr and Cd in certain plastic toys, Isfahan City

Directory of Open Access Journals (Sweden)

F Kavehzadeh

2006-04-01

Full Text Available Introduction: Recent investigations have detected the presence of significant levels of heavy metals (chromium, lead and cadmium in toys and other PVC products manufactured for children. In some countries, addition of compounds containing toxic metals to toys are limited or prohibited. Methods: To evaluate the safety of some of the plastic toys in the city of Isfahan with respect to toxic trace metals, pb, cr and cd, 75 samples of three types of toys were collected from the toy shop’s and were digested with acid with the two methods ISIRI and ASTM. The heavy metals were determined using atomic absorption spectrophotometer. Variance analysis and T-test were used for data analysis. Results: The result of the study showed that the products tested contained lead, chromium and cadmium and the highest and lowest concentration were related to Pb and Cd, respectively. The statistical analysis of the samples showed that there are no significant differences between ASTM and ISIRI digestion methods. The study revealed that none of the heavy metals in the toy samples exceeded the recommended standard levels. Highest average concentration of Pb and Cd were related to toys with green color and the highest Cr concentration was related to yellow toys in this study. Conclusion: Extensive studies are required to evaluate the quality of the toys being used by children and the toxic trace elements should be eliminated from the plastic materials used for making toys.

Toxicity of pyrolysis gases from polyether sulfone

Science.gov (United States)

Hilado, C. J.; Olcomendy, E. M.

1979-01-01

A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

The role of intestinal microbiota in development of irinotecan toxicity and in toxicity reduction through dietary fibres in rats.

Directory of Open Access Journals (Sweden)

Xiaoxi B Lin

Full Text Available CPT-11 is a drug used as chemotherapy for colorectal cancer. CPT-11 causes toxic side-effects in patients. CPT-11 toxicity has been attributed to the activity of intestinal microbiota, however, intestinal microbiota may also have protective effects in CP!-11 chemotherapy. This study aimed to elucidate mechanisms through which microbiota and dietary fibres could modify host health. Rats bearing a Ward colon carcinoma were treated with a two-cycle CPT-11/5-fluorouracil therapy recapitulating clinical therapy of colorectal cancer. Animals were fed with a semi-purified diet or a semi-purified diet was supplemented with non-digestible carbohydrates (isomalto-oligosaccharides, resistant starch, fructo-oligosaccharides, or inulin in 3 independent experiments. Changes in intestinal microbiota, bacteria translocating to mesenteric lymphnodes, cecal GUD activity, and cecal SCFA production, and the intestinal concentration of CPT-11 and its metabolites were analysed. Non-digestible carbohydrates significantly influenced feed intake, body weight and other indicators of animal health. The identification of translocating bacteria and their quantification in cecal microbiota indicated that overgrowth of the intestine by opportunistic pathogens was not a major contributor to CPT-11 toxicity. Remarkably, fecal GUD activity positively correlated to body weight and feed intake but negatively correlated to cecal SN-38 concentrations and IL1-β. The reduction in CPT-11 toxicity by non-digestible carbohydrates did not correlate to stimulation of specific bacterial taxa. However, cecal butyrate concentrations and feed intake were highly correlated. The protective role of intestinal butyrate production was substantiated by a positive correlation of the host expression of MCT1 (monocarboxylate transporter 1 with body weight as well as a positive correlation of the abundance of bacterial butyryl-CoA gene with cecal butyrate concentrations. These correlations support the

Review of Phthalates Exposure and Toxicity

Directory of Open Access Journals (Sweden)

Samaneh Taghilou

2015-12-01

Full Text Available The dialkyl- or alkyl/aryl esters of 1, 2-benzenedicarboxylic acid, which are known as Phthalates, are high-production volume synthetic chemicals and considered as environmental pollutants, due to high production and uses in community, plastics industry and common consuming products. Di-(2-ethylhexyl phthalate (DEHP is the most abundant phthalate in the environment. Human exposure with DEHP could be done via different chemical compounds including food packaging, household furnishings, nutritional supplements, cleaning materials and insecticides. Besides, exposure of human with phthalates occurs through different pathways such as direct contact and using Phthalate-containing products, and indirectly through leaching into other products, or general environmental contaminations. Historically, the diet has been considered the major source of phthalate exposure in the general population, but in all sources, pathways, and their relative contributions to human exposures are not well understood. Medical devices are other source of significant exposure in human. Furthermore, cosmetics, personal care products, pharmaceuticals, nutritional supplements, herbal remedies and insecticides, may result in significant but poorly quantified human exposure with this compounds. In the present review article, we tried to discuss about metabolism of phthalates in human, toxicity, monitoring of phthalates in foods, environment, and cosmetic products and then metabolites of phthalates. Finally, evaluation of human exposure through biological control is discussed.

Toxic Hazards in Aviation.

Science.gov (United States)

1981-04-01

Pasteur, Lillm,FRANCE. (2) CONISH H.H., EARTH M.L.& IANNi F.L, "Comparative Toxicology of Platics during Thar-modecoqiorition Intsw-re8posium on...Pyrolysnis and Combustion of Materials" Firm and Materials (1976).1, 29-35 (8) ALAAIE Y."Toxicity of Platic dacomposition ProductsŖd Annu~al Progress

Kidney toxicity related to herbs and dietary supplements: Online table of case reports. Part 3 of 5 series.

Science.gov (United States)

Brown, Amy Christine

2017-09-01

No tabular summary of potentially life-threatening, kidney-toxic dietary supplements (DS; includes herbs) based on PubMed case reports is currently available online and continually updated to forewarn United States consumers, clinicians, and companies manufacturing DS. The purpose of this review was to create an online research summary table of kidney toxicity case reports related to DS. Documented PubMed case reports (1966 to May 2016, and cross-referencing) of DS appearing to contribute to kidney toxicity were listed in "DS Toxic Tables." Keywords included "herb" or "dietary supplement" combined with "kidney" to generate an overview list, and possibly "toxicity" to narrow the selection. Case reports were excluded if they involved herb combinations (some exceptions), Chinese herb mixtures, teas of mixed herb contents, mushrooms, poisonous plants, self-harm, excessive doses (except vitamins/minerals), legal or illegal drugs, drug-herbal interactions, and confounders of drugs or diseases. Since commercial DS often include a combination of ingredients, they were treated separately; so were foods. A few foods with kidney-toxic effects were listed in a fourth table. The spectrum of herbal or DS-induced kidney injuries included kidney stones, nephritis, nephrotic syndrome, necrosis, acute kidney injury (AKI; previously known as acute renal failure [ARF]), chronic kidney disease, kidney transplant, and death. Approximately 7 herbs (minus 4 no longer for sale) and 10 dietary supplements (minus 3 excluded due to excessive doses + germanium that is no longer sold) have been related to kidney injury case reports published in PubMed (+crosslisting) in the last 50 + years (1966 to May 2016). The implicated herbs include Chinese yew (Taxus celbica) extract, impila (Callilepis laureola), morning cypress (Cupressus funebris Endl), St. John's wort (Hypericum perforatum), thundergod vine (Tripterygium wilfordii hook F), tribulus (Tribulus terrestris) and wormwood (Artemisia

Paracetamol degradation intermediates and toxicity during photo-Fenton treatment using different iron species.

Science.gov (United States)

Trovó, Alam G; Pupo Nogueira, Raquel F; Agüera, Ana; Fernandez-Alba, Amadeo R; Malato, Sixto

2012-10-15

The photo-Fenton degradation of paracetamol (PCT) was evaluated using FeSO(4) and the iron complex potassium ferrioxalate (FeOx) as iron source under simulated solar light. The efficiency of the degradation process was evaluated considering the decay of PCT and total organic carbon concentration and the generation of carboxylic acids, ammonium and nitrate, expressed as total nitrogen. The results showed that the degradation was favored in the presence of FeSO(4) in relation to FeOx. The higher concentration of hydroxylated intermediates generated in the presence of FeSO(4) in relation to FeOx probably enhanced the reduction of Fe(III) to Fe(II) improving the degradation efficiency. The degradation products were determined using liquid chromatography electrospray time-of-flight mass spectrometry. Although at different concentrations, the same intermediates were generated using either FeSO(4) or FeOx, which were mainly products of hydroxylation reactions and acetamide. The toxicity of the sample for Vibrio fischeri and Daphnia magna decreased from 100% to less than 40% during photo-Fenton treatment in the presence of both iron species, except for D. magna in the presence of FeOx due to the toxicity of oxalate to this organism. The considerable decrease of the sample toxicity during photo-Fenton treatment using FeSO(4) indicates a safe application of the process for the removal of this pharmaceutical. Copyright © 2012 Elsevier Ltd. All rights reserved.

Drug metabolizing enzyme systems and their relationship to toxic mechanisms

International Nuclear Information System (INIS)

Boyd, M.R.; Ravindranath, V.; Burka, L.T.

1983-01-01

The metabolism and toxicity of 3-methylfuran (3-MF) are described. The major product of metabolic activation of 3-MF appears to be disemicarbazones. Cursory description of toxic effects of 3-MF on lung and kidneys are provided. 18 refs

Predictors of severe late radiotherapy-related toxicity after hyperfractionated radiotherapy with or without concomitant cisplatin in locally advanced head and neck cancer. Secondary retrospective analysis of a randomized phase III trial (SAKK 10/94)

International Nuclear Information System (INIS)

Ghadjar, Pirus; Simcock, Mathew; Zimmermann, Frank; Betz, Michael; Bodis, Stephan; Bernier, Jacques; Studer, Gabriela; Aebersold, Daniel M.

2012-01-01

Background and purpose: This secondary analysis was performed to identify predictive factors for severe late radiotherapy (RT)-related toxicity after treatment with hyperfractionated RT +/− concomitant cisplatin in locally advanced head and neck cancer. Materials and methods: Patients were retrospectively analyzed from the previously reported randomized phase III trial: SAKK 10/94. Severe late RT-related toxicity was defined as late RTOG ⩾ grade 3 toxicity starting 3 months after end of RT and/or potential treatment-related death within 3 years of randomization. Results: Two hundred and thirteen randomized patients were analyzed; 84 (39%) experienced severe late RT-related toxicity. With median follow-up of 9.7 years (range, 0.4–15.4 years), median time to severe late RT-related toxicity was 9.6 years. In the univariate Cox proportional hazards model the following variables were associated with severe late RT-related toxicity: advanced N-classification (p < 0.001); technically unresectable disease (p = 0.04); weight loss ratio (p = 0.003); supportive measures (p = 0.009) and severe acute dysphagia (p = 0.001). In the subsequent multivariate analysis all variables except use of supportive measures remained statistically significant. Conclusions: Chemotherapy did not appear to affect severe late RT-related toxicity, but advanced N-classification, technically unresectable disease, weight loss ratio, and severe acute dysphagia were independent predictive factors for severe late RT-related toxicity.

Membrane engineering via trans unsaturated fatty acids production improves Escherichia coli robustness and production of biorenewables.

Science.gov (United States)

Tan, Zaigao; Yoon, Jong Moon; Nielsen, David R; Shanks, Jacqueline V; Jarboe, Laura R

2016-05-01

Constructing microbial biocatalysts that produce biorenewables at economically viable yields and titers is often hampered by product toxicity. For production of short chain fatty acids, membrane damage is considered the primary mechanism of toxicity, particularly in regards to membrane integrity. Previous engineering efforts in Escherichia coli to increase membrane integrity, with the goal of increasing fatty acid tolerance and production, have had mixed results. Herein, a novel approach was used to reconstruct the E. coli membrane by enabling production of a novel membrane component. Specifically, trans unsaturated fatty acids (TUFA) were produced and incorporated into the membrane of E. coli MG1655 by expression of cis-trans isomerase (Cti) from Pseudomonas aeruginosa. While the engineered strain was found to have no increase in membrane integrity, a significant decrease in membrane fluidity was observed, meaning that membrane polarization and rigidity were increased by TUFA incorporation. As a result, tolerance to exogenously added octanoic acid and production of octanoic acid were both increased relative to the wild-type strain. This membrane engineering strategy to improve octanoic acid tolerance was found to require fine-tuning of TUFA abundance. Besides improving tolerance and production of carboxylic acids, TUFA production also enabled increased tolerance in E. coli to other bio-products, e.g. alcohols, organic acids, aromatic compounds, a variety of adverse industrial conditions, e.g. low pH, high temperature, and also elevated styrene production, another versatile bio-chemical product. TUFA permitted enhanced growth due to alleviation of bio-product toxicity, demonstrating the general effectiveness of this membrane engineering strategy towards improving strain robustness. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Toxicity of tritium

International Nuclear Information System (INIS)

Dobson, R.L.

1979-01-01

Among radionuclides of importance in atomic energy, 3 H has relatively low toxicity. The main health and environmental worry is the possibility that significant biological effects may follow from protracted exposure to low concentrations in water. To examine this possible hazard and measure toxicity at low tritium concentrations, chronic exposure studies were done on mice and monkeys. During vulnerable developmental periods animals were exposed to 3 HOH, and mice were exposed also to 60 Co gamma irradiation and energy-related chemical agents. The biological endpoint measured was the irreversible loss of female germ cells. Effects from tritium were observed at surprisingly low concentrations where 3 H was found more damaging than previously thought. Comparisons between tritium and gamma radiation showed the relative biological effectiveness (RBE) to be greater than 1 and to reach approximately 3 at very low exposures. For perspective, other comparisons were made: between radiation and chemical agents, which revealed parallels in action on germ cells, and between pre- and postnatal exposure, which warn of possible special hazard to the fetus from both classes of energy-related byproducts

Toxicity of diuron in human cancer cells.

Science.gov (United States)

Huovinen, Marjo; Loikkanen, Jarkko; Naarala, Jonne; Vähäkangas, Kirsi

2015-10-01

Diuron is a substituted phenylurea used as a herbicide to control broadleaf and grass weeds and as a biocidal antifouling agent. Diuron is carcinogenic in rat urinary bladder and toxic to the reproductive system of oysters, sea urchins and lizards. The few studies carried out in human cells do not include the genotoxicity of diuron. We have investigated the toxicity of diuron in human breast adenocarcinoma (MCF-7) and human placental choriocarcinoma (BeWo) cells. The production of reactive oxygen species (ROS) was statistically significantly increased in both cell lines but only at the highest 200 μM concentration. Diuron clearly reduced the viability of BeWo, but not MCF-7 cells. The relative cell number was decreased in both cell lines indicative of inhibition of cell proliferation. In the Comet assay, diuron increased DNA fragmentation in MCF-7 but not in BeWo cells. The expressions of p53 protein, a marker for cell stress, and p21 protein, a transcriptional target of p53, were increased, but only in MCF-7 cells. In conclusion, our results suggest that diuron is cytotoxic and potentially genotoxic in a tissue-specific manner and that ROS play a role in its toxicity. Thus, exposure to diuron may exert harmful effects on fetal development and damage human health. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experimental outgassing of toxic chemicals to simulate the characteristics of hazards tainting globally shipped products.

Directory of Open Access Journals (Sweden)

Lygia Therese Budnik

Full Text Available Ambient monitoring analyses may identify potential new public health hazards such as residual levels of fumigants and industrial chemicals off gassing from products and goods shipped globally. We analyzed container air with gas chromatography coupled to mass spectrometry (TD-2D-GC-MS/FPD and assessed whether the concentration of the volatiles benzene and 1,2-dichloroethane exceeded recommended exposure limits (REL. Products were taken from transport containers and analyzed for outgassing of volatiles. Furthermore, experimental outgassing was performed on packaging materials and textiles, to simulate the hazards tainting from globally shipped goods. The mean amounts of benzene in analyzed container air were 698-fold higher, and those of ethylene dichloride were 4.5-fold higher than the corresponding REL. More than 90% of all containers struck with toluene residues higher than its REL. For 1,2-dichloroethane 53% of containers, transporting shoes exceeded the REL. In standardized experimental fumigation of various products, outgassing of 1,2-dichloroethane under controlled laboratory conditions took up to several months. Globally produced transported products tainted with toxic industrial chemicals may contribute to the mixture of volatiles in indoor air as they are likely to emit for a long period. These results need to be taken into account for further evaluation of safety standards applying to workers and consumers.

WDVV equation and triple-product relation

International Nuclear Information System (INIS)

Shigechi, Keiichi; Wadati, Miki; Wang Ning

2005-01-01

We study the relation between the WDVV equations and the τ-function of the noncommutative KP (NCKP) hierarchy. WDVV-like equations (Hirota triple-product relation) in the noncommutative context appear as a consequence of the nontrivial equation for τ-function of the NC KP hierarchy, while the prepotential in the Seiberg-Witten (SW) theory has been identified to the τ-function of the Whitham hierarchy. We show that the spectral curve for the SW theory is the same as the Toda-chain hierarchy. We also show explicitly that Whitham hierarchy includes commutative Toda/KP hierarchy. Further, we comment on the origin of the Hirota triple-product relation in the context of the SW theory

COMPARATIVE ACUTE TOXICITY OF CHLORPYRIFOS-ETHYL ...

African Journals Online (AJOL)

MR OKEY

disintegration and low toxicity to birds and mammals (Maud et ... banned in some developed countries, are still being heavily used in Africa, and particularly in Nigeria. Multinational. Corporations continue to market banned products in.

Toxic effects of di(2-ethylhexyl)phthalate on mortality, growth, reproduction and stress-related gene expression in the soil nematode Caenorhabditis elegans.

Science.gov (United States)

Roh, Ji-Yeon; Jung, In-Ho; Lee, Jai-Young; Choi, Jinhee

2007-07-31

In this study, di(2-ethylhexyl)phthalate (DEHP) toxicities to Caenorhabditis elegans were investigated using multiple toxic endpoints, such as mortality, growth, reproduction and stress-related gene expression, focusing on the identification of chemical-induced gene expression as a sensitive biomarker for DEHP monitoring. The possible use of C. elegans as a sentinel organism in the monitoring of soil ecosystem health was also tested by conducting the experiment on the exposure of nematode to field soil. Twenty-four-hour median lethal concentration (LC50) data suggest that DEHP has a relatively high potential of acute toxicity to C. elegans. Decreases in body length and egg number per worm observed after 24h of DEHP exposure may induce long-term alteration in the growth and reproduction of the nematode population. Based on the result from the C. elegans genome array and indicated in the literatures, stress proteins, metallothionein, vitellogenin, xenobiotic metabolism enzymes, apoptosis-related proteins, and antioxidant enzyme genes were selected as stress-related genes and their expression in C. elegans by DEHP exposure was analyzed semi-quantitatively. Expression of heat shock protein (hsp)-16.1 and hsp-16.2 genes was decreased by DEHP exposure. Expression of cytochrome P450 (cyp) 35a2 and glutathione-S-transferease (gst)-4, phase I and phase II of xenobiotic metabolism enzymes, was increased by DEHP exposure in a concentration-dependent manner. An increase in stress-related gene expressions occurred concomitantly with the deterioration on the physiological level, which suggests an increase in expression of those genes may not be considered as a homeostatic response but as a toxicity that might have physiological consequences. The experiment with the soil from the landfill site suggests that the potential of the C. elegans biomarker identified in laboratory conditions should be calibrated and validated for its use in situ.

Comparative toxicity of petrol and kerosene to periwinkle ...

African Journals Online (AJOL)

The comparative toxicities of two petroleum products, petrol and kerosene were examined by exposing Tympanotonus fuscatus to acute concentrations (60, 90, 120 and 150ml/L) of these toxicants for 96 hours. The 48th hour LC50 for petrol was 177.36 ml/L, while that of kerosene was 306.16 ml/L. The 96th hour LC50 was ...

Comparative chronic toxicity of imidacloprid, clothianidin, and thiamethoxam to Chironomus dilutus and estimation of toxic equivalency factors.

Science.gov (United States)

Cavallaro, Michael C; Morrissey, Christy A; Headley, John V; Peru, Kerry M; Liber, Karsten

2017-02-01

Nontarget aquatic insects are susceptible to chronic neonicotinoid insecticide exposure during the early stages of development from repeated runoff events and prolonged persistence of these chemicals. Investigations on the chronic toxicity of neonicotinoids to aquatic invertebrates have been limited to a few species and under different laboratory conditions that often preclude direct comparisons of the relative toxicity of different compounds. In the present study, full life-cycle toxicity tests using Chironomus dilutus were performed to compare the toxicity of 3 commonly used neonicotinoids: imidacloprid, clothianidin, and thiamethoxam. Test conditions followed a static-renewal exposure protocol in which lethal and sublethal endpoints were assessed on days 14 and 40. Reduced emergence success, advanced emergence timing, and male-biased sex ratios were sensitive responses to low-level neonicotinoid exposure. The 14-d median lethal concentrations for imidacloprid, clothianidin, and thiamethoxam were 1.52 μg/L, 2.41 μg/L, and 23.60 μg/L, respectively. The 40-d median effect concentrations (emergence) for imidacloprid, clothianidin, and thiamethoxam were 0.39 μg/L, 0.28 μg/L, and 4.13 μg/L, respectively. Toxic equivalence relative to imidacloprid was estimated through a 3-point response average of equivalencies calculated at 20%, 50%, and 90% lethal and effect concentrations. Relative to imidacloprid (toxic equivalency factor [TEF] = 1.0), chronic (lethality) 14-d TEFs for clothianidin and thiamethoxam were 1.05 and 0.14, respectively, and chronic (emergence inhibition) 40-d TEFs were 1.62 and 0.11, respectively. These population-relevant endpoints and TEFs suggest that imidacloprid and clothianidin exert comparable chronic toxicity to C. dilutus, whereas thiamethoxam induced comparable effects only at concentrations an order of magnitude higher. However, the authors caution that under field conditions, thiamethoxam readily degrades to

Marine toxicity and persistence of surfactants used in the petroleum producing industry

International Nuclear Information System (INIS)

Maddin, C.M.

1991-01-01

This paper presents a survey of marine toxicity and biodegradability data for surfactants used in the petroleum industry. Surfactants are key chemicals in the formulation of products such as emulsifiers, demulsifiers, dispersants and inhibitors. They are also used directly as foaming and defoaming agents. Because they function at low concentrations, below 1%, and have a tendency to adsorb on solid surfaces, their long-term environmental effects are minimal. In applications such as cementing, surfactants cannot migrate into the environment and, thus, have no bioavailability. The possibility of environmental contamination has caused well operators and regulatory agencies to require fish toxicity and persistence data for products used in servicing wells. This data has been organized for nonionic, anionic, cationic and amphoteric surfactants. Nonionic surfactants are toxic to fish at concentrations below 10 mg/L to over 2500 mg/L depending on their chemical compositions. Anionic surfactants are toxic to fish at concentrations under 1 mg/L to several hundred mg/L depending on their chemical compositions. cationic and amphoteric surfactants are generally toxic to fish at concentrations below 50 mg/L. Overall efforts are aimed at low toxicity and high biodegradability with the least compromise in product efficiency. This requires the continual testing and environmental evaluation of surfactants summarized herein

Decomposing one-relator products of cyclic groups into free products with amalgamation

International Nuclear Information System (INIS)

Benyash-Krivets, V V

1998-01-01

The problem of the decomposition of one-relator products of cyclics into non-trivial free products with amalgamation is considered. Two theorems are proved, one of which is as follows. Let G= 2n =R m (a,b)=1>, where n≥0, m≥2, and R(a,b) is a cyclically reduced word containing b in the free group on a and b. Then G is a non-trivial free product with amalgamation. One consequence of this theorem is a proof of the conjecture of Fine, Levin, and Rosenberger that each two-generator one-relator group with torsion is a non-trivial free product with amalgamation

Acute skin toxicity-related, out-of-pocket expenses in patients with breast cancer treated with external beam radiotherapy: a descriptive, exploratory study.

Science.gov (United States)

Schnur, Julie B; Graff Zivin, Joshua; Mattson, David M K; Green, Sheryl; Jandorf, Lina H; Wernicke, A Gabriella; Montgomery, Guy H

2012-12-01

Acute skin toxicity is one of the most common side effects of breast cancer radiotherapy. To date, no one has estimated the nonmedical out-of-pocket expenses associated with this side effect. The primary aim of the present descriptive, exploratory study was to assess the feasibility of a newly developed skin toxicity costs questionnaire. The secondary aims were to: (1) estimate nonmedical out-of-pocket costs, (2) examine the nature of the costs, (3) explore potential background predictors of costs, and (4) explore the relationship between patient-reported dermatologic quality of life and expenditures. A total of 50 patients (mean age = 54.88, Stage 0-III) undergoing external beam radiotherapy completed a demographics/medical history questionnaire as well as a seven-item Skin Toxicity Costs (STC) questionnaire and the Skindex-16 in week 5 of treatment. Mean skin toxicity costs were $131.64 (standard error [SE] = $23.68). Most frequently incurred expenditures were new undergarments and products to manage toxicity. Education was a significant unique predictor of spending, with more educated women spending more money. Greater functioning impairment was associated with greater costs. The STC proved to be a practical, brief measure which successfully indicated specific areas of patient expenditures and need. Results reveal the nonmedical, out-of-pocket costs associated with acute skin toxicity in the context of breast cancer radiotherapy. To our knowledge, this study is the first to quantify individual costs associated with this treatment side effect, as well as the first to present a scale specifically designed to assess such costs. In future research, the STC could be used as an outcome variable in skin toxicity prevention and control research, as a behavioral indicator of symptom burden, or as part of a needs assessment.

A proposal for a classification of product-related dependencies in development of mechatronic products

DEFF Research Database (Denmark)

Torry-Smith, Jonas; Mortensen, Niels Henrik; Achiche, Sofiane

2014-01-01

to the classification of product-related dependencies. Traditionally these dependencies have been described as appearing between the following product attributes: function, properties and structure. By analysing three mechatronic projects from industry we identified and classified 13 types of product......-related dependencies. Each product-related dependency is described and illustrated using the practical examples from the industrial projects. The value of the classification is evaluated by applying it to an industrial development setting not used for the analysis. The evaluation shows that delays in the project...

Effects of toxic metals and chemicals on biofilm and biocorrosion.

Science.gov (United States)

Fang, Herbert H P; Xu, Li-Chong; Chan, Kwong-Yu

2002-11-01

Microbes in marine biofilms aggregated into clusters and increased the production of extracellular polymeric substances (EPS), by over 100% in some cases, when the seawater media containing toxic metals and chemicals, such as Cd(II), Cu(II), Pb(II), Zn(II), AI(III), Cr(III), glutaraldehyde, and phenol. The formation of microbial cluster and the increased production of EPS, which contained 84-92% proteins and 8-16% polysaccharides, accelerated the corrosion of the mild steel. However, there was no quantitative relationship between the degree of increased corrosion and the toxicity of metals/chemicals towards sulfate-reducing bacteria, or the increased EPS production.

Trichothecenes: structure-toxic activity relationships.

Science.gov (United States)

Wu, Qinghua; Dohnal, Vlastimil; Kuca, Kamil; Yuan, Zonghui

2013-07-01

Trichothecenes comprise a large family of structurally related toxins mainly produced by fungi belonging to the genus Fusarium. Among trichothecenes, type A and type B are of the most concern due to their broad and highly toxic nature. In order to address structure-activity relationships (SAR) of trichothecenes, relationships between structural features and biological effects of trichothecene mycotoxins in mammalian systems are summarized in this paper. The double bond between C-9-C-10 and the 12,13-epoxide ring are essential structural features for trichothecene toxicity. Removal of these groups results in a complete loss of toxicity. A hydroxyl group at C-3 enhances trichothecene toxicity, while this activity decreases gradually when C-3 is substituted with either hydrogen or an acetoxy group. The presence of a hydroxyl group at C-4 promotes slightly lower toxicity than an acetoxy group at the same position. The toxicity for type B trichothecenes decreases if the substituent at C-4 is changed from acetoxy to hydroxyl or hydrogen at C-4 position. The presence of hydroxyl and hydrogen groups on C-15 decreases the trichothecene toxicity in comparison with an acetoxy group attached to this carbon. Trichothecenes toxicity increases when a macrocyclic ring exists between the C-4 and C-15. At C-8 position, an oxygenated substitution at C-8 is essential for trichothecene toxicity, indicating a decrease in the toxicity if substituent change from isovaleryloxy through hydrogen to the hydroxyl group. The presence of a second epoxy ring at C-7-C-8 reduces the toxicity, whereas epoxidation at C-9-C-10 of some macrocyclic trichothecenes increases the activity. Conjugated trichothecenes could release their toxic precursors after hydrolysis in animals, and present an additional potential risk. The SAR study of trichothecenes should provide some crucial information for a better understanding of trichothecene chemical and biological properties in food contamination.

Price-related promotions for tobacco products on Twitter.

Science.gov (United States)

Jo, Catherine L; Kornfield, Rachel; Kim, Yoonsang; Emery, Sherry; Ribisl, Kurt M

2016-07-01

This cross-sectional study examined price-related promotions for tobacco products on Twitter. Through the Twitter Firehose, we obtained access to all public tweets posted between 6 December 2012 and 20 June 2013 that contained a keyword suggesting a tobacco-related product or behaviour (eg, cigarette, vaping) in addition to a keyword suggesting a price promotion (eg, coupon, discount). From this data set of 155 249 tweets, we constructed a stratified sampling frame based on the price-related keywords and randomly sampled 5000 tweets (3.2%). Tweets were coded for product type and promotion type. Non-English tweets and tweets unrelated to a tobacco or cessation price promotion were excluded, leaving an analytic sample of 2847 tweets. The majority of tweets (97.0%) mentioned tobacco products while 3% mentioned tobacco cessation products. E-cigarettes were the most frequently mentioned product (90.1%), followed by cigarettes (5.4%). The most common type of price promotion mentioned across all products was a discount. About a third of all e-cigarette-related tweets included a discount code. Banned or restricted price promotions comprised about 3% of cigarette-related tweets. This study demonstrates that the vast majority of tweets offering price promotions focus on e-cigarettes. Future studies should examine the extent to which Twitter users, particularly youth, notice or engage with these price promotion tweets. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Chronic Dermal Toxicity of Epoxy Resins I. Skin Carcinogenic Potency and General Toxicity

Energy Technology Data Exchange (ETDEWEB)

Holland, J.M.

2001-01-16

Epoxy resins are a diverse class of chemicals that differ in structure, physical properties, and, presumably, biological activity. The purpose of these experiments was to compare the chronic dermal toxicity and carcinogenicity of selected commercial epoxy resins and to determine the potential for positive synergistic carcinogenic interactions between different resins. This work is an extension and continuation of a Department of Energy sponsored program to evaluate epoxy resins for potential occupational health risks. The materials examined were chosen on the basis of their interest to the U.S. government. They are representative of the manufacturer's production at the time, and therefore the data are completely valid only for the specific production period. Results of the experimental exposures will be reported in two parts. This report describes the test materials, their chemical and physical characteristics and the experimental design. General (systemic) toxicity will be evaluated and the skin carcinogenicity of the materials compared. A subsequent report will provide morphological descriptions of skin and significant internal pathology induced by the various treatments.

Productivity loss at work; health-related and work-related factors.

Science.gov (United States)

van den Heuvel, Swenne G; Geuskens, Goedele A; Hooftman, Wendela E; Koppes, Lando L J; van den Bossche, Seth N J

2010-09-01

Productivity loss is an increasing problem in an aging working population that is decreasing in numbers. The aim of this study is to identify work-related and health-related characteristics associated with productivity loss, due to either sickness absence or reduced performance at work. In this cross-sectional study, data of the Netherlands Working Conditions Survey of 2007 were used, which includes a national representative sample of 22,759 employees aged 15 to 64 years. Demographic characteristics, health-related and work-related factors were assessed with a questionnaire. Logistic regression analyses were carried out to study the relationship of work-related and health-related factors with low performance at work and sickness absence in the past 12 months. Poor general health, the number of longstanding health conditions, and most types of longstanding health conditions were associated with productivity loss. Health-related factors were in general stronger associated with sickness absence than with low performance at work. Performance: poor health OR 1.54 CI 1.38-1.71, >1 health conditions OR 1.21 CI 1.09-1.35; sickness absence: poor health OR 2.62 CI 2.33-2.93, >1 health conditions OR 2.47 CI 2.21-2.75. Of the different types of longstanding health conditions, only psychological complaints and to a small extent musculoskeletal symptoms, were associated with low performance (respectively OR 1.54 CI 1.27-1.87; OR 1.09 CI 1.00-1.18). Low performance at work was less likely among employees with high physically demanding work (shift work OR 0.70 CI 0.63-0.76, using force OR 0.78 CI 0.72-0.84, and repetitive movements OR 0.74 CI 0.70-0.79). Psychosocial factors were stronger associated with low performance at work than with sickness absence (performance: job autonomy OR 1.28 CI 1.21-1.37, job demands OR 1.23 CI 1.16-1.31, emotionally demanding work OR 1.73 CI 1.62-1.85; sickness absence: job autonomy ns, job demands OR 1.09 CI 1.03-1.17, emotionally demanding work OR

Algal toxicity of the alternative disinfectants performic acid (PFA), peracetic acid (PAA), chlorine dioxide (ClO2) and their by-products hydrogen peroxide (H2O2) and chlorite (ClO2-).

Science.gov (United States)

Chhetri, Ravi Kumar; Baun, Anders; Andersen, Henrik Rasmus

2017-05-01

Environmental effect evaluation of disinfection of combined sewer overflow events with alternative chemical disinfectants requires that the environmental toxicity of the disinfectants and the main by-products of their use are known. Many disinfectants degrade quickly in water which should be included in the evaluation of both their toxicity as determined in standardized tests and their possible negative effect in the water environment. Here we evaluated according to the standardized ISO 8692 test the toxicity towards the green microalgae, Pseudokirchneriella subcapitata, of three disinfectants: performic acid (PFA), peracetic acid (PAA) and chlorine dioxide (ClO 2 ) as well as two by-products of their use: hydrogen peroxide (H 2 O 2 ) and chlorite. All of the five chemicals investigated showed clear toxicity to the algae with well-defined dose response curves. The EC 50 values ranged from 0.16 to 2.9mg/L based on nominal concentrations leading to the labeling of the chemicals as either toxic or very toxic. The five investigated chemicals decreased in toxicity in the order chlorine dioxide, performic acid, peracetic acid, chlorite and hydrogen peroxide. The stability of the chemicals increased in the same order as the toxicity decrease. This indicates that even though ClO 2 has the highest environmental hazard potential, it may still be suitable as an alternative disinfectant due to its rapid degradation in water. Copyright © 2016 Elsevier GmbH. All rights reserved.

Hyperfunctioning thyroid nodules in toxic multinodular goiter share activating thyrotropin receptor mutations with solitary toxic adenoma.

Science.gov (United States)

Tonacchera, M; Chiovato, L; Pinchera, A; Agretti, P; Fiore, E; Cetani, F; Rocchi, R; Viacava, P; Miccoli, P; Vitti, P

1998-02-01

Toxic multinodular goiter is a cause of nonautoimmune hyperthyroidism and is believed to differ in its nature and pathogenesis from toxic adenoma. Gain-of-function mutations of the TSH receptor gene have been identified as a cause of toxic adenoma. The pathogenesis at the molecular level of hyperfunctioning nodules in toxic multinodular goiter has yet not been reported. Six patients with a single hot nodule within a multinodular goiter and 11 patients with toxic thyroid adenoma were enrolled in our study. At histology five hyperfunctioning nodules in multinodular goiters showed the features of adenomas, and one was identified as a hyperplastic nodule. The entire exon 10 of the TSH receptor gene was directly sequenced after PCR amplification from genomic DNA obtained from surgical specimens. Functional studies of mutated receptors were performed in COS-7 cells. Five out of 6 (83%) hyperfunctioning nodules within toxic multinodular goiters harbored a TSH receptor mutation. A TSH receptor mutation was also evident in the hyperfunctioning nodule that at histology had the features of noncapsulated hyperplastic nodule. Among toxic adenomas, 8 out of 11 (72%) nodules harbored a TSH receptor mutation. All the mutations were heterozygotic and somatic. Nonfunctioning nodules, whether adenomas or hyperplastic nodules present in association with hyperfunctioning nodules in the same multinodular goiters, had no TSH receptor mutation. All the mutations identified had constitutive activity as assessed by cAMP production after expression in COS-7 cells. Hyperfunctioning thyroid nodules in multinodular goiters recognize the same pathogenetic event (TSH receptor mutation) as toxic adenoma. Other mechanisms are implicated in the growth of nonfunctioning thyroid nodules coexistent in the same gland.

Update on ocular toxicity of ethambutol

Directory of Open Access Journals (Sweden)

Priscilla Makunyane

2016-08-01

Full Text Available The purpose of this review is to update clinicians on available literature on the ocular toxicity of ethambutol and the type of eye care to be provided to patients treated with these medications. Ethambutol is a commonly used first-line anti-tuberculosis drug. Since its first use in the 1960s, ocular toxicity is described as related to dose and duration, and it is reversible on therapy discontinuation. However, the reversibility of the toxic optic neuropathy remains controversial. The mechanism of ocular toxicity owing to ethambutol is still under investigation. Other than discontinuing the drug, no specific treatment is available for the optic neuropathy caused by ethambutol. Doctors prescribing ethambutol should be aware of the ocular toxicity, and the drug should be used with proper patient education and ophthalmic monitoring.

Pulmonary toxicity of manufactured nanoparticles

Science.gov (United States)

Peebles, Brian Christopher

Manufactured nanomaterials have become ubiquitous in science, industry, and medicine. Although electron microscopy and surface probe techniques have improved understanding of the physicochemical properties of nanomaterials, much less is known about what makes nanomaterials toxic. Particulate matter less than 2.5 mum in effective aerodynamic diameter is easily inhaled and taken deep into the lungs. The toxicity of inhaled particulate matter is related to its size and surface chemistry; for instance, the smaller the size of particles, the greater their specific surface area. The chemistry and toxicity of insoluble particles depends on their surface area, since chemical reactions may happen with the environment on the surface. Oxidation and reduction may occur on the surfaces of particles after they are produced. For instance, it is known that carbonaceous particles from vehicle exhaust and industrial emission may interact with reactive species like ozone in their ambient environment, altering the surface chemistry of the particles. Reaction with species in the environment may cause changes in the chemical functionality of the surface and change the toxic properties of the particles when they are inhaled. Furthermore, metals on the surface of inhalable particles can contribute to their toxicity. Much attention has been given to the presence of iron on the surfaces of inhalable particles in the environment. After particle inhalation, particles are endocytosed by alveolar macrophages in the immune response to foreign matter. They are exposed to hydrogen peroxide in the oxidative burst, which can cause the iron-mediated production of hydroxyl free radicals via the Fenton reaction, causing oxidative stress that leads to inflammation and cell death. The toxicity of particles that contain metals depends on the redox activity and bioavailability of the metals, the causes of thich have not yet been adequately explored. In this thesis, electron paramagnetic spectroscopy showed

Compound toxicity screening and structure-activity relationship modeling in Escherichia coli.

Science.gov (United States)

Planson, Anne-Gaëlle; Carbonell, Pablo; Paillard, Elodie; Pollet, Nicolas; Faulon, Jean-Loup

2012-03-01

Synthetic biology and metabolic engineering are used to develop new strategies for producing valuable compounds ranging from therapeutics to biofuels in engineered microorganisms. When developing methods for high-titer production cells, toxicity is an important element to consider. Indeed the production rate can be limited due to toxic intermediates or accumulation of byproducts of the heterologous biosynthetic pathway of interest. Conversely, highly toxic molecules are desired when designing antimicrobials. Compound toxicity in bacteria plays a major role in metabolic engineering as well as in the development of new antibacterial agents. Here, we screened a diversified chemical library of 166 compounds for toxicity in Escherichia coli. The dataset was built using a clustering algorithm maximizing the chemical diversity in the library. The resulting assay data was used to develop a toxicity predictor that we used to assess the toxicity of metabolites throughout the metabolome. This new tool for predicting toxicity can thus be used for fine-tuning heterologous expression and can be integrated in a computational-framework for metabolic pathway design. Many structure-activity relationship tools have been developed for toxicology studies in eukaryotes [Valerio (2009), Toxicol Appl Pharmacol, 241(3): 356-370], however, to the best of our knowledge we present here the first E. coli toxicity prediction web server based on QSAR models (EcoliTox server: http://www.issb.genopole.fr/∼faulon/EcoliTox.php). Copyright © 2011 Wiley Periodicals, Inc.

Relative toxicity of bifenthrin to Hyalella azteca in 10 day versus 28 day exposures.

Science.gov (United States)

Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Petersen, Megan A; Jennings, Lydia L; Fojut, Tessa L; Vasquez, Martice E; Siegler, Catherine; Tjeerdema, Ronald S

2015-04-01

Many watersheds in the Central Valley region of California are listed as impaired due to pyrethroid-associated sediment toxicity. The Central Valley Regional Water Quality Control Board is developing numeric sediment quality criteria for pyrethroids, beginning with bifenthrin. Criteria are being developed using existing data, along with data from 10 d and 28 d toxicity tests with Hyalella azteca conducted as part of the current study. A single range-finder and 2 definitive tests were conducted for each test duration. Median lethal concentrations (LC50s), as well as LC20s and inhibition concentrations (IC20s) were calculated based on measured whole sediment bifenthrin concentrations and interstitial water concentrations. Sediment LC50s were also corrected for organic C content. Average LC50s were not significantly different in 10 d versus 28 d tests with H. azteca: 9.1 and 9.6 ng/g bifenthrin for 10 d and 28 d tests, respectively. Average LC20 values were also similar with concentrations at 7.1 and 7.0 for 10 d and 28 d tests, respectively. Bifenthrin inhibition concentrations (IC20s) based on amphipod growth were variable, particularly in the 28 d tests, where a clear dose-response relationship was observed in only 1 of the definitive experiments. Average amphipod growth IC20s were 3.9 and 9.0 ng/g for 10 d and 28 d tests, respectively. Amphipod growth calculated as biomass resulted in IC20s of 4.1 and 6.3 ng/g for the 10 d and 28 d tests, respectively. Lack of a clear growth effect in the longer term test may be related to the lack of food adjustment to account for amphipod mortality in whole sediment exposures. The average C-corrected LC50s were 1.03 and 1.09 μg/g OC for the 10 d and 28 d tests, respectively. Interstitial water LC50s were determined as the measured dissolved concentration of bifenthrin relative to interstitial water dissolved organic carbon. The average LC50s for dissolved interstitial water bifenthrin were

[Toxicity and apple production in southern Brazil].

Science.gov (United States)

Klanovicz, Jó

2010-03-01

The article explores the links between the controversial apprehension of contaminated apples in southern Brazil in 1989 and the reactions of the apple industry to press reports on the use of pesticides in Brazilian orchards. The issue is framed within a broader analysis of the notions of toxicity and 'danger' surrounding the consumption of healthier food and the idea of 'food security,' notions that have begun taking hold in public and private life. It is argued that apple growers' responses to the problem can be better understood through a historical reading of the interactions between the biology of the apple tree, the agroecology of this monoculture, and the structures, actors, and discourses of the human and non-human groups in Brazil's apple-producing region.

Related regulation of quality control of industrial products

International Nuclear Information System (INIS)

1983-04-01

This book introduce related regulation of quality control of industrial products, which includes regulations of industrial products quality control, enforcement ordinance of industrial products quality control, enforcement regulation of quality control of industrial products, designated items with industrial production quality indication, industrial production quality test, and industrial production quality test organization and management tips of factory quality by grade.

Impact assessment of WHO TobReg proposals for mandated lowering of selected mainstream cigarette smoke toxicants.

Science.gov (United States)

Eldridge, Alison C; McAdam, Kevin G; Betson, Tatiana R; Gama, Marcos V; Proctor, Christopher J

2017-06-01

The WHO Tobacco Product Regulation Study Group (TobReg) has proposed three regulatory models for cigarettes, each creating mandatory limits for emissions of nine smoke toxicants. One approach proposes country-specific limits, using median or 1.25× median toxicant/nicotine emission ratios. A second model provides fixed toxicant-ratio limits. The third model limits were three times the lowest toxicant emission on a market. Currently, the practical implications of these models are largely unknown. An impact assessment was conducted using cigarette data from 79 countries to identify four diverse test markets. We sampled all products from each market but limited product availability led to incomplete (80-97%) sourcing. Analysis showed that the country-specific model led to diverse (up to threefold) toxicant limits across the four markets. 70%-80% of products were non-compliant, rising to 100% in some countries with the second and the third models. With each regulatory model the main drivers of non-compliance were the tobacco-specific nitrosamines, the simultaneous application of limits for nine poorly correlated smoke toxicants, and analytical variability. Use of nicotine ratios led to compliance of some high toxicant emission products due to high nicotine emissions. Our findings suggest that these proposals would have greater impact on global markets than TobReg's stated aims. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Linezolid Trough Concentrations Correlate with Mitochondrial Toxicity-Related Adverse Events in the Treatment of Chronic Extensively Drug-Resistant Tuberculosis.

Science.gov (United States)

Song, Taeksun; Lee, Myungsun; Jeon, Han-Seung; Park, Yumi; Dodd, Lori E; Dartois, Véronique; Follman, Dean; Wang, Jing; Cai, Ying; Goldfeder, Lisa C; Olivier, Kenneth N; Xie, Yingda; Via, Laura E; Cho, Sang Nae; Barry, Clifton E; Chen, Ray Y

2015-11-01

Long-term linezolid use is limited by mitochondrial toxicity-associated adverse events (AEs). Within a prospective, randomized controlled trial of linezolid to treat chronic extensively drug-resistant tuberculosis, we serially monitored the translational competence of mitochondria isolated from peripheral blood of participants by determining the cytochrome c oxidase/citrate synthase activity ratio. We compared this ratio with AEs associated with mitochondrial dysfunction. Linezolid trough concentrations were determined for 38 participants at both 600 mg and 300 mg doses. Those on 600 mg had a significantly higher risk of AE than those on 300 mg (HR 3·10, 95% CI 1·23-7 · 86). Mean mitochondrial function levels were significantly higher in patients before starting linezolid compared to their concentrations on 300 mg (P = 0·004) or 600 mg (P linezolid trough concentrations were associated with lower mitochondrial function levels (Spearman's ρ = - 0.48; P = 0.005). Mitochondrial toxicity risk increased with increasing linezolid trough concentrations, with all patients with mean linezolid trough > 2 μg/ml developing an AE related to mitochondrial toxicity, whether on 300 mg or 600 mg. Therapeutic drug monitoring may be useful to prevent the development of mitochondrial toxicity associated with long-term linezolid use.

Toxic pollutants emitted from thermal decomposition of phthalimide compounds

Energy Technology Data Exchange (ETDEWEB)

Chen Kai; Mackie, John C.; Wojtalewicz, Dominika; Kennedy, Eric M. [Process Safety and Environmental Protection Research Group, School of Engineering, The University of Newcastle, Callaghan, New South Wales 2308 (Australia); Dlugogorski, Bogdan Z., E-mail: Bogdan.Dlugogorski@newcastle.edu.au [Process Safety and Environmental Protection Research Group, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308 (Australia)

2011-03-15

Phthalimide (PI) and tetrahydrophthalimide (THPI) are two structurally similar compounds extensively used as intermediates for the synthesis of variety of industrial chemicals. This paper investigates the thermal decomposition of PI and THPI under oxygen rich to oxygen lean conditions, quantifying the production of toxicants and explaining their formation pathways. The experiments involved a plug flow reactor followed by silica cartridges, activated charcoal trap and a condenser, with the decomposition products identified and quantified by Fourier transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC-MS) and micro gas chromatography ({mu}GC). The density functional theory (DFT) calculations served to obtain dissociation energies and reaction pathways, to elucidate the reaction mechanism. The oxidation of PI and THPI produced several toxic nitrogen-containing gases and volatile organic compounds, including hydrogen cyanide, isocyanic acid, nitrogen oxides, benzonitrile, maleimide and tentatively identified benzenemethanimine. The detection of dibenzo-p-dioxin (DD) and dibenzofuran (DF) suggests potential formation of the toxic persistent organic pollutants (POPs) in fires involving PI and THPI, in presence of a chlorine source. The oxidation of THPI produced 2-cyclohexen-1-one, a toxic unsaturated ketone. The results of the present study provide the data for quantitative risk assessments of emissions of toxicants in combustion processes involving PI and THPI.

Toxic pollutants emitted from thermal decomposition of phthalimide compounds

International Nuclear Information System (INIS)

Chen Kai; Mackie, John C.; Wojtalewicz, Dominika; Kennedy, Eric M.; Dlugogorski, Bogdan Z.

2011-01-01

Phthalimide (PI) and tetrahydrophthalimide (THPI) are two structurally similar compounds extensively used as intermediates for the synthesis of variety of industrial chemicals. This paper investigates the thermal decomposition of PI and THPI under oxygen rich to oxygen lean conditions, quantifying the production of toxicants and explaining their formation pathways. The experiments involved a plug flow reactor followed by silica cartridges, activated charcoal trap and a condenser, with the decomposition products identified and quantified by Fourier transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC-MS) and micro gas chromatography (μGC). The density functional theory (DFT) calculations served to obtain dissociation energies and reaction pathways, to elucidate the reaction mechanism. The oxidation of PI and THPI produced several toxic nitrogen-containing gases and volatile organic compounds, including hydrogen cyanide, isocyanic acid, nitrogen oxides, benzonitrile, maleimide and tentatively identified benzenemethanimine. The detection of dibenzo-p-dioxin (DD) and dibenzofuran (DF) suggests potential formation of the toxic persistent organic pollutants (POPs) in fires involving PI and THPI, in presence of a chlorine source. The oxidation of THPI produced 2-cyclohexen-1-one, a toxic unsaturated ketone. The results of the present study provide the data for quantitative risk assessments of emissions of toxicants in combustion processes involving PI and THPI.

Early Combination of Material Characteristics and Toxicology Is Useful in the Design of Low Toxicity Carbon Nanofiber

Directory of Open Access Journals (Sweden)

Tore Syversen

2012-09-01

Full Text Available This paper describes an approach for the early combination of material characterization and toxicology testing in order to design carbon nanofiber (CNF with low toxicity. The aim was to investigate how the adjustment of production parameters and purification procedures can result in a CNF product with low toxicity. Different CNF batches from a pilot plant were characterized with respect to physical properties (chemical composition, specific surface area, morphology, surface chemistry as well as toxicity by in vitro and in vivo tests. A description of a test battery for both material characterization and toxicity is given. The results illustrate how the adjustment of production parameters and purification, thermal treatment in particular, influence the material characterization as well as the outcome of the toxic tests. The combination of the tests early during product development is a useful and efficient approach when aiming at designing CNF with low toxicity. Early quality and safety characterization, preferably in an iterative process, is expected to be efficient and promising for this purpose. The toxicity tests applied are preliminary tests of low cost and rapid execution. For further studies, effects such as lung inflammation, fibrosis and respiratory cancer are recommended for the more in-depth studies of the mature CNF product.

Evaluation of metals, metalloids, and ash mixture toxicity using sediment toxicity testing.

Science.gov (United States)

Stojak, Amber; Bonnevie, Nancy L; Jones, Daniel S

2015-01-01

In December 2008, a release of 4.1 million m(3) of coal ash from the Tennessee Valley Authority Kingston Fossil Plant occurred. Ash washed into the Emory River and migrated downstream into the Clinch and Tennessee Rivers. A Baseline Ecological Risk Assessment evaluated risks to ecological receptors from ash in the river system post-dredging. This article describes the approach used and results from sediment toxicity tests, discussing any causal relationships between ash, metals, and toxicity. Literature is limited in the realm of aquatic coal combustion residue (CCR) exposures and the potential magnitude of effects on benthic invertebrates. Sediment samples along a spectrum of ash content were used in a tiered toxicity testing approach and included a combination of 10 day sediment toxicity acute tests and longer-term, partial life cycle "definitive" tests with 2 species (Hyalella azteca and Chironomus dilutus). Arsenic, and to a lesser extent Se, in the ash was the most likely toxicant causing observed effects in the laboratory toxicity tests. Sites in the Emory River with the greatest statistical and biologically significant effects had As concentrations in sediments twice the probable effects concentration of 33 mg/kg. These sites contained greater than 50% ash. Sites with less than approximately 50% ash in sediments exhibited fewer significant toxic responses relative to the reference sediment in the laboratory. The results discussed here present useful evidence of only limited effects occurring from a worst-case exposure pathway. These results provided a valuable line of evidence for the overall assessment of risks to benthic invertebrates and to other ecological receptors, and were crucial to risk management and development of project remediation goals. © 2014 SETAC.

Chapter 6: Selenium Toxicity to Aquatic Organisms

Science.gov (United States)

This chapter addresses the characteristics and nature of organic selenium (Se) toxicity to aquatic organisms, based on the most current state of scientific knowledge. As such, the information contained in this chapter relates to the 'toxicity assessment' phase of aquatic ecologi...

Toxicity of simple mixtures to the nematode Caenhorhabditis elegans in relation to soil sorption

NARCIS (Netherlands)

Jonker, M.J.; Sweijen, R.A.J.C.; Kammenga, J.E.

2004-01-01

Single and combined toxicity of copper-zinc, copper-cadmium, cadmium-lead, copper-carbendazim, and copper-carbendazimiprodione to the nematode Caenorhabditis elegans in soil was studied. The one-week population increase was estimated as the toxicity endpoint. The aim was to study the relationship

Effects of soil properties on copper toxicity to earthworm Eisenia fetida in 15 Chinese soils.

Science.gov (United States)

Duan, Xiongwei; Xu, Meng; Zhou, Youya; Yan, Zengguang; Du, Yanli; Zhang, Lu; Zhang, Chaoyan; Bai, Liping; Nie, Jing; Chen, Guikui; Li, Fasheng

2016-02-01

The bioavailability and toxicity of metals in soil are influenced by a variety of soil properties, and this principle should be recognized in establishing soil environmental quality criteria. In the present study, the uptake and toxicity of Cu to the earthworm Eisenia fetida in 15 Chinese soils with various soil properties were investigated, and regression models for predicting Cu toxicity across soils were developed. The results showed that earthworm survival and body weight change were less sensitive to Cu than earthworm cocoon production. The soil Cu-based median effective concentrations (EC50s) for earthworm cocoon production varied from 27.7 to 383.7 mg kg(-1) among 15 Chinese soils, representing approximately 14-fold variation. Soil cation exchange capacity and organic carbon content were identified as key factors controlling Cu toxicity to earthworm cocoon production, and simple and multiple regression models were developed for predicting Cu toxicity across soils. Tissue Cu-based EC50s for earthworm cocoon production were also calculated and varied from 15.5 to 62.5 mg kg(-1) (4-fold variation). Compared to the soil Cu-based EC50s for cocoon production, the tissue Cu-based EC50s had less variation among soils, indicating that metals in tissue were more relevant to toxicity than metals in soil and hence represented better measurements of bioavailability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Presence, origin and importance of toxic substances in drinking water

Energy Technology Data Exchange (ETDEWEB)

Seemayer, N H

1980-01-01

The ubiquitous, environmental toxic substances representing a risk to health, and of importance with respect to the production of drinking water, largely belong to the following groups: cancerogenic, polycyclic, aromatic hydrocarbons, aromatic amines, N-nitroso compounds, pesticides. In addition the following substances: polychlorinated biphenyls, hormones, antibiotics, halogen hydrocarbons and heavy metals such as mercury, cadmium, lead, vanadium, chromium etc. Today, there is full appreciation of the qualitative aspects associated with the burdening of the environmental factor 'water' with toxic substances. However, as to the quantitative aspects, especially those relating to a combined effect of toxic substances adding to the total burden of man with noxious environmental agents, data are still lacking. The assessment of the chronic action exercised by minute and very minute concentrations of potentially toxic, cancerogenic or mutagenic substances possess a particularly complex problem for the environmental and water hygiene. Nowadays, there are basically 3 possibilities of solving this problem: epidemiological-statistical analyses, long-term animal experiments and in-vitro short-term tests. The epidemiological-statistical analysis can make a valuable contribution to the evaluation of the risk to human health of polluted drinking water and may also furnish the first clues to an incipient danger. However, it has to be considered that epidemiological studies deal with multifactorial events and that a monocausality is difficult to establish.

Toxicity evaluation of boron nitride nanospheres and water-soluble boron nitride in Caenorhabditis elegans

Directory of Open Access Journals (Sweden)

Wang N

2017-08-01

Full Text Available Ning Wang,1 Hui Wang,2 Chengchun Tang,3 Shijun Lei,1 Wanqing Shen,1 Cong Wang,1 Guobin Wang,4 Zheng Wang,1,4 Lin Wang1,5 1Research Center for Tissue Engineering and Regenerative Medicine, Union Hospital, 2Department of Medical Genetics, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 3Boron Nitride Research Center, School of Materials Science and Engineering, Hebei University of Technology, Tianjin, 4Department of Gastrointestinal Surgery, 5Department of Clinical Laboratory, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China Abstract: Boron nitride (BN nanomaterials have been increasingly explored for potential biological applications. However, their toxicity remains poorly understood. Using Caenorhabditis elegans as a whole-animal model for toxicity analysis of two representative types of BN nanomaterials – BN nanospheres (BNNSs and highly water-soluble BN nanomaterial (named BN-800-2 – we found that BNNSs overall toxicity was less than soluble BN-800-2 with irregular shapes. The concentration thresholds for BNNSs and BN-800-2 were 100 µg·mL-1 and 10 µg·mL-1, respectively. Above this concentration, both delayed growth, decreased life span, reduced progeny, retarded locomotion behavior, and changed the expression of phenotype-related genes to various extents. BNNSs and BN-800-2 increased oxidative stress levels in C. elegans by promoting reactive oxygen species production. Our results further showed that oxidative stress response and MAPK signaling-related genes, such as GAS1, SOD2, SOD3, MEK1, and PMK1, might be key factors for reactive oxygen species production and toxic responses to BNNSs and BN-800-2 exposure. Together, our results suggest that when concentrations are lower than 10 µg·mL-1, BNNSs are more biocompatible than BN-800-2 and are potentially biocompatible material. Keywords: boron nitride nanomaterials, Caenorhabditis elegans, nanotoxicology

Treatment efficacy and methotrexate-related toxicity in patients with rheumatoid arthritis receiving methotrexate in combination with adalimumab.

Science.gov (United States)

Burmester, Gerd R; Kaeley, Gurjit S; Kavanaugh, Arthur F; Gabay, Cem; MacCarter, Daryl K; Nash, Peter; Takeuchi, Tsutomu; Goss, Sandra L; Rodila, Ramona; Chen, Kun; Kupper, Hartmut; Kalabic, Jasmina

2017-01-01

Treatment of rheumatoid arthritis (RA) with a combination of methotrexate (MTX)+adalimumab (ADA) is more effective than ADA monotherapy. We assessed the toxicity of different doses of MTX and treatment efficacy of ADA+MTX in two trials. Data originated from CONCERTO, in patients with early RA initiating ADA+ 2.5, 5, 10 or 20 mg/week MTX for 26 weeks; and MUSICA, in patients with an inadequate response to MTX initiating ADA+ 7.5 or 20 mg/week MTX for 24 weeks. Efficacy was assessed by the American College of Rheumatology 50 (ACR50). Patient-reported MTX-related toxicity information was collected at each visit on 18 prespecified MTX-related adverse events (AE) in the MTX label. In CONCERTO, ACR50 rates increased over time, ranging from 54% to 68% at week 26, while AE rates remained steady, ranging from 2.4% to 17.8% at week 26. Of 395 patients, 113 (28.6%) reported 345 MTX-related AEs, including one serious AE (SAE, excessive fatigue and/or malaise); 10 AEs (in two patients) led to study discontinuation. In MUSICA, ACR50 rates increased over time, and were 32.3% and 37.5% at week 24, while MTX-related AE rates remained steady and were 6.5% at week 24. Of 309 patients, 71 (23%) reported 185 MTX-related AEs, including 5 SAEs (four infections and one fever/chills); six AEs (in four patients) led to study discontinuation. In patients with RA initiating ADA+MTX combination, treatment efficacy was achieved and increased throughout both trials, while rates of MTX-related AEs remained steady. MTX-related AEs were observed in up to 30% of patients and most were mild. MTX was discontinued by 0.5%-1.3% of patients. MUSICA (NCT01185288), CONCERTO (NCT01185301), Post results.

Boron in plants: deficiency and toxicity.

Science.gov (United States)

Camacho-Cristóbal, Juan J; Rexach, Jesús; González-Fontes, Agustín

2008-10-01

Boron (B) is an essential nutrient for normal growth of higher plants, and B availability in soil and irrigation water is an important determinant of agricultural production. To date, a primordial function of B is undoubtedly its structural role in the cell wall; however, there is increasing evidence for a possible role of B in other processes such as the maintenance of plasma membrane function and several metabolic pathways. In recent years, the knowledge of the molecular basis of B deficiency and toxicity responses in plants has advanced greatly. The aim of this review is to provide an update on recent findings related to these topics, which can contribute to a better understanding of the role of B in plants.

Toxic effects of neem products (Azadirachta indica A. Juss) on ...

African Journals Online (AJOL)

SERVER

2007-12-17

Dec 17, 2007 ... *Corresponding author. E-mail. E-mail: raymondndione@yahoo.fr. Phone: (221) ... others related compounds in neem products exhibit various modes of action .... microscope "Motic" connected to a computer, permitting us to get ..... Bacillus sphaericus Neide as a pathogen of mosquitoes. J. Invert. Pathol., 7: ...

The influence of product- and person-related factors on consumer hedonic responses to soy products

NARCIS (Netherlands)

Fenko, Anna; Backhaus, Birte W.; van Hoof, Joris Jasper

2015-01-01

Consumers in Western countries increasingly appreciate health benefits of soy products. However, several barriers prevent full acceptance of these products. This study investigates the effects of product-related factors (perceived familiarity and expected healthiness) and person-related factors

Effect of concentration, exposure time, temperature, and relative humidity on the toxicity of sulfur dioxide to the spores of Botrytis cinerea

Energy Technology Data Exchange (ETDEWEB)

Couey, H.M.; Uota, M.

1961-12-01

When spores of Botrytis cinerea are exposed to SO/sub 2/ gas, the subsequent reduction in spore germination is quantitatively proportional to the SO/sub 2/ concentration and the exposure time. The toxicity of SO/sub 2/ increases with increasing relative humidity. In an atmosphere of 96% RH, SO/sub 2/ is more than 20 times as effective as at 75% RH. The toxicity also increases about 1.5 times for each 10/sup 0/C rise in temperature between 0/sup 0/ and 30/sup 0/C. 8 references, 4 figures, 1 table.

Tobacco and Nicotine Product Testing

Science.gov (United States)

Biener, Lois; Leischow, Scott J.; Zeller, Mitch R.

2012-01-01

Introduction: Tobacco product testing is a critical component of the Family Smoking Prevention and Tobacco Control Act (FSPTCA), which grants the Food and Drug Administration the authority to regulate tobacco products. The availability of methods and measures that can provide accurate data on the relative health risks across types of tobacco products, brands, and subbrands of tobacco products on the validity of any health claims associated with a product, and on how consumers perceive information on products toxicity or risks is crucial for making decisions on the product's potential impact on public health. These tools are also necessary for making assessments of the impact of new indications for medicinal products (other than cessation) but more importantly of tobacco products that may in the future be marketed as cessation tools. Objective: To identify research opportunities to develop empirically based and comprehensive methods and measures for testing tobacco and other nicotine-containing products so that the best science is available when decisions are made about products or policies. Methods: Literature was reviewed to address sections of the FSPTCA relevant to tobacco product evaluation; research questions were generated and then reviewed by a committee of research experts. Results: A research agenda was developed for tobacco product evaluation in the general areas of toxicity and health risks, abuse liability, consumer perception, and population effects. Conclusion: A cohesive, systematic, and comprehensive assessment of tobacco products is important and will require building consensus and addressing some crucial research questions. PMID:21460383

Extended Producer Responsibility and Product Stewardship for Tobacco Product Waste.

Science.gov (United States)

Curtis, Clifton; Collins, Susan; Cunningham, Shea; Stigler, Paula; Novotny, Thomas E

2014-09-01

This paper reviews several environmental principles, including Extended Producer Responsibility (EPR), Product Stewardship (PS), the Polluter Pays Principle (PPP), and the Precautionary Principle, as they may apply to tobacco product waste (TPW). The review addresses specific criteria that apply in deciding whether a particular toxic product should adhere to these principles; presents three case studies of similar approaches to other toxic and/or environmentally harmful products; and describes 10 possible interventions or policy actions that may help prevent, reduce, and mitigate the effects of TPW. EPR promotes total lifecycle environmental improvements, placing economic, physical, and informational responsibilities onto the tobacco industry, while PS complements EPR, but with responsibility shared by all parties involved in the tobacco product lifecycle. Both principles focus on toxic source reduction, post-consumer take-back, and final disposal of consumer products. These principles when applied to TPW have the potential to substantially decrease the environmental and public health harms of cigarette butts and other TPW throughout the world. TPW is the most commonly littered item picked up during environmental, urban, and coastal cleanups globally.

Potential fluoride toxicity from oral medicaments: A review.

Science.gov (United States)

Ullah, Rizwan; Zafar, Muhammad Sohail; Shahani, Nazish

2017-08-01

The beneficial effects of fluoride on human oral health are well studied. There are numerous studies demonstrating that a small amount of fluoride delivered to the oral cavity decreases the prevalence of dental decay and results in stronger teeth and bones. However, ingestion of fluoride more than the recommended limit leads to toxicity and adverse effects. In order to update our understanding of fluoride and its potential toxicity, we have described the mechanisms of fluoride metabolism, toxic effects, and management of fluoride toxicity. The main aim of this review is to highlight the potential adverse effects of fluoride overdose and poorly understood toxicity. In addition, the related clinical significance of fluoride overdose and toxicity has been discussed.

Ozonides: intermediates in ozone-induced toxicity : a study on their mechanism of toxic action and detoxification by antioxidants

NARCIS (Netherlands)

Hempenius, R.A.

2000-01-01

Ozone is a major constituent of photochemical smog. The toxicity of ozone is well documented and has been related to its strong oxidative potential. The principal target organ for ozone toxicity is the respiratory system. Unsaturated fatty acids, which are present in both the lipids of the

Spatial and temporal distributions of toxicity in receiving waters around an oil effluent discharge site

International Nuclear Information System (INIS)

Krause, P.R.

1994-01-01

Distributions of pollutants from a point source discharge within the water column may vary in both time and space. In this study, they examined the spatial and temporal patterns of toxicity from an oil production effluent (produced water) discharge plume using sea urchin fertilization and development bioassays. Specifically, they tested the sensitivity and response patterns of sea urchin gametes and early life stages exposed to receiving waters sampled along a 1 km transact near an active produced water outfall. Fertilization success and development of larvae to the pluteus stage varied significantly with proximity to the outfall, with reduced fertilization and larval development found closer to the outfall. Although estimated toxicity in receiving water samples, based on fertilization success, was variable in time -- perhaps responding to variation in the quantity or make-up of produced water discharges -- the general spatial pattern of toxicity along the sampling transact remained relatively constant. Strong evidence that field toxicity was directly attributable to produced water effluents was provided by sampling the receiving waters while the produced water discharge was not operating. At such a time, no toxicity was found at any of the field sites. Receiving water toxicity data, along with toxicity data from the effluent itself, were used to prepare a ''map'' of effective effluent concentrations along the sampling transect

Thyroid cancer in toxic and non-toxic multinodular goiter

Directory of Open Access Journals (Sweden)

Cerci C

2007-01-01

Full Text Available Background : Many authors have claimed that hyperthyroidism protects against thyroid cancer and believed that the incidence of malignancy is lower in patients with toxic multinodular goiter (TMG than in those with non-toxic multinodular goiter. But in recent studies, it was reported that the incidence of malignancy with TMG is not as low as previously thought. Aim : To compare the thyroid cancer incidence in patients with toxic and non-toxic multinodular goiter. Settings and Design : Histology reports of patients treated surgically with a preoperative diagnosis of toxic and non-toxic multinodular goiter were reviewed to identify the thyroid cancer incidence. Patients having a history of neck irradiation or radioactive iodine therapy were excluded from the study. Materials and Methods : We reviewed 294 patients operated between 2001-2005 from toxic and non-toxic multinodular goiter. One hundred and twenty-four of them were toxic and 170 were non-toxic. Hyperthyroidism was diagnosed by elevated tri-iodothyroinine / thyroxine ratios and low thyroid-stimulating hormone with clinical signs and symptoms. All patients were evaluated with ultrasonography and scintigraphy and fine needle aspiration biopsy. Statistical Analysis Used : Significance of the various parameters was calculated by using ANOVA test. Results : The incidence of malignancy was 9% in the toxic and 10.58% in the non-toxic multinodular goiter group. Any significant difference in the incidence of cancer and tumor size between the two groups could not be detected. Conclusions : The incidence of malignancy in toxic multinodular goiter is not very low as thought earlier and is nearly the same in non-toxic multinodular goiter.

Toxicity assessment of carbon black waste: A by-product from oil refineries

Energy Technology Data Exchange (ETDEWEB)

Zhen, Xu; Ng, Wei Cheng [NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602 (Singapore); Fendy; Tong, Yen Wah [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore); Dai, Yanjun [School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai, 200240 (China); Neoh, Koon Gee, E-mail: chenkg@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore); Wang, Chi-Hwa, E-mail: chewch@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore)

2017-01-05

Highlights: • Carbon black waste extract decreased cell viability in a dose and time-dependent manner. • Apoptosis of human cell lines was induced by carbon black waste extract. • Carbon black waste extract elicited oxidative stress by increasing intracellular ROS generation. • Carbon black waste extract impaired antioxidant enzymatic activities of human cell lines. • The high toxicity of carbon black waste extract could be attributed mainly to the effect of vanadium. - Abstract: In Singapore, approximately 30 t/day of carbon-based solid waste are produced from petrochemical processes. This carbon black waste has been shown to possess physical properties that are characteristic of a good adsorbent such as high external surface area. Therefore, there is a growing interest to reutilize and process this carbon black waste into secondary materials such as adsorbents. However, the carbon black waste obtained from petrochemical industries may contain heavy metals that are hazardous to human health and the environment, hence restricting its full potential for re-utilization. Therefore, it is important to examine the possible toxicity effects and toxicity mechanism of carbon black waste on human health. In this study, inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis showed that the heavy metals, vanadium (V), molybdenum (Mo) and nickel (Ni), were present in the carbon black waste in high concentrations. Three human cell lines (HepG2 cells, MRC-5 cells and MDA-MB-231 cells) were used to investigate the toxicity of carbon black waste extract in a variety of in vitro assays. Results from MTS assays indicated that carbon black waste extract decreased the viability of all three cell lines in a dose and time-dependent manner. Observations from confocal microscopy further confirmed this phenomenon. Flow cytometry assay also showed that carbon black waste extract induced apoptosis of human cell lines, and the level of apoptosis increased with

Toxicity assessment of carbon black waste: A by-product from oil refineries

International Nuclear Information System (INIS)

Zhen, Xu; Ng, Wei Cheng; Fendy; Tong, Yen Wah; Dai, Yanjun; Neoh, Koon Gee; Wang, Chi-Hwa

2017-01-01

Highlights: • Carbon black waste extract decreased cell viability in a dose and time-dependent manner. • Apoptosis of human cell lines was induced by carbon black waste extract. • Carbon black waste extract elicited oxidative stress by increasing intracellular ROS generation. • Carbon black waste extract impaired antioxidant enzymatic activities of human cell lines. • The high toxicity of carbon black waste extract could be attributed mainly to the effect of vanadium. - Abstract: In Singapore, approximately 30 t/day of carbon-based solid waste are produced from petrochemical processes. This carbon black waste has been shown to possess physical properties that are characteristic of a good adsorbent such as high external surface area. Therefore, there is a growing interest to reutilize and process this carbon black waste into secondary materials such as adsorbents. However, the carbon black waste obtained from petrochemical industries may contain heavy metals that are hazardous to human health and the environment, hence restricting its full potential for re-utilization. Therefore, it is important to examine the possible toxicity effects and toxicity mechanism of carbon black waste on human health. In this study, inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis showed that the heavy metals, vanadium (V), molybdenum (Mo) and nickel (Ni), were present in the carbon black waste in high concentrations. Three human cell lines (HepG2 cells, MRC-5 cells and MDA-MB-231 cells) were used to investigate the toxicity of carbon black waste extract in a variety of in vitro assays. Results from MTS assays indicated that carbon black waste extract decreased the viability of all three cell lines in a dose and time-dependent manner. Observations from confocal microscopy further confirmed this phenomenon. Flow cytometry assay also showed that carbon black waste extract induced apoptosis of human cell lines, and the level of apoptosis increased with

Feeding Behavior-Related Toxicity due to Nandina domestica in Cedar Waxwings (Bombycilla cedrorum

Directory of Open Access Journals (Sweden)

Moges Woldemeskel

2010-01-01

Full Text Available Dozens of Cedar Waxwings were found dead in Thomas County, Georgia, USA, in April 2009. Five of these were examined grossly and microscopically. Grossly, all the examined birds had pulmonary, mediastinal, and tracheal hemorrhages. Microscopically, several tissues and organs were diffusely congested and hemorrhagic. Congestion and hemorrhage were marked in the lungs. Intact and partly digested berries of Nandina domestica Thunb. were the only ingesta found in the gastrointestinal tract of these birds. Due to their voracious feeding behavior, the birds had eaten toxic doses of N. domestica berries. N. domestica contains cyanide and is one of the few berries readily available at this time of the year in the region. The gross and microscopic findings are consistent with lesions associated with cyanide toxicity. This paper for the first time documents toxicity associated with N. domestica in Cedar Waxwings.

Toxicity of Nickel Oxide Nanoparticles on a Freshwater Green Algal Strain of Chlorella vulgaris

Directory of Open Access Journals (Sweden)

Abdallah Oukarroum

2017-01-01

Full Text Available A freshwater microalga strain of Chlorella vulgaris was used to investigate toxic effects induced by nickel oxide nanoparticles (NiO-NPs in suspension. Algal cells were exposed during 96 h to 0–100 mg L−1 of NiO-NPs and analyzed by flow cytometry. Physicochemical characterization of nanoparticles in tested media showed a soluble fraction (free Ni2+ of only 6.42% for 100 mg L−1 of NiO-NPs, indicating the low solubility capacity of these NPs. Toxicity analysis showed cellular alterations which were related to NiO-NPs concentration, such as inhibition in cell division (relative cell size and granularity, deterioration of the photosynthetic apparatus (chlorophyll synthesis and photochemical reactions of photosynthesis, and oxidative stress (ROS production. The change in cellular viability demonstrated to be a very sensitive biomarker of NiO-NPs toxicity with EC50 of 13.7 mg L−1. Analysis by TEM and X-ray confirmed that NiO-NPs were able to cross biological membranes and to accumulate inside algal cells. Therefore, this study provides a characterization of both physicochemical and toxicological properties of NiO-NPs suspensions in tested media. The use of the freshwater strain of C. vulgaris demonstrated to be a sensitive bioindicator of NiO-NPs toxicity on the viability of green algae.

Kombucha--toxicity alert.

Science.gov (United States)

The Kombucha mushroom, also known as Manchurian mushroom, is a mail-order product touted to lower blood pressure and raise T-cell counts. No controlled trials have been conducted to test these claims. Aspergillus, a mold that may grow on the Kombucha mushroom, attacks the brain and may be fatal to persons with weakened immune systems. Reported toxicity reactions have included stomach problems and yeast infections. Taking Kombucha in combination with other drugs may affect the drugs potency.

Comparison of Dissolved Nickel and Nickel Nanoparticles Toxicity in Larval Zebrafish in Terms of Gene Expression and DNA Damage.

Science.gov (United States)

Boran, Halis; Şaffak, Savaş

2018-01-01

With the use of nanoparticles (NPs) in many industrial activities and consumer products, it is important to evaluate the effects of their release into the environment. Metal NPs (e.g., Ni-NPs or Cu-NPs) can release metal ions that are toxic to aquatic organisms; however, whether the toxicity is from metal ions rather than unique "nano-scale" effects of the NPs is unresolved. This research investigated Ni-NP toxicity in zebrafish Danio rerio larvae to clarify whether toxic effects are attributable to release of Ni ions. First, the acute (96-h lethal) toxicity of Ni-NPs was determined in comparison to aqueous Ni in fish exposed to Ni(II) by water-soluble NiCl 2 . Subsequently, sublethal experiments with Ni-NPs and Ni(II) were conducted to assess changes in expression of stress-related genes (mt2, rad51, and p53) by quantitative PCR. Acute toxicity of Ni in fish exposed to Ni(II) was higher (96-h LC 50  = 32.6 mg/L) than for fish exposed to Ni-NPs (96-h LC 50  = 122.2 mg/L). Also, DNA strand breaks were higher in Ni(II)- than Ni-NPs-exposed larvae. Induction of stress-related genes in larvae was complex and was not directly related to Ni-NPs and Ni(II) concentration, although there was a significant induction in the mt2 and p53 gene of the larvae exposed to Ni-NPs and Ni(II) relative to controls. Results indicated that while Ni-NPs induced gene expression (presumably by the release of Ni ions), the differences in concentration relationships of gene expression between Ni-NPs and Ni(II) suggest that factors in addition to the release of Ni ions from Ni-NPs influence acute toxicity of Ni-NPs.

Oxidation of indometacin by ferrate (VI): kinetics, degradation pathways, and toxicity assessment.

Science.gov (United States)

Huang, Junlei; Wang, Yahui; Liu, Guoguang; Chen, Ping; Wang, Fengliang; Ma, Jingshuai; Li, Fuhua; Liu, Haijin; Lv, Wenying

2017-04-01

The oxidation of indometacin (IDM) by ferrate(VI) (Fe(VI)) was investigated to determine the reaction kinetics, transformation products, and changes in toxicity. The reaction between IDM and Fe(VI) followed first-order kinetics with respect to each reactant. The apparent second-order rate constants (k app ) decreased from 9.35 to 6.52 M -1  s -1 , as the pH of the solution increased from 7.0 to 10.0. The pH dependence of k app might be well explained by considering the species-specific rate constants of the reactions of IDM with Fe(VI). Detailed product studies using liquid chromatography-tandem mass spectrometry (LC-MS/MS) indicated that the oxidation products were primarily derived from the hydrolysis of amide linkages, the addition of hydroxyl groups, and electrophilic oxidation. The toxicity of the oxidation products was evaluated using the Microtox test, which indicated that transformation products exhibited less toxicity to the Vibrio fischeri bacteria. Quantitative structure-activity relationship (QSAR) analysis calculated by the ecological structure activity relationship (ECOSAR) revealed that all of the identified products exhibited lower acute and chronic toxicity than the parent pharmaceutical for fish, daphnid, and green algae. Furthermore, Fe(VI) was effective in the degradation IDM in water containing carbonate ions or fulvic acid (FA), and in lake water samples; however, higher Fe(VI) dosages would be required to completely remove IDM in lake water in contrast to deionized water.

Research on the Relationships between Endogenous Biomarkers and Exogenous Toxic Substances of Acute Toxicity in Radix Aconiti.

Science.gov (United States)

Zhou, Haonan; Zhang, Pengjie; Hou, Zhiguo; Xie, Jiabin; Wang, Yuming; Yang, Bin; Xu, Yanyan; Li, Yubo

2016-11-25

Radix Aconiti , a classic traditional Chinese medicine (TCM), has been widely used throughout China for disease treatment due to its various pharmacological activities, such as anti-inflammatory, cardiotonic, and analgesic effects. However, improper use of Radix Aconiti often generated severe acute toxicity. Currently, research on the toxic substances of Radix Aconiti is not rare. In our previous study, acute toxic biomarkers of Radix Aconiti have been found. However, few studies were available to find the relationships between these endogenous biomarkers and exogenous toxic substances. Therefore, in this study, toxic substances of Radix Aconiti have been found using UPLC-Q-TOF-MS technology. Then, we used biochemical indicators as a bridge to find the relationships between biomarkers and toxic substances of Radix Aconiti through Pearson correlation analysis and canonical correlation analysis (CCA). Finally, the CCA results showed that LysoPC(22:5) is related to 14-acetyl-talatisamine, mesaconitine, talatisamine and deoxyaconitine in varying degrees; l-acetylcarnitine is negatively correlated with deoxyaconitine and demethyl-14-acetylkaracoline; shikimic acid has a good correlation with karacoline, demethyl-14-acetylkaracoline and deoxyaconitine; and valine is correlated with talatisamine and deoxyaconitine. Research on these relationships provides an innovative way to interpret the toxic mechanism of traditional Chinese medicine, and plays a positive role in the overall study of TCM toxicity.

Role of oxidative stress in cadmium toxicity and carcinogenesis

International Nuclear Information System (INIS)

Liu Jie; Qu Wei; Kadiiska, Maria B.

2009-01-01

Cadmium (Cd) is a toxic metal, targeting the lung, liver, kidney, and testes following acute intoxication, and causing nephrotoxicity, immunotoxicity, osteotoxicity and tumors after prolonged exposures. Reactive oxygen species (ROS) are often implicated in Cd toxicology. This minireview focused on direct evidence for the generation of free radicals in intact animals following acute Cd overload and discussed the association of ROS in chronic Cd toxicity and carcinogenesis. Cd-generated superoxide anion, hydrogen peroxide, and hydroxyl radicals in vivo have been detected by the electron spin resonance spectra, which are often accompanied by activation of redox sensitive transcription factors (e.g., NF-κB, AP-1 and Nrf2) and alteration of ROS-related gene expression. It is generally agreed upon that oxidative stress plays important roles in acute Cd poisoning. However, following long-term Cd exposure at environmentally-relevant low levels, direct evidence for oxidative stress is often obscure. Alterations in ROS-related gene expression during chronic exposures are also less significant compared to acute Cd poisoning. This is probably due to induced adaptation mechanisms (e.g., metallothionein and glutathione) following chronic Cd exposures, which in turn diminish Cd-induced oxidative stress. In chronic Cd-transformed cells, less ROS signals are detected with fluorescence probes. Acquired apoptotic tolerance renders damaged cells to proliferate with inherent oxidative DNA lesions, potentially leading to tumorigenesis. Thus, ROS are generated following acute Cd overload and play important roles in tissue damage. Adaptation to chronic Cd exposure reduces ROS production, but acquired Cd tolerance with aberrant gene expression plays important roles in chronic Cd toxicity and carcinogenesis.

USE OF SENSITIVITY ANALYSIS ON A PHYSIOLOGICALLY-BASED PHARMACOKINETIC (PBPK) MODEL FOR CHLOROFORM IN RATS TO DETERMINE AGE-RELATED TOXICITY

Science.gov (United States)

USE OF SENSITIVITY ANALYSIS ON A PHYSIOLOGICALLY BASED PHARMACOKINETIC (PBPK) MODEL FOR CHLOROFORM IN RATS TO DETERMINE AGE-RELATED TOXICITY.CR Eklund, MV Evans, and JE Simmons. US EPA, ORD, NHEERL, ETD,PKB, Research Triangle Park, NC. Chloroform (CHCl3) is a disinfec...

Characterization of aircraft deicer and anti-icer components and toxicity in airport snowbanks and snowmelt runoff

Science.gov (United States)

Corsi, S.R.; Geis, S.W.; Loyo-Rosales, J. E.; Rice, C.P.; Sheesley, R.J.; Failey, G.G.; Cancilla, Devon A.

2006-01-01

Snowbank samples were collected from snowbanks within a medium-sized airport for four years to characterize aircraft deicer and anti-icer (ADAF) components and toxicity. Concentrations of ADAF components varied with median glycol concentrations from individual sampling periods ranging from 65 to 5940 mg/L. Glycol content in snowbanks ranged from 0.17 to 11.4% of that applied to aircraft. Glycol, a freezing point depressant, was selectively removed during melt periods before snow and ice resulting in lower glycol concentrations after melt periods. Concentrations of ADAF components in airport runoff were similar during periods of snowmelt as compared to active ADAF application periods; however, due to the long duration of snowmelt events, greater masses of glycol were transported during snowmelt events. Alkylphenol ethoxylates (APEO), selected APEO degradation products, and 4- and 5-methyl-1H-benzotriazole were detected in snowbank samples and airport snowmelt. Concentrations of APEO parent products were greater in snowbank samples than in runoff samples. Relative abundance of APEO degradation products increased in the downstream direction from the snowbank to the outfalls and the receiving stream with respect to APEO parent compounds and glycol. Toxicity in Microtox assays remained in snowbanks after most glycol had been removed during melt periods. Increased toxicity in airport snowbanks as compared to other urban snowbanks was not explained by additional combustion or fuel contribution in airport snow. Organic markers suggest ADAF additives as a possible explanation for this increased toxicity. Results indicate that glycol cannot be used as a surrogate for fate and transport of other ADAF components. ?? 2006 American Chemical Society.

Toxicovigilance: A new approach for the hazard identification and risk assessment of toxicants in human beings

International Nuclear Information System (INIS)

Descotes, Jacques; Testud, Francois

2005-01-01

The concept of toxicovigilance encompasses the active detection, validation and follow-up of clinical adverse events related to toxic exposures in human beings. Poison centers are key players in this function as poisoning statistics are essential to define the cause, incidence and severity of poisonings occurring in the general population. In addition, the systematic search for unexpected shifts in the recorded causes of poisonings, e.g., following the introduction of a new product, or change in the formulation or recommended use of an old product, allows for a rapid detection of potential adverse health consequences and the implementation of preventive or corrective measures. However, toxicovigilance is genuinely a medical and not only a statistical approach of human toxicity issues. In contrast to epidemiology, toxicovigilance is based on the in-depth medical assessment of acute or chronic intoxications on an individual basis, which requires detailed information that poison centers can rarely obtain via emergency telephone calls and that epidemiologists cannot collect or process. Validation of this medical information must primarily be based on toxicological expertise to help identify causal links between otherwise unexplained pathological conditions and documented toxic exposures. Thus, toxicovigilance can contribute to hazard identification and risk assessment by providing medically validated data which are often overlooked in the process of risk assessment. So far, very few structured toxicovigilance systems have been set up and hopefully national and international initiatives will bridge this gap in our knowledge of the toxicity of many chemicals and commercial products in human beings

Toxicovigilance: a new approach for the hazard identification and risk assessment of toxicants in human beings.

Science.gov (United States)

Descotes, Jacques; Testud, François

2005-09-01

The concept of toxicovigilance encompasses the active detection, validation and follow-up of clinical adverse events related to toxic exposures in human beings. Poison centers are key players in this function as poisoning statistics are essential to define the cause, incidence and severity of poisonings occurring in the general population. In addition, the systematic search for unexpected shifts in the recorded causes of poisonings, e.g., following the introduction of a new product, or change in the formulation or recommended use of an old product, allows for a rapid detection of potential adverse health consequences and the implementation of preventive or corrective measures. However, toxicovigilance is genuinely a medical and not only a statistical approach of human toxicity issues. In contrast to epidemiology, toxicovigilance is based on the in-depth medical assessment of acute or chronic intoxications on an individual basis, which requires detailed information that poison centers can rarely obtain via emergency telephone calls and that epidemiologists cannot collect or process. Validation of this medical information must primarily be based on toxicological expertise to help identify causal links between otherwise unexplained pathological conditions and documented toxic exposures. Thus, toxicovigilance can contribute to hazard identification and risk assessment by providing medically validated data which are often overlooked in the process of risk assessment. So far, very few structured toxicovigilance systems have been set up and hopefully national and international initiatives will bridge this gap in our knowledge of the toxicity of many chemicals and commercial products in human beings.

Herbicide toxicity on river biofilms assessed by pulse amplitude modulated (PAM) fluorometry

International Nuclear Information System (INIS)

Kim Tiam, Sandra; Laviale, Martin; Feurtet-Mazel, Agnès; Jan, Gwilherm; Gonzalez, Patrice; Mazzella, Nicolas; Morin, Soizic

2015-01-01

Highlights: • Rapid Light Curves were shown to be early markers of toxicant exposure. • Diuron and norflurazon effects were significant at environmentally realistic concentrations. • Toxic effects in intact biofilms seem to be delayed compared to disrupted biofilms. - Abstract: The use of Rapid light curves (RLCs) as a toxicity endpoint for river biofilms was examined in this study and compared to “classical fluorescence parameters” i.e. minimal fluorescence (F 0 ), optimal and effective quantum yields of photosystem II (F v /F m and Φ PSII ). Measurements were performed after exposure to five concentrations of diuron (from 0.3 to 33.4 μg L −1 ), its main degradation product (DCPMU) (from 1.0 to 1014 μg L −1 ) and norflurazon (from 0.6 to 585 μg L −1 ) with the lowest exposure concentrations corresponding to levels regularly encountered in chronically contaminated sites. Biofilm responses were evaluated after 1, 5, 7 and 14 days of exposure to the different toxicants. Overall, the responses of both “classical fluorescence parameters” and RLC endpoints were highly time dependent and related to the mode of action of the different compounds. Interestingly, parameters calculated from RLCs (α, ETR max and I k ) were useful early markers of pesticide exposure since they revealed significant effects of all the tested toxicants from the first day of exposure. In comparison, classical fluorescence endpoints (F 0 and F v /F m ) measured at day 1 were only affected in the DCPMU treatment. Our results demonstrated the interest of RLCs as early markers of toxicant exposure particularly when working with toxicants with less specific mode of action than PSII inhibitors

General aspects of metal toxicity.

Science.gov (United States)

Kozlowski, H; Kolkowska, P; Watly, J; Krzywoszynska, K; Potocki, S

2014-01-01

This review is focused on the general mechanisms of metal toxicity in humans. The possible and mainly confirmed mechanisms of their action are discussed. The metals are divided into four groups due to their toxic effects. First group comprises of metal ions acting as Fenton reaction catalyst mainly iron and copper. These types of metal ions participate in generation of the reactive oxygen species. Metals such as nickel, cadmium and chromium are considered as carcinogenic agents. Aluminum, lead and tin are involved in neurotoxicity. The representative of the last group is mercury, which may be considered as a generally toxic metal. Fenton reaction is a naturally occurring process producing most active oxygen species, hydroxyl radical: Fe(2+) + He2O2 ↔ Fe(3+) + OH(-) + OH(•) It is able to oxidize most of the biomolecules including DNA, proteins, lipids etc. The effect of toxicity depends on the damage of molecules i.e. production site of the hydroxyl radical. Chromium toxicity depends critically on its oxidation state. The most hazardous seems to be Cr(6+) (chromates) which are one of the strongest inorganic carcinogenic agents. Cr(6+) species act also as oxidative agents damaging among other nucleic acids. Redox inactive Al(3+), Cd(2+) or Hg(2+) may interfere with biology of other metal ions e.g. by occupying metal binding sites in biomolecules. All these aspects will be discussed in the review.

Chemical oxidation of unsymmetrical dimethylhydrazine transformation products in water

NARCIS (Netherlands)

Abilev, M.; Kenessov, B.N.; Batyrbekova, S.; Grotenhuis, J.T.C.

2015-01-01

Oxidation of unsymmetrical dimethylhydrazine (UDMH) during a water treatment has several disadvantages including formation of stable toxic byproducts. Effectiveness of treatment methods in relation to UDMH transformation products is currently poorly studied. This work considers the effectiveness of

Evaluation of the water disinfection by-product dichloroacetonitrile-induced biochemical, oxidative, histopathological, and mitochondrial functional alterations: Subacute oral toxicity in rats.

Science.gov (United States)

Dong, Ying; Li, Fang; Shen, Haijun; Lu, Rongzhu; Yin, Siqi; Yang, Qi; Li, Zhuangfa; Wang, Suhua

2018-03-01

Dichloroacetonitrile (DCAN), an emerging nitrogenous disinfection by-product, is more genotoxic and cytotoxic than the currently regulated carbonaceous disinfection by-products such as haloacetic acids. Few mechanistic studies have been conducted on the hepatic and renal toxicities of DCAN. This study examined the clinical biochemical, hematological, histopathological, oxidative, and mitochondrial functional alterations to evaluate the systematic toxicity after subacute oral exposure of 11 or 44 mg/kg/day in rats for 28 days. Body and spleen weights were lower, and organ-to-body weight ratios of the liver and kidney were higher in rats administered 44-mg/kg DCAN than in controls. The activities of serum alanine aminotransferase and alkaline phosphatase, and concentrations of blood serum urea nitrogen and retinol-binding protein were increased in rats administered 44-mg/kg DCAN compared with those of controls, thereby indicating hepatic and renal damage in this group. This was confirmed by histopathological alterations, including hepatic sinus dilation, extensive hemorrhage, vacuolar degeneration in the liver and glomerulus hemorrhage, and renal tubular swelling, in DCAN-exposed rats. Exposure to 44-mg/kg DCAN induced hepatic oxidative damage shown by the significant increase in malonaldehyde levels, a poisonous product of lipid peroxidation. Exposure to 44-mg/kg DCAN significantly increased hepatic glutathione content and mitochondrial bioenergy as noted by the elevation of mitochondrial membrane potential and cytochrome c oxidase activity, which might be attributed to compensatory pathophysiologic responses to DCAN-induced hepatic mitochondrial damage.

In situ and laboratory bioassays with Chironomus riparius larvae to assess toxicity of metal contamination in rivers: the relative toxic effect of sediment versus water contamination.

Science.gov (United States)

Faria, Mafalda S; Lopes, Ricardo J; Nogueira, António J A; Soares, Amadeu M V M

2007-09-01

We used bioassays employing head capsule width and body length increase of Chironomus riparius larvae as end points to evaluate metal contamination in streams. Bioassays were performed in situ near an abandoned Portuguese goldmine in the spring of 2003 and 2004. Bioassays also were performed under laboratory conditions with water and sediment collected from each stream to verify if laboratory bioassays could detect in situ toxicity and to evaluate the relative contribution of sediment and water to overall toxicity. We used field sediments with control water and control sediments with field water to discriminate between metal contamination in water and sediment. Field water with dry and sieved, organic matter-free, and nontreated sediments was used to determine the toxicity of heavy metals that enter the organism through ingested material. In both in situ and laboratory bioassays, body length increase was significantly inhibited by metal contamination, whereas head capsule width was not affected. Body length increase was more affected by contaminated sediment compared to contaminated water. The lowest-effect level of heavy metals was observed in the dry and sieved sediment that prevented ingestion of sediment particles by larvae. These results suggest that body length increase of C. riparius larvae can be used to indicate the impact of metal contamination in rivers. Chironomus riparius larvae are more affected by heavy metals that enter the organism through ingested sediment than by heavy metals dissolved in the water column. Nevertheless, several factors, such as the particle size and organic matter of sediment, must be taken into account.

Thermal Stress and Toxicity | Science Inventory | US EPA

Science.gov (United States)

Elevating ambient temperature above thermoneutrality exacerbates toxicity of most air pollutants, insecticides, and other toxic chemicals. On the other hand, safety and toxicity testing of toxicants and drugs is usually performed in mice and rats maintained at subthermoneutral temperatures of —22 °C. When exposed to chemical toxicants under these relatively cool conditions, rodents typically undergo a regulated hypothermic response, characterized by preference for cooler ambient temperatures and controlled reduction in core temperature. Reducing core temperature delays the clearance of most toxicants from the body; however, a mild hypothermia also improves recovery and survival from the toxicant. Raising ambient temperature to thermoneutrality and above increases the rate of clearance of the toxicant but also exacerbates toxicity. Furthermore, heat stress combined with work or exercise is likely to worsen toxicity. Body temperature of large mammals, including humans, does not decrease as much in response to exposure to a toxicant. However, heat stress tan nonetheless worsen toxic outcome in humans through a variety of mechanisms. For example, heat-induced sweating and elevation in skin blood flow accelerates uptake of some insecticides. Epidemiological studies suggest that thermal stress may exacerbate the toxicity of airborne pollutants such as ozone and particulate matter. Overall, translating results of studies in rodents to that of humans is a formidable

[Toxicity effects of phthalate substitute plasticizers used in toys].

Science.gov (United States)

Hirata-Koizumi, Mutsuko; Takahashi, Mika; Matsumoto, Mariko; Kawamura, Tomoko; Ono, Atsushi; Hirose, Akihiko

2012-01-01

Phthalate esters are widely used as plasticizers in polyvinyl chloride products. Because of human health concerns, regulatory authorities in Japan, US, Europe and other countries control the use of di(2-ethylhexyl) phthalate, diisononyl phthalate, di-n-butyl phthalate, butylbenzyl phthalate, diisodecyl phthalate and di-n-octyl phthalate for the toys that can be put directly in infants' mouths. While these regulatory actions will likely reduce the usage of phthalate esters, there is concern that other plasticizers that have not been sufficiently evaluated for safety will be used more frequently. We therefore collected and evaluated the toxicological information on di(2-ethylhexyl) terephthalate (DEHT), 1,2-cyclohexanedicarboxylic acid, diisononyl ester (DINCH), diisononyl adipate (DINA), 2,2,4-trimetyl-1,3-pentanediol diisobutyrate (TXIB), tri-n-butyl citrate (TBC) and acetyl tri-n-butyl citrate (ATBC) which were detected at a relatively high frequency in toys. The collected data have shown that chronic exposure to DEHT affects the eye and nasal turbinate, and DINCH exerts effects on the thyroid and kidney in rats. DINA and TXIB have been reported to have hepatic and renal effects in dogs or rats, and ATBC slightly affected the liver in rats. The NOAELs for repeated dose toxicity are relatively low for DINCH (40 mg/kg bw/day) and TXIB (30 mg/kg bw/day) compared with DEHT, DINA and ATBC. DEHT, TXIB and ATBC have been reported to have reproductive/developmental effects at relatively high doses in rats. For DINA and TBC, available data are insufficient for assessing the hazards, and therefore, adequate toxicity studies should be conducted. In the present review, the toxicity information on 6 alternatives to phthalate plasticizers is summarized, focusing on the effects after oral exposure, which is the route of most concern.

Serum Levels of Toxic AGEs (TAGE May Be a Promising Novel Biomarker for the Onset/Progression of Lifestyle-Related Diseases

Directory of Open Access Journals (Sweden)

Masayoshi Takeuchi

2016-06-01

Full Text Available Advanced glycation end-products (AGEs generated with aging or in the presence of diabetes mellitus, particularly AGEs derived from the glucose/fructose metabolism intermediate glyceraldehyde (Glycer-AGEs; termed toxic AGEs (TAGE, were recently shown to be closely involved in the onset/progression of diabetic vascular complications via the receptor for AGEs (RAGE. TAGE also contribute to various diseases, such as cardiovascular disease; nonalcoholic steatohepatitis; cancer; Alzheimer’s disease, and; infertility. This suggests the necessity of minimizing the influence of the TAGE-RAGE axis in order to prevent the onset/progression of lifestyle-related diseases (LSRD and establish therapeutic strategies. Changes in serum TAGE levels are closely associated with LSRD related to overeating, a lack of exercise, or excessive ingestion of sugars/dietary AGEs. We also showed that serum TAGE levels, but not those of hemoglobin A1c, glucose-derived AGEs, or Nε-(carboxymethyllysine, have potential as a biomarker for predicting the progression of atherosclerosis and future cardiovascular events. We herein introduce the usefulness of serum TAGE levels as a biomarker for the prevention/early diagnosis of LSRD and the evaluation of the efficacy of treatments; we discuss whether dietary AGE/sugar intake restrictions reduce the generation/accumulation of TAGE, thereby preventing the onset/progression of LSRD.

Potential fluoride toxicity from oral medicaments: A review

Directory of Open Access Journals (Sweden)

Rizwan Ullah

2017-08-01

Full Text Available The beneficial effects of fluoride on human oral health are well studied. There are numerous studies demonstrating that a small amount of fluoride delivered to the oral cavity decreases the prevalence of dental decay and results in stronger teeth and bones. However, ingestion of fluoride more than the recommended limit leads to toxicity and adverse effects. In order to update our understanding of fluoride and its potential toxicity, we have described the mechanisms of fluoride metabolism, toxic effects, and management of fluoride toxicity. The main aim of this review is to highlight the potential adverse effects of fluoride overdose and poorly understood toxicity. In addition, the related clinical significance of fluoride overdose and toxicity has been discussed.

Phytochemical screening, proximate analysis and acute toxicity ...

African Journals Online (AJOL)

Phytochemical screening results indicate the presence of saponins, flavonoids, phytosterols and phenols. Acute toxicity study showed there was no mortality at 8000 mg/kg of the extract. The results indicate that the plant is rich in phytochemicals and is relatively safe. Key words: Phytochemicals, acute toxicity, proximate ...

Potential for photoenhanced toxicity of spilled oil in Prince William Sound and Gulf of Alaska Waters

International Nuclear Information System (INIS)

Barron, M.G.; Ka'aihue, L.

2001-01-01

Photoenhanced toxicity is the increase in the toxicity of a chemical in the presence of ultraviolet light (UV) compared to a standard laboratory test conducted with fluorescent lighting (minimal UV). Oil products, weathered oil, and specific polycyclic aromatic compounds present in oil are 2 to greater than 1000 times more toxic in the presence of UV. The photoenhanced toxicity of oil to fish and aquatic invertebrates appears to occur through a process of photosensitization, rather than photomodification of the aqueous phase oil. In photosensitization, the bioaccumulated chemical transfers light energy to other molecules causing toxicity through tissue damage rather than a narcosis mechanism. The available evidence indicates that phototoxic components of oil are specific 3-5 ring polycyclic aromatic hydrocarbons (PAHs) and heterocycles. Determinants of photoenhanced toxicity include the extent of oil bioaccumulation in aquatic organisms and the spectra and intensity of UV exposure. No studies have specifically investigated the photoenhanced toxicity of spilled oil in Alaska waters. Although there are substantial uncertainties, the results of this evaluation indicate there is potential for photoenhanced toxicity of spilled oil in Prince William Sound and the Gulf of Alaska. The potential hazard of photoenhanced toxicity may be greatest for embryo and larval stages of aquatic organisms that are relatively translucent to UV and inhabit the photic zone of the water column and intertidal areas. Photoenhanced toxicity should be considered in oil spill response because the spatial and temporal extent of injury to aquatic organisms may be underestimated if based on standard laboratory bioassays and existing toxicity databases. Additionally, the choice of counter measures and oil removal operations may influence the degree of photoenhanced toxicity. (author)

EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (Volume 1) (Interagency Science Discussion Draft)

Science.gov (United States)

EPA is releasing the draft report, EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (Volume 1), that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the Nature Relation Between Climatic Variables and Cotton Production

Directory of Open Access Journals (Sweden)

Zakaria M. Sawan

2014-08-01

Full Text Available This study investigated the effect of climatic variables on flower and boll production and retention in cotton (Gossypium barbadense. Also, this study investigated the relationship between climatic factors and production of flowers and bolls obtained during the development periods of the flowering and boll stage, and to determine the most representative period corresponding to the overall crop pattern. Evaporation, sunshine duration, relative humidity, surface soil temperature at 1800 h, and maximum air temperature, are the important climatic factors that significantly affect flower and boll production. The least important variables were found to be surface soil temperature at 0600 h and minimum temperature. There was a negative correlation between flower and boll production and either evaporation or sunshine duration, while that correlation with minimum relative humidity was positive. Higher minimum relative humidity, short period of sunshine duration, and low temperatures enhanced flower and boll formation.

Comparison of toxicity of class-based organic chemicals to algae and fish based on discrimination of excess toxicity from baseline level.

Science.gov (United States)

Li, Jin J; Tai, Hong W; Yu, Yang; Wen, Yang; Wang, Xiao H; Zhao, Yuan H

2015-07-01

Toxicity data to fish and algae were used to investigate excess toxicity between species. Results show that chemicals exhibiting excess toxicity to fish also show excess toxicity to algae for most of the compounds. This indicates that they share the same mode of action between species. Similar relationships between logKOW and toxicities to fish and algae for baseline and less inert compounds suggest that they have similar critical body residues in the two species. Differences in excess toxicity for some compounds suggest that there is a difference of physiological structure and metabolism between fish and algae. Some reactive compounds (e.g. polyamines) exhibit greater toxic effects for algae than those for fish because of relatively low bio-uptake potential of these hydrophilic compounds in fish as compared with that in algae. Esters exhibiting greater toxicity in fish than that in algae indicate that metabolism can affect the discrimination of excess toxicity from baseline level. Algae growth inhibition is a very good surrogate for fish lethality. This is not only because overall toxicity sensitivity to algae is greater than that to fish, but also the excess toxicity calculated from algal toxicity can better reflect reactivity of compounds with target molecules than fish toxicity. Copyright © 2015 Elsevier B.V. All rights reserved.

Bilirubin and its oxidation products damage brain white matter

Science.gov (United States)

Lakovic, Katarina; Ai, Jinglu; D'Abbondanza, Josephine; Tariq, Asma; Sabri, Mohammed; Alarfaj, Abdullah K; Vasdev, Punarjot; Macdonald, Robert Loch

2014-01-01

Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke. PMID:25160671

Airborne uranium, its concentration and toxicity in uranium enrichment facilities

International Nuclear Information System (INIS)

Thomas, J.; Mauro, J.; Ryniker, J.; Fellman, R.

1979-02-01

The release of uranium hexafluoride and its hydrolysis products into the work environment of a plant for enriching uranium by means of gas centrifuges is discussed. The maximum permissible mass and curie concentration of airborne uranium (U) is identified as a function of the enrichment level (i.e., U-235/total U), and chemical and physical form. A discussion of the chemical and radiological toxicity of uranium as a function of enrichment and chemical form is included. The toxicity of products of UF 6 hydrolysis in the atmosphere, namely, UO 2 F 2 and HF, the particle size of toxic particulate material produced from this hydrolysis, and the toxic effects of HF and other potential fluoride compounds are also discussed. Results of an investigation of known effects of humidity and temperature on particle size of UO 2 F 2 produced by the reaction of UF 6 with water vapor in the air are reported. The relationship of the solubility of uranium compounds to their toxic effects was studied. Identification and discussion of the standards potentially applicable to airborne uranium compounds in the working environment are presented. The effectiveness of High Efficiency Particulate (HEPA) filters subjected to the corrosive environment imposed by the presence of hydrogen fluoride is discussed

Identification of manganese as a toxicant in a groundwater treatment system: Addressing naturally occurring toxicants

International Nuclear Information System (INIS)

Goodfellow, W. Jr.; Sohn, V.; Richey, M.; Yost, J.

1995-01-01

Effluent from a groundwater remediation system at a bulk oil storage and distribution terminal has been chronically toxic to Ceriodaphnia dubia. The remediation system was designed in response to a hydrocarbon plume in the area of the terminal. The remediation system consists of a series of groundwater recovery wells and groundwater intercept trench systems with groundwater treatment and phased-separated hydrocarbon recovery systems. The groundwater treatment and petroleum recovery systems consist of oil/water separators, product recovery tanks, air strippers, filters, and carbon adsorption units. The characteristics of this effluent are low total suspended solids, total dissolved solids, and hardness concentrations as well as meeting stringent NPDES permit requirements for lead, copper, zinc, mercury, total petroleum hydrocarbons, and BTEX. Additional priority pollutant evaluations revealed no compounds of concern. Performance of a Toxicity identification Evaluation (TIE) indicated that manganese was the principle toxicant in the effluent. Manganese is a naturally occurring constituent in this groundwater source and is not added to the treatment system. This paper will present the results of the TIE with a discussion of treatability/control options for manganese control at this facility. Recommendations for addressing naturally occurring toxicants that are not a result of the facility's operations will also be presented

Human Toxicity

DEFF Research Database (Denmark)

Jolliet, Olivier; Fantke, Peter

2015-01-01

all chemicals and impact pathways characterizes the contribution of each factor to the total variation of 10–12 orders of magnitude in impacts per kg across all chemicals. This large variation between characterisation factors for different chemicals as well as the 3 orders of magnitude uncertainty....... As a whole, the assessment of toxicity in LCA has progressed on a very sharp learning curve during the past 20 years. This rapid progression is expected to continue in the coming years, focusing more on direct exposure of workers to chemicals during manufacturing and of consumers during product use...

Toxic Elements in Food: Occurrence, Binding, and Reduction Approaches

DEFF Research Database (Denmark)

Hajeb, P.; Sloth, Jens Jørgen; Shakibazadeh, Sh

2014-01-01

Toxic elements such as mercury, arsenic, cadmium, and lead, sometimes called heavy metals, can diminish mental and central nervous system function; elicit damage to blood composition as well as the kidneys, lungs, and liver; and reduce energy levels. Food is considered one of the main routes...... of their entry into the human body. Numerous studies have been performed to examine the effects of common food processing procedures on the levels of toxic elements in food. While some studies have reported negative effects of processing, several have shown that processing practices may have a positive effect...... on the reduction of toxic elements in foodstuffs. A number of studies have also introduced protocols and suggested chemical agents that reduce the amount of toxic elements in the final food products. In this review, the reported methods employed for the reduction of toxic elements are discussed with particular...

Human and Environmental Toxicity of Sodium Lauryl Sulfate (SLS): Evidence for Safe Use in Household Cleaning Products.

Science.gov (United States)

Bondi, Cara Am; Marks, Julia L; Wroblewski, Lauren B; Raatikainen, Heidi S; Lenox, Shannon R; Gebhardt, Kay E

2015-01-01

Environmental chemical exposure is a major concern for consumers of packaged goods. The complexity of chemical nomenclature and wide availability of scientific research provide detailed information but lends itself to misinterpretation by the lay person. For the surfactant sodium lauryl sulfate (SLS), this has resulted in a misunderstanding of the environmental health impact of the chemical and statements in the media that are not scientifically supported. This review demonstrates how scientific works can be misinterpreted and used in a manner that was not intended by the authors, while simultaneously providing insight into the true environmental health impact of SLS. SLS is an anionic surfactant commonly used in consumer household cleaning products. For decades, this chemical has been developing a negative reputation with consumers because of inaccurate interpretations of the scientific literature and confusion between SLS and chemicals with similar names. Here, we review the human and environmental toxicity profiles of SLS and demonstrate that it is safe for use in consumer household cleaning products.

Triclosan: environmental exposure, toxicity and mechanisms of action.

Science.gov (United States)

Dann, Andrea B; Hontela, Alice

2011-05-01

Triclosan [5-chloro-2-(2,4-dichlorophenoxy)phenol; TCS] is a broad spectrum antibacterial agent used in personal care, veterinary, industrial and household products. TCS is commonly detected in aquatic ecosystems, as it is only partially removed during the wastewater treatment process. Sorption, biodegradation and photolytic degradation mitigate the availability of TCS to aquatic biota; however the by-products such as methyltriclosan and other chlorinated phenols may be more resistant to degradation and have higher toxicity than the parent compound. The continuous exposure of aquatic organisms to TCS, coupled with its bioaccumulation potential, have led to detectable levels of the antimicrobial in a number of aquatic species. TCS has been also detected in breast milk, urine and plasma, with levels of TCS in the blood correlating with consumer use patterns of the antimicrobial. Mammalian systemic toxicity studies indicate that TCS is neither acutely toxic, mutagenic, carcinogenic, nor a developmental toxicant. Recently, however, concern has been raised over TCS's potential for endocrine disruption, as the antimicrobial has been shown to disrupt thyroid hormone homeostasis and possibly the reproductive axis. Moreover, there is strong evidence that aquatic species such as algae, invertebrates and certain types of fish are much more sensitive to TCS than mammals. TCS is highly toxic to algae and exerts reproductive and developmental effects in some fish. The potential for endocrine disruption and antibiotic cross-resistance highlights the importance of the judicious use of TCS, whereby the use of TCS should be limited to applications where it has been shown to be effective. Copyright © 2011 John Wiley & Sons, Ltd.

Thermochemical Wastewater Valorization via Enhanced Microbial Toxicity Tolerance

Energy Technology Data Exchange (ETDEWEB)

Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Thelhawadigedara, Lahiru Niroshan Jayakody [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Johnson, Christopher W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Pleitner, Brenna P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cleveland, Nicholas S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Michener, William E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Olstad-Thompson, Jessica L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Whitham, Jason M. [Oak Ridge National Laboratory; Giannone, Richard J. [Oak Ridge National Laboratory; Klingeman, Dawn M. [Oak Ridge National Laboratory; Brown, Robert C. [Iowa State University; Brown, Steven D. [Oak Ridge National Laboratory; LanzaTech, Inc.; Hettich, Robert L. [Oak Ridge National Laboratory; Guss, Adam M. [Oak Ridge National Laboratory

2018-04-17

Thermochemical (TC) biomass conversion processes such as pyrolysis and liquefaction generate considerable amounts of wastewater, which often contains highly toxic compounds that are incredibly challenging to convert via standard wastewater treatment approaches such as anaerobic digestion. These streams represent a cost for TC biorefineries, and a potential valorization opportunity, if effective conversion methods are developed. The primary challenge hindering microbial conversion of TC wastewater is toxicity. In this study, we employ a robust bacterium, Pseudomonas putida, with TC wastewater streams to demonstrate that aldehydes are the most inhibitory compounds in these streams. Proteomics, transcriptomics, and fluorescence-based immunoassays of P. putida grown in a representative wastewater stream indicate that stress results from protein damage, which we hypothesize is a primary toxicity mechanism. Constitutive overexpression of the chaperone genes, groEL, groES, and clpB, in a genome-reduced P. putida strain improves the tolerance towards multiple TC wastewater samples up to 200-fold. Moreover, the concentration ranges of TC wastewater are industrially relevant for further bioprocess development for all wastewater streams examined here, representing different TC process configurations. Furthermore, we demonstrate proof-of-concept polyhydroxyalkanoate production from the usable carbon in an exemplary TC wastewater stream. Overall, this study demonstrates that protein quality control machinery and repair mechanisms can enable substantial gains in microbial tolerance to highly toxic substrates, including heterogeneous waste streams. When coupled to other metabolic engineering advances such as expanded substrate utilization and enhanced product accumulation, this study generally enables new strategies for biological conversion of highly-toxic, organic-rich wastewater via engineered aerobic monocultures or designer consortia.

Mining Intention-Related Products on Online Q & A Community

Institute of Scientific and Technical Information of China (English)

段俊文; 陈毅恒; 刘挺; 丁效

2015-01-01

User generated content on social media has attracted much attention from service/product providers, as it contains plenty of potential commercial opportunities. However, previous work mainly focuses on user consumption intention (CI) identification, and little effort has been spent to mine intention-related products. In this paper, focusing on the Baby &Child Care domain, we propose a novel approach to mine intention-related products on online question and answer (Q&A) community. Making use of the question-answering pairs as data source, we first automatically extract candidate products based on dependency parser. And then by means of the collocation extraction model, we identify the real intention-related products from the candidate set. The experimental results on our carefully constructed evaluation dataset show that our approach achieves better performance than two natural baseline methods.

Promising Diabetes Therapy Based on the Molecular Mechanism for Glucose Toxicity: Usefulness of SGLT2 Inhibitors as well as Incretin-Related Drugs.

Science.gov (United States)

Kaneto, Hideaki; Obata, Atsushi; Shimoda, Masashi; Kimura, Tomohiko; Hirukawa, Hidenori; Okauchi, Seizo; Matsuoka, Taka-Aki; Kaku, Kohei

2016-01-01

Pancreatic β-cell dysfunction and insulin resistance are the main characteristics of type 2 diabetes. Chronic exposure of β-cells to hyperglycemia leads to the deterioration of β-cell function. Such phenomena are well known as pancreatic β-cell glucose toxicity. MafA, a strong transactivator of insulin gene, is particularly important for the maintenance of mature β-cell function, but its expression level is significantly reduced under diabetic conditions which is likely associated with β-cell failure. Reduction of incretin receptor expression level in β-cells in diabetes is also likely associated with β-cell failure. On the other hand, incretin-related drugs and sodium-glucose co-transporter 2 (SGLT2) inhibitors are promising diabetes therapy based on the mechanism for pancreatic β-cell glucose toxicity. Indeed, it was shown that incretin-related drugs exerted protective effects on β-cells through the augmentation of IRS-2 expression especially in the presence of pioglitazone. It was also shown that incretin-related drug and/or pioglitazone exerted more protective effects on β-cells at the early stage of diabetes compared to the advanced stage. SGLT2 inhibitors, new hypoglycemic agents, also exert beneficial effects for the protection of pancreatic β-cells as well as for the reduction of insulin resistance in various insulin target tissues. Taken together, it is important to select appropriate therapy based on the molecular mechanism for glucose toxicity.

The effect of toxic carbon source on the reaction of activated sludge in the batch reactor.

Science.gov (United States)

Wu, Changyong; Zhou, Yuexi; Zhang, Siyu; Xu, Min; Song, Jiamei

2018-03-01

The toxic carbon source can cause higher residual effluent dissolved organic carbon than easily biodegraded carbon source in activated sludge process. In this study, an integrated activated sludge model is developed as the tool to understand the mechanism of toxic carbon source (phenol) on the reaction, regarding the carbon flows during the aeration period in the batch reactor. To estimate the toxic function of phenol, the microbial cells death rate (k death ) is introduced into the model. The integrated model was calibrated and validated by the experimental data and it was found the model simulations matched the all experimental measurements. In the steady state, the toxicity of phenol can result in higher microbial cells death rate (0.1637 h -1 vs 0.0028 h -1 ) and decay rate coefficient of biomass (0.0115 h -1 vs 0.0107 h -1 ) than acetate. In addition, the utilization-associated products (UAP) and extracellular polymeric substances (EPS) formation coefficients of phenol are higher than that of acetate, indicating that more carbon flows into the extracellular components, such as soluble microbial products (SMP), when degrading toxic organics. In the non-steady state of feeding phenol, the yield coefficient for growth and maximum specific growth rate are very low in the first few days (1-10 d), while the decay rate coefficient of biomass and microbial cells death rate are relatively high. The model provides insights into the difference of the dynamic reaction with different carbon sources in the batch reactor. Copyright © 2017 Elsevier Ltd. All rights reserved.

DOE contractor's meeting on chemical toxicity

Energy Technology Data Exchange (ETDEWEB)

1987-01-01

The Office of Health and Environmental Research (OHER) is required to determine the potential health and environmental effects associated with energy production and use. To ensure appropriate communication among investigators and scientific disciplines that these research studies represent, OHER has sponsored workshops. This document provides a compilation of activities at the Third Annual DOE/OHER Workshop. This year's workshop was broadened to include all OHER activities identified as within the chemical effects area. The workshop consisted of eight sessions entitled Isolation and Detection of Toxic chemicals; Adduct Formation and Repair; Chemical Toxicity (Posters); Metabolism and Genotoxicity; Inhalation Toxicology; Gene Regulation; Metals Toxicity; and Biological Mechanisms. This document contains abstracts of the information presented by session.

Research on the Relationships between Endogenous Biomarkers and Exogenous Toxic Substances of Acute Toxicity in Radix Aconiti

Directory of Open Access Journals (Sweden)

Haonan Zhou

2016-11-01

Full Text Available Radix Aconiti, a classic traditional Chinese medicine (TCM, has been widely used throughout China for disease treatment due to its various pharmacological activities, such as anti-inflammatory, cardiotonic, and analgesic effects. However, improper use of Radix Aconiti often generated severe acute toxicity. Currently, research on the toxic substances of Radix Aconiti is not rare. In our previous study, acute toxic biomarkers of Radix Aconiti have been found. However, few studies were available to find the relationships between these endogenous biomarkers and exogenous toxic substances. Therefore, in this study, toxic substances of Radix Aconiti have been found using UPLC-Q-TOF-MS technology. Then, we used biochemical indicators as a bridge to find the relationships between biomarkers and toxic substances of Radix Aconiti through Pearson correlation analysis and canonical correlation analysis (CCA. Finally, the CCA results showed that LysoPC(22:5 is related to 14-acetyl-talatisamine, mesaconitine, talatisamine and deoxyaconitine in varying degrees; l-acetylcarnitine is negatively correlated with deoxyaconitine and demethyl-14-acetylkaracoline; shikimic acid has a good correlation with karacoline, demethyl-14-acetylkaracoline and deoxyaconitine; and valine is correlated with talatisamine and deoxyaconitine. Research on these relationships provides an innovative way to interpret the toxic mechanism of traditional Chinese medicine, and plays a positive role in the overall study of TCM toxicity.

An Embryonic Field of Study: The Aquatic Fate and Toxicity of Diluted Bitumen.

Science.gov (United States)

Alsaadi, Ftoon; Hodson, Peter V; Langlois, Valerie S

2018-01-01

Canada has experienced a significant increase in the transport of diluted bitumen (dilbit), a predominant oil sands product that combines bitumen with diluents derived from oil-gas condensates and other proprietary compounds. The proportion of diluent and the chemical composition of dilbit vary to meet seasonal transport requirements. While the toxic effects of a variety of crude and refined oils are well-studied, the toxicity of dilbit to aquatic species is less well known. This focused review summarizes dilbit production, chemistry, and the few data on toxicity to aquatic species. These data suggest that un-weathered dilbit would cause effects on fish equivalent to those of conventional oils, but its toxicity may be lower, depending on interactions among test conditions, the behavior of dilbit added to water and the species tested.

Reaction of diazepam and related benzodiazepines with chlorine. Kinetics, transformation products and in-silico toxicological assessment.

Science.gov (United States)

Carpinteiro, Inmaculada; Rodil, Rosario; Quintana, José Benito; Cela, Rafael

2017-09-01

In this work, the reaction of four benzodiazepines (diazepam, oxazepam, nordazepam and temazepam) during water chlorination was studied by means of liquid chromatography-quadrupole-time of flight-mass spectrometry (LC-QTOF-MS). For those compounds that showed a significant degradation, i.e. diazepam, oxazepam and nordazepam, parameters affecting to the reaction kinetics (pH, chlorine and bromide level) were studied in detail and transformation products were tentatively identified. The oxidation reactions followed pseudofirst-order kinetics with rate constants in the range of 1.8-42.5 M -1  s -1 , 0.13-1.16 M -1  s -1 and 0.04-20.4 M -1  s -1 corresponding to half-life values in the range of 1.9-146 min, 1.8-87 h and 2.5-637 h for oxazepam, nordazepam and diazepam, respectively, depending of the levels of studied parameters. Chlorine and pH affected significantly the reaction kinetics, where an increase of the pH resulted into a decrease of the reaction rate, whereas higher chlorine dosages led to faster kinetics, as expected in this case. The transformation of the studied benzodiazepines occurs mainly at the 1,4-diazepine 7-membered-ring, resulting in ring opening to form benzophenone derivatives or the formation of a 6-membered pyrimidine ring, leading to quinazoline derivatives. The formation of these by-products was also tested in real surface water samples observing kinetics of oxazepam degradation slower in river than in creek water, while the degradation of the two other benzodiazepines occurred only in the simpler sample (creek water). Finally, the acute and chronical toxicity and mutagenicity of precursors and transformation products were estimated using quantitative structure-activity relationship (QSAR) software tools: Ecological Structure Activity Relationships (ECOSAR) and Toxicity Estimation Software Tool (TEST), finding that some transformation products could be more toxic/mutagenic than the precursor drug, but additional test would be needed

Influence of nutrient medium composition on uranium toxicity and choice of the most sensitive growth related endpoint in Lemna minor.

Science.gov (United States)

Horemans, Nele; Van Hees, May; Saenen, Eline; Van Hoeck, Arne; Smolders, Valérie; Blust, Ronny; Vandenhove, Hildegarde

2016-01-01

Uranium (U) toxicity is known to be highly dependent on U speciation and bioavailability. To assess the impact of uranium on plants, a growth inhibition test was set up in the freshwater macrophyte Lemna minor. First growth media with different compositions were tested in order to find a medium fit for testing U toxicity in L. minor. Following arguments were used for medium selection: the ability to sustain L. minor growth, a high solubility of U in the medium and a high percentage of the more toxic U-species namely UO2(2+). Based on these selection criteria a with a low phosphate concentration of 0.5 mg L(-1) and supplemented with 5 mM MES (2-(N-morpholino)ethanesulfonic acid) to ensure pH stability was chosen. This medium also showed highest U toxicity compared to the other tested media. Subsequently a full dose response curve for U was established by exposing L. minor plants to U concentrations ranging from 0.05 μM up to 150 μM for 7 days. Uranium was shown to adversely affect growth of L. minor in a dose dependent manner with EC10, EC30 and EC50 values ranging between 1.6 and 4.8 μM, 7.7-16.4 μM and 19.4-37.2 μM U, respectively, depending on the growth endpoint. Four different growth related endpoints were tested: frond area, frond number, fresh weight and dry weight. Although differences in relative growth rates and associated ECx-values calculated on different endpoints are small (maximal twofold difference), frond area is recommended to be used to measure U-induced growth effects as it is a sensitive growth endpoint and easy to measure in vivo allowing for measurements over time. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of a new optic-enabled portable X-ray fluorescence spectrometry instrument for measuring toxic metals/metalloids in consumer goods and cultural products

Science.gov (United States)

Guimarães, Diana; Praamsma, Meredith L.; Parsons, Patrick J.

2016-08-01

X-ray fluorescence spectrometry (XRF) is a rapid, non-destructive multi-elemental analytical technique used for determining elemental contents ranging from percent down to the μg/g level. Although detection limits are much higher for XRF compared to other laboratory-based methods, such as inductively coupled plasma mass spectrometry (ICP-MS), ICP-optical emission spectrometry (OES) and atomic absorption spectrometry (AAS), its portability and ease of use make it a valuable tool, especially for field-based studies. A growing necessity to monitor human exposure to toxic metals and metalloids in consumer goods, cultural products, foods and other sample types while performing the analysis in situ has led to several important developments in portable XRF technology. In this study, a new portable XRF analyzer based on the use of doubly curved crystal optics (HD Mobile®) was evaluated for detecting toxic elements in foods, medicines, cosmetics and spices used in many Asian communities. Two models of the HD Mobile® (a pre-production and a final production unit) were investigated. Performance parameters including accuracy, precision and detection limits were characterized in a laboratory setting using certified reference materials (CRMs) and standard solutions. Bias estimates for key elements of public health significance such as As, Cd, Hg and Pb ranged from - 10% to 11% for the pre-production, and - 14% to 16% for the final production model. Five archived public health samples including herbal medicine products, ethnic spices and cosmetic products were analyzed using both XRF instruments. There was good agreement between the pre-production and final production models for the four key elements, such that the data were judged to be fit-for-purpose for the majority of samples analyzed. Detection of the four key elements of interest using the HD Mobile® was confirmed using archived samples for which ICP-OES data were available based on digested sample materials. The HD

A Toxicological Framework for the Prioritization of Children’s Safe Product Act Data

Directory of Open Access Journals (Sweden)

Marissa N. Smith

2016-04-01

Full Text Available In response to concerns over hazardous chemicals in children’s products, Washington State passed the Children’s Safe Product Act (CSPA. CSPA requires manufacturers to report the concentration of 66 chemicals in children’s products. We describe a framework for the toxicological prioritization of the ten chemical groups most frequently reported under CSPA. The framework scores lifestage, exposure duration, primary, secondary and tertiary exposure routes, toxicokinetics and chemical properties to calculate an exposure score. Four toxicological endpoints were assessed based on curated national and international databases: reproductive and developmental toxicity, endocrine disruption, neurotoxicity and carcinogenicity. A total priority index was calculated from the product of the toxicity and exposure scores. The three highest priority chemicals were formaldehyde, dibutyl phthalate and styrene. Elements of the framework were compared to existing prioritization tools, such as the United States Environmental Protection Agency’s (EPA ExpoCast and Toxicological Prioritization Index (ToxPi. The CSPA framework allowed us to examine toxicity and exposure pathways in a lifestage-specific manner, providing a relatively high throughput approach to prioritizing hazardous chemicals found in children’s products.

Relative toxicity of oil dispersants to Mytilus viridis and Macrobrachium idella

Digital Repository Service at National Institute of Oceanography (India)

DeSilva, C.; Row, A.

) was almost identical for both the species tested, although there was a significant shift in the range of LC sub(50) values, indicating that one species is less sensitive than the other. Oil dispersant mixtures were less toxic than the dispersants alone...

Acute Toxicity and Ecological Risk Assessment of Benzophenone and N,N-Diethyl-3 Methylbenzamide in Personal Care Products

Directory of Open Access Journals (Sweden)

Hong-Qin Sun

2016-09-01

Full Text Available Benzophenone (BP and N,N-diethyl-3-methylbenzamide (DEET are two chemicals often used in personal care products (PCPs. There is a lack of systematic ecotoxicological evaluations about the two chemicals to aquatic organisms. In the present study, the acute toxic effects on Chlorella vulgaris, Daphnia Magana, and Brachydanio rerio were tested and the ecotoxicological risks were evaluated. For BP, the 96-h half-maximal effective concentration (EC50 on C. vulgaris was 6.86 mg/L; the 24-h median lethal concentration (LC50 on D. magana was 7.63 mg/L; the 96-h LC50 on B. rerio was 14.73 mg/L. For DEET, those were 270.72 mg/L, 40.74 mg/L, and 109.67 mg/L, respectively. The mixture toxicity of BP and DEET, on C. vulgaris, D. magana, and B. rerio all showed an additive effect. The induced predicted no-effect concentrations (PNECs for BP and DEET by assessment factor (AF method are 0.003 mg/L and 0.407 mg/L, respectively. Both are lower than the concentrations detected from environment at present, verifying that BP and DEET are low-risk chemicals to the environment.

Acute toxicity of vanadium to the threespine stickleback, Gasterosteus aculeatus

Energy Technology Data Exchange (ETDEWEB)

Gravenmier, J.J.; Johnston, D.W.; Arnold, W.R. [Blasland Bouck & Lee Inc, Petaluma, CA (US)

2005-02-15

Vanadium is widely distributed, occurring in many types of minerals, coal, and petroleum. Anthropogenic sources of vanadium originate from the production, processing, and wastes of these materials. The aquatic toxicity of vanadium to fish species is not well characterized. This study focused on the three-spined stickleback, Gasterosteus aculeatus, a small and widely distributed euryhaline species of fish. The three-spined stickleback is used as an effluent-monitoring species in both Canada and the United States. Five 96-h static renewal acute toxicity tests were performed in moderately hard water with adult fish. The geometric mean and range of the five 96-h LC{sup 50}s based on measured concentrations of total vanadium in the test solution were 3.17 and 2.35-4.07 mg V/L, respectively. A conservative estimation of a safe concentration of vanadium that would not affect survival of adult three-spined sticklebacks over a 96-h exposure period in moderately hard water is approximately 0.30 mg V/L. A comparison with other fish species previously tested suggests that the three-spined stickleback is intermediate in sensitivity to vanadium. Information reported from this study may be useful in effluent toxicity identification evaluations and ecological risk assessments related to vanadium.

The effect of soil properties on the toxicity of silver to the soil nitrification process.

Science.gov (United States)

Langdon, Kate A; McLaughlin, Mike J; Kirby, Jason K; Merrington, Graham

2014-05-01

Silver (Ag) is being increasingly used in a range of consumer products, predominantly as an antimicrobial agent, leading to a higher likelihood of its release into the environment. The present study investigated the toxicity of Ag to the nitrification process in European and Australian soils in both leached and unleached conditions. Overall, leaching of soils was found to have a minimal effect on the final toxicity data, with an average leaching factor of approximately 1. Across the soils, the toxicity was found to vary by several orders of magnitude, with concentrations of Ag causing a 50% reduction in nitrification relative to the controls (EC50) ranging from 0.43 mg Ag/kg to >640 mg Ag/kg. Interestingly, the dose-response relationships in most of the soils showed significant stimulation in nitrification at low Ag concentrations (i.e., hormesis), which in some cases produced responses up to double that observed in the controls. Soil pH and organic carbon were the properties found to have the greatest influence on the variations in toxicity thresholds across the soils, and significant relationships were developed that accounted for approximately 90% of the variability in the data. The toxicity relationships developed from the present study will assist in future assessment of potential Ag risks and enable the site-specific prediction of Ag toxicity. © 2014 SETAC.

Can Dietary Polyphenols Prevent the Formation of Toxic Compounds from Maillard Reaction?

Science.gov (United States)

Del Turco, Serena; Basta, Giuseppina

2016-01-01

Polyphenols are functional compounds in edible vegetable and food such as tea, coffee and red wine and increasing evidence demonstrates a positive link between consumption of polyphenol-rich foods and disease prevention. In this review we have focused on the current knowledge of the potential anti-glycation effects of polyphenols, particularly in regard to their influence on Maillard reaction, a non-enzymatic reaction between amino acids and reducing sugars that contributes to the production of toxic compounds, mainly reactive carbonyl species, advanced glycation end-products (AGEs) and other toxicants. The Maillard reaction occurs in the human body during hyperglycemic condition, but it is well known as browning reaction in thermally processed foods and it is responsible for flavor and toxicant formation. Dietary polyphenols can have anti-glycation effects and actively participate in Maillard reaction, mitigating the AGE formation and the heat-induced production of toxic compounds. In a time in which the role of a healthy diet in the prevention of chronic diseases is welcome and the borderline between food and medicine is becoming very thin, an improved mechanistic knowledge of how polyphenols can function to reduce harmful and unhealthy substances is mandatory.

Evaluation of Toxic and Essential Metals in Some Selected Chewing Food Products and their Daily Intake by the Population of Karachi, Pakistan

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Shahid Bhutto

2017-12-01

Full Text Available The present study focused on different brands of chewing food products which containing some toxic metals (TMs and essential metals and these samples were analyzed to determine the levels of some toxic metals (Pb, Cd, Ni, Cr and Mn and essential metals (Ca, Cu, Fe, K, Mg, Na and Zn. The samples of gutka (100, sweet supari (63, sweet paan (16 and paan masala (21 were randomly collected from different shops of Karachi, Pakistan. The validity of conventional wet acid digestion method (CAD was assessed by analyzing two certified reference materials (CRM Virgina tobacco leaf (CTA-VTL-2 and Bovine liver (1577b and standard addition recovery test. The limit of detections (LODs, n=10 of the method were found to be 0.144, 14.4, 8.89, 2.76, 4.06, 15.3 and 2.99, 22.9, 9.97, 4.54, 1.89, 1.76 µg L-1 for Ca, Cu, Fe, K, Mg, Na, Zn, Cd, Cr, Mn, Ni and Pb, respectively. The CAD method was successfully applied to real samples for the determination of toxic and essential metals. 

Illness related wage and productivity losses: Valuing 'presenteeism'.

Science.gov (United States)

Zhang, Wei; Sun, Huiying; Woodcock, Simon; Anis, Aslam

2015-12-01

One source of productivity loss due to illness is the reduced "quantity" or "quality" of labor input while working, often referred to as presenteeism. Illness-related presenteeism has been found to be potentially more costly than absenteeism. To value presenteeism, existing methods use wages as a proxy for marginal productivity at the firm level. However, wage may not equal marginal productivity in some scenarios. One instance is when a job involves team production and perfect substitutes for workers are not readily available. Using a Canadian linked employer-employee survey (2001-2005), we test whether relative wage equals relative marginal productivity among team workers and non-team workers with different frequencies of presenteeism (reduction at work due to illness). For the pooled cross-sectional estimates (2001, 2003, 2005) we obtain 13,755 observations with 6842 unique workplaces. There are 6490 observations for the first differences estimates from the odd years and 5263 observations for the first differences estimates from 2001 to 2002 and 2003 to 2004. We find that in both small and large firms, team workers with frequent reductions at work are less productive but earn similarly compared with non-team workers without reductions. We also find that in small firms, workers with occasional work reductions are more productive than workers without reductions, but the reverse is true in large firms. The study findings partially support the literature stating that productivity loss resulting from employee presenteeism could exceed wages if team work is involved. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of the waste products storage on the environmental pollution by toxic organic compounds

Directory of Open Access Journals (Sweden)

Aleksandra Lewkiewicz-Małysa

2005-11-01

Full Text Available A permanent deposition of industrial wastes is a method of its neutralization. A storage yard for toxic materials must meet specific site and construction conditions. The storage place region of toxic organic waste materials has to be monitored. The environmental impact of this waste on the groundwater quality, especially the migration of persistent organic pollutants, was discussed on the example of a chemical plant.

Herbicide toxicity on river biofilms assessed by pulse amplitude modulated (PAM) fluorometry

Energy Technology Data Exchange (ETDEWEB)

Kim Tiam, Sandra, E-mail: sandra.kimtiam@gmail.com [Irstea, UR EABX, 50 Avenue de Verdun, F-33612, Cestas Cedex (France); Université de Bordeaux, EPOC, UMR 5805, F-33120 Arcachon (France); Laviale, Martin [Departamento de Biologia and CESAM – Centro de Estudos do Ambiente e do Mar Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Sorbonne Universités, UPMC Univ Paris 06, UMR 7093, LOV, Observatoire Océanologique, F-06230, Villefranche-Sur-Mer (France); CNRS, UMR 7093, LOV, Observatoire Océanologique, F-06230, Villefranche-Sur-Mer France (France); Feurtet-Mazel, Agnès [Université de Bordeaux, EPOC, UMR 5805, F-33120 Arcachon (France); Jan, Gwilherm [Irstea, UR EABX, 50 Avenue de Verdun, F-33612, Cestas Cedex (France); Gonzalez, Patrice [Université de Bordeaux, EPOC, UMR 5805, F-33120 Arcachon (France); Mazzella, Nicolas; Morin, Soizic [Irstea, UR EABX, 50 Avenue de Verdun, F-33612, Cestas Cedex (France)

2015-08-15

Highlights: • Rapid Light Curves were shown to be early markers of toxicant exposure. • Diuron and norflurazon effects were significant at environmentally realistic concentrations. • Toxic effects in intact biofilms seem to be delayed compared to disrupted biofilms. - Abstract: The use of Rapid light curves (RLCs) as a toxicity endpoint for river biofilms was examined in this study and compared to “classical fluorescence parameters” i.e. minimal fluorescence (F{sub 0}), optimal and effective quantum yields of photosystem II (F{sub v}/F{sub m} and Φ{sub PSII}). Measurements were performed after exposure to five concentrations of diuron (from 0.3 to 33.4 μg L{sup −1}), its main degradation product (DCPMU) (from 1.0 to 1014 μg L{sup −1}) and norflurazon (from 0.6 to 585 μg L{sup −1}) with the lowest exposure concentrations corresponding to levels regularly encountered in chronically contaminated sites. Biofilm responses were evaluated after 1, 5, 7 and 14 days of exposure to the different toxicants. Overall, the responses of both “classical fluorescence parameters” and RLC endpoints were highly time dependent and related to the mode of action of the different compounds. Interestingly, parameters calculated from RLCs (α, ETR{sub max} and I{sub k}) were useful early markers of pesticide exposure since they revealed significant effects of all the tested toxicants from the first day of exposure. In comparison, classical fluorescence endpoints (F{sub 0} and F{sub v}/F{sub m}) measured at day 1 were only affected in the DCPMU treatment. Our results demonstrated the interest of RLCs as early markers of toxicant exposure particularly when working with toxicants with less specific mode of action than PSII inhibitors.

Nanoparticulate-induced toxicity and related mechanism in vitro and in vivo

International Nuclear Information System (INIS)

Kim, Hye Won; Ahn, Eun-Kyung; Jee, Bo Keun; Yoon, Hyoung-Kyu; Lee, Kweon Haeng; Lim, Young

2009-01-01

In urban areas, the quantity of exhaust particles from vehicle emissions is tremendous and has been regarded as the main contributor to particulate matter (PM) pollution. Recently, the nano-sized PM on public health has begun to raise the attention. The increased toxicity of nanoparticulate can be largely explained by their small size, high airborne concentration, extensive surface area and high content of organic carbon and transition metals. We have attempted to address the toxicity of nano sized-particlulate matter by comparing various particulates including micro-SiO 2 (mSiO 2 ), nano-SiO 2 (nSiO 2 ), micro-TiO 2 (mTiO 2 ), and nano-TiO 2 (nTiO 2 ) in RAW264.7 cells and in vivo. The cell viability of all particulates decreased dose dependently. 24-h incubation with nSiO2 demonstrated apoptosis in RAW264.7 using Annexin-V binding immunofluorescent microscopy, but not in any other particulates. In vivo, cytotoxicity of nanosized was higher than micro-sized particulates. As higher the concentration of particulates, the more pulmonary injury and neutrophilic infiltration were observed in nano-sized than micro-sized particulates, respectively. Particularly, 5.0 mg/kg of mTiO 2 never shows any increase of neutrophile even with high cellularity of total cells and macrophages. From these results, we suggested that particulate-induced respiratory toxicity be influenced by component, size, and dose of particulates including the characteristic nature of the target cells in vitro and in vivo.

Seeking a Mechanism for the Toxicity of Oligomeric α-Synuclein

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Hazel L. Roberts

2015-03-01

Full Text Available In a number of neurological diseases including Parkinson’s disease (PD, α‑synuclein is aberrantly folded, forming abnormal oligomers, and amyloid fibrils within nerve cells. Strong evidence exists for the toxicity of increased production and aggregation of α-synuclein in vivo. The toxicity of α-synuclein is popularly attributed to the formation of “toxic oligomers”: a heterogenous and poorly characterized group of conformers that may share common molecular features. This review presents the available evidence on the properties of α-synuclein oligomers and the potential molecular mechanisms of their cellular disruption. Toxic α-synuclein oligomers may impact cells in a number of ways, including the disruption of membranes, mitochondrial depolarization, cytoskeleton changes, impairment of protein clearance pathways, and enhanced oxidative stress. We also examine the relationship between α-synuclein toxic oligomers and amyloid fibrils, in the light of recent studies that paint a more complex picture of α-synuclein toxicity. Finally, methods of studying and manipulating oligomers within cells are described.

Reduction of Fumonisin Toxicity by Extrusion and Nixtamalization (Alkaline Cooking).

Science.gov (United States)

Voss, Kenneth; Ryu, Dojin; Jackson, Lauren; Riley, Ronald; Gelineau-van Waes, Janee

2017-08-23

Fumonisins are mycotoxins found in corn. They are toxic to animals and cause cancer in rodents and neural tube defects in LM/Bc mice. Reducing their concentrations in corn-based foods is therefore desirable. Chemical analysis or in vitro bioassays of food extracts might not detect toxic fumonisin reaction products that are unknown or unextractable from food matrices, thus potentially underestimating in vivo toxicity. The effectiveness of two common cooking methods, extrusion and nixtamalization (alkaline cooking), to reduce the toxicity of fumonisin-contaminated corn grits (extrusion) and whole kernel corn (nixtamalization) was shown by means of rat feeding bioassays using fumonisin-specific kidney effects as indicators of potential toxicity. A third bioassay showed that in contrast to fumonisin B 1 (FB 1 ), hydrolyzed fumonisin B 1 (HFB 1 ; formed from FB 1 during nixtamalization) did not cause neural tube defects in LM/Bc mice. The findings indicate that extrusion and nixtamalization reduce the potential toxicity of FB 1 -contaminated corn.

Triphenyl phosphate-induced developmental toxicity in zebrafish: Potential role of the retinoic acid receptor

Energy Technology Data Exchange (ETDEWEB)

Isales, Gregory M.; Hipszer, Rachel A.; Raftery, Tara D. [Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC (United States); Chen, Albert; Stapleton, Heather M. [Division of Environmental Sciences and Policy, Nicholas School of the Environment, Duke University, Durham, NC (United States); Volz, David C., E-mail: volz@mailbox.sc.edu [Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC (United States)

2015-04-15

Highlights: • Triphenyl phosphate-induced toxicity in zebrafish embryos is enhanced in the presence of a retinoic acid receptor antagonist. • Triphenyl phosphate uptake or metabolism within zebrafish embryos is not altered in the presence of a retinoic acid receptor antagonist. • Triphenyl phosphate decreases expression of cytochrome P450 26a1 in zebrafish embryos. • Triphenyl phosphate inhibits retinoic acid-induced activation of human retinoic acid receptors. - Abstract: Using zebrafish as a model, we previously reported that developmental exposure to triphenyl phosphate (TPP) – a high-production volume organophosphate-based flame retardant – results in dioxin-like cardiac looping impairments that are independent of the aryl hydrocarbon receptor. Using a pharmacologic approach, the objective of this study was to investigate the potential role of retinoic acid receptor (RAR) – a nuclear receptor that regulates vertebrate heart morphogenesis – in mediating TPP-induced developmental toxicity in zebrafish. We first revealed that static exposure of zebrafish from 5–72 h post-fertilization (hpf) to TPP in the presence of non-toxic concentrations of an RAR antagonist (BMS493) significantly enhanced TPP-induced toxicity (relative to TPP alone), even though identical non-toxic BMS493 concentrations mitigated retinoic acid (RA)-induced toxicity. BMS493-mediated enhancement of TPP toxicity was not a result of differential TPP uptake or metabolism, as internal embryonic doses of TPP and diphenyl phosphate (DPP) – a primary TPP metabolite – were not different in the presence or absence of BMS493. Using real-time PCR, we then quantified the relative change in expression of cytochrome P450 26a1 (cyp26a1) – a major target gene for RA-induced RAR activation in zebrafish – and found that RA and TPP exposure resulted in a ∼5-fold increase and decrease in cyp26a1 expression, respectively, relative to vehicle-exposed embryos. To address whether TPP may

New Tobacco and Tobacco-Related Products: Early Detection of Product Development, Marketing Strategies, and Consumer Interest.

Science.gov (United States)

Staal, Yvonne Cm; van de Nobelen, Suzanne; Havermans, Anne; Talhout, Reinskje

2018-05-28

A wide variety of new tobacco and tobacco-related products have emerged on the market in recent years. To understand their potential implications for public health and to guide tobacco control efforts, we have used an infoveillance approach to identify new tobacco and tobacco-related products. Our search for tobacco(-related) products consists of several tailored search profiles using combinations of keywords such as "e-cigarette" and "new" to extract information from almost 9000 preselected sources such as websites of online shops, tobacco manufacturers, and news sites. Developments in e-cigarette design characteristics show a trend toward customization by possibilities to adjust temperature and airflow, and by the large variety of flavors of e-liquids. Additionally, more e-cigarettes are equipped with personalized accessories, such as mobile phones, applications, and Bluetooth. Waterpipe products follow the trend toward electronic vaping. Various heat-not-burn products were reintroduced to the market. Our search for tobacco(-related) products was specific and timely, though advances in product development require ongoing optimization of the search strategy. Our results show a trend toward products resembling tobacco cigarettes vaporizers that can be adapted to the consumers' needs. Our search for tobacco(-related) products could aid in the assessment of the likelihood of new products to gain market share, as a possible health risk or as an indicator for the need on independent and reliable information of the product to the general public. ©Yvonne CM Staal, Suzanne van de Nobelen, Anne Havermans, Reinskje Talhout. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 28.05.2018.

Algal toxicity of the alternative disinfectants performic acid (PFA), peracetic acid (PAA), chlorine dioxide (ClO2) and their by-products hydrogen peroxide (H2O2) and chlorite (ClO2-)

DEFF Research Database (Denmark)

Chhetri, Ravi Kumar; Baun, Anders; Andersen, Henrik Rasmus

2017-01-01

Environmental effect evaluation of disinfection of combined sewer overflow events with alternative chemical disinfectants requires that the environmental toxicity of the disinfectants and the main by-products of their use are known. Many disinfectants degrade quickly in water which should......: performic acid (PFA), peracetic acid (PAA) and chlorine dioxide (ClO2) as well as two by-products of their use: hydrogen peroxide (H2O2) and chlorite. All of the five chemicals investigated showed clear toxicity to the algae with well-defined dose response curves. The EC50 values ranged from 0.16 to 2.9 mg...

9 CFR 101.3 - Biological products and related terms.

Science.gov (United States)

2010-01-01

... as required by the regulations. (e) Released product. A finished product released for marketing after... total quantity of completed product which has been thoroughly mixed in a single container and identified... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Biological products and related terms...

Assessment of herbal medicinal products: Challenges, and opportunities to increase the knowledge base for safety assessment

International Nuclear Information System (INIS)

Jordan, Scott A.; Cunningham, David G.; Marles, Robin J.

2010-01-01

Although herbal medicinal products (HMP) have been perceived by the public as relatively low risk, there has been more recognition of the potential risks associated with this type of product as the use of HMPs increases. Potential harm can occur via inherent toxicity of herbs, as well as from contamination, adulteration, plant misidentification, and interactions with other herbal products or pharmaceutical drugs. Regulatory safety assessment for HMPs relies on both the assessment of cases of adverse reactions and the review of published toxicity information. However, the conduct of such an integrated investigation has many challenges in terms of the quantity and quality of information. Adverse reactions are under-reported, product quality may be less than ideal, herbs have a complex composition and there is lack of information on the toxicity of medicinal herbs or their constituents. Nevertheless, opportunities exist to capitalise on newer information to increase the current body of scientific evidence. Novel sources of information are reviewed, such as the use of poison control data to augment adverse reaction information from national pharmacovigilance databases, and the use of more recent toxicological assessment techniques such as predictive toxicology and omics. The integration of all available information can reduce the uncertainty in decision making with respect to herbal medicinal products. The example of Aristolochia and aristolochic acids is used to highlight the challenges related to safety assessment, and the opportunities that exist to more accurately elucidate the toxicity of herbal medicines.

Peculiarities of toxic effects exerted by hexyl ether of 5-aminolevulinic acid and grounds for working our regulations of its safe production and application

Directory of Open Access Journals (Sweden)

Е.К. Vlasenko

2017-09-01

Full Text Available Our research object was hexyl ether of 5-aminolevulinic acid applied as plants growth regulator which was synthe-sized with an original technology by Bioorganic Chemistry Institute of Belarus National Academy of science. Our research goal was to determine peculiarities of toxic effects exerted by this new plants protector on experimental models in vivo/in vitro and to give grounds for hygienic standards of its contents in various media which were to provide its safe production and application. We conducted our research with the use of toxicological, physiological, hematological, biochemical, immu-nologic, cytogenetic, cytological, and statistical methods. We were the first to perform toxicological assessment of this new plants growth regulator under different regimes, doses and ways of introduction into laboratory animals' bodies and it helped us to detect its toxicometric parameters and peculiarities of its biological effects which became apparent through skin-resorptive and cumulative properties, irritating impacts on mucous tunics, moderate reproductive toxicity without sub-stantial signs of gonadotropic, mutagenic, and allergenic impacts on a body. We detected that toxic impacts exerted by the examined substance on a body was combined with membrane-tropic and cytotoxic effects. We determined criteria and limit-ing parameters of hazardous effects exerted by hexyl ether of 5-aminolevulinic acid in the course of a chronic experiment, and it gave us grounds for fixing allowable daily dose for a man and for working out a number of regulations on the sub-stance contents in environmental objects (working area air, water, and soil, in food raw materials, and in food products (grain, rape, rape and linen oil. The obtained results were used as a basis for fixing 9 hygienic standards and were used for the state registration of this plant growth regulator; it will provide its safe production and application in agriculture.

Earthworm cast production as a new behavioural biomarker for toxicity testing

Energy Technology Data Exchange (ETDEWEB)

Capowiez, Yvan, E-mail: capowiez@avignon.inra.f [INRA, UR1115 ' Plantes et Systemes Horticoles' , Domaine Saint Paul, 84914 Avignon Cedex 09 (France); Dittbrenner, Nils [INRA, UR1115 ' Plantes et Systemes Horticoles' , Domaine Saint Paul, 84914 Avignon Cedex 09 (France); Animal Physiological Ecology, University of Tuebingen, Konrad-Adenauer-Str. 20, D-72072 Tuebingen (Germany); Rault, Magali [UAPV, UMR406 ' Abeilles et Environnement' , Domaine Saint Paul, 84914 Avignon Cedex 09 (France); Triebskorn, Rita [Animal Physiological Ecology, University of Tuebingen, Konrad-Adenauer-Str. 20, D-72072 Tuebingen (Germany); Hedde, Mickael [INRA, UR251 ' PESSAC' , RD10, 78026 Versailles Cedex (France); Mazzia, Christophe [UAPV, UMR406 ' Abeilles et Environnement' , Domaine Saint Paul, 84914 Avignon Cedex 09 (France)

2010-02-15