[Risk assessment of carcinogenic and non-carcinogenic effects in the use of food].

Science.gov (United States)

Frolova, O A; Karpova, M V

2012-01-01

Application of methodology for assessing the risk of diseases associated with consumption of contaminated foods, is aimed at predicting possible changes in the future and helps to create a framework for the prevention of negative effects on public health. The purpose of the study is assessment of health risks formed under the influence of chemical contaminants that pollute the food. Exponential average daily dose of receipt of chemicals in the body, non-carcinogenic and carcinogenic risks were calculated.

The assessment of the carcinogenic effects of low dose radiation

International Nuclear Information System (INIS)

Tubiana, M.; Lafuma, J.; Masse, R.; Latarjet, R.

1991-01-01

It is concluded that the exclusion of patients for the purposes of risk estimation, the choice of a particular relative risk projection model and of a dose reduction factor equal to 2 are all decisions which result in an overestimation of the actual risk. These choices can be understood when the aim is radiation protection and when it is safer to overestimate the risk; however, they are open to criticism if the aim is a realistic assessment of the risk. For low doses, below 50 mSv/year, and when all causes of uncertainty are added, the actual risk might be markedly lower than the risk estimated with the ICRP (1991) carcinogenic risk coefficient and the DRF estimated by ICRP. Future studies should aim at providing direct and more precise assessments of risk coefficients in the low dose region. (Author)

Most cancer in firefighters is due to radio-frequency radiation exposure not inhaled carcinogens.

Science.gov (United States)

Milham, S

2009-11-01

Recent reviews and reports of cancer incidence and mortality in firefighters conclude that they are at an increased risk of a number of cancers. These include leukemia, multiple myeloma, non-Hodgkin's lymphoma, male breast cancer, malignant melanoma, and cancers of the brain, stomach, colon, rectum, prostate, urinary bladder, testes, and thyroid. Firefighters are exposed to a long list of recognized or probable carcinogens in combustion products and the presumed route of exposure to these carcinogens is by inhalation. Curiously, respiratory system cancers and diseases are usually not increased in firefighters as they are in workers exposed to known inhaled carcinogens. The list of cancers with increased risk in firefighters strongly overlaps the list of cancers at increased risk in workers exposed to electromagnetic fields (EMF) and radiofrequency radiation (RFR). Firefighters have increased exposure to RFR in the course of their work, from the mobile two-way radio communications devices which they routinely use while fighting fires, and at times from firehouse and fire vehicle radio transmitters. I suggest that some of the increased cancer risk in firefighters is caused by RFR exposure, and is therefore preventable. The precautionary principle should be applied to reduce the risk of cancer in firefighters, and workman's compensation rules will necessarily need to be modified.

An estimation of the carcinogenic risk associated with the intake of multiple relevant carcinogens found in meat and charcuterie products.

Science.gov (United States)

Hernández, Ángel Rodríguez; Boada, Luis D; Almeida-González, Maira; Mendoza, Zenaida; Ruiz-Suárez, Norberto; Valeron, Pilar F; Camacho, María; Zumbado, Manuel; Henríquez-Hernández, Luis A; Luzardo, Octavio P

2015-05-01

Numerous epidemiological studies have demonstrated a link between excessive meat consumption and the incidence of various cancers, especially colorectal cancer, and it has been suggested that environmental carcinogens present in meat might be related to the increased risk of cancer associated with this food. However, there are no studies evaluating the carcinogenic potential of meat in relation to its content of carcinogens. Our purpose was to emphasize the relevance of environmental carcinogens existing in meat as a determinant of the association between cancer and meat consumption. Because within Europe, Spain shows high consumption of meat and charcuterie, we performed this study focusing on Spanish population. Based on the preferences of consumers we acquired 100 samples of meat and charcuterie that reflect the variety available in the European market. We quantified in these samples the concentration of 33 chemicals with calculated carcinogenic potential (PAHs, organochlorine pesticides, and dioxin-like PCBs). The carcinogenic risk of these contaminants was assessed for each food using a risk ratio based on the current consumption of meat and charcuterie and the maximum tolerable intake of these foods depending on the level of contamination by the carcinogens they contain. Our results indicate that the current consumption of beef, pork, lamb, chicken, and "chorizo", represents a relevant carcinogenic risk for consumers (carcinogenic risk quotient between 1.33 and 13.98). In order to reduce carcinogenic risk, the study population should halve the monthly consumption of these foods, and also not to surpass the number of 5 servings of beef/pork/chicken (considered together). Copyright © 2015 Elsevier B.V. All rights reserved.

Risk-based indicators of Canadians' exposures to environmental carcinogens.

Science.gov (United States)

Setton, Eleanor; Hystad, Perry; Poplawski, Karla; Cheasley, Roslyn; Cervantes-Larios, Alejandro; Keller, C Peter; Demers, Paul A

2013-02-12

Tools for estimating population exposures to environmental carcinogens are required to support evidence-based policies to reduce chronic exposures and associated cancers. Our objective was to develop indicators of population exposure to selected environmental carcinogens that can be easily updated over time, and allow comparisons and prioritization between different carcinogens and exposure pathways. We employed a risk assessment-based approach to produce screening-level estimates of lifetime excess cancer risk for selected substances listed as known carcinogens by the International Agency for Research on Cancer. Estimates of lifetime average daily intake were calculated using population characteristics combined with concentrations (circa 2006) in outdoor air, indoor air, dust, drinking water, and food and beverages from existing monitoring databases or comprehensive literature reviews. Intake estimates were then multiplied by cancer potency factors from Health Canada, the United States Environmental Protection Agency, and the California Office of Environmental Health Hazard Assessment to estimate lifetime excess cancer risks associated with each substance and exposure pathway. Lifetime excess cancer risks in excess of 1 per million people are identified as potential priorities for further attention. Based on data representing average conditions circa 2006, a total of 18 carcinogen-exposure pathways had potential lifetime excess cancer risks greater than 1 per million, based on varying data quality. Carcinogens with moderate to high data quality and lifetime excess cancer risk greater than 1 per million included benzene, 1,3-butadiene and radon in outdoor air; benzene and radon in indoor air; and arsenic and hexavalent chromium in drinking water. Important data gaps were identified for asbestos, hexavalent chromium and diesel exhaust in outdoor and indoor air, while little data were available to assess risk for substances in dust, food and beverages. The ability to

Critical reevaluation of the dose-response relationships for carcinogenic effects of low-level ionizing radiation

International Nuclear Information System (INIS)

Upton, A.C.

2003-01-01

In recent decades, it has been customary, for radiation protection purposes, to assume that the overall risk of radiation-induced cancer increases as a linear-nonthreshold function of the dose. The existing data do not exclude the existence of a threshold, however, and the dose-response relationship is known to vary, depending on the type of cancer in queation, the dose, dose rate, and LET of the radiation, the age, sex, and physiological state of the exposed individuals, and other variables, including the potential influence of adaptive responses and bystander effects at low doses. In light of advncing knowledge, therefore, the dose-response relationship for carcinogenic effects of low-level radiation has been reevaluated periodically by the National Council on Radiation Protection and Measurements, the International Commission of Radiological Protection, the United Nations Scientific Committee on the Effects of Atomic Radiation, the U.S. National Academy of Sciences, and other organizations. The most recent such reviews have generally found the weight of evidence to suggest that lesions which are precursors to cancer (i.e., mutations and chromosome aberrations), and certain types of cancer as well, may increase in frequency linearly with the dose in the low-dose domain. On this basis, it is concluded that no alternative dose-response model for the carcinogenic effects of low-level radiation is more plausible than the linear-nonthreshold model, although other dose-response relationships cannot be excluded. (authors)

Factors that modify risks of radiation-induced cancer

International Nuclear Information System (INIS)

Fabrikant, J.I.

1988-11-01

The collective influence of biologic and physical factors that modify risks of radiation-induced cancer introduces uncertainties sufficient to deny precision of estimates of human cancer risk that can be calculated for low-dose radiation in exposed populations. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, minimum latent period, time-to-tumor recognition, and the influence of individual host (age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Other modifying factors include other carcinogens, and other biological sources (hormonal status, immune status, hereditary factors)

Critical reevaluation of the dose-response relationships for carcinogenic effects of low-level ionizing radiation

International Nuclear Information System (INIS)

Upton, Arthur C.

2002-01-01

In recent decades, it has been customary, for radiation protection purposes, to assume that the overall risk of radiation- included cancer increases as a linear-nonthreshold function of the dose. The existing data do not exclude the existence of a threshold, however, and the dose-response relationship is known to vary depending on the type of cancer in question, the dose, dose rate and LET of the radiation, the age, sex and physiological state of the exposed individuals, and other variables, including the potential influence of adaptive responses and bystander effects at low doses. In light of advancing knowledge, therefore, the dose-response relationship for carcinogenic effects of low-level radiation has been reevaluated periodically by the National Council on Radiation Protection and Measurements, the International Commission of Radiological Protection, the United Nations Scientific Committee on the Effects of Atomic Radiation, the U.S. National Academy of Sciences Committee on the Effects of Atomic Radiation, the U.S. National Academy of Sciences, and other organizations. The most recent such reviews have generally found the weight of evidence to suggest that lesions which are precursors to cancer (i.e., mutations and chromosome aberrations), and certain types of cancer as well, may increase in frequency linearly aberrations), and certain types of cancer as well, may increase in frequency linearly with the dose in the low-dose domain. On this basis, it is concluded that no alternative dose-response model for the carcinogenic effects of low-level radiation is ore plausible than the linear-nonthreshold model, although other dose-response relationships cannot be excluded. (author)

Evaluation of carcinogenic risk to public health of the republic of Khakassia associated with consumption of drinking water

Directory of Open Access Journals (Sweden)

E.A. Pivovarov

2016-09-01

Full Text Available During the observation period for 2011–2015 in the Republic of Khakassia it has been revealed that 63.2 % of samples of drinking water contain the excess of А α due to natural radionuclides 234 U, 238 U. Within the limits of MPC the carcinogenic hazardous substances: cadmium, lead, arsenic, beryllium, chromium have been detected. Individual risks of occurrence of stochastic effects in the form of malignant tumors, caused by natural radionuclides in drinking water in different administrative territories of the Republic, vary in the range of 3.14–7.81•10 –6 cases/year; collective risks 0.013–0.288 cases/year on the corresponding amount of population. Individual cancer risks are determined by the content of carcinogenic chemicals in drinking water, in different administrative territories of the Republic it varies in the range between 5.29•10 –5 – 1.04•10 –4 cases/year; collective risks of 0.88–2.704 event/year on the corresponding amount of population. The total population carcinogenic risks caused by content of carcinogenic chemicals and PRN in drinking water, for the period of observation were as follows: Altaisky (2.903 at 26.000 of population, Beysky (1.123 at 18.500 of population, Bogradsky (0,98 at 15,000 of population, Shirinsky (2.63 at 27100 of population, Ordzhonikidzevsky (1.178 at 11900 of population, and Ust-Abakansky (2.79 at 41100 of population. The contribution of drinking water into primary ontological morbidity of population in administrative territories of the Republic was equaled to 0.5–1 %. Therefore, currently, the events aimed at reducing the carcinogenic risks caused by drinking water are not required. At the same time, due to the high seismic activity in the Republic for the last five years, the laboratory monitoring of drinking water on indicators of radiation safety and the evaluation of the carcinogenic risks continues in the prescribed amount.

Synthetic risks, risk potency, and carcinogen regulation.

Science.gov (United States)

Viscusi, W K; Hakes, J K

1998-01-01

This article analyzes a comprehensive sample of over 350 chemicals tested for carcinogenicity to assess the determinants of the probability of regulation. Controlling for differences in the risk potency and noncancer risks, synthetic chemicals have a significantly higher probability of regulation overall: this is due to the greater likelihood of U.S. Food and Drug Administration (FDA) regulation. Measures of risk potency increase the probability of regulation by the U.S. Environmental Protection Agency (EPA), have a somewhat weaker positive effect on regulation by the U.S. Occupational Safety and Health Administration (OSHA), and decrease the likelihood of regulation by the FDA. The overall regulatory pattern is one in which the FDA targets synthetic chemicals and chemicals that pose relatively minor cancer risk. The EPA particularly performed more sensibly than many critics have suggested.

In vitro transformation: interactions of chemical carcinogens and radiation

International Nuclear Information System (INIS)

DiPaolo, J.A.

1976-01-01

The development of reproducible quantitative in vitro procedures resulting in neoplastic transformation of mammalian cells has made possible the separation of events related to the process leading to transformation from secondary events that interfere with the early recognition of transformation. The use of chemical carcinogens on Syrian hamster cell strains results in a dose-response relation consistent with a Poisson distribution, indicating that the transformation phenomenon is inductive. In some circumstances, the joint action or interaction of chemical carcinogens with other agents results in an increased incidence of transformation. The pretreatment of Syrian hamster cells with ionizing radiation (250 R) or alkylating chemicals enhances the frequency of transformation on a cell or colony basis ordinarily obtained with known chemical carcinogens. Pretreatment with non-ionizing irradiation (uv, 254 nm) did not have a similar effect. The two types of irradiation and the alkylating agents reduced the cloning efficiency of the cells. X ray alone produced no transformation; the alkylating chemicals produced transformations infrequently, whereas uv produced a significant number of transformations. The number of transformations associated with uv is increased by pretreatment of the cells by x-irradiation. The enhancement of transformation by x-ray or x-ray-type agents appears to be independent of the type of second carcinogen used

Carcinogenic risk assessment and management of ionising radiation, asbestos and nickel: a comparative approach

International Nuclear Information System (INIS)

Schneider, T.; Lepicard, S.; Oudiz, A.; Heriard Dubreuil, G.; Gadbois, S.

2000-01-01

The objective of this study is to identify the similarities as well as the differences of risk assessment and management of ionizing radiation, asbestos and nickel in France. The comparison has been performed at three levels of analysis: concepts, regulation and practices. Ionizing radiation (IR) is compared with asbestos as far as occupational exposure is concerned and to nickel and nickel compounds as far as general population exposure is concerned. The three main stages of risk assessment were considered: hazard identification, exposure-risk relationship, exposure assessment. Alternative risk management policies were reviewed. The main results are the following: At the conceptual level, the risk assessment and management frameworks present many similarities: exposure-risk relationships exist, and low dose extrapolation is considered as legitimate. Comparison of protection strategies can be carried out with reference to the 'optimization' principle developed for IR. At the regulatory level, the status of the IR dose limits differs from the status of the exposure limit values set for asbestos and nickel. For IR, compliance with the dose limit cannot be seen as the final objective of protection: the burden is put on the requirement to maintain the doses as low as reasonably achievable, social and economical factors being taken into account (ALARA). In most of the situations, actual exposure to IR in industry appear to be significantly lower than the dose limit. In the case of asbestos and nickel, the exposure limit values are very low and compliance with the limits is indeed a quite ambitious objective. At the practical level, some noticeable differences exist as far as the decision aiding procedures are concerned. A process which may be considered as an ALARA approach is applied, in the case of nickel: seeking for the 'best available technologies', defining and implementing with stakeholdes regional plans for air quality. In the case of asbestos, the predictive

[Occupational risk related to optical radiation exposure in construction workers].

Science.gov (United States)

Gobba, F; Modenese, A

2012-01-01

Optical Radiation is a relevant occupational risk in construction workers, mainly as a consequence of the exposure to the ultraviolet (UV) component of solar radiation (SR). Available data show that UV occupational limits are frequently exceeded in these workers, resulting in an increased occupational risk of various acute and chronic effects, mainly to skin and to the eye. One of the foremost is the carcinogenic effect: SR is indeed included in Group 1 IARC (carcinogenic to humans). UV exposure is related to an increase of the incidence of basal cell carcinoma, squamous cell carcinoma of the skin and cutaneous malignant melanoma (CMM). The incidence of these tumors, especially CMM, is constantly increasing in Caucasians in the last 50 years. As a conclusion, an adequate evaluation of the occupational risk related to SR, and adequate preventive measures are essential in construction workers. The role of occupational physicians in prevention is fundamental.

Factors modifying sensitivity to carcinogens and the problem of threshold in carcinogenesis

International Nuclear Information System (INIS)

Anisimov, V.N.

1983-01-01

Maximum allowable concentrations of chemical carcinogens and dose rates of ionizing radiation have been under extensive study both experimentally and epidemiologically. The problem of the carcinogenic hazards of low-level radiation is a very difficult one: in epidemiological studies it is hard to take into account the many factors (e.g. diseases, diet, genetic peculiarities) that may affect sensitivity to radiation; in experimental studies it is hard to extrapolate with accuracy from one species to another or from the individual threshold to that of the whole population. Age, enzyme activity, sex, and DNA repair capability also modify sensitivity to radiation; when factors such as these are better understood it is expected that epidemiological studies will give a solution that allows estimation of the carcinogenic risk from low-level radiation and hence establishment of a threshold dose. (author)

Risk assessment of DNA-reactive carcinogens in food.

Science.gov (United States)

Jeffrey, A M; Williams, G M

2005-09-01

Risk assessment of DNA-reactive carcinogens in food requires knowledge of the extent of DNA damage in the target organ which results from the competition between DNA adduct formation and repair. Estimates of DNA adduct levels can be made by direct measurement or indirectly as a consequence of their presence, for example, by tumor formation in animal models or exposed populations epidemiologically. Food-borne DNA-reactive carcinogens are present from a variety of sources. They are generally not intrinsically DNA-reactive but require bioactivation to DNA-reactive metabolites a process which may be modulated by the compound itself or the presence of other xenobiotics. A single DNA reactant may form several distinct DNA adducts each undergoing different rates of repair. Some DNA reactants may be photochemically activated or produce reactive oxygen species and thus indirect oxidative DNA damage. The levels of DNA adducts arising from exposures influenced by variations in the doses, the frequency with which an individual is exposed, and rates of DNA repair for specific adducts. Each adduct has a characteristic efficiency with which it induces mutations. Based on experience with the well-studied DNA-reactive food carcinogen aflatoxin B(1) (AFB(1)), a limit of 20 ppb or approximately 30 microg/day has been set and is considered a tolerable daily intake (TDI). Since AFB(1) is considered a potent carcinogen, doses of carcinogens is made.

Assessment of radiation risk as a part of ecological risk in the Republic of Belarus after the Chernobyl accident

International Nuclear Information System (INIS)

Saltanova, Irina; Saltanov, Eugene

2008-01-01

Full text: The purpose of the work: foundation for principles of planning protection measures, that provide safety for population activity on the territories, contaminated with radio-nuclides, by analysing radio-chemical situation, using risk assessment methods. Problems set in the work: -) Analyses of radiation risk in the structure of ecological risk in the territory of the Republic of Belarus after the Chernobyl accident; -) Investigation of chemical risk level, connected with air pollution from stationary objects exhausts, for the territories, contaminated with Chernobyl radio-nuclides; -) Modelling of the combined impact of ionising radiation and chemical carcinogen for the possible ecological risk assessment; -) Involving modern geo informational systems in the radio-ecological risk assessment process; -) Foundation for the assessment methodology of the complex influence of negative factors in the territories, contaminated with Chernobyl radio-nuclides. The problems are solved by carrying out specific experiments and by analysing published and own data on radioactive and chemical contamination of some regions of Belarus. Major findings: Radiation input to the really registered carcinogens is estimated to app. 10 %. In case of multiple factors influence of different contaminators of industrial and natural origin (i.e. radiation is not the only negative factor), ignorance of non-radiation origin factors may seriously distort estimation of radiation risk, when it is related to the registered effects. Radiation should be in no way treated as the major factor of real ecological risk in Belarus. Method for comparative analysis of territories' ecological risk level is developed and implemented. A GIS segment, that includes subsystem of the real and forecasted radio-ecological mapping, is created. The authors grounded the experimental model for study the complex influence of radioactive and non-radioactive (chemical carcinogen) factors. Revealed dependencies 'dose

Radiation risks in perspective

International Nuclear Information System (INIS)

Pochin, E.E.

1987-01-01

The problem of risk assessment is greater at the low effective dose rates now observed in the majority of all forms of exposure, usually of less than 3 mSv per year from natural causes, from occupational exposure, and from exposure of 'critical groups' of the general public. For most populations there are particular problems also in epidemiological studies at low dose, in addition to those due to the very large numbers of person-years that need to be studied and the long latencies of most radiation effects. Adequate estimates can, however, now be made of the carcinogenic risk of exposure at higher dose of various organs selectively and of the whole body uniformly, and of modes of inference to the risk at lower dose. Estimates can also be made of the risks of inducing major types of inheritable and developmental abnormality. An essential step in viewing the sum of all such radiation risks in the perspective of other occupational and public risks must now be to develop an informed consensus on the relative weight that is regarded as attaching to hazards of different kind and severity. (author)

[Solar radiation exposure in agriculture: an underestimated risk].

Science.gov (United States)

Gobba, F

2012-01-01

Solar Radiation (SR) is a major occupational risk in agriculture, mainly related to its ultraviolet (UV) component. Available data show that UV occupational limits are frequently exceeded in these workers, resulting in an increased occupational risk of various acute and chronic effects, mainly to skin and to the eye. One of the foremost is the carcinogenic effect: SR is indeed included in Group 1 IARC (carcinogenic to humans). UV exposure is related to an increase of the incidence of basal cell carcinoma and squamous cell carcinoma of the skin, and cutaneous malignant melanoma (CMM). The incidence of these tumors, especially CMM, is constantly increasing in Caucasians in the last 50 years. As a conclusion, an adequate evaluation of the occupational risk related to SR, and adequate preventive measures are essential in agriculture. The role of the Occupational Physician in prevention is fundamental.

Radiation risk from CT: implications for cancer screening.

Science.gov (United States)

Albert, Jeffrey M

2013-07-01

The cancer risks associated with patient exposure to radiation from medical imaging have become a major topic of debate. The higher doses necessary for technologies such as CT and the increasing utilization of these technologies further increase medical radiation exposure to the population. Furthermore, the use of CT for population-based cancer screening continues to be explored for common malignancies such as lung cancer and colorectal cancer. Given the known carcinogenic effects of ionizing radiation, this warrants evaluation of the balance between the benefit of early cancer detection and the risk of screening-induced malignancy. This report provides a brief review of the process of radiation carcino-genesis and the literature evaluating the risk of malignancy from CT, with a focus on the risks and benefits of CT for cancer screening. The available data suggest a small but real risk of radiation-induced malignancy from CT that could become significant at the population level with widespread use of CT-based screening. However, a growing body of literature suggests that the benefits of CT screening for lung cancer in high-risk patients and CT colonography for colorectal cancer may significantly outweigh the radiation risk. Future studies evaluating the benefits of CT screening should continue to consider potential radiation risks.

Evaluation of the carcinogenic risks at the influence of POPs.

Science.gov (United States)

Nazhmetdinova, Aiman; Kassymbayev, Adlet; Chalginbayeva, Altinay

2017-12-20

Kazakhstan is included in the list of environmentally vulnerable countries and Kyzylorda oblast in particular. This is due to its geographical, spatial and temporal and socioeconomic features. As part of the program "Integrated approaches in the management of public health in the Aral region", we have carried out an expertise on many samples of natural environments and products. Samples were selected in accordance with sampling procedures according to regulatory documents by specialists of the Pesticide Toxicology Laboratory. It is accredited by the State Standard of the Republic of Kazakhstan, for compliance with ST RK ISO/IEC 17025-2007 "General requirements for the competence of test and calibration laboratories". Gas chromatograph was used for the determination of residues of organochlorine pesticides. For the determination of dioxins, polychlorinated biphenyl was conducted on the gas chromatomass spectrometer with quadruple detector produce by Agilent Company, USA. To assess the risk, we carried out the mathematical calculations according to the risk of chemicals polluting (No P 2.1.10.1920-04, Russia). Calculation of the carcinogenic risk was carried out with the use of data on the size of the exposure and meanings of carcinogenic potential factors (slope factor and unit risk). The evaluation of persistent organic pollutants (POPs), based on the previous results of the research concerning water, soil and food products, was held in five population settlements in Kyzylorda oblast villages: Ayteke bi, Zhalagash, Zhosaly, Shieli and Aralsk town. Pollution with the POPs in the environmental objects by means of exposition and evaluation of the carcinogenic risk to human health is confirmed by the data of the statistical reporting about some morbidity in Kyzylorda oblast, such as skin diseases and subcutaneous tissue, endocrine system diseases, pregnancy complications etc. The received levels of carcinogenic risks, which were first carried out in the Republic of

Health effects of low-level ionising radiation: biological basis for risk assessment

International Nuclear Information System (INIS)

Upton, A.C.

1987-01-01

The biological basis for risk assessment is discussed. The risks of carcinogenic effects, teratogenic effects, and genetic (heritable) effects are estimated to vary in proportion with the dose of radiation in the low-dose domain; however, the risks also appear to vary with the LET of the radiation, age at the time of irradiation, and other variables. Although the data suffice to place the risks in perspective with other hazards of modern life, further research to refine the reliability of the risk assessment is called for. (author)

Risk assessment of DNA-reactive carcinogens in food

International Nuclear Information System (INIS)

Jeffrey, A.M.; Williams, G.M.

2005-01-01

Risk assessment of DNA-reactive carcinogens in food requires knowledge of the extent of DNA damage in the target organ which results from the competition between DNA adduct formation and repair. Estimates of DNA adduct levels can be made by direct measurement or indirectly as a consequence of their presence, for example, by tumor formation in animal models or exposed populations epidemiologically. Food-borne DNA-reactive carcinogens are present from a variety of sources. They are generally not intrinsically DNA-reactive but require bioactivation to DNA-reactive metabolites a process which may be modulated by the compound itself or the presence of other xenobiotics. A single DNA reactant may form several distinct DNA adducts each undergoing different rates of repair. Some DNA reactants may be photochemically activated or produce reactive oxygen species and thus indirect oxidative DNA damage. The levels of DNA adducts arising from exposures influenced by variations in the doses, the frequency with which an individual is exposed, and rates of DNA repair for specific adducts. Each adduct has a characteristic efficiency with which it induces mutations. Based on experience with the well-studied DNA-reactive food carcinogen aflatoxin B 1 (AFB 1 ), a limit of 20 ppb or ∼30 μg/day has been set and is considered a tolerable daily intake (TDI). Since AFB 1 is considered a potent carcinogen, doses of 32 P-postlabeling or the use of surrogates such as hemoglobin adducts, together with approaches to evaluate the results. A discussion of approaches to estimating possible threshold effects for DNA-reactive carcinogens is made

The influence of thresholds on the risk assessment of carcinogens in food.

Science.gov (United States)

Pratt, Iona; Barlow, Susan; Kleiner, Juliane; Larsen, John Christian

2009-08-01

The risks from exposure to chemical contaminants in food must be scientifically assessed, in order to safeguard the health of consumers. Risk assessment of chemical contaminants that are both genotoxic and carcinogenic presents particular difficulties, since the effects of such substances are normally regarded as being without a threshold. No safe level can therefore be defined, and this has implications for both risk management and risk communication. Risk management of these substances in food has traditionally involved application of the ALARA (As Low as Reasonably Achievable) principle, however ALARA does not enable risk managers to assess the urgency and extent of the risk reduction measures needed. A more refined approach is needed, and several such approaches have been developed. Low-dose linear extrapolation from animal carcinogenicity studies or epidemiological studies to estimate risks for humans at low exposure levels has been applied by a number of regulatory bodies, while more recently the Margin of Exposure (MOE) approach has been applied by both the European Food Safety Authority and the Joint FAO/WHO Expert Committee on Food Additives. A further approach is the Threshold of Toxicological Concern (TTC), which establishes exposure thresholds for chemicals present in food, dependent on structure. Recent experimental evidence that genotoxic responses may be thresholded has significant implications for the risk assessment of chemicals that are both genotoxic and carcinogenic. In relation to existing approaches such as linear extrapolation, MOE and TTC, the existence of a threshold reduces the uncertainties inherent in such methodology and improves confidence in the risk assessment. However, for the foreseeable future, regulatory decisions based on the concept of thresholds for genotoxic carcinogens are likely to be taken case-by-case, based on convincing data on the Mode of Action indicating that the rate limiting variable for the development of cancer

Occuptional radiation exposures and thyroid cancer risk among radiologic technologists

Energy Technology Data Exchange (ETDEWEB)

Moon, Eun Kyeong; Lee, Won Jin [Korea University, Seoul (Korea, Republic of); Ha, Mina [Dankook University Seoul (Korea, Republic of); Kim, Jae Young [Keimyung University, Daegu (Korea, Republic of); Jun, Jae Kwan [National Cancer Center, Seoul (Korea, Republic of); Jin, Young Won [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2016-04-15

Medical radiation workers were among the earliest occupational groups exposed to external ionizing radiation due to their administration of a range of medical diagnostic procedures and accounted for 7.4 million worldwide in 2008. Ionizing radiation is the confirmed human carcinogen for most organ sites. The aims of the study is to evaluate the association between occupational practices including radiation exposure and thyroid cancer risk among radiologic technologists. We found no significant association between the risk of thyroid cancer and the majority of work practices among diagnostic radiation technologists in general. However workers performing fluoroscopy and interventional procedures showed increased risks although the lack of a clear exposure– response gradient makes it difficult to draw clear conclusions. Future studies with larger sample size and detailed work practices implementation are needed to clarify the role of occupational radiation work in thyroid cancer carcinogenesis.

Occuptional radiation exposures and thyroid cancer risk among radiologic technologists

International Nuclear Information System (INIS)

Moon, Eun Kyeong; Lee, Won Jin; Ha, Mina; Kim, Jae Young; Jun, Jae Kwan; Jin, Young Won

2016-01-01

Medical radiation workers were among the earliest occupational groups exposed to external ionizing radiation due to their administration of a range of medical diagnostic procedures and accounted for 7.4 million worldwide in 2008. Ionizing radiation is the confirmed human carcinogen for most organ sites. The aims of the study is to evaluate the association between occupational practices including radiation exposure and thyroid cancer risk among radiologic technologists. We found no significant association between the risk of thyroid cancer and the majority of work practices among diagnostic radiation technologists in general. However workers performing fluoroscopy and interventional procedures showed increased risks although the lack of a clear exposure– response gradient makes it difficult to draw clear conclusions. Future studies with larger sample size and detailed work practices implementation are needed to clarify the role of occupational radiation work in thyroid cancer carcinogenesis.

Approaches to the risk assessment of genotoxic carcinogens in food: a critical appraisal.

Science.gov (United States)

O'Brien, J; Renwick, A G; Constable, A; Dybing, E; Müller, D J G; Schlatter, J; Slob, W; Tueting, W; van Benthem, J; Williams, G M; Wolfreys, A

2006-10-01

The present paper examines the particular difficulties presented by low levels of food-borne DNA-reactive genotoxic carcinogens, some of which may be difficult to eliminate completely from the diet, and proposes a structured approach for the evaluation of such compounds. While the ALARA approach is widely applicable to all substances in food that are both carcinogenic and genotoxic, it does not take carcinogenic potency into account and, therefore, does not permit prioritisation based on potential risk or concern. In the absence of carcinogenicity dose-response data, an assessment based on comparison with an appropriate threshold of toxicological concern may be possible. When carcinogenicity data from animal bioassays are available, a useful analysis is achieved by the calculation of margins of exposure (MOEs), which can be used to compare animal potency data with human exposure scenarios. Two reference points on the dose-response relationship that can be used for MOE calculation were examined; the T25 value, which is derived from linear extrapolation, and the BMDL10, which is derived from mathematical modelling of the dose-response data. The above approaches were applied to selected food-borne genotoxic carcinogens. The proposed approach is applicable to all substances in food that are DNA-reactive genotoxic carcinogens and enables the formulation of appropriate semi-quantitative advice to risk managers.

Ionizing radiation causing a risk of cancer in man

International Nuclear Information System (INIS)

Fichardt, T.; Sandison, A.G.; Savage, D.J.

1977-01-01

An attempt has been made to present, in short review, the most important carcinogens that have been implicated in the development of cancer in the various organ sites of the human body and to demonstrate the relatively minor role played by ionizing radiation, especially radiotherapy, in causing a risk of cancer in man

Risk approaches in setting radiation standards

International Nuclear Information System (INIS)

Whipple, C.

1984-01-01

This paper discusses efforts to increase the similarity of risk regulation approaches for radiation and chemical carcinogens. The risk assessment process in both cases involves the same controversy over the extrapolation from high to low doses and dose rates, and in both cases the boundaries between science and policy in risk assessment are indistinct. Three basic considerations are presented to approach policy questions: the economic efficiency of the regulatory approach, the degree of residual risk, and the technical opportunities for risk control. It is the author's opinion that if an agency can show that its standard-setting policies are consistent with those which have achieved political and judicial acceptance in other contexts, the greater the predictability of the regulatory process and the stability of this process

Quantitative comparison of genotoxic (mutagenic and carcinogenic) risks and the choice of energy sources

International Nuclear Information System (INIS)

Latarjet, R.

1983-01-01

For 25 years, pollution for radiation has been governed by restrictive rules enacted and periodically revised by an international commission, and adopted by all countries. Nothing similar exists for mutagenic and carcinogenic chemicals. Since these substances affect the genetic material in the cells with reactions often similar to those caused by radiation, quantitative comparisons are possible, in particular for some of those compounds produced by the combustion of coal, oil and gaz. This paper describes the main results obtained at the Institut Curie, since 1975, with ethylene, ethylene oxide and vinyl chloride monomer. The consequences are discussed for: a) the establishement of control rules for the main genotoxic chemical pollutions; b) the assessment of long term risks in the cases of nuclear energy and of the energies obtained by combustion [fr

[Cardiovascular risk, occupation and exposure to occupational carcinogens in a group of workers in Salamanca].

Science.gov (United States)

González-Sánchez, Jesús

2015-01-01

Identify the cardiovascular risk factors in a group of workers in the province of Salamanca, protected by external prevention services, as regards exposure to occupational carcinogens, by sector of activity and gender. An observational descriptive epidemiological study was conducted. The sample selection was by stratified random sampling in each entity. The variables collected by questionnaire were, sociodemographic characteristics, exposure to occupational carcinogens, and cardiovascular risk factors (smoking, hypertension, dyslipidemia, and diabetes), using the clinical-work histories as a source of information. Statistically significant differences were observed in cardiovascular risk according to the exposure to occupational carcinogens (p cardiovascular risk in the work place. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

The potential carcinogenic risk of tanning beds: clinical guidelines and patient safety advice

International Nuclear Information System (INIS)

Mogensen, Mette; Jemec, Gregor BE

2010-01-01

In 2009, the WHO listed ultraviolet (UV) radiation as a group 1 carcinogen. In spite of this, each year, millions of people tan indoor in Western countries. The aim of this review is to summarize evidence of tanning bed carcinogenesis and to present guidelines for use of tanning beds and patient safety advice. A narrative review of the literature was conducted based on both PubMed and Medline searches and on literature review of the retrieved papers. Use of indoor tanning beds represents a significant and avoidable risk factor for the development of both melanoma and nonmelanoma skin cancers. Frequent tanners are more often adolescent females. Tanning beds have additional potential adverse effects such as burns, solar skin damage, infection, and possibly also addictive behavior. The effort in preventing UV light-induced carcinogenesis should currently be aimed at developing new strategies for public health information. Tanning beds are one preventable source of UV radiation. In the majority of people solar UV radiation continues to be the major factor and therefore anti-tanning campaigns must always include sunbathers

Relationship between dose and risk, and assessment of carcinogenic risks associated with low doses of ionizing radiation

International Nuclear Information System (INIS)

Tubiana, M.; Aurengo, A.

2005-01-01

This report raises doubts on the validity of using LNT (linear no-threshold) relationship for evaluating the carcinogenic risk of low doses (< 100 mSv) and even more for very low doses (< 10 mSv). The LNT concept can be a useful pragmatic tool for assessing rules in radioprotection for doses above 10 mSv; however since it is not based on biological concepts of our current knowledge, it should not be used without precaution for assessing by extrapolation the risks associated with low and even more so, with very low doses (< 10 mSv), especially for benefit-risk assessments imposed on radiologists by the European directive 97-43. The biological mechanisms are different for doses lower than a few dozen mSv and for higher doses. The eventual risks in the dose range of radiological examinations (0.1 to 5 mSv, up to 20 mSv for some examinations) must be estimated taking into account radiobiological and experimental data. An empirical relationship which has been just validated for doses higher than 200 mSv may lead to an overestimation of risks (associated with doses one hundred fold lower), and this overestimation could discourage patients from undergoing useful examinations and introduce a bias in radioprotection measures against very low doses (< 10 mSv). Decision makers confronted with problems of radioactive waste or risk of contamination, should re-examine the methodology used for the evaluation of risks associated with very low doses and with doses delivered at a very low dose rate. This report confirms the inappropriateness of the collective dose concept to evaluate population irradiation risks

Risk assessment of nickel carcinogenicity and occupational lung cancer.

OpenAIRE

Shen, H M; Zhang, Q F

1994-01-01

Recent progress in risk assessment of nickel carcinogenicity and its correlation with occupational lung cancer in nickel-exposed workers is reviewed. Epidemiological investigations provide reliable data indicating the close relation between nickel exposure and high lung cancer risk, especially in nickel refineries. The nickel species-specific effects and the dose-response relationship between nickel exposure and lung cancer are among the main questions that are explored extensively. It is als...

Thyroid Cancer Induction: Nitrates as Independent Risk Factors or Risk Modulators after Radiation Exposure, with a Focus on the Chernobyl Accident.

Science.gov (United States)

Drozd, Valentina M; Branovan, Igor; Shiglik, Nikolay; Biko, Johannes; Reiners, Christoph

2018-03-01

In recent decades, differentiated thyroid cancer (DTC) incidence has been increasing worldwide. The important contributions to this phenomenon of "overdiagnosis" driven by wider use of improved ultrasound systems are amply documented, notwithstanding the "real" carcinogenic effects of ionizing radiation, e.g., from the Chernobyl accident or health care interventions. Less well understood is the role of nitrates - as environmental pollutants, in diet, and in medication - in thyroid carcinogenesis. Increasing exposure to nitrates is associated with rising incidence of esophageal, stomach, bladder, and colon cancers. Recent data suggest that in agricultural areas with higher mean nitrate levels in groundwater, DTC risk is also elevated. Our work in Belarus after Chernobyl has shown that children in districts with high nitrate concentrations in drinking water had significantly higher thyroid cancer incidence after irradiation than did their counterparts in areas with lower nitrate concentrations. Notwithstanding thyroid shielding, increasing use of computed tomography and dental X-rays heightens radiation exposure of the salivary glands in the general population, especially in children and adolescents. When nitrate intake is increased, salivary gland irradiation may potentially result in carcinogenic elevations in plasma nitric oxide concentrations. In conclusion, excess nitrate intake seems to be an independent risk factor for DTC. Additionally, we hypothesize from our data that high nitrate levels modulate the carcinogenic effect of radiation on the thyroid. Cohort studies, case-control studies, or both, are needed to quantify the effects of nitrates on DTC risk in the presence or absence of radiation exposure, e.g., that associated with diagnostic or therapeutic health care interventions.

Lifetime attributable risk for cancer from occupational radiation exposure among radiologic technologists

Energy Technology Data Exchange (ETDEWEB)

Moon, Eun Kyeong; Lee, Won Jin [Dept. of Preventive Medicine, Korea University College of Medicine, Seoul (Korea, Republic of)

2016-12-15

Medical radiation workers were among the earliest occupational groups exposed to external ionizing radiation due to their administration of a range of medical diagnostic procedures. Ionizing radiation is a confirmed human carcinogen for most organ sites. This study, therefore, was aimed to estimate lifetime cancer risk from occupational exposure among radiologic technologists that has been recruited in 2012-2013. Our findings showed a small increased cancer risk in radiologic technologists from their occupational radiation exposure in Korea. However, continuous dose monitoring and strict regulation on occupational safety at the government level should be emphasized to prevent any additional health hazards from occupational radiation exposure. Our findings showed a small increased cancer risk in radiologic technologists from their occupational radiation exposure in Korea. However, continuous dose monitoring and strict regulation on occupational safety at the government level should be emphasized to prevent any additional health hazards from occupational radiation exposure.

Lifetime attributable risk for cancer from occupational radiation exposure among radiologic technologists

International Nuclear Information System (INIS)

Moon, Eun Kyeong; Lee, Won Jin

2016-01-01

Medical radiation workers were among the earliest occupational groups exposed to external ionizing radiation due to their administration of a range of medical diagnostic procedures. Ionizing radiation is a confirmed human carcinogen for most organ sites. This study, therefore, was aimed to estimate lifetime cancer risk from occupational exposure among radiologic technologists that has been recruited in 2012-2013. Our findings showed a small increased cancer risk in radiologic technologists from their occupational radiation exposure in Korea. However, continuous dose monitoring and strict regulation on occupational safety at the government level should be emphasized to prevent any additional health hazards from occupational radiation exposure. Our findings showed a small increased cancer risk in radiologic technologists from their occupational radiation exposure in Korea. However, continuous dose monitoring and strict regulation on occupational safety at the government level should be emphasized to prevent any additional health hazards from occupational radiation exposure.

Carcinogenic effectiveness of combined dust-and-radiation effect under experimental and occupational conditions

International Nuclear Information System (INIS)

Ivanov, Z.; Mikhajlov, M.; Todorov, A.

1988-01-01

Consideration is made of the latest reports, reflecting the statistically significant increase of the lung cancer among workers in underground working sites at cumulative exposure to radon decay products under 60 monthly working levels. The significance of the non-radiation components of the occupational environment, participating in the carcinogenic process together with the classical noxiousness are emphasized. The significance of the functional sufficiency of the immune and endocrine systems, the tobacco smoking and the role of the inflammation respiratory tract diseases , etc. is denoted. Inferences are made for the complexity and multiformity of the occupational carcinogenesis according to the intensity, classical mutagenic factors and multitude of noncarcinogenic components of the occupational environment. Paralelly to the sanitary-technical fool-proof rendering of the respective productions, the necessity of purposeful balneotherapeutic and medical treatment of the risk worker contingents is pointed out

Comparative risk assessment of carcinogens in alcoholic beverages using the margin of exposure approach.

Science.gov (United States)

Lachenmeier, Dirk W; Przybylski, Maria C; Rehm, Jürgen

2012-09-15

Alcoholic beverages have been classified as carcinogenic to humans. As alcoholic beverages are multicomponent mixtures containing several carcinogenic compounds, a quantitative approach is necessary to compare the risks. Fifteen known and suspected human carcinogens (acetaldehyde, acrylamide, aflatoxins, arsenic, benzene, cadmium, ethanol, ethyl carbamate, formaldehyde, furan, lead, 4-methylimidazole, N-nitrosodimethylamine, ochratoxin A and safrole) occurring in alcoholic beverages were identified based on monograph reviews by the International Agency for Research on Cancer. The margin of exposure (MOE) approach was used for comparative risk assessment. MOE compares a toxicological threshold with the exposure. MOEs above 10,000 are judged as low priority for risk management action. MOEs were calculated for different drinking scenarios (low risk and heavy drinking) and different levels of contamination for four beverage groups (beer, wine, spirits and unrecorded alcohol). The lowest MOEs were found for ethanol (3.1 for low risk and 0.8 for heavy drinking). Inorganic lead and arsenic have average MOEs between 10 and 300, followed by acetaldehyde, cadmium and ethyl carbamate between 1,000 and 10,000. All other compounds had average MOEs above 10,000 independent of beverage type. Ethanol was identified as the most important carcinogen in alcoholic beverages, with clear dose response. Some other compounds (lead, arsenic, ethyl carbamate, acetaldehyde) may pose risks below thresholds normally tolerated for food contaminants, but from a cost-effectiveness point of view, the focus should be on reducing alcohol consumption in general rather than on mitigative measures for some contaminants that contribute only to a limited extent (if at all) to the total health risk. Copyright © 2012 UICC.

Cancer risks following diagnostic and therapeutic radiation exposure in children

Energy Technology Data Exchange (ETDEWEB)

Kleinerman, Ruth A. [National Institutes of Health, Division of Cancer Epidemiology and Genetics, National Cancer Institute, EPS 7044, Rockville, MD (United States)

2006-09-15

The growing use of interventional and fluoroscopic imaging in children represents a tremendous benefit for the diagnosis and treatment of benign conditions. Along with the increasing use and complexity of these procedures comes concern about the cancer risk associated with ionizing radiation exposure to children. Children are considerably more sensitive to the carcinogenic effects of ionizing radiation than adults, and children have a longer life expectancy in which to express risk. Numerous epidemiologic cohort studies of childhood exposure to radiation for treatment of benign diseases have demonstrated radiation-related risks of cancer of the thyroid, breast, brain and skin, as well as leukemia. Many fewer studies have evaluated cancer risk following diagnostic radiation exposure in children. Although radiation dose for a single procedure might be low, pediatric patients often receive repeated examinations over time to evaluate their conditions, which could result in relatively high cumulative doses. Several cohort studies of girls and young women subjected to multiple diagnostic radiation exposures have been informative about increased mortality from breast cancer with increasing radiation dose, and case-control studies of childhood leukemia and postnatal diagnostic radiation exposure have suggested increased risks with an increasing number of examinations. Only two long-term follow-up studies of cancer following cardiac catheterization in childhood have been conducted, and neither reported an overall increased risk of cancer. Most cancers can be induced by radiation, and a linear dose-response has been noted for most solid cancers. Risks of radiation-related cancer are greatest for those exposed early in life, and these risks appear to persist throughout life. (orig.)

Cancer risks following diagnostic and therapeutic radiation exposure in children

International Nuclear Information System (INIS)

Kleinerman, Ruth A.

2006-01-01

The growing use of interventional and fluoroscopic imaging in children represents a tremendous benefit for the diagnosis and treatment of benign conditions. Along with the increasing use and complexity of these procedures comes concern about the cancer risk associated with ionizing radiation exposure to children. Children are considerably more sensitive to the carcinogenic effects of ionizing radiation than adults, and children have a longer life expectancy in which to express risk. Numerous epidemiologic cohort studies of childhood exposure to radiation for treatment of benign diseases have demonstrated radiation-related risks of cancer of the thyroid, breast, brain and skin, as well as leukemia. Many fewer studies have evaluated cancer risk following diagnostic radiation exposure in children. Although radiation dose for a single procedure might be low, pediatric patients often receive repeated examinations over time to evaluate their conditions, which could result in relatively high cumulative doses. Several cohort studies of girls and young women subjected to multiple diagnostic radiation exposures have been informative about increased mortality from breast cancer with increasing radiation dose, and case-control studies of childhood leukemia and postnatal diagnostic radiation exposure have suggested increased risks with an increasing number of examinations. Only two long-term follow-up studies of cancer following cardiac catheterization in childhood have been conducted, and neither reported an overall increased risk of cancer. Most cancers can be induced by radiation, and a linear dose-response has been noted for most solid cancers. Risks of radiation-related cancer are greatest for those exposed early in life, and these risks appear to persist throughout life. (orig.)

Chemical characteristic of PM2.5 emission and inhalational carcinogenic risk of domestic Chinese cooking

International Nuclear Information System (INIS)

Zhang, Nan; Han, Bin; He, Fei; Xu, Jia; Zhao, Ruojie; Zhang, Yujuan; Bai, Zhipeng

2017-01-01

To illustrate chemical characteristic of PM 2.5 emission and assess inhalational carcinogenic risk of domestic Chinese cooking, 5 sets of duplicate cooking samples were collected, using the most used 5 types of oil. The mass abundance of 14 elements, 5 water-soluble ions, organic carbon (OC), elemental carbon (EC) and 11 polycyclic aromatic hydrocarbons (PAHs) were calculated; the signature and diagnostic ratio of cooking in the domestic kitchen were analyzed; and carcinogenic risks of heavy metals and PAHs via inhalation were assessed in two scenarios. The analysis showed that OC was the primary composition in the chemical profile; Na was the most abundant element that might be due to the usage of salt; Cr and Pb, NO 3 − and SO 4 2- , Phe, FL and Pyr were the main heavy metals/water-soluble ions/PAHs, respectively. Phe and FL could be used to separate cooking and stationary sources, while diagnostic ratios of BaA/(BaA + CHR), BaA/CHR, BaP/BghiP and BaP/BeP should be applied with caution, as they were influenced by various cooking conditions. Carcinogenic risks of heavy metals and PAHs were evaluated in two scenarios, simulating the condition of cooking with no ventilation and with the range hood on, respectively. The integrated risk of heavy metals and PAHs was 2.7 × 10 −3 and 5.8 × 10 −6 , respectively, during cooking with no ventilation. While with the usage of range hood, only Cr(VI), As and Ni might induce potential carcinogenic risk. The difference in the chemical abundance in cooking sources found between this and other studies underlined the necessity of constructing locally representative source profiles under real conditions. The comparison of carcinogenic risk suggested that the potentially adverse health effects induced by inorganic compositions from cooking sources should not be ignored. Meanwhile, intervention methods, such as the operation of range hood, should be applied during cooking for health protection. - Highlights: • PM 2

Protection by caffeine against oxic radiation damage and chemical carcinogens : mechanistic considerations

International Nuclear Information System (INIS)

Kesavan, P.C.

1992-01-01

There is little doubt that caffeine administered after exposure to UV light enhances the damage to cells and organisms by inhibiting photoreactivation, excision and/or recombinational repair. However, when already present in the system, it affords remarkable protection not only against O 2 -dependent component of radiation damage, but also against chemical carcinogens that require metabolic activation. Possible mechanistic aspects are discussed briefly. (author). 81 refs

Non-carcinogenic late effects of ionizing radiation; human data

International Nuclear Information System (INIS)

Beebe, G.W.

1979-01-01

The late effects of ionizing radiation may be somatic effect or potential effect, about which such informations as follows are required: teratogenesis the disturbances in growth and development, cataracts, infertility, cytogenetic aberration, and accelerated aging. Although much is known about the nature of the malformations produced by ionizing radiation, and about the vulnerability of human embryonal and fetal tissues during various stages of organogenesis, the quantitative information is uncertain and incomplete. The data on A-bomb survivors were flawed by confounding radiation dose with nutritional and other influences caused by the disasters created by war-time bombings. If the effects of radiation are real, they are quite small for the dose below 100 rad (kerma), are confined to the children of pre-pubertal age at the time of exposure, and are of much less consequence for low-LET radiation than for high. Radiation-induced lenticular changes are of graded severity, and as for cataracts, the threshold is in the range from 600 to 1,000 rad of low-LET radiation, and perhaps 75 to 100 rad for fast neutrons; the average latent period is 2 to 7 years. The estimate of the RBE for neutrons is in the range from 2 to 10, and dose-dependent. Ionizing radiation has important effects on fertility only at very high dose. The relationship of the quantitative aspects of the biologic significance of chromosomal aberration in somatic cells to dose may provide an interesting parallel to the carcinogenic effect. For neutrons, the dose-response curve appears to be linear, at least for stable aberration. (Yamashita, S.)

Interaction between radiation and other breast cancer risk factors

International Nuclear Information System (INIS)

Boice, J.D. Jr.; Stone, B.J.

1978-01-01

A follow-up study was conducted of 1764 women institutionalized for pulmonary tuberculosis between 1930 and 1954. Among 1047 women exposed to fluoroscopic chest X-rays during air collapse therapy of the lung, an excess of breast cancer was observed and previously reported (41 cases observed versus 23.3 expected). Among 717 comparison patients who received other treatments, no excess breast cancer risk was apparent (15 cases observed versus 14.1 expected). To determine whether breast cancer risk factors modify the carcinogenic effect of radiation, analyses were performed evaluating the interaction of radiation with indicators of breast cancer risk. The greatest radiation risk was found when radiation exposure occurred just before and during menarche. Similarly, exposures during first pregnancy appeared substantially more hazardous than exposures occurring before or after first pregnancy, suggesting that the condition of the breast at the time of pregnancy modifies the effect of radiation in such a way as to enhance the risk. Age at menopause did not appear to influence the risk of radiation exposure. Other than radiation, benign breast disease was the most significant breast cancer risk indicator. Benign breast disease was not seen to modify the effect of radiation exposure; however, excessive radiation exposure might have increased the incidence of benign breast disease, complicating the interaction analysis. Because of the uncertainty due to small-number sampling variation, these study results will require confirmation by a larger series. They do, however, suggest that stages when breast tissue undergoes high mitotic activity, e.g. menarche and pregnancy, are times of special vulnerability to the harmful effects of ionizing radiation

FTIR analysis and evaluation of carcinogenic and mutagenic risks of nitro-polycyclic aromatic hydrocarbons in PM1.0.

Science.gov (United States)

Schneider, Ismael Luís; Teixeira, Elba Calesso; Agudelo-Castañeda, Dayana Milena; Silva E Silva, Gabriel; Balzaretti, Naira; Braga, Marcel Ferreira; Oliveira, Luís Felipe Silva

2016-01-15

Nitro-polycyclic aromatic hydrocarbons (NPAHs) represent a group of organic compounds of significant interest due to their presence in airborne particulates of urban centers, wide distribution in the environment, and mutagenic and carcinogenic properties. These compounds, associated with atmospheric particles of size PM1.0) using infrared spectrometry. Carcinogenic and mutagenic risks of the studied NPAHs associated with PM1.0 samples were also determined for two sampling sites: Canoas and Sapucaia do Sul. The results showed that NPAH standard spectra can effectively identify NPAHs in PM1.0 samples. The transmittance and emissivity sample spectra showed broader bands and lower relative intensity than the standard NPAH spectra. The carcinogenic risk and the total mutagenic risk were calculated using the toxic equivalent factors and mutagenic potency factors, respectively. Canoas showed the highest total carcinogenic risk, while Sapucaia do Sul had the highest mutagenic risk. The seasonal analysis suggested that in the study area the ambient air is more toxic during the cold periods. These findings might of significant importance for the decision and policy making authorities.

An overview of the report: Correlation between carcinogenic potency and the maximum tolerated dose: Implications for risk assessment

International Nuclear Information System (INIS)

Krewski, D.; Gaylor, D.W.; Soms, A.P.; Szyszkowicz, M.

1993-01-01

Current practice in carcinogen bioassay calls for exposure of experimental animals at doses up to and including the maximum tolerated dose (MTD). Such studies have been used to compute measures of carcinogenic potency such as the TD 50 as well as unit risk factors such as q 1 for predicting low-dose risks. Recent studies have indicated that these measures of carcinogenic potency are highly correlated with the MTD. Carcinogenic potency has also been shown to be correlated with indicators of mutagenicity and toxicity. Correlation of the MTDs for rats and mice implies a corresponding correlation in TD 50 values for these two species. The implications of these results for cancer risk assessment are examined in light of the large variation in potency among chemicals known to induce tumors in rodents. 119 refs., 2 figs., 4 tabs

Chemical characteristic of PM2.5 emission and inhalational carcinogenic risk of domestic Chinese cooking.

Science.gov (United States)

Zhang, Nan; Han, Bin; He, Fei; Xu, Jia; Zhao, Ruojie; Zhang, Yujuan; Bai, Zhipeng

2017-08-01

To illustrate chemical characteristic of PM 2.5 emission and assess inhalational carcinogenic risk of domestic Chinese cooking, 5 sets of duplicate cooking samples were collected, using the most used 5 types of oil. The mass abundance of 14 elements, 5 water-soluble ions, organic carbon (OC), elemental carbon (EC) and 11 polycyclic aromatic hydrocarbons (PAHs) were calculated; the signature and diagnostic ratio of cooking in the domestic kitchen were analyzed; and carcinogenic risks of heavy metals and PAHs via inhalation were assessed in two scenarios. The analysis showed that OC was the primary composition in the chemical profile; Na was the most abundant element that might be due to the usage of salt; Cr and Pb, NO 3 - and SO 4 2- , Phe, FL and Pyr were the main heavy metals/water-soluble ions/PAHs, respectively. Phe and FL could be used to separate cooking and stationary sources, while diagnostic ratios of BaA/(BaA + CHR), BaA/CHR, BaP/BghiP and BaP/BeP should be applied with caution, as they were influenced by various cooking conditions. Carcinogenic risks of heavy metals and PAHs were evaluated in two scenarios, simulating the condition of cooking with no ventilation and with the range hood on, respectively. The integrated risk of heavy metals and PAHs was 2.7 × 10 -3 and 5.8 × 10 -6 , respectively, during cooking with no ventilation. While with the usage of range hood, only Cr(VI), As and Ni might induce potential carcinogenic risk. The difference in the chemical abundance in cooking sources found between this and other studies underlined the necessity of constructing locally representative source profiles under real conditions. The comparison of carcinogenic risk suggested that the potentially adverse health effects induced by inorganic compositions from cooking sources should not be ignored. Meanwhile, intervention methods, such as the operation of range hood, should be applied during cooking for health protection. Copyright © 2017 Elsevier Ltd

The multitude and diversity of environmental carcinogens

International Nuclear Information System (INIS)

Belpomme, D.; Irigaray, P.; Hardell, L.; Clapp, R.; Montagnier, L.; Epstein, S.; Sasco, A.J.

2007-01-01

We have recently proposed that lifestyle-related factors, screening and aging cannot fully account for the present overall growing incidence of cancer. In order to propose the concept that in addition to lifestyle related factors, exogenous environmental factors may play a more important role in carcinogenesis than it is expected, and may therefore account for the growing incidence of cancer, we overview herein environmental factors, rated as certainly or potentially carcinogenic by the International Agency for Research on Cancer (IARC). We thus analyze the carcinogenic effect of microorganisms (including viruses), radiations (including radioactivity, UV and pulsed electromagnetic fields) and xenochemicals. Chemicals related to environmental pollution appear to be of critical importance, since they can induce occupational cancers as well as other cancers. Of major concerns are: outdoor air pollution by carbon particles associated with polycyclic aromatic hydrocarbons; indoor air pollution by environmental tobacco smoke, formaldehyde and volatile organic compounds such as benzene and 1,3 butadiene, which may particularly affect children, and food pollution by food additives and by carcinogenic contaminants such as nitrates, pesticides, dioxins and other organochlorines. In addition, carcinogenic metals and metalloids, pharmaceutical medicines and cosmetics may be involved. Although the risk fraction attributable to environmental factors is still unknown, this long list of carcinogenic and especially mutagenic factors supports our working hypothesis according to which numerous cancers may in fact be caused by the recent modification of our environment

Radiation, chemicals and combined effects

International Nuclear Information System (INIS)

Sinclair, W.K.

1991-01-01

A brief background has been provided on current carcinogenic risks from ionizing radiation and their magnitude in background circumstances. The magnitude of the risks from possibly carcinogenic chemicals at background levels in air, water and food are surprisingly similar. The exception is, perhaps, for the single source of radon which, while variable, on the average stands out above all other sources. Some basic principles concerning the interaction of combined radiation and chemicals and some practical examples where the two interact synergistically to enhance radiation effects has also been provided. Areas for human research in the future are discussed. (Author)

The importance of radiation risk assessment

International Nuclear Information System (INIS)

Pochin, E.E.

1979-01-01

In its Publication 26, ICRP recommends a system of radiation dose limitation that is designed to ensure adequate protection from the harmful effects of radiation in conditions both of occupational and of environmental exposure. Clearly, however, no such system can be recommended or accepted as sufficiently safe unless the risks of the resultant exposures have been quantitatively assessed. Publication 26 reflects the increasing quantitative information that is now available on (a) carcinogenic risks of radiation in man, both from exposure of the whole body and from that of individual organs, at moderate exposures; (b) theoretical bases for inference of risk, from moderate to lower exposures; (c) genetic risks in the mouse, and inferences from such risks to those in man; (d) the dose equivalent levels at which certain non-stochastic effects may be induced. Despite a number of uncertainties, substantially improved estimates can therefore be made of the levels of safety that are likely to be achieved by observing the Commission's recommended dose limits, and the associated system of limitation of exposures to levels as low as reasonably achievable below these limits. Both for occupational exposure and for the exposure of the members of the public, these estimates are expressed in Publication 26 in terms of the risk of inducing fatal malignancies or serious hereditary ill health. These frequencies are compared with those of occupational fatalities in other industries or with accidental fatalities amongst the general public. The comparison between harm from radiation and from other agents in different industries is extended in ICRP-27 (on ''Problems Involved in Developing an Index of Harm'') in a review of the time lost through occupational diseases and non-fatal accidents, as well as from fatal diseases and accidents, so that the levels of safety achievable by the Commission's recommendations can be reviewed in the general perspective of occupational safety. (author)

Participation of IPEN in the international program of information about occupational exposure to carcinogen risks

International Nuclear Information System (INIS)

Osores, Jose; Gonzales, Susana

2014-01-01

During 2014, the Peruvian Nuclear Energy Institute participated in the mapping of risks to carcinogens due to occupational exposure for our country through CAREX program because all radioactive substances are considered by the International Agency for Research Cancer as type 1 carcinogens (high risk) and the presence of these substances in the work environment are unknown to professionals from other institutions. This occasion allowed the incorporation of Natural Occurring Radioactive Materials (NORM) as indicators in all work activities that were not considered by the Energy and Mining Sector. (authors).

Prevention of cancer and the dose-effect relationship: the carcinogenic effects of ionizing radiations

International Nuclear Information System (INIS)

Tubiana, M.

2009-01-01

Cancer prevention has to be based on robust biological and epidemiological data, therefore its reappraisal becomes mandatory in view of recent progress in the understanding of carcinogenesis. The first phase of the carcinogenic process, that of initiation, is generally associated with mutation; however the role of extrinsic mutagens is less critical than was thought two decades ago. During intracellular oxygen metabolism, reactive oxygen species (R.O.S.) are made which are potent mutagens. Defense mechanisms against these intrinsic mutagens include scavenger and enzymatic systems which destroy them (catalase, superoxide dismutase). When the radiation dose is low, DNA repair is very effective as well as the elimination of cells with unrepaired or bad repaired DNA. Therefore a small increase in the number of R.O.S., such as that caused by a small dose of radiation has most probably no significant effect on the risk of DNA damage. These conclusions are consistent with the concept of a practical threshold. The second phase, that of promotion, appears to be the key one. During the promotion phase, initiated cells must acquire new properties (immortalization, release of angiogenic factors, resistance to hypoxia, etc.) in order to become pre-cancerous. This evolution is due to the accumulation in the genome of 6 to 10 new alteration defects. In the clone of initiated cells, the occurrence in one cell of a mutation or an epigenetic event gives birth to a sub clone. There is a Darwinian type competition between the sub clones and those with the more rapid growth because dominant (the acceleration of the growth rate can be due to shorter cell cycles or to an alleviation of cell proliferation exerted by the neighboring cells or the microenvironment). In the dominant sub clones new genomic events provoke the appearance of new sub clones growing more rapidly and having greater autonomy. The process is very slow because the specific genetic events that favour this evolution

Carcinogenic effects of radiation-introduction

International Nuclear Information System (INIS)

Setlow, R.B.

1976-01-01

The weight of experimental evidence reviewed indicates that UV damage to DNA, probably pyrimidine dimers, is the best molecular candidate for the initiating damage that leads to skin cancer. It is postulated that the carcinogenic action spectrum should be similar to the DNA action spectrum filtered through the upper layer of skin

Carcinogenic and neurotoxic risks of acrylamide consumed through caffeinated beverages among the lebanese population.

Science.gov (United States)

El-Zakhem Naous, Ghada; Merhi, Areej; Abboud, Martine I; Mroueh, Mohamad; Taleb, Robin I

2018-06-06

The present study aims to quantify acrylamide in caffeinated beverages including American coffee, Lebanese coffee, espresso, instant coffee and hot chocolate, and to determine their carcinogenic and neurotoxic risks. A survey was carried for this purpose whereby 78% of the Lebanese population was found to consume at least one type of caffeinated beverages. Gas Chromatography Mass Spectrometry analysis revealed that the average acrylamide level in caffeinated beverages is 29,176 μg/kg sample. The daily consumption of acrylamide from Lebanese coffee (10.9 μg/kg-bw/day), hot chocolate (1.2 μg/kg-bw/day) and Espresso (7.4 μg/kg-bw/day) was found to be higher than the risk intake for carcinogenicity and neurotoxicity as set by World Health Organization (WHO; 0.3-2 μg/kg-bw/day) at both the mean (average consumers) and high (high consumers) dietary exposures. On the other hand, American coffee (0.37 μg/kg-bw/day) was shown to pose no carcinogenic or neurotoxic risks among the Lebanese community for consumers with a mean dietary exposure. The study shows alarming results that call for regulating the caffeinated product industry by setting legislations and standard protocols for product preparation in order to limit the acrylamide content and protect consumers. In order to avoid carcinogenic and neurotoxic risks, we propose that WHO/FAO set acrylamide levels in caffeinated beverages to 7000 μg acrylamide/kg sample, a value which is 4-folds lower than the average acrylamide levels of 29,176 μg/kg sample found in caffeinated beverages sold in the Lebanese market. Alternatively, consumers of caffeinated products, especially Lebanese coffee and espresso, would have to lower their daily consumption to 0.3-0.4 cups/day. Copyright © 2018 Elsevier Ltd. All rights reserved.

The potential carcinogenic risk of tanning beds: clinical guidelines and patient safety advice

Directory of Open Access Journals (Sweden)

Mette Mogensen

2010-10-01

Full Text Available Mette Mogensen1, Gregor BE Jemec21Department of Dermatology, Gentofte Hospital, Hellerup, Denmark; 2Department of Dermatology, Roskilde Hospital, Health Sciences Faculty, University of Copenhagen, Roskilde, DenmarkIntroduction: In 2009, the WHO listed ultraviolet (UV radiation as a group 1 carcinogen. In spite of this, each year, millions of people tan indoor in Western countries. The aim of this review is to summarize evidence of tanning bed carcinogenesis and to present guidelines for use of tanning beds and patient safety advice.Methods: A narrative review of the literature was conducted based on both PubMed and Medline searches and on literature review of the retrieved papers.Results: Use of indoor tanning beds represents a significant and avoidable risk factor for the development of both melanoma and nonmelanoma skin cancers. Frequent tanners are more often adolescent females. Tanning beds have additional potential adverse effects such as burns, solar skin damage, infection, and possibly also addictive behavior.Discussion: The effort in preventing UV light-induced carcinogenesis should currently be aimed at developing new strategies for public health information. Tanning beds are one preventable source of UV radiation. In the majority of people solar UV radiation continues to be the major factor and therefore anti-tanning campaigns must always include sunbathers.Keywords: tanning beds, skin cancers, melanoma, nonmelanoma

[Mobile phones radiate--risk to the health?].

Science.gov (United States)

Jokela, Kari; Auvinen, Anssi; Hämäläinen, Heikki

2011-01-01

The mobile phones radiate electromagnetic energy which is partly absorbed into the tissues in the vicinity of the phone. The minor heating, in maximum up to 0.3 degrees C, may cause some alterations in the expression of genes and proteins similar to physiological response to other stimuli. Biophysical studies at the cellular and molecular level have not revealed any well established interaction mechanism, through which mobile phone radiation could induce toxic effects below the thermal effect level. Research results on various biological effects in vitro and in vivo are continuously published but there is no consistent evidence on well established harmful effects. The mobile phone radiation is not carcinogenic for experimental animals or genotoxic for cells. According to epidemiological studies and psychophysiological brain function studies the use of mobile phones does not seem to increase the risk of tumors in the head and brain or disturb the function of central nervous system. However, there is a need for more research on the long-term effects of mobile phone radiation particularly on children.

Comparative experimental study of cancer induced by ionizing radiations or by chemical carcinogens

International Nuclear Information System (INIS)

Lafuma, J.

1983-01-01

Animal experiments have contributed to specify a number of parameters used in setting human safety limits for ionizing radiation. In the same way, comparisons have been made between cancers induced in man and in animals in well-defined conditions. In order to use the same experimental data for chemical carcinogens, the mechanisms of carcinogenesis should be the same, i.e. additivity of responses instead of synergy of effects, which requires the development of a new experimental method [fr

The genetics of radiation-induced osteosarcoma

International Nuclear Information System (INIS)

Rosemann, M.; Kuosaite, V.; Nathrath, M.; Atkinson, M.J.

2002-01-01

Individual genetic variation can influence susceptibility to the carcinogenic effects of many environmental carcinogens. In radiation-exposed populations those individuals with a greater genetically determined susceptibility would be at greater risk of developing cancer. To include this modification of risk into radiation protection schemes it is necessary to identify the genes responsible for determining individual sensitivity. Alpha-particle-induced osteosarcoma in the mouse has been adopted as a model of human radiation carcinogenesis, and genome-wide screens have been conducted for allelic imbalance and genetic linkage. These studies have revealed a series of genes involved in determining the sensitivity to radiogenic osteosarcoma formation. (author)

Probabilistic health risk assessment of carcinogenic emissions from a MSW gasification plant.

Science.gov (United States)

Lonati, Giovanni; Zanoni, Francesca

2012-09-01

Health risk assessment due to the atmospheric emissions of carcinogenic pollutants (PCDD/Fs and Cd) from a waste gasification plant is performed by means of a probabilistic approach based on probability density functions for the description of the input data of the model parameters involved in the assessment. These functions incorporate both the epistemic and stochastic uncertainty of the input data (namely, the emission rate of the pollutants) and of all the parameters used for individual exposure assessment through the pathways of inhalation, soil ingestion and dermal contact, and diet. The uncertainty is propagated throughout the evaluation by Monte Carlo technique, resulting in the probability distribution of the individual risk. The median risk levels nearby the plant are in the 10(-8)-10(-10) range, ten-fold lower than the deterministic estimate based on precautionary values for the input data; however, the very upper percentiles (>95th) of the risk distribution can exceed the conventional 10(-6) reference value. The estimated risk is almost entirely determined by the Cd exposure through the diet; the pathways arising from PCDD/Fs exposure are without any practical significance, suggesting that the emission control should focus on Cd in order to reduce the carcinogenic risk. Risk variance decomposition shows the prevailing influence on the estimated risk of the Cd concentration at the emission stack: thus, for a more accurate risk assessment the efforts should focus primarily on the definition of its probability density function. Copyright © 2012 Elsevier Ltd. All rights reserved.

Risk concepts in various fields including radiation protection. A historical review and some recent topics

International Nuclear Information System (INIS)

Kai, Michiaki

2000-01-01

This is a review by the expert group concerning risks in radiation protection and in chemical management, recent state of protection and of health-risk assessment of low dose radiation, and risk concepts in other fields. Risk concepts in radiation protection are described mainly on ICRP: Its history leading to its Publication 1 (1958), Pub. 9 (1965), Pub. 26 (1977) and Pub. 60 (1990). In that recent publication, the term, risk, is used only for the established one like estimated risk or excess relative risk. Risk management of chemicals involves that against pollution from environmental and ecological aspects, and assessment of dioxin and chemicals from toxicology and carcinogenicity aspects. Recently, risks of low dose radiation have been actively discussed conceivably because of possible reduction of the exposure limit in ICRP Recommendation 1990, Chernobyl accident, advances of radiation biology and radiation protection problem in the radioactive waste disposition. Globally, many academic societies such as American Health-Physics Society published Position Statements and Reports and there are activities like the Research program plan for the risk and an international conference of bridging radiation policy and science. Risk concepts involve technological and ecological ones, insurance ones and health ones. Risk assessment or analysis is done through recognition, measurement and prediction, thus through the scientific process based on objective facts. (K.H.)

Health effects of low-level radiations

International Nuclear Information System (INIS)

Tubiana, M.

1982-01-01

Epidemiological surveys have attempted to assess the carcinogenic risk induced by exposure to low doses of ionizing radiation. Such studies are difficult to carry out because the incidence of radiation induced cancers is of only a few per cent, even following relativity large doses, and because there is no way to distinguish radiation induced cancer from the background of natural human cancers; moreover these surveys are exposed to many biases due to relatively small sizes of the populations studied and the difficulties of finding an appropriate control group, of estimating the absorbed doses and of collecting the data. A few national or international expert committees have analysed the available data and evaluated the carcinogenic effects. Their estimations of the risk, are similar and allow one to quantify the carcinogenic risk for doses above 100 rads. The risks of lower doses must be determined by extrapolation from human data at high doses. This extrapolation requires the knowledge of the dose-effect relationship. A linear extrapolation is most common and probably leads to a conservative estimate of the risk. A linear-quadratic function is probably more realistic and in better accordance with most scientific data. However the validity of its use for the estimation of carcinogenic risk is still debated. In experimental animals, the influence of dose-rate is important and some data suggest that this is the same for the carcinogenic effect in human beings. The genetic effects are probably less important than was feared a few years ago. The most important recent observation is the absence of any significant genetic effect in the progeny of the survivors of the A. bombs in Hiroshima and Nagasaki. This allows a conservative estimate of the maximum genetic risk for human beings [fr

Radiation protection standards: A practical exercise in risk assessment

Energy Technology Data Exchange (ETDEWEB)

Clarke, Roger H [National Radiological Protection Board (United Kingdom)

1992-07-01

Within 12 months of the discovery of x-rays in 1895, it was reported that large doses of radiation were harmful to living human tissues. The first radiation protection standards were set to avoid the early effects of acute irradiation. By the 1950s, evidence was mounting for late somatic effects - mainly a small excess of cancers - in irradiated populations. In the late 1980's, sufficient human epidemiological data had been accumulated to allow a comprehensive assessment of carcinogenic radiation risks following the delivery of moderately high doses. Workers and the public are exposed to lower doses and dose-rates than the groups from whom good data are available so that risks have had to be estimated for protection purposes. However, in the 1990s, some confirmation of these risk factors has been derived occupationally exposed populations. If an estimate is made of the risk per unit dose, then in order to set dose limits, an unacceptable level of risk must be established for both workers and the public. There has been and continues to be a debate about the definitions of 'acceptable' and 'tolerable' and the attributing of numerical values to these definitions. This paper discusses the issues involved in the quantification of these terms and their application to setting dose limits on risk grounds. Conclusions are drawn about the present protection standards and the application of the methods to other fields of risk assessment. (author)

Radiation protection standards: A practical exercise in risk assessment

International Nuclear Information System (INIS)

Clarke, Roger H.

1992-01-01

Within 12 months of the discovery of x-rays in 1895, it was reported that large doses of radiation were harmful to living human tissues. The first radiation protection standards were set to avoid the early effects of acute irradiation. By the 1950s, evidence was mounting for late somatic effects - mainly a small excess of cancers - in irradiated populations. In the late 1980's, sufficient human epidemiological data had been accumulated to allow a comprehensive assessment of carcinogenic radiation risks following the delivery of moderately high doses. Workers and the public are exposed to lower doses and dose-rates than the groups from whom good data are available so that risks have had to be estimated for protection purposes. However, in the 1990s, some confirmation of these risk factors has been derived occupationally exposed populations. If an estimate is made of the risk per unit dose, then in order to set dose limits, an unacceptable level of risk must be established for both workers and the public. There has been and continues to be a debate about the definitions of 'acceptable' and 'tolerable' and the attributing of numerical values to these definitions. This paper discusses the issues involved in the quantification of these terms and their application to setting dose limits on risk grounds. Conclusions are drawn about the present protection standards and the application of the methods to other fields of risk assessment. (author)

Unique loss of heterozygosity of murine thymic lymphomas as a candidate of radiation signature

Energy Technology Data Exchange (ETDEWEB)

Shimada, Yoshiya; Nishimura, Mayumi; Kakinuma, Shizuko [National Inst. of Radiological Sciences, Chiba (Japan); Wakana, Shigeharu; Okumoto, Masaaki

1999-06-01

Signature(s) of prior exposure to carcinogens have immediate application to the identification of environmental risk factors. Such signatures have been sought to aid in developing policies for the protection from risks of environmental carcinogens. Although ionizing radiation is a potent carcinogenic agent, little is known about possible radiation signatures. This is because radiation induces a broad spectrum of DNA lesions. Here we describe a diversity of K-ras mutations and a unique locus with frequent loss of heterozygisity (LOH) on chromosome 11 of radiation induced thymic lymphomas. The latter locus has never been observed to be similarly altered in either ethylnitrosourea-induced or spontaneously developed lymphomas. These results describe, to our knowledge for the first time, a molecular basis for radiation signature. (author)

Cancer risks: Strategies for elimination

International Nuclear Information System (INIS)

Bannasch, P.

1987-01-01

This book deals with the possibilities for identifying and eliminating cancer risk factors. The current state of knowledge on the detection, assessment and elimination of chemical, physical (radiation), and biological (viruses) risk factors are comprehensively presented in 15 contributions. Chemical risk factors resulting from smoking and environmental contamination are given special attention. The coverage of cancer risks by radiation includes some of the consequences of the Chernobyl disaster. Finally, the discussion of the possible risks that certain viruses hold for cancer in man is intended to further the development of vaccinations against these viral infections. The information is directed not only at specialists, but also at a wider interested audience. Its primary aim is to convey established findings that are already being used for cancer prevention. Furthermore, the book aims to promote more intense research in the field of primary cancer prevention. Contents: General aspects; chemical carcinogens: Risk assessment; chemical carcinogens: Primary prevention; physical carcinogens - Oncogenic viruses and subject index

Carcinogenic risk for workers exposed to ionizing radiation. A critical review of present epidemiologic studies

International Nuclear Information System (INIS)

Tirmarche, M.

1987-01-01

Epidemiologic studies on workers who have been exposed to ionizing radiation have allowed to demonstrate certain cancer risks associated with elevated, often retrospectively reconstituted exposures. Present studies on still active workers or workers having worked for the last 15 years are indispensable to define the risk associated with low irradiation doses; they must, however, take into account confounding factors that may play a role in the etiology of the cancer studied

Chromium carcinogenicity: California strategies.

Science.gov (United States)

Alexeeff, G V; Satin, K; Painter, P; Zeise, L; Popejoy, C; Murchison, G

1989-10-01

Hexavalent chromium was identified by California as a toxic air contaminant (TAC) in January 1986. The California Department of Health Services (CDHS) concurred with the findings of the International Agency for Research on Cancer that there is sufficient evidence to demonstrate the carcinogenicity of chromium in both animals and humans. CDHS did not find any compelling evidence demonstrating the existence of a threshold with respect to chromium carcinogenesis. Experimental data was judged inadequate to assess potential human reproductive risks from ambient exposures. Other health effects were not expected to occur at ambient levels. The theoretically increased lifetime carcinogenic risk from a continuous lifetime exposure to hexavalent chromium fell within the range 12-146 cancer cases per nanogram hexavalent chromium per cubic meter of air per million people exposed, depending on the potency estimate used. The primary sources found to contribute significantly to the risk of exposure were chrome platers, chromic acid anodizing facilities and cooling towers utilizing hexavalent chromium as a corrosion inhibitor. Evaluation of genotoxicity data, animal studies and epidemiological studies indicates that further consideration should be given to the potential carcinogenicity of hexavalent chromium via the oral route.

Bioavailable serum estradiol may alter radiation risk of postmenopausal breast cancer: a nested case-control study.

Science.gov (United States)

Grant, Eric J; Cologne, John B; Sharp, Gerald B; Eguchi, Hidetaka; Stevens, Richard G; Izumi, Shizue; Kim, Young-Min; Berrington de González, Amy; Ohishi, Waka; Nakachi, Kei

2018-02-01

Ionizing radiation and high levels of circulating estradiol are known breast cancer carcinogens. We investigated the risk of first primary postmenopausal breast cancer in relation to the combined effects of whole-body ionizing radiation exposure and prediagnostic levels of postmenopausal sex hormones, particularly bioavailable estradiol (bE 2 ). A nested case-control study of 57 incident breast cancer cases matched with 110 controls among atomic bomb survivors. Joint effects of breast radiation dose and circulating levels of sex hormones were assessed using binary regression and path analysis. Radiation exposure, higher levels of bE 2 , testosterone and progesterone, and established reproductive risk factors were positively associated with postmenopausal breast cancer risk. A test for mediation of the effect of radiation via bE 2 level suggested a small (14%) but significant mediation (p = 0.004). The estimated interaction between radiation and bE 2 was large but not significant (interaction = 3.86; p = 0.32). There is accumulating evidence that ionizing radiation not only damages DNA but also alters other organ systems. While caution is needed, some portion of the radiation risk of postmenopausal breast cancer appeared to be mediated through bE 2 levels, which may be evidence for cancer risks due to both direct and indirect effects of radiation.

Low-level radiation

International Nuclear Information System (INIS)

Myers, D.K.

1982-05-01

It is known that the normal incidence of cancer in human populations is increased by exposure to moderately high doses of ionizing radiation. At background radiation levels or at radiation levels which are 100 times greater, the potential health risks are considered to be directly proportional to the total accumulated dose of radiation. Some of the uncertainties associated with this assumption and with the accepted risk estimates have been critically reviewed in this document. The general scientific consensus at present suggests that the accepted risk estimates may exaggerate the actual risk of low levels of sparsely ionizing radiations (beta-, gamma- or X-rays) somewhat but are unlikely to overestimate the actual risks of densely ionizing radiations (fast neutrons, alpha-particles). At the maximum permissible levels of exposure for radiation workers in nuclear power stations, the potential health hazards in terms of life expectancy would be comparable to those encountered in transportation and public utilities or in the construction industry. At the average radiation exposures received by these workers in practice, the potential health hazards are similar to those associated with safe categories of industries. Uranium mining remains a relativly hazardous occupation. In terms of absolute numbers, the genetic hazards, which are less well established, are thought to be smaller than the carcinogenic hazards of radiation when only the first generation is considered but to be of the same order of magnitude as the carcinogenic hazards when the total number of induced genetic disorders is summed over all generations

The effect of radiation in combination with carcinogens on the growth of normal urothelium in explant culture

International Nuclear Information System (INIS)

Mothersill, C.; O'Brien, A.

1990-01-01

Radiation is known to be carcinogenic to humans but attempts to demonstrate the process using human tissue culture models have met with little success. In the present study explants were established from urothelium and exposed to radiation and a range of chemical carcinogens, suspected promotor or metabolic agents. The resulting outgrowth was monitored for growth rate, proliferating epithelial fraction and development and differentiation of endothelial cells in culture. The results indicate that enhanced growth of epithelial cells can be seen when cultures are irradiated in the presence of various nitrosamines, benzo(a)pyrene or aniline. Radiation alone reduced the overall growth area measured but several proliferative foci developed on the resulting outgrowth. Their ultrastructural appearance reveals that they carry severe mitochondrial damage and exposure of treated cultures to metabolic inhibitors confirms that their respiration is defective. Endothelial cells proliferated over the surface of the epithelial monolayer and both the number and the degree of differentiation of the endothelial cells increased with increasing dose up to 10 Gy. While the cultures are not immortalised by the treatment, it appears that the epithelial cells have an extended lifespan (division capacity) and that a subpopulation has undergone a number of premalignant changes. Changes in endothelial cell proliferation also occur. (orig.)

Exposure to dust-bound PAHs and associated carcinogenic risk in primitive and traditional cooking practices in Pakistan.

Science.gov (United States)

Kamal, Atif; Malik, Riffat Naseem; Martellini, Tania; Cincinelli, Alessandra

2015-08-01

The aim of this study was to determine the abundance and distribution of polycyclic aromatic hydrocarbons (PAHs) in dust samples collected from the selected professional cooking workplaces (WCs) and residential household cooking areas (WRs), where traditional and primitive cooking practices are still prevelent. Another aim of this study was to investigate the carcinogenic risk for Pakistani human exposure to dust-bound PAHs via the routes of inhalation, ingestion, and dermal contact. Generally, the concentration of individual congeners of PAHs in surface dust samples of WC sites was higher than those measured in WR sites (p < 0.05). The benzo(a)pyrene (B(a)P), a very high carcinogenic compound, was present in the dust samples from WC sites in the highest mean concentration (630 ng g(-1) dry weight (d.w.)). The BaP mean concentration in WC workplaces was almost eight times higher than the mean value found in WR exposure sites. Moreover, the average concentration of ∑PAHs, combustion origin PAHs (∑COMB) and sum total of 7-carcinogenic PAHs (∑7-carcinogens) were also significantly higher in WC dusts samples than that in WR workplaces. Principal component analysis (PCA) and diagnostic ratios suggested coal/wood combustion as major PAH emission sources in both exposure sites. The average incremental lifetime cancer risk (ILCR) suggested a moderate to potential high cancer risk for adults and children exposed to dust-bound PAHs in both exposure sites, in particular via both dermal and ingestion contact pathways.

Transplacental exposure to environmental carcinogens: Association with childhood cancer risks and the role of modulating factors.

Science.gov (United States)

Fucic, A; Guszak, V; Mantovani, A

2017-09-01

Biological responses to carcinogens from environmental exposure during adulthood are modulated over years or decades. Conversely, during transplacental exposure, the effects on the human foetus change within weeks, intertwining with developmental mechanisms: even short periods of transplacental exposure may be imprinted in the organism for a lifetime. The pathways leading to childhood and juvenile cancers, such as leukaemias, neuroblastoma/brain tumours, hepatoblastoma, and Willm's tumour involve prenatally-induced genomic, epigenomic and/or non-genomic effects caused by xenobiotics. Pregnant women most often live in complex environmental settings that cause transplacental exposure of the foetus to xenobiotic mixtures. Mother-child biomonitoring should integrate the analysis of chemicals/radiation present in the living and workplace environment with relevant risk modulators related to life style. The interdisciplinary approach for transplacental cancer risk assessment in high-pressure areas should be based on an integrated model for mother-child exposure estimation via profiling the exposure level by water quality analysis, usage of emission grids, and land use maps. Copyright © 2017. Published by Elsevier Inc.

The comparative estimation of the radiation and chemical carcinogenic risk induced by the atmosphere contamination due to releases from coal-fired power plants

International Nuclear Information System (INIS)

Knizhnikov, V.A.; Komleva, V.A.; Shandala, N.K.

1992-01-01

In experiments with 1000 white mongrel mice which inhaled benzo (a) pyrene (BP) and fly coal ash for a long time, these agents increased significantly lung tumour incidence, with the latent period shortened. BP is found to be 10-1000 fold more carcinogenic then fly coal ash. The BP inhalation at a sanitary standard level (0.1 μg/100m 3 ) appeared to be equivalent, in murine risk, to the whole-body exposure to a total gamma dose of about 2 Sv. The coal ash inhalation in a concentration of 0.05 mg/m 3 caused the same risk as a dose of 0.05 Sv. (author)

Quantitative assessment of exposure and risk for three carcinogenics in long-standing pollution sites

International Nuclear Information System (INIS)

Wichmann, H.E.; Wuppertal Univ.; Ihme, W.; Mekel, O.C.L.; Wuppertal Univ.

1993-01-01

The project attempts a quantitative assessment of risks for three carcinogenics that are common in sites of long-standing pollution. Benzo(a)pyrene stands for the group of polycyclic aromatic hydrocarbons, cadmium for heavy metals, and benzene for volatile aromatic compounds. The report discusses the general fundamentals of exposure and risk assessment. The exposure model is described in detail and applied to the three test substances. (orig./MG) [de

A biological basis for the linear non-threshold dose-response relationship for low-level carcinogen exposure

International Nuclear Information System (INIS)

Albert, R.E.

1981-01-01

This chapter examines low-level dose-response relationships in terms of the two-stage mouse tumorigenesis model. Analyzes the feasibility of the linear non-threshold dose-response model which was first adopted for use in the assessment of cancer risks from ionizing radiation and more recently from chemical carcinogens. Finds that both the interaction of B(a)P with epidermal DNA of the mouse skin and the dose-response relationship for the initiation stage of mouse skin tumorigenesis showed a linear non-threshold dose-response relationship. Concludes that low level exposure to environmental carcinogens has a linear non-threshold dose-response relationship with the carcinogen acting as an initiator and the promoting action being supplied by the factors that are responsible for the background cancer rate in the target tissue

Carcinogenic compounds in alcoholic beverages: an update.

Science.gov (United States)

Pflaum, Tabea; Hausler, Thomas; Baumung, Claudia; Ackermann, Svenja; Kuballa, Thomas; Rehm, Jürgen; Lachenmeier, Dirk W

2016-10-01

The consumption of alcoholic beverages has been classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC) since 1988. More recently, in 2010, ethanol as the major constituent of alcoholic beverages and its metabolite acetaldehyde were also classified as carcinogenic to humans. Alcoholic beverages as multi-component mixtures may additionally contain further known or suspected human carcinogens as constituent or contaminant. This review will discuss the occurrence and toxicology of eighteen carcinogenic compounds (acetaldehyde, acrylamide, aflatoxins, arsenic, benzene, cadmium, ethanol, ethyl carbamate, formaldehyde, furan, glyphosate, lead, 3-MCPD, 4-methylimidazole, N-nitrosodimethylamine, pulegone, ochratoxin A, safrole) occurring in alcoholic beverages as identified based on monograph reviews by the IARC. For most of the compounds of alcoholic beverages, quantitative risk assessment provided evidence for only a very low risk (such as margins of exposure above 10,000). The highest risk was found for ethanol, which may reach exposures in ranges known to increase the cancer risk even at moderate drinking (margin of exposure around 1). Other constituents that could pose a risk to the drinker were inorganic lead, arsenic, acetaldehyde, cadmium and ethyl carbamate, for most of which mitigation by good manufacturing practices is possible. Nevertheless, due to the major effect of ethanol, the cancer burden due to alcohol consumption can only be reduced by reducing alcohol consumption in general or by lowering the alcoholic strength of beverages.

Radiation-induced mammary carcinogenesis in rodent models. What's different from chemical carcinogenesis?

International Nuclear Information System (INIS)

Imaoka, Tatsuhiko; Nishimura, Mayumi; Iizuka, Daisuke; Daino, Kazuhiro; Takabatake, Takashi; Okamoto, Mieko; Kakinuma, Shizuko; Shimada, Yoshiya

2009-01-01

Ionizing radiation is one of a few well-characterized etiologic factors of human breast cancer. Laboratory rodents serve as useful experimental models for investigating dose responses and mechanisms of cancer development. Using these models, a lot of information has been accumulated about mammary gland cancer, which can be induced by both chemical carcinogens and radiation. In this review, we first list some experimental rodent models of breast cancer induction. We then focus on several topics that are important in understanding the mechanisms and risk modification of breast cancer development, and compare radiation and chemical carcinogenesis models. We will focus on the pathology and natural history of cancer development in these models, genetic changes observed in induced cancers, indirect effects of carcinogens, and finally risk modification by reproductive factors and age at exposure to the carcinogens. In addition, we summarize the knowledge available on mammary stem/progenitor cells as a potential target of carcinogens. Comparison of chemical and radiation carcinogenesis models on these topics indicates certain similarities, but it also indicates clear differences in several important aspects, such as genetic alterations of induced cancers and modification of susceptibility by age and reproductive factors. Identification of the target cell type and relevant translational research for human risk management may be among the important issues that are addressed by radiation carcinogenesis models. (author)

Three-dimensional dose-response models of risk for radiation injury carcinogenesis

International Nuclear Information System (INIS)

Raabe, O.G.

1988-01-01

The use of computer graphics in conjunction with three-dimensional models of dose-response relationships for chronic exposure to ionizing radiation dramaticly clarifies the separate and interactive roles of competing risks. The three dimensions are average dose rate, exposure time, and risk. As an example, the functionally injurious and carcinogenic responses after systemic uptake of Ra-226 by beagles, mice and people with consequent alpha particle irradiation of the bone are represented by three-dimensional dose-rate/time/response surfaces that demonstrate the contributions with the passage of time of the competing deleterious responses. These relationships are further evaluated by mathematical stripping with three-dimensional illustrations that graphically show the resultant separate contribution of each effect. Radiation bone injury predominates at high dose rates and bone cancer at intermediate dose rates. Low dose rates result in spontaneous deaths from natural aging, yielding a type of practical threshold for bone cancer induction. Risk assessment is benefited by the insights that become apparent with these three-dimensional models. The improved conceptualization afforded by them contributes to planning and evaluating epidemiological analyses and experimental studies

Exposure to polycyclic aromatic hydrocarbons in atmospheric PM1.0 of urban environments: Carcinogenic and mutagenic respiratory health risk by age groups.

Science.gov (United States)

Agudelo-Castañeda, Dayana M; Teixeira, Elba C; Schneider, Ismael L; Lara, Sheila Rincón; Silva, Luis F O

2017-05-01

We investigated the carcinogenic and mutagenic respiratory health risks related to the exposure to atmospheric PAHs in an urban area. Our study focused in the association of these pollutants and their possible effect in human health, principally respiratory and circulatory diseases. Also, we determined a relationship between the inhalation risk of PAHs and meteorological conditions. We validated the hypothesis that in winter PAHs with high molecular weight associated to submicron particles (PM 1 ) may increase exposure risk, especially for respiratory diseases, bronchitis and pneumonia diseases. Moreover, in our study we verified the relationship between diseases and several carcinogenic PAHs (Ind, BbkF, DahA, BaP, and BghiP). These individual PAHs contributed the most to the potential risk of exposure for inhalation of PM 1.0 . Even at lower ambient concentrations of BaP and DahA in comparison with individual concentrations of other PAHs associated to PM 1.0 . Mainly, research suggests to include carcinogenic and mutagenic PAHs in future studies of environmental health risk due to their capacity to associate to PM 10 . Such carcinogenic and mutagenic PAHs are likely to provide the majority of the human exposure, since they originate from dense traffic urban areas were humans congregate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radiation risk in Republics Belarus after Chernobyl accident

International Nuclear Information System (INIS)

Saltanova, I.

2006-01-01

under observation by the year 2004. The obtained results conform to the other authors' conclusions (Malko M.V., 2001, 2003). In the framework of the ICRP model it's shown that a maximum possible influence of the radiation contamination factor can't be a source of the actually registered carcinogenic risk. In this connection, an analysis of the ecological hazard non-radiation components is of importance. By now, the scientific community has achieved the understanding of the fact that a chemical pollution risk can be compared with a risk of the radiation contamination even in the regions mostly suffered from the accident at the Chernobyl atomic power station. Furthermore, under a combined influence of a complex of factors, there is a risk of a nonlinear enhancement of the adverse effects. In this connection, an urgent problem appeared consisting of the new approach elaboration on the evaluation of the technogenic environment contamination, under which an influence of different adverse factors would be expressed in comparable values, suitable for their comparative analysis. This problem solving refers first of all to the decision making optimization at the safety arrangements planning on the contaminated territories. (author)

Identification and monitoring of non-radiological carcinogens

Energy Technology Data Exchange (ETDEWEB)

Chuaqui, C A; Petkau, A; Greenstock, C L; Brown, C P [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

1995-09-01

This study examines the feasibility of identifying and monitoring occupational exposures to non-radiological carcinogens in the workplace at Canadian nuclear establishments (Whiteshell Laboratories, Pickering Nuclear Generating Station, Cameco Limited and Canadian General Electric Company Limited). Recent epidemiological studies recommended that potential confounding factors of a non-radiological nature be identified and analyzed, particularly non-radiological carcinogens that may be present in the workplace at nuclear facilities. The feasibility of identifying and measuring occupational exposures to non-radiological carcinogens in Canadian nuclear facilities is examined. Also, the report describes the problem of chemical carcinogens and the mechanisms involved in chemical carcinogenesis; the epidemiology related to the problem, followed by a description of the analytical aspects of detection, monitoring and analysis of carcinogens, as well as a discussion on the regulatory aspects and the regulations in place; and the findings, recommendations and concluding remarks of this study. Several problem areas became apparent as the study proceeded. For example, the classification of a chemical as a human carcinogen is a difficult problem, as is its adequate monitoring and analysis. This situation reflects, in turn, the regulatory aspects in the workplace. A list of chemical carcinogens used industrially at the four Canadian nuclear facilities has been identified. The list includes arsenic, asbestos, benzene, cadmium, beryllium, nickel, polychlorinated biphenyls, lead and trichloroethylene. Several recommendations are made in relation to the need for practical and efficient monitoring methods for chemical carcinogens, the definition of radiation and chemical dose equivalencies, and the classification of human chemical carcinogens, as well as their disposal. (author). 122 refs., 8 tabs., 6 figs.

Identification and monitoring of non-radiological carcinogens

International Nuclear Information System (INIS)

Chuaqui, C.A.; Petkau, A.; Greenstock, C.L.; Brown, C.P.

1995-09-01

This study examines the feasibility of identifying and monitoring occupational exposures to non-radiological carcinogens in the workplace at Canadian nuclear establishments (Whiteshell Laboratories, Pickering Nuclear Generating Station, Cameco Limited and Canadian General Electric Company Limited). Recent epidemiological studies recommended that potential confounding factors of a non-radiological nature be identified and analyzed, particularly non-radiological carcinogens that may be present in the workplace at nuclear facilities. The feasibility of identifying and measuring occupational exposures to non-radiological carcinogens in Canadian nuclear facilities is examined. Also, the report describes the problem of chemical carcinogens and the mechanisms involved in chemical carcinogenesis; the epidemiology related to the problem, followed by a description of the analytical aspects of detection, monitoring and analysis of carcinogens, as well as a discussion on the regulatory aspects and the regulations in place; and the findings, recommendations and concluding remarks of this study. Several problem areas became apparent as the study proceeded. For example, the classification of a chemical as a human carcinogen is a difficult problem, as is its adequate monitoring and analysis. This situation reflects, in turn, the regulatory aspects in the workplace. A list of chemical carcinogens used industrially at the four Canadian nuclear facilities has been identified. The list includes arsenic, asbestos, benzene, cadmium, beryllium, nickel, polychlorinated biphenyls, lead and trichloroethylene. Several recommendations are made in relation to the need for practical and efficient monitoring methods for chemical carcinogens, the definition of radiation and chemical dose equivalencies, and the classification of human chemical carcinogens, as well as their disposal. (author). 122 refs., 8 tabs., 6 figs

Epidemiological studies on the effects of low-level ionizing radiation on cancer risk

International Nuclear Information System (INIS)

Akiba, Suminori

2010-01-01

The health effects of low-level ionizing radiation are yet unclear. As pointed out by Upton in his review (Upton, 1989), low-level ionizing radiation seems to have different biological effects from what high-level radiation has. If so, the hazard identification of ionizing radiation should he conducted separately for low- and high-level ionizing radiation; the hazard identification of low-level radiation is yet to be completed. What makes hazard identification of ionizing radiation difficult, particularly in the case of carcinogenic effect, is the difficulty in distinguishing radiation-induced cancer from other cancers with respect to clinicopathological features and molecular biological characteristics. Actually, it is suspected that radiation-induced carcinogenesis involves mechanisms not specific for radiation, such as oxidative stress. Excess risk per dose in medium-high dose ranges can be extrapolated to a low-dose range if dose-response can be described by the linear-non-threshold model. The cancer risk data of atomic-bomb survivors describes leukemia risk with a linear-quadratic (LQ) model and solid-cancer risk with linear non-threshold (LNT) model. The LQ model for leukemia and the LNT model for solid cancer correspond to the two-hit model and the one-hit model, respectively. Although the one-hit model is an unlikely dose-response for carcinogenesis, there is no convincing epidemiological evidence supporting the LQ model or non-threshold model for solid cancer. It should be pointed out, however, even if the true dose response is non-linear various noises involved in epidemiological data may mask the truth. In this paper, the potential contribution of epidemiological studies on nuclear workers and residents in high background radiation areas will be discussed. (author)

[The implementation of polymerase chain reaction technique: the real time to reveal and differentiate the viruses of human papilloma of high carcinogenic risk].

Science.gov (United States)

Andosova, L D; Kontorshchikova, K N; Blatova, O L; Kudel'kina, S Iu; Kuznetsova, I A; Belov, A V; Baĭkova, R A

2011-07-01

The polymerase chain reaction technique was applied in "real time" format to evaluate the occurrence rate and infection ratio of various genotypes of human papilloma of high carcinogenic risk in virus-positive women and contact persons. The examination sampling consisted of 738 women aged of 17-50 years. The examination results permitted to establish high percentage of infection of 546 patients (74%) by carcinogenic papilloma viruses. The analysis of detection rate of various genotypes of human papilloma of high carcinogenic risk established that the 56th and 16th types of high carcinogenic risk are revealed more often than others--in 33% and 15.4% correspondingly. In males, first place in occurrence rate is for those types of virus of human papilloma: the 56th n = 10 (33.3%), 16th n = 3 (10%), 45th n = 3 (10%), 51th n = 3 (10%). The rest of genotypes are detected in 3-7% cases.

A perspective on the radiation protection problem and risk analysis for the nuclear era

International Nuclear Information System (INIS)

Vohra, K.G.

1977-01-01

The projected large scale use of nuclear energy and sources of ionizing radiations would involve the radiation exposure of larger numbers of occupational workers, individuals and groups in the population, and the population-at-large. There is an urgent need for projecting these exposures in a proper perspective, by comparing the associated risks with the risks from alternative energy sources, e.g. with those from the combustion products released by the fossil fuel plants. A comparative study of the risk of cancer mortality from radiations and airborne chemical pollutants has been presented. Radiation risk data is given in terms of cancer deaths per million per year for a given dose rate, based on the human experience. The lung cancer risks of the combined products of coal burning and a specific carcinogen benzo(a)pyrene have also been estimated, based on the extensive epidemiological data available for different countries. Using the dose-response data for radiation exposure at different annual dose rates, dose equivalents of chemical pollutants have been determined. Whereas the estimated risk for power reactor effluents is found to be only 1% of the risk at the ICRP dose limits for ionizing radiations, the current urban levels of benzo(a)pyrene (a product of fossil fuel combustion) are already large enough to present a 100 fold higher risk, equivalent to that of the ICRP dose limit for ionizing radiations. Comparison shows that percentage contributions to the overall risk are 0.06, 5.5 and 19.0 for nuclear power, fossil fuel pollutant benzo(a)pyrene (per ng/m 3 ) and total coal pollutants (per ton/capita consumption), respectively. Risk estimates for different stages of the nuclear fuel cycle, including the fast breeder reactor fuel cycle, are also presented

The carcinogenic risk of high dose total body irradiation in non-human primates

International Nuclear Information System (INIS)

Broerse, J.J.; Bartstra, R.W.; Bekkum, D.W. van; Hage, M.H. van der; Zurcher, C.; Zwieten, M.J. van; Hollander, C.F.

2000-01-01

High dose total body irradiation (TBI) in combination with chemotherapy, followed by rescue with bone marrow transplantation (BMT), is increasingly used for the treatment of haematological malignancies. With the increasing success of this treatment and its current introduction for treating refractory autoimmune diseases the risk of radiation carcinogenesis is of growing concern. Studies on turnout induction in non-human primates are of relevance in this context since the response of this species to radiation does not differ much from that in man. Since the early sixties, studies have been performed on acute effects in Rhesus monkeys and the protective action of bone marrow transplantation after irradiation with X-rays (average total body dose 6.8 Gy) and fission neutrons (average dose 3.4 Gy). Of those monkeys, which were irradiated and reconstituted with autologous bone marrow, 20 animals in the X-irradiated group and nine animals in the neutron group survived more than 3 years. A group of 21 non-irradiated Rhesus monkeys of a comparable age distribution served as controls. All animals were regularly screened for the occurrence of neoplasms. Complete necropsies were performed after natural death or euthanasia. At post-irradiation intervals of 4-21 years an appreciable number of tumours was observed. In the neutron irradiated group eight out of nine animals died with one or more malignant tumours. In the X-irradiated group this fraction was 10 out of 20. The tumours in the control group, in seven out of the 21 animals, appeared at much older a-e compared with those in the irradiated cohorts. The histogenesis of the tumours was diverse with a preponderance of renal carcinoma, sarcomas among which osteosarcormas, and malignant glomus tumours in the irradiated groups. When corrected for competing risks, the carcinogenic risk of TBI in the Rhesus monkeys is similar to that derived from the studies of the Japanese atomic bomb survivors. The increase of the risk by a

Breast cancer risk in relation to occupations with exposure to carcinogens and endocrine disruptors: a Canadian case-control study.

Science.gov (United States)

Brophy, James T; Keith, Margaret M; Watterson, Andrew; Park, Robert; Gilbertson, Michael; Maticka-Tyndale, Eleanor; Beck, Matthias; Abu-Zahra, Hakam; Schneider, Kenneth; Reinhartz, Abraham; Dematteo, Robert; Luginaah, Isaac

2012-11-19

Endocrine disrupting chemicals and carcinogens, some of which may not yet have been classified as such, are present in many occupational environments and could increase breast cancer risk. Prior research has identified associations with breast cancer and work in agricultural and industrial settings. The purpose of this study was to further characterize possible links between breast cancer risk and occupation, particularly in farming and manufacturing, as well as to examine the impacts of early agricultural exposures, and exposure effects that are specific to the endocrine receptor status of tumours. 1005 breast cancer cases referred by a regional cancer center and 1146 randomly-selected community controls provided detailed data including occupational and reproductive histories. All reported jobs were industry- and occupation-coded for the construction of cumulative exposure metrics representing likely exposure to carcinogens and endocrine disruptors. In a frequency-matched case-control design, exposure effects were estimated using conditional logistic regression. Across all sectors, women in jobs with potentially high exposures to carcinogens and endocrine disruptors had elevated breast cancer risk (OR = 1.42; 95% CI, 1.18-1.73, for 10 years exposure duration). Specific sectors with elevated risk included: agriculture (OR = 1.36; 95% CI, 1.01-1.82); bars-gambling (OR = 2.28; 95% CI, 0.94-5.53); automotive plastics manufacturing (OR = 2.68; 95% CI, 1.47-4.88), food canning (OR = 2.35; 95% CI, 1.00-5.53), and metalworking (OR = 1.73; 95% CI, 1.02-2.92). Estrogen receptor status of tumors with elevated risk differed by occupational grouping. Premenopausal breast cancer risk was highest for automotive plastics (OR = 4.76; 95% CI, 1.58-14.4) and food canning (OR = 5.70; 95% CI, 1.03-31.5). These observations support hypotheses linking breast cancer risk and exposures likely to include carcinogens and endocrine disruptors, and demonstrate the value of detailed work

Breast cancer risk in relation to occupations with exposure to carcinogens and endocrine disruptors: a Canadian case–control study

Science.gov (United States)

2012-01-01

Background Endocrine disrupting chemicals and carcinogens, some of which may not yet have been classified as such, are present in many occupational environments and could increase breast cancer risk. Prior research has identified associations with breast cancer and work in agricultural and industrial settings. The purpose of this study was to further characterize possible links between breast cancer risk and occupation, particularly in farming and manufacturing, as well as to examine the impacts of early agricultural exposures, and exposure effects that are specific to the endocrine receptor status of tumours. Methods 1005 breast cancer cases referred by a regional cancer center and 1146 randomly-selected community controls provided detailed data including occupational and reproductive histories. All reported jobs were industry- and occupation-coded for the construction of cumulative exposure metrics representing likely exposure to carcinogens and endocrine disruptors. In a frequency-matched case–control design, exposure effects were estimated using conditional logistic regression. Results Across all sectors, women in jobs with potentially high exposures to carcinogens and endocrine disruptors had elevated breast cancer risk (OR = 1.42; 95% CI, 1.18-1.73, for 10 years exposure duration). Specific sectors with elevated risk included: agriculture (OR = 1.36; 95% CI, 1.01-1.82); bars-gambling (OR = 2.28; 95% CI, 0.94-5.53); automotive plastics manufacturing (OR = 2.68; 95% CI, 1.47-4.88), food canning (OR = 2.35; 95% CI, 1.00-5.53), and metalworking (OR = 1.73; 95% CI, 1.02-2.92). Estrogen receptor status of tumors with elevated risk differed by occupational grouping. Premenopausal breast cancer risk was highest for automotive plastics (OR = 4.76; 95% CI, 1.58-14.4) and food canning (OR = 5.70; 95% CI, 1.03-31.5). Conclusions These observations support hypotheses linking breast cancer risk and exposures likely to include carcinogens and endocrine disruptors, and

Breast cancer risk in relation to occupations with exposure to carcinogens and endocrine disruptors: a Canadian case–control study

Directory of Open Access Journals (Sweden)

Brophy James T

2012-11-01

Full Text Available Abstract Background Endocrine disrupting chemicals and carcinogens, some of which may not yet have been classified as such, are present in many occupational environments and could increase breast cancer risk. Prior research has identified associations with breast cancer and work in agricultural and industrial settings. The purpose of this study was to further characterize possible links between breast cancer risk and occupation, particularly in farming and manufacturing, as well as to examine the impacts of early agricultural exposures, and exposure effects that are specific to the endocrine receptor status of tumours. Methods 1005 breast cancer cases referred by a regional cancer center and 1146 randomly-selected community controls provided detailed data including occupational and reproductive histories. All reported jobs were industry- and occupation-coded for the construction of cumulative exposure metrics representing likely exposure to carcinogens and endocrine disruptors. In a frequency-matched case–control design, exposure effects were estimated using conditional logistic regression. Results Across all sectors, women in jobs with potentially high exposures to carcinogens and endocrine disruptors had elevated breast cancer risk (OR = 1.42; 95% CI, 1.18-1.73, for 10 years exposure duration. Specific sectors with elevated risk included: agriculture (OR = 1.36; 95% CI, 1.01-1.82; bars-gambling (OR = 2.28; 95% CI, 0.94-5.53; automotive plastics manufacturing (OR = 2.68; 95% CI, 1.47-4.88, food canning (OR = 2.35; 95% CI, 1.00-5.53, and metalworking (OR = 1.73; 95% CI, 1.02-2.92. Estrogen receptor status of tumors with elevated risk differed by occupational grouping. Premenopausal breast cancer risk was highest for automotive plastics (OR = 4.76; 95% CI, 1.58-14.4 and food canning (OR = 5.70; 95% CI, 1.03-31.5. Conclusions These observations support hypotheses linking breast cancer risk and exposures likely to include carcinogens and

A proposed framework for consistent regulation of public exposures to radionuclides and other carcinogens

International Nuclear Information System (INIS)

Kocher, D.C.; Hoffman, F.O.

1991-01-01

This paper discusses a proposed framework for consistent regulation of carcinogenic risks to the public based on establishing de manifestis (i.e., unacceptable) and de minimis (i.e., trivial) lifetime risks from exposure to any carcinogens at levels of about 10 -1 --10 -3 and 10 -4 --10 -6 , respectively, and reduction of risks above de minimis levels as low as reasonably achievable (ALARA). We then discuss certain differences in the way risks from exposure to radionuclides and other carcinogens currently are regulated or assessed which would need to be considered in implementing the proposed regulatory framework for all carcinogens

Health effect of low dose/low dose rate radiation

International Nuclear Information System (INIS)

Kodama, Seiji

2012-01-01

The clarified and non-clarified scientific knowledge is discussed to consider the cause of confusion of explanation of the title subject. The low dose is defined roughly lower than 200 mGy and low dose rate, 0.05 mGy/min. The health effect is evaluated from 2 aspects of clinical symptom/radiation hazard protection. In the clinical aspect, the effect is classified in physical (early and late) and genetic ones, and is classified in stochastic (no threshold value, TV) and deterministic (with TV) ones from the radioprotection aspect. Although the absence of TV in the carcinogenic and genetic effects has not been proved, ICRP employs the stochastic standpoint from the safety aspect for radioprotection. The lowest human TV known now is 100 mGy, meaning that human deterministic effect would not be generated below this dose. Genetic deterministic effect can be observable only in animal experiments. These facts suggest that the practical risk of exposure to <100 mGy in human is the carcinogenesis. The relationship between carcinogenic risk in A-bomb survivors and their exposed dose are found fitted to the linear no TV model, but the epidemiologic data, because of restriction of subject number analyzed, do not always mean that the model is applicable even below the dose <100 mGy. This would be one of confusing causes in explanation: no carcinogenic risk at <100 mGy or risk linear to dose even at <100 mGy, neither of which is scientifically conclusive at present. Also mentioned is the scarce risk of cancer in residents living in the high background radiation regions in the world in comparison with that in the A-bomb survivors exposed to the chronic or acute low dose/dose rate. Molecular events are explained for the low-dose radiation-induced DNA damage and its repair, gene mutation and chromosome aberration, hypothesis of carcinogenesis by mutation, and non-targeting effect of radiation (bystander effect and gene instability). Further researches to elucidate the low dose

Respiratory carcinogenicity assessment of soluble nickel compounds.

Science.gov (United States)

Oller, Adriana R

2002-10-01

The many chemical forms of nickel differ in physicochemical properties and biological effects. Health assessments for each main category of nickel species are needed. The carcinogenicity assessment of water-soluble nickel compounds has proven particularly difficult. Epidemiologic evidence indicates an association between inhalation exposures to nickel refinery dust containing soluble nickel compounds and increased risk of respiratory cancers. However, the nature of this association is unclear because of limitations of the exposure data, inconsistent results across cohorts, and the presence of mixed exposures to water-insoluble nickel compounds and other confounders that are known or suspected carcinogens. Moreover, well-conducted animal inhalation studies, where exposures were solely to soluble nickel, failed to demonstrate a carcinogenic potential. Similar negative results were seen in animal oral studies. A model exists that relates respiratory carcinogenic potential to the bioavailability of nickel ion at nuclear sites within respiratory target cells. This model helps reconcile human, animal, and mechanistic data for soluble nickel compounds. For inhalation exposures, the predicted lack of bioavailability of nickel ion at target sites suggests that water-soluble nickel compounds, by themselves, will not be complete human carcinogens. However, if inhaled at concentrations high enough to induce chronic lung inflammation, these compounds may enhance carcinogenic risks associated with inhalation exposure to other substances. Overall, the weight of evidence indicates that inhalation exposure to soluble nickel alone will not cause cancer; moreover, if exposures are kept below levels that cause chronic respiratory toxicity, any possible tumor-enhancing effects (particularly in smokers) would be avoided.

The use of dose-response data in a margin of exposure approach to carcinogenic risk assessment for genotoxic chemicals in food.

Science.gov (United States)

Benford, Diane J

2016-05-01

Genotoxic substances are generally not permitted for deliberate use in food production. However, an appreciable number of known or suspected genotoxic substances occur unavoidably in food, e.g. from natural occurrence, environmental contamination and generation during cooking and processing. Over the past decade a margin of exposure (MOE) approach has increasingly been used in assessing the exposure to substances in food that are genotoxic and carcinogenic. The MOE is defined as a reference point on the dose-response curve (e.g. a benchmark dose lower confidences limit derived from a rodent carcinogenicity study) divided by the estimated human intake. A small MOE indicates a higher concern than a very large MOE. Whilst the MOE cannot be directly equated to risk, it supports prioritisation of substances for further research or for possible regulatory action, and provides a basis for communicating to the public. So far, the MOE approach has been confined to substances for which carcinogenicity data are available. In the absence of carcinogenicity data, evidence of genotoxicity is used only in hazard identification. The challenge to the genetic toxicology community is to develop approaches for characterising risk to human health based on data from genotoxicity studies. In order to achieve wide acceptance, it would be important to further address the issues that have been discussed in the context of dose-response modelling of carcinogenicity data in order to assign levels of concern to particular MOE values, and also whether it is possible to make generic conclusions on how potency in genotoxicity assays relates to carcinogenic potency. © Crown copyright 2015.

Oxidative Stress in the Carcinogenicity of Chemical Carcinogens

International Nuclear Information System (INIS)

Kakehashi, Anna; Wei, Min; Fukushima, Shoji; Wanibuchi, Hideki

2013-01-01

This review highlights several in vivo studies utilizing non-genotoxic and genotoxic chemical carcinogens, and the mechanisms of their high and low dose carcinogenicities with respect to formation of oxidative stress. Here, we survey the examples and discuss possible mechanisms of hormetic effects with cytochrome P 450 inducers, such as phenobarbital, α-benzene hexachloride and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane. Epigenetic processes differentially can be affected by agents that impinge on oxidative DNA damage, repair, apoptosis, cell proliferation, intracellular communication and cell signaling. Non-genotoxic carcinogens may target nuclear receptors and induce post-translational modifications at the protein level, thereby impacting on the stability or activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. We further discuss role of oxidative stress focusing on the low dose carcinogenicities of several genotoxic carcinogens such as a hepatocarcinogen contained in seared fish and meat, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, arsenic and its metabolites, and the kidney carcinogen potassium bromate

Oxidative Stress in the Carcinogenicity of Chemical Carcinogens

Energy Technology Data Exchange (ETDEWEB)

Kakehashi, Anna; Wei, Min [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585 (Japan); Fukushima, Shoji [Japan Bioassay Research Center, Japan Industrial Safety and Health Association, 2445 Hirasawa, Hadano, Kanagawa 257-0015 (Japan); Wanibuchi, Hideki, E-mail: wani@med.osaka-cu.ac.jp [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585 (Japan)

2013-10-28

This review highlights several in vivo studies utilizing non-genotoxic and genotoxic chemical carcinogens, and the mechanisms of their high and low dose carcinogenicities with respect to formation of oxidative stress. Here, we survey the examples and discuss possible mechanisms of hormetic effects with cytochrome P{sub 450} inducers, such as phenobarbital, α-benzene hexachloride and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane. Epigenetic processes differentially can be affected by agents that impinge on oxidative DNA damage, repair, apoptosis, cell proliferation, intracellular communication and cell signaling. Non-genotoxic carcinogens may target nuclear receptors and induce post-translational modifications at the protein level, thereby impacting on the stability or activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. We further discuss role of oxidative stress focusing on the low dose carcinogenicities of several genotoxic carcinogens such as a hepatocarcinogen contained in seared fish and meat, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, arsenic and its metabolites, and the kidney carcinogen potassium bromate.

[Assessment of non-carcinogenic risk for the health of the child population under the consumption of drinking water].

Science.gov (United States)

Stepanova, N V; Valeeva, E R; Fomina, S F; Ziyatdinova, A I

In the article there are given results of the evaluation of non-carcinogenic risks for the health of the child population residing in different areas (districts) of the city of Kazan with the aim of the subsequent comprehensive assessment of the pollutants in drinking water. Assessment of the risk for the human health was performed correspondingly to with the P 2.1.10.1920-04 for oral route of exposure in accordance to the chemical composition of drinking water with account for the standard and regional factors of the exposure. The results of the risk assessment under the consumption of drinking tap water by the child population with localized place of residence permit to reveal areas with a high level of health risk in the city. The screening assessment of carcinogenic risk due to the consumption of chemicals with drinking water revealed differences in regional and standard values of the exposure factors. This affects both on the value of the chronic average daily intake of chemical contaminants in drinking water and the level of risk under the consumption of drinking water by the child population.

Carcinogenic risk in diagnostic nuclear medicine: biological and epidemiological considerations

International Nuclear Information System (INIS)

Overbeek, F.; Pauwels, E.K.J.; Broerse, J.J.

1994-01-01

During the last decade new data have become available on the mechanism of carcinogenesis and on cancer induction by ionizing radiation. This review concentrates on these two items in relation to the use of radiopharmaceuticals in diagnostic nuclear medicine. On the basis of reports of expert committees, the concept of radiation risk is elucidated for high and low doses. Mortality risk factors due to ionizing radiation are put in perspective to other risks. The extra risk for patients who undergo a scintigraphic examination for fatal cancer is very small and is of the order of 1.4 x 10 -4 . It is most unlikely that this figure can even be verified by actual measurement since the majority of nuclear medicine patients will die of other causes before the radiogenic cancer manifests itself. (orig.)

Comparative evaluation of carcinogenesis risk in case of radiation effect and pollution of atmospheric air with coal ashes and benzo(a)pyrene

International Nuclear Information System (INIS)

Knizhnikov, V.A.; Shandala, N.K.; Komleva, V.A.; Likhovajdo, N.V.; Shvetsov, A.I.

1993-01-01

Assessment of the risk of lung carcinogenesis under the effect of benzo(a)pyrene (BP) and volatil coal ash in the atmospheric air was performed as well as comparison of this risk with the risk due to ionizing radiation effect from natural and technogenic sources. White mice were used as experimental animals. It was shown that BP was rather more carcinogenic than volatile coal ash. BP inhalation at a maximum permissible concentration level (0.1 μg/100 m 3 of air) corresponds to the equivalent risk of whole-body gamma exposure at bout 2 Sv. Coal ash inhalation at the concentration of 0.05 mg/m 3 corresponds to the same equivalent risk as for radiation dose 0.05 Sv. Conclusion is made that safety standards for coal ash and BP contents in the air do not remove carcinogenesis risk for the population. Whereas carcinogenesis risk due to irradiation at the level of radiation safety standards is considerably lower

Oxidative Stress in the Carcinogenicity of Chemical Carcinogens

Directory of Open Access Journals (Sweden)

Hideki Wanibuchi

2013-10-01

Full Text Available This review highlights several in vivo studies utilizing non-genotoxic and genotoxic chemical carcinogens, and the mechanisms of their high and low dose carcinogenicities with respect to formation of oxidative stress. Here, we survey the examples and discuss possible mechanisms of hormetic effects with cytochrome P450 inducers, such as phenobarbital, a-benzene hexachloride and 1,1-bis(p-chlorophenyl-2,2,2-trichloroethane. Epigenetic processes differentially can be affected by agents that impinge on oxidative DNA damage, repair, apoptosis, cell proliferation, intracellular communication and cell signaling. Non-genotoxic carcinogens may target nuclear receptors and induce post-translational modifications at the protein level, thereby impacting on the stability or activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. We further discuss role of oxidative stress focusing on the low dose carcinogenicities of several genotoxic carcinogens such as a hepatocarcinogen contained in seared fish and meat, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, arsenic and its metabolites, and the kidney carcinogen potassium bromate.

Mycotoxins as human carcinogens-the IARC Monographs classification.

Science.gov (United States)

Ostry, Vladimir; Malir, Frantisek; Toman, Jakub; Grosse, Yann

2017-02-01

Humans are constantly exposed to mycotoxins (e.g. aflatoxins, ochratoxins), mainly via food intake of plant and animal origin. The health risks stemming from mycotoxins may result from their toxicity, in particular their carcinogenicity. In order to prevent these risks, the International Agency for Research on Cancer (IARC) in Lyon (France)-through its IARC Monographs programme-has performed the carcinogenic hazard assessment of some mycotoxins in humans, on the basis of epidemiological data, studies of cancer in experimental animals and mechanistic studies. The present article summarizes the carcinogenic hazard assessments of those mycotoxins, especially aflatoxins (aflatoxin B 1 , B 2 , G 1 , G 2 and M 1 ), fumonisins (fumonisin B 1 and B 2 ) and ochratoxin A (OTA). New information regarding the genotoxicity of OTA (formation of OTA-DNA adducts), the role of OTA in oxidative stress and the identification of epigenetic factors involved in OTA carcinogenesis-should they indeed provide strong evidence that OTA carcinogenicity is mediated by a mechanism that also operates in humans-could lead to the reclassification of OTA.

The impact on radiation risk estimates of effect modifiers and confounders

International Nuclear Information System (INIS)

Sharp, G.B.; Cologne, J.B.; Pierce, D.A.; Tokuoka, S.

2003-01-01

We have conducted studies of the joint effects of radiation with other risk factors for liver, lung, and breast cancer in the cohort of Japanese survivors of the 1945 atomic bombings. Based on follow-up of 45,113 subjects from 1958 through 1994, of whom 592 developed lung cancer, we found the effects of smoking and radiation to be significantly non-multiplicative and consistent with additivity. Adjustment for smoking reduced the female:male ratio of radiation risk estimates for lung cancer in this cohort from 5.8 to 1.6, a ratio more similar to that for all solid cancers. We conducted cross sectional and case control studies within the A-bomb survivor cohort to assess the joint effects of radiation with hepatitis B virus (HBV) and C virus (HCV) infections on the etiology of liver cirrhosis and hepatocellular carcinoma (HCC). Our study of 268 pathologist-confirmed cirrhosis cases and 843 subjects without cirrhosis, found no relationship between A-bomb radiation and cirrhosis after adjustment for viral hepatitis. In terms of HCC, our study of 238 pathologist-confirmed cases and 894 controls showed super-multiplicative interaction between radiation and HCV infections. Our results suggest that while chronic radiation exposure acts as a complete carcinogen for HCC, acute irradiation may act in concert with an agent such as HCV that is associated with liver cell proliferation. Studies in progress of the joint effects of radiation with insulin-like growth factor 1 (IGF-1) and IGF Binding Protein 3 (IGFBP-3), and total estradiol on the etiology of breast cancer, a particularly radiogenic tumor, will also be discussed

Risk equivalent of exposure versus dose of radiation

International Nuclear Information System (INIS)

Bond, V.P.

1986-01-01

Radiation is perhaps unique among all agents of interest in the Health Sciences in that it alone is both a therapeutic agent for the control of cancer and an essentially ubiquitous environmental agent with a potential for increasing the cancer rate in human populations. Therapy of tumors is accomplished with the high-level exposure (HLE) to radiation in order to effect control or a cure. Thus, it conforms to the concepts and approaches of pharmacology, toxicology, and therapeutic medicine. Only one function, that which relates the object-oriented and nonstochastic independent variable organ dose to its effect on a cancer or an organ, is needed to estimate the probability, P 2 , of a quantal response. Only P 2 is needed because P 1 , that the cancer slated for such treatment will receive some amount of the agent and be affected to some degree, is effectively unity. The health problem involving low-level exposure (LLE) to radiation, in contrast, is not at all analogous to those of pharmacology, toxicology, and medicine. Rather, it presents a public health problem in that it is a health population, albeit of cells, that is exposed in a radiation field composed of moving radiation particles with some attendant low-order carcinogenic or mutagenic risk. Thus, the concepts, quantities, and terminology applied to low-level radiation must be modified from their present orientation toward pharmacology, toxicology, medicine, and dose to conform to those of public health and accident statistics, in which both P 1 and P 2 for the exposed cells must be estimated

Epidemiology and quantitation of environmental risk in humans from radiation and other agents

International Nuclear Information System (INIS)

Castellani, Amleto

1985-01-01

The identification and quantitation of environmental risk in humans is one of the main problems to be solved in order to improve the protection of individuals and of human populations against physical and chemical pollutants. Epidemiology plays a central role in the evaluation of health risk directly in human populations. In this volume are collected 33 lectures presented at the AS! course on ''Epidemiology and quantitation of environmental risk in humans from radiation and other agents: potential and limitations'', sponsored by NATO and Italian Association of Radiobiology and organized by ENEA. The course has been devoted to a number of aspects of environmental risk analysis and evaluation based on epidemiological investigation. Basic epidemiological concepts and methods have been reviewed. Fundamentals of dosimetry and microdosimetry were presented in relation to the contribution of epidemiology in defining the dose effect relationships for radiation carcinogenesis and its relation with age, sex and ethnicity. The mechanisms of carcinogenesis as a multi-stage process were illustrated. One of the main topics was 'cancer epidemiology' and its correlation with: - occupational and non-occupational exposure to radiation - diagnostic and therapeutic irradiation - cancer proneness - hereditary and familiar diseases - abnormal response to carcinogens - environmental pollution in air and water - exposure to radon in mines and in building material - atomic bomb explosion - chemotherapy - dioxin and related compounds

Leisure time activities related to carcinogen exposure and lung cancer risk in never smokers. A case-control study

International Nuclear Information System (INIS)

Ruano-Ravina, Alberto; García-Lavandeira, José Antonio; Torres-Durán, María; Prini-Guadalupe, Luciana; Parente-Lamelas, Isaura; Leiro-Fernández, Virginia; Montero-Martínez, Carmen; González-Barcala, Francisco Javier; Golpe-Gómez, Antonio; Martínez, Cristina; Castro-Añón, Olalla; Mejuto-Martí, María José

2014-01-01

We aim to assess the relationship between leisure time activities related to exposure to carcinogenic substances and lung cancer risk in a hospital-based case-control study performed in never smokers. We included never smoking cases with anatomopathologically confirmed lung cancer and never smoking controls undergoing trivial surgery, at 8 Spanish hospitals. The study was conducted between January 2011 and June 2013. Participants were older than 30 and had no previous neoplasms. All were personally interviewed focusing on lifestyle, environmental tobacco smoke exposure, occupational history and leisure time activities (including duration of such activities). Results were analyzed through logistic regression and adjusted also by residential radon and education level. We included 513 never smokers, 191 cases and 322 controls. The OR for those performing the studied leisure time activities was 1.43 (95%CI 0.78–2.61). When we restricted the analysis to those performing do-it-yourself activities for more than 10 years the OR was 2.21 (95%CI 0.93–5.27). Environmental tobacco smoke exposure did not modify this association. The effect for the different lung cancer histological types was very close to significance for adenocarcinoma but only when these activities were performed for more than 10 years. We encourage health professionals to recommend protective measures for those individuals while performing these hobbies to reduce the risk of lung cancer. - Highlights: • Some leisure time activities are associated with the exposure to carcinogenic substances. • These activities are model-making, painting (artistic or not), furniture refinishing or wood working. • Few studies have assessed lung cancer risk due to these hobbies and none in never-smokers. • Leisure activities related to exposure to carcinogenic substances present higher lung cancer risk. • The risk is higher when these activities are performed for more than 10 years

Leisure time activities related to carcinogen exposure and lung cancer risk in never smokers. A case-control study

Energy Technology Data Exchange (ETDEWEB)

Ruano-Ravina, Alberto, E-mail: alberto.ruano@usc.es [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); CIBER de Epidemiología y Salud Pública CIBERESP, Barcelona (Spain); García-Lavandeira, José Antonio [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); Department of Preventive Medicine, A Coruña University Hospital Complex, Coruña (Spain); Torres-Durán, María [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); Service of Neumology, University Hospital Complex of Vigo, Vigo (Spain); Prini-Guadalupe, Luciana [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); Parente-Lamelas, Isaura [Service of Neumology, Ourense Hospital Complex, Ourense (Spain); Leiro-Fernández, Virginia [Service of Neumology, University Hospital Complex of Vigo, Vigo (Spain); Montero-Martínez, Carmen [Service of Neumology, University Hospital Complex of A Coruña, Coruña (Spain); González-Barcala, Francisco Javier; Golpe-Gómez, Antonio [Service of Neumology, Santiago de Compostela University Clinic Hospital, Santiago de Compostela (Spain); Martínez, Cristina [National Institute of Silicosis, University Hospital of Asturias, Oviedo, Asturias (Spain); Castro-Añón, Olalla [Service of Neumology, Hospital Lucus Augusti, Lugo (Spain); Mejuto-Martí, María José [Service of Neumology, Hospital Arquitecto Marcide, Ferrol (Spain); and others

2014-07-15

We aim to assess the relationship between leisure time activities related to exposure to carcinogenic substances and lung cancer risk in a hospital-based case-control study performed in never smokers. We included never smoking cases with anatomopathologically confirmed lung cancer and never smoking controls undergoing trivial surgery, at 8 Spanish hospitals. The study was conducted between January 2011 and June 2013. Participants were older than 30 and had no previous neoplasms. All were personally interviewed focusing on lifestyle, environmental tobacco smoke exposure, occupational history and leisure time activities (including duration of such activities). Results were analyzed through logistic regression and adjusted also by residential radon and education level. We included 513 never smokers, 191 cases and 322 controls. The OR for those performing the studied leisure time activities was 1.43 (95%CI 0.78–2.61). When we restricted the analysis to those performing do-it-yourself activities for more than 10 years the OR was 2.21 (95%CI 0.93–5.27). Environmental tobacco smoke exposure did not modify this association. The effect for the different lung cancer histological types was very close to significance for adenocarcinoma but only when these activities were performed for more than 10 years. We encourage health professionals to recommend protective measures for those individuals while performing these hobbies to reduce the risk of lung cancer. - Highlights: • Some leisure time activities are associated with the exposure to carcinogenic substances. • These activities are model-making, painting (artistic or not), furniture refinishing or wood working. • Few studies have assessed lung cancer risk due to these hobbies and none in never-smokers. • Leisure activities related to exposure to carcinogenic substances present higher lung cancer risk. • The risk is higher when these activities are performed for more than 10 years.

Workshop on problem areas associated with developing carcinogen guidelines

Energy Technology Data Exchange (ETDEWEB)

1984-06-01

A workshop was conducted to discuss problem areas associated with developing carcinogen guidelines. Session topics included (1) definition of a carcinogen for regulatory purposes; (2) potency; (3) risk assessment; (4) uncertainties; (5) de minimis quantity; and (6) legal and regulatory issues. Separate abstracts have been prepared for individual papers. (ACR)

Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

International Nuclear Information System (INIS)

Fabrikant, J.I.

1981-05-01

The current knowledge of the carcinogenic effect of radiation in man is considered. The discussion is restricted to dose-incidence data in humans, particularly to certain of those epidemiological studies of human populations that are used most frequently for risk estimation for low-dose radiation carcinogenesis in man. Emphasis is placed solely on those surveys concerned with nuclear explosions and medical exposures

Impact of occupational carcinogens on lung cancer risk in a general population

NARCIS (Netherlands)

De Matteis, S.; Consonni, D.; Lubin, J.H.; Tucker, M.; Peters, S.; Vermeulen, R.; Kromhout, H.; Bertazzi, P.A.; Caporaso, N.E.; Pesatori, A.C.; Wacholder, S.; Landi, M.T.

2012-01-01

BACKGROUND: Exposure to occupational carcinogens is an important preventable cause of lung cancer. Most of the previous studies were in highly exposed industrial cohorts. Our aim was to quantify lung cancer burden attributable to occupational carcinogens in a general population. METHODS: We applied

Carcinogen susceptibility is regulated by genome architecture and predicts cancer mutagenesis.

Science.gov (United States)

García-Nieto, Pablo E; Schwartz, Erin K; King, Devin A; Paulsen, Jonas; Collas, Philippe; Herrera, Rafael E; Morrison, Ashby J

2017-10-02

The development of many sporadic cancers is directly initiated by carcinogen exposure. Carcinogens induce malignancies by creating DNA lesions (i.e., adducts) that can result in mutations if left unrepaired. Despite this knowledge, there has been remarkably little investigation into the regulation of susceptibility to acquire DNA lesions. In this study, we present the first quantitative human genome-wide map of DNA lesions induced by ultraviolet (UV) radiation, the ubiquitous carcinogen in sunlight that causes skin cancer. Remarkably, the pattern of carcinogen susceptibility across the genome of primary cells significantly reflects mutation frequency in malignant melanoma. Surprisingly, DNase-accessible euchromatin is protected from UV, while lamina-associated heterochromatin at the nuclear periphery is vulnerable. Many cancer driver genes have an intrinsic increase in carcinogen susceptibility, including the BRAF oncogene that has the highest mutation frequency in melanoma. These findings provide a genome-wide snapshot of DNA injuries at the earliest stage of carcinogenesis. Furthermore, they identify carcinogen susceptibility as an origin of genome instability that is regulated by nuclear architecture and mirrors mutagenesis in cancer. © 2017 The Authors.

On ionising radiation and breast cancer risk

Energy Technology Data Exchange (ETDEWEB)

Mattson, Anders

1999-05-01

A cohort of 3,090 women with clinical diagnosis of benign breast disease (BBD) was studied. Of these, 1,216 were treated with radiation therapy during 1925-54 (median age 40 years). The mean dose to the breasts was 5.8 Gy (range 0-50 Gy). Among other organs the lung received the highest scattered dose (0.75 Gy; range 0.004-8.98 Gy) and the rectum the lowest (0.008 Gy; range 0-0.06 Gy). A pooled analysis of eight breast cancer incidence cohorts was done, including: tumour registry data on breast cancer incidence among women in the Life Span Study cohort of atomic bomb survivors; women in Massachusetts who received repeated chest fluoroscopic during lung collapse treatment for tuberculosis; women who received x-ray therapy for acute post-partum mastitis; women who were irradiated in infancy for enlarged thymus glands ; two Swedish cohorts of women who received radiation treatments during infancy for skin hemangioma; and the BBD cohort. Together the cohorts included almost 78,000 women (-35,000 were exposed), around 1.8 million woman-years and 1500 cases. The breast cancer incidence rate as a function of breast dose was analysed using linear-quadratic Poisson regression models. Cell-killing effects and other modifying effects were incorporated through additional log-linear terms. Additive (EAR) and multiplicative (ERR) models were compared in estimating the age-at-exposure patterns and time related excess. The carcinogenic risks associated with radiation in mammographic mass screening is evaluated. Assessment was made in terms of breast cancer mortality and years of life. Effects were related to rates not influenced by a mammographic mass screening program and based on a hypothetical cohort of 100,000 40-year old women with no history of breast cancer being followed to 100 years of age. Two radiation risk assumptions were compared. The dose-response relationship is linear with little support in data for an upward curvature at low to medium doses. The competing effect

On ionising radiation and breast cancer risk

International Nuclear Information System (INIS)

Mattson, Anders

1999-01-01

A cohort of 3,090 women with clinical diagnosis of benign breast disease (BBD) was studied. Of these, 1,216 were treated with radiation therapy during 1925-54 (median age 40 years). The mean dose to the breasts was 5.8 Gy (range 0-50 Gy). Among other organs the lung received the highest scattered dose (0.75 Gy; range 0.004-8.98 Gy) and the rectum the lowest (0.008 Gy; range 0-0.06 Gy). A pooled analysis of eight breast cancer incidence cohorts was done, including: tumour registry data on breast cancer incidence among women in the Life Span Study cohort of atomic bomb survivors; women in Massachusetts who received repeated chest fluoroscopic during lung collapse treatment for tuberculosis; women who received x-ray therapy for acute post-partum mastitis; women who were irradiated in infancy for enlarged thymus glands ; two Swedish cohorts of women who received radiation treatments during infancy for skin hemangioma; and the BBD) cohort. Together the cohorts included almost 78,000 women (-35,000 were exposed), around 1.8 million woman-years and 1500 cases. The breast cancer incidence rate as a function of breast dose was analysed using linear-quadratic Poisson regression models. Cell-killing effects and other modifying effects were incorporated through additional log-linear terms. Additive (EAR) and multiplicative (ERR) models were compared in estimating the age-at-exposure patterns and time related excess. The carcinogenic risks associated with radiation in mammographic mass screening is evaluated. Assessment was made in terms of breast cancer mortality and years of life. Effects were related to rates not influenced by a mammographic mass screening program and based on a hypothetical cohort of 100,000 40-year old women with no history of breast cancer being followed to 100 years of age. Two radiation risk assumptions were compared. The dose-response relationship is linear with little support in data for an upward curvature at low to medium doses. The competing effect

''Risk versus benefit'' for diagnostic X-rays and radionuclides

International Nuclear Information System (INIS)

Uzunov, I.

1975-01-01

In the fifties, when a radiation protection program in medicine was initiated in the country, permissible population exposure standards were based solely on genetic risk, and medical irradiations were excluded from these standards. It is currently thought, however, that somatic-stochastic consequences of the carcinogenic effect of ionizing radiations are commensurable with genetic lesions. Since carcinogenic risk is determined by organ dose, it is much higher than the genetic risk in most X-ray and radionuclide examinations. Furthermore, the majority of authors feel that medical radiation should be included in total maximum permissible population dose (5 rem up to 30 years of age). Taking into consideration that over 95% of population exposure in the following decades is expected to result from medical radiation, and that the risk of induction of malignancies cannot be taken to be ''negligible'' even at an exposure level of the order of natural background, it is evident that in any specific case where radiation is to be applied, ''risk vs. benefit'' should be appraised with adequate precision. This will necessitate a thorough revision of problems involving patient protection, particularly so since shortcomings in this respect have lately been brought to light (for instance, cardiac catheterization or roentgenoscopic examination for expertise purposes), unmotivated mass screening tests, etc.), such cases occurring mostly because of unsatisfactory regulatory activities, especially as regards use of X-rays by non-radiologists. The paper discusses carcinogenic risk for a number of specific procedure types and stresses the need for a symposium on radiation protection in medical practice, with participation of physicians employed in areas of medicine relevant to X-ray and radionuclide diagnostics, in order to arrive at reasonable decisions enabling the achievement of a drastic reduction in population exposure. (author)

Carcinogenic effects of ionizing radiation administered at perinatal stage of mice

International Nuclear Information System (INIS)

Sasaki, Shunsaku; Sato, Fumiaki; Kasuga, Takeshi; Kawashima, Naoyuki

1978-01-01

Mice of F 1 hybrids of (C57BL/6 x WHT) strains (B6WF 1 ) were exposed to 200 kVp x-rays at the late fetal stage (17 days postcoitum, 150 R, 300 R), the neonatal stage (0 - 24 hr postpartum, 400 R) or the juvenile stage (5-week-old, 400 R). Mice were allowed to live through their life span, and incidences of various tumors were compared with those of the unirradiated control mice. Characteristics of each of the ages concerning radiation-induced carcinogenesis have been revealed as follows. The late fetal stage: This stage of mice was shown to have a susceptibility to carcinogenic action of x-rays, which was not so high and was restricted to several organs and tissues. Pituitary tumors, pulmonary tumors and hepatocellular tumors developed in excess, but lympho-reticular tissue tumors and myeloid leukemias were not induced by x-irradiation at the late fetal stage. The neonatal stage: X-irradiation to the neonatal mice resulted in enhancement of incidences of various tumors such as thymic lymphomas, hepatocellular tumors, pituitary tumors, ovarian tumors and Harderian gland tumors. Expecially, hepatocellular tumors developed at a very high incidence. The juvenile stage: Incidences of ovarian tumors and Harderian gland tumors were higher in mice irradiated at the juvenile stage than those irradiated at the younger age. These results lead to a conclusion that the age-dependency of susceptibility to radiation-induced carcinogenesis differs with organs and tissues. (author)

Diagnostic radiation risks

Energy Technology Data Exchange (ETDEWEB)

Sherwood, T [Addenbrooke' s Hospital, Cambridge (UK)

1980-04-01

A brief discussion on diagnostic radiation risks is given. First some fundamental facts on the concepts and units of radiation measurement are clarified. Medical diagnostic radiation doses are also compared to the radiation doses received annually by man from natural background radiation. The controversy concerning the '10-day rule' in X-raying women of child-bearing age is discussed; it would appear that the risk of malformation in an unborn child due to X-radiation is very much less than the natural level of risk of malformation. The differences in the radiographic techniques and thus the different X-ray doses needed to make adequate X-ray images of different parts of the body are considered. The radiation burden of nuclear medicine investigations compared to X-ray procedures is also discussed. Finally, the problems of using volunteers in radiation research are aired.

Identifying occupational carcinogens: an update from the IARC Monographs.

Science.gov (United States)

Loomis, Dana; Guha, Neela; Hall, Amy L; Straif, Kurt

2018-05-16

The recognition of occupational carcinogens is important for primary prevention, compensation and surveillance of exposed workers, as well as identifying causes of cancer in the general population. This study updates previously published lists of known occupational carcinogens while providing additional information on cancer type, exposure scenarios and routes, and discussing trends in the identification of carcinogens over time. Data were extracted from International Agency for Research on Cancer (IARC) Monographs covering the years 1971-2017, using specific criteria to ensure occupational relevance and provide high confidence in the causality of observed exposure-disease associations. Selected agents were substances, mixtures or types of radiation classified in IARC Group 1 with 'sufficient evidence of carcinogenicity' in humans from studies of exposed workers and evidence of occupational exposure documented in the pertinent monograph. The number of known occupational carcinogens has increased over time: 47 agents were identified as known occupational carcinogens in 2017 compared with 28 in 2004. These estimates are conservative and likely underestimate the number of carcinogenic agents present in workplaces. Exposure to these agents causes a wide range of cancers; cancers of the lung and other respiratory sites, followed by skin, account for the largest proportion. The dominant routes of exposure are inhalation and dermal contact. Important progress has been made in identifying occupational carcinogens; nevertheless, there is an ongoing need for research on the causes of work-related cancer. Most workplace exposures have not been evaluated for their carcinogenic potential due to inadequate epidemiologic evidence and a paucity of quantitative exposure data. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

OVERVIEW OF DRINKING WATER MUTAGENICITY AND CARCINOGENICITY AND RISK FOR BLADDER CANCER

Science.gov (United States)

Among the 11 disinfection by-products (DBPs) in drinking water that are regulated by the U.S. EPA, (a) 2 DBPs (chloroacetic acid and chlorite) are not carcinogenic-in either of 2 species; (b) chlorite is not carcinogenic in 3 rodent assays and has never been tested for genotoxici...

What physicians think about the need for informed consent for communicating the risk of cancer from low-dose radiation

International Nuclear Information System (INIS)

Karsli, Tijen; Kalra, Mannudeep K.; Self, Julie L.; Rosenfeld, Jason Anders; Butler, Susan; Simoneaux, Stephen

2009-01-01

The National Institute of Environmental Health Sciences, a subsidiary of the Food and Drug Administration, has declared that X-ray radiation at low doses is a human carcinogen. The purpose of our study was to determine if informed consent should be obtained for communicating the risk of radiation-induced cancer from radiation-based imaging. Institutional review board approval was obtained for the prospective survey of 456 physicians affiliated with three tertiary hospitals by means of a written questionnaire. Physicians were asked to state their subspecialty, number of years in practice, frequency of referral for CT scanning, level of awareness about the risk of radiation-induced cancer associated with CT, knowledge of whether such information is provided to patients undergoing CT, and opinions about the need for obtaining informed consent as well as who should provide information about the radiation-induced cancer risk to patients. Physicians were also asked to specify their preference among different formats of informed consent for communicating the potential risk of radiation-induced cancer. Statistical analyses were performed using the chi-squared test. Most physicians stated that informed consent should be obtained from patients undergoing radiation-based imaging (71.3%, 325/456) and the radiology department should provide information about the risk of radiation-induced cancer to these patients (54.6%, 249/456). The informed consent format that most physicians agreed with included modifications to the National Institute of Environmental Health Services report on cancer risk from low-dose radiation (20.2%, 92/456) or included information on the risk of cancer from background radiation compared to that from low-dose radiation (39.5%, 180/456). Most physicians do not know if patients are informed about cancer risk from radiation-based imaging in their institutions. However, they believe that informed consent for communicating the risk of radiation-induced cancer

[Carcinogens exposure risk control: balance and strategies of action within the most emblematic industrial divisions].

Science.gov (United States)

Silvestri, Stefano

2009-01-01

In Italy during the last three decades important changes in employment have occurred. During the '70s, thanks to a variety of factors, the hygiene conditions of work have undergone a process of slow, but gradual improvement, which has not been arrested during the following decades. New legislation, partly deriving from European directives, has been introduced, and processes of outsourcing have moved the most burdensome and pollutants industrial productions to developing countries. Nevertheless, the estimates of the number of exposed (or even potentially so) workers, to carcinogens remain quite high. Currently, in absence of the planned National Information System on Prevention, it is impossible to estimate in how many and which workplaces primary prevention plans and facilities have been already installed. This paper aims to describe the situation related to most occupationally diffused carcinogenic agents: asbestos, wood and crystalline silica dusts, each one for its specificity. It also describes the innovations introduced by the most recent legislation, in particular with regard to the asbestos risk control. Finally, it stresses the need for a reform of the insurance premiums in order to introduce a mechanism for rewarding those employers who implement primary prevention facilities and penalizing those who don't. The economic advantages should gradually cover the cost of risk control technology.

Immunologic methods for monitoring carcinogen exposure

Science.gov (United States)

Santella, Regina M.; Perera, Frederica P.; Zhang, Yu J.; Chen, Chen J.; Young, Tie L.

1993-03-01

Immunologic methods have been developed for monitoring human exposure to environmental and occupational carcinogens. These methods involve the development of monoclonal and polyclonal antisera which specifically recognize the carcinogens themselves or their DNA or protein adducts. Antisera recognizing the DNA adducts of several polycyclic aromatic hydrocarbon diol epoxides have been used in competitive enzyme-linked immunosorbent assays to monitor adducts in tissue or blood samples. Elevated levels of DNA adducts have been seen in mononuclear cells of smokers and in total white blood cells of foundry and coke oven workers. Environmental exposure to PAH has been measured in individuals living in a highly polluted region of Poland. Antisera recognizing PAH-DNA adducts have also been used in immunohistochemical studies to monitor adducts in specific cells of biopsy samples. The DNA adducts of aflatoxin B1 have been monitored in liver tissue of hepatocellular carcinoma patients in Taiwan. Detectable adducts were seen in 50 - 70% of the patients suggesting that dietary exposure to this carcinogen may be a risk factor for cancer induction. Thus, immunoassays for monitoring exposure to carcinogens are an important tool in epidemiologic studies.

Carcinogenicity of methyl-tertiary butyl ether in gasoline.

Science.gov (United States)

Mehlman, Myron A

2002-12-01

Methyl tertiary butyl ether (MTBE) was added to gasoline on a nationwide scale in 1992 without prior testing of adverse, toxic, or carcinogenic effects. Since that time, numerous reports have appeared describing adverse health effects of individuals exposed to MTBE, both from inhalation of fumes in the workplace and while pumping gasoline. Leakage of MTBE, a highly water-soluble compound, from underground storage tanks has led to contamination of the water supply in many areas of the United States. Legislation has been passed by many states to prohibit the addition of MTBE to gasoline. The addition of MTBE to gasoline has not accomplished its stated goal of decreasing air pollution, and it has posed serious health risks to a large portion of the population, particularly the elderly and those with respiratory problems, asthma, and skin sensitivity. Reports of animal studies of carcinogenicity of MTBE began to appear in the 1990s, prior to the widespread introduction of MTBE into gasoline. These reports were largely ignored. In ensuing years, further studies have shown that MTBE causes various types of malignant tumors in mice and rats. The National Toxicology Program (NTP) Board of Scientific Counselors' Report on Carcinogens Subcommittee met in December 1998 to consider listing MTBE as "reasonably anticipated to be a human carcinogen." In spite of recommendations from Dr. Bailer, the primary reviewer, and other scientists on the committee, the motion to list MTBE in the report was defeated by a six to five vote, with one abstention. On the basis of animal studies, it is widely accepted that if a chemical is carcinogenic in appropriate laboratory animal test systems, it must be treated as though it were carcinogenic in humans. In the face of compelling evidence, NTP Committee members who voted not to list MTBE as "reasonably anticipated to be a human carcinogen" did a disservice to the general public; this action may cause needless exposure of many to health risks

Indoor air - assessment: Methods of analysis for environmental carcinogens

International Nuclear Information System (INIS)

Peterson, M.R.; Naugle, D.F.; Berry, M.A.

1990-06-01

The monograph describes, in a general way, published sampling procedures and analytical approaches for known and suspected carcinogens. The primary focus is upon carcinogens found in indoor air, although the methods described are applicable to other media or environments. In cases where there are no published methods for a particular pollutant in indoor air, methods developed for the workplace and for ambient air are included since they should be adaptable to indoor air. Known and suspected carcinogens have been grouped into six categories for the purposes of this and related work. The categories are radon, asbestos, organic compounds, inorganic species, particles, and non-ionizing radiation. Some methods of assessing exposure that are not specific to any particular pollutant category are covered in a separate section. The report is the fifth in a series of EPA/Environmental Criteria and Assessment Office Monographs

Ecological risk assessment and carcinogen health risk assessment of arsenic in soils from part area of the Daye City, China

Science.gov (United States)

Li, F.; Wang, T.; Xiao, M. S.; Cai, Y.; Zhuang, Z. Y.

2018-01-01

Soils in four sampling sites from part area of the Daye City were collected. Concentrations of arsenic (As) in soils in sampling sites were detected by Atomic Fluorescence Spectrometry, ecological risk was calculated by potential ecological risk index (RI) and human health risk was measured by human health risk assessment model established by USEPA. The results showed that, the total content of As in soils in Daye was decreased in the order of S4 (66.58 mg/kg)>S2 (44.73 mg/kg)>S3 (34.86 mg/kg) >S1 (21.84 mg/kg), concentrations in all sampling sites were higher than background values of Hubei Province. The potential risk and human health risk were decreased in the order of S4>S2>S3>S1 and S4>S3>S2>S1, respectively. Specially, S1, S2 and S3 were at low potential ecological risk while S4 was at moderate ecological risk. But there was no carcinogenic risk for human exposure to As in soil in Daye.

Food derived carcinogenic amnoimidazoazaarenes

DEFF Research Database (Denmark)

Frandsen, Henrik

Carcinogenic aminoimidazoazaarenes are formed during cooking of meat and fish. Important factors for the formation of these compounds are meat type, cooking temperature and time. The compounds are genotoxic in bacterial and mammalian cells. In animal feeding studies the compounds tested so far were...... of the exocyclic amino group. Estimations of human cancer risk have indicated that ingestion of food containing aminoimidazoazaarenes are of importance....

The carcinogenic effects of fetal and postnatal radiation in female mice

International Nuclear Information System (INIS)

Kusama, Tomoko; Yoshizawa, Yasuo

1982-01-01

The present study was designed to investigate the carcinogenic effects of fetal and postnatal irradiation in female mice. The C57BL/6J mice were subjected to whole-body exposure to 1-Gy or 4-Gy 137 Cs γ-ray irradiation on the 15th fetal day or the 30th postnatal day. Following this, all mice were observed throughout their respective life spans under conventional rearing conditions. The tumor incidence rate, average latent period and distributions of various tumors were used as the quantitative parameters of radiation-induced carcinogenesis. The following conclusions can be draw: (1) The mean life span of mice that underwent 4-Gy irradiation at the age of 30 days was shorter than that of non-irradiated control mice. (2) In control mice, the tumor incidence was 75.7%. (3) In order to estimate the mean age and tumor incidence, an adjustment for competing death is necessary. (4) The adjusted tumor incidences of thymic lymphoma and breast tumor of the irradiated groups were not different from those of control group. On the other hand, there was a significant difference between the two in the adjusted incidence of reticular tissue neoplasm. (author)

Enhanced replication of UV-damaged Simian virus 40 DNA in carcinogen-treated mammalian cells

International Nuclear Information System (INIS)

Maga, J.A.

1983-01-01

The replication of UV-damaged Simian virus 40 (SV40) in carcinogen-treated monkey cells has been studied to elucidate the mechanism of carcinogen-enhanced reactivation. Carcinogen enhanced reactivation is the observed increase in UV-irradiated virus survival in host cells treated with low doses of carcinogen compared to UV-irradiated virus survival in untreated hosts. Carcinogen treatment of monkey kidney cells with either N-acetoxy-2-acetylaminofluorene (AAAF) or UV radiation leads to an enhanced capacity to replicate UV-damaged virus during the first round of infection. To further define the mechanism leading to enhanced replication, a detailed biochemical analysis of replication intermediates in carcinogen-treated cells was performed. Several conclusions can be drawn. First enhanced replication can be observed in the first four rounds of replication after UV irradiation of viral templates. The second major finding is that the relaxed circular intermediate model proposed for the replication of UV-damaged templates in untreated cells appears valid for replication of UV-damaged templates in carcinogen-treated cells. Possible mechanisms and the supporting evidence are discussed and future experiments outlined

Ultraviolet radiation and immunosuppression.

LENUS (Irish Health Repository)

Murphy, G M

2009-11-01

Ultraviolet (UV) radiation is a complete carcinogen. The effects of UV radiation are mediated via direct damage to cellular DNA in the skin and suppression of image surveillance mechanisms. In the context of organ transplantation, addiction of drugs which suppress the immune system add greatly to the carcinogenicity of UV radiation. This review considers the mechanisms of such effects.

Radiation and risk

International Nuclear Information System (INIS)

Jacobi, W.

1983-01-01

From the beginnings of the peaceful utilization of nuclear energy, the principles of prevention and optimization have greatly limited the emission of radioactive substances. In this way, the radiation exposure associated with emissions from nuclear power plants during normal operation has been kept low compared with natural radiation exposure and its variance. This also applies to the local public in the vicinities of such plants. The present health hazard to the public arising from ionizing radiation is only a small fraction of the man-made risk to which the public is exposed in this country. This is also due to the fact that radiation protection employs the principle of prevention, which has been laid down in legal regulations. In this respect, the concepts and criteria developed in radiation protection for evaluation, limitation and optimization may be useful examples to other areas of safety at work and environmental protection. The acceptance of nuclear power is decisively influenced by the remaining residual risk of accidents. Extremely careful inspection and supervision of the technical safety of such plants is indispensable to prevent major accidents. The German Risk Study for Nuclear Power Plants has made an important contribution to this end. It is being continued. However, risk research must always be accompanied by risk comparison to allow numerical risk data to be evaluated properly and important features to be distinguished from unimportant ones. (orig.) [de

Genotoxic and carcinogenic risks associated with the dietary consumption of repeatedly heated coconut oil.

Science.gov (United States)

Srivastava, Smita; Singh, Madhulika; George, Jasmine; Bhui, Kulpreet; Murari Saxena, Anand; Shukla, Yogeshwer

2010-11-01

Repeated heating of vegetable oils at high temperatures during cooking is a very common cooking practice. Repeated heating of edible oils can generate a number of compounds, including polycyclic aromatic hydrocarbons (PAH), some of which have been reported to have carcinogenic potential. Consumption of these repeatedly heated oils can pose a serious health hazard. The objectives of the present study were to evaluate the genotoxic and carcinogenic risks associated with the consumption of repeatedly heated coconut oil (RCO), which is one of the commonly consumed cooking and frying medium. The PAH were analysed using HPLC in fresh CO, single-heated CO (SCO) and RCO. Results revealed the presence of certain PAH, known to possess carcinogenic potential, in RCO when compared with SCO. Oral intake of RCO in Wistar rats resulted in a significant induction of aberrant cells (P<0·05) and micronuclei (P<0·05) in a dose-dependent manner. Oxidative stress analysis showed a significant (P<0·05) decrease in the levels of antioxidant enzymes such as superoxide dismutase and catalase with a concurrent increase in reactive oxygen species and lipid peroxidation in the liver. In addition, RCO given alone and along with diethylnitrosamine for 12 weeks induced altered hepatic foci as noticed by alteration in positive (γ-glutamyl transpeptidase and glutathione-S-transferase) and negative (adenosine triphosphatase, alkaline phosphatase and glucose-6-phosphatase) hepatospecific biomarkers. A significant decrease in the relative and absolute hepatic weight of RCO-supplemented rats was recorded (P<0·05). In conclusion, dietary consumption of RCO can cause a genotoxic and preneoplastic change in the liver.

Risk of cancer formation by radiotherapy

International Nuclear Information System (INIS)

Fuji, Hiroshi

2011-01-01

Described are the difference between exposures to radiation for medical purpose and to environmental radiation at low dose, estimation of carcinogenic risk by medical radiation, and notice for referring the risk at clinical practice. ICRP employs linear non-threshold (LNT) model for risk of cancer formation even at <200 mSv for safety, with a recognition that it is scientifically obscure. The model essentially stands on data of A-bomb survivors (the Gold Standard), where the relationship between 5-10% excess relative risk (ERR) of cancer formation and dose 0.05-2.5 Sv is linear. Analyses of the secondary carcinogenesis after radiotherapy have begun to be reported since around 2005: e.g., the secondary thyroid cancer risk in pediatric patients treated with radiotherapy has a peak at 20 Gy, suggesting the actual risk depends both on the linearity of carcinogenic increase and on the exponential probability of cell death increase. On this concept, the risk of cancer formation is not always linear to dose. At the practical radiotherapy, its secondary carcinogenic risk should be estimated not only on the dose but also on other factors such as the individual organ, patient's age and attainable age/time after the treatment. In treated teen-ager patients, ERRs of mortality/Gy are 2.28 for cancers of the skin of non-malignant melanoma, 1.32 of bladder and 1.21 of thyroid and in patients of fifties, 1.15 of bladder and lung. The EER tends to become lower as the treated age is older. Pediatric cancer patients to be treated with radiotherapy should be informed about the secondary cancer that the low dose risk given by ICRP is not always appropriate, a certain cancer risk has a peak dose, and ERR of cancer mortality is not a cancer risk of an organ. Many factors like anticancers and immuno-modifiers, modify the outcome of radiotherapy and should be carefully speculated for evaluating the outcome. (T.T.)

Ionizing radiation from tobacco

International Nuclear Information System (INIS)

Westin, J.B.

1987-01-01

Accidents at nuclear power facilities seem inevitably to bring in their wake a great deal of concern on the part of both the lay and medical communities. Relatively little attention, however, is given to what may be the largest single worldwide source of effectively carcinogenic ionizing radiation: tobacco. The risk of cancer deaths from the Chernobyl disaster are tobacco smoke is discussed

Carcinogenic and antitumor effects of aminotriazole on acatalasemic and normal catalase mice

International Nuclear Information System (INIS)

Feinstein, R.N.; Fry, R.J.M.; Staffeidt, E.F.

1978-01-01

Dietary 3-amino-1H-1,2,4-triazole (AT), although carcinogenic when administered alone, was an antitumor agent when combined with certain other carcinogenic stimuli. The carcinogenic effect was prominent in the livers of C3H mice; thyroid tumors were less common because they required a longer period of development, and the life-span of the animal was shortened by the AT diet. The antitumor effects of AT included: delay in appearance of mammary tumors, striking reduction in γ-radiation-induced lymphomas, and sharp reduction in neutron radiation-induced harderian gland and ovarian tumors. On an AT diet, the inbred C3H acatalasemic mouse substrain developed more liver tumors, starting earlier, than did the C3H normal catalase substrain. We suggest that our findings pointed to a possible relevance of catalase and H 2 O 2 in carcinogenesis. The most probable mechanism for the increased incidence of liver tumors in AT-treated acatalasemic mice was the diminished rate of degradation of endogenous H 2 O 2

Genetic instability model for cancer risk in A-bomb survivors

International Nuclear Information System (INIS)

Niwa, Ohtsura

1998-01-01

This review was written rather against Mendelsohn's reductionist model for cancer risk in A-bomb survivors in following chapters. Assumptions for carcinogenic process: mutation of a cell to the cancer cell and its proliferation. Multi-step theory for carcinogenesis and age of crisis: induction of cancer by accumulation of cancer-related gene mutations which being linear to time (age). Effect of exogenous hit in the multi-step theory: radiation as an exogenous hit to damage DNA. Dose-effect relationship for cancer risk in the survivors and the problem for the latent period: for solid tumors, dose-effect relationship is linear and shortening of the latent period is not observed. Considerations on cancer data in adulthood exposure/Indirect effect model in radiation carcinogenesis: solid cancer data supporting the indirect effect model. Possible mechanism for radiation-induced long-term increase of natural mutation frequency: genetic instability remaining in the irradiated cells which being a basis of the indirect effect model. Notes for considerations of carcinogenicity in exposed people/Difference in carcinogenic mechanisms due to age. The author concluded that the radiation-induced carcinogenesis is deeply related with the natural carcinogenesis and particularly for solid cancers, it can not be explained by the classic reductionist model. (K.H.)

Radiation exposures: risks and realities

International Nuclear Information System (INIS)

Ganesh, G.

2010-01-01

Discovery of radioactivity in 1869 by Henry Becquerel and artificial radioactivity by Irene Curie in 1934 led to the development of nuclear field and nuclear materials in 20th century. They are widely used for man-kind across the globe in electricity production, carbon dating, treatment and diagnosis of diseases etc. While deriving benefits and utilizing nuclear resources for the benefit of man-kind, it is inevitable that exposure to radiation can not be avoided. Radiation exists all around us either natural or man-made which can not be totally eliminated or avoided. Radiation exposures from natural background contribute 2.4 to 3.6 mSv in a year. Radiation exposures incurred by a member of public due to nuclear industries constitute less than one hundredth of annual dose due to natural background. Hence it is important to understand the risk posed by radiation and comparison of radiation risk with various risks arising due to other sources. Studies have indicated that risks due to environmental pollution, cigarette smoking, alcohol consumption, heart diseases are far higher in magnitude compared to radiation risks from man made sources. This paper brings about the details and awareness regarding radiation exposures, radiation risk, various risks associated with other industries and benefits of radiation exposures. (author)

Carcinogenic and mutagenic properties of chemicals in drinking water

Energy Technology Data Exchange (ETDEWEB)

Bull, R J

1985-12-01

Isolated cases of careless handling of industrial and domestic waste has lead to a wide variety of dangerous chemicals being inadvertently introduced into drinking water. However, chemicals with established carcinogenic and mutagenic properties that occur with a high frequency and in multiple locations are limited in number. To date, the chief offenders have been chemicals of relatively low carcinogenic potency. Some of the more common chemicals are formed as by-products of disinfection. The latter process is generally regarded as essential to the production of a ''microbiologically safe'' drinking water. Consequently, any reductions in what may be a relatively small carcinogenic risk must be balanced against a potential for a higher frequency of waterborne infectious disease. The results of recent toxicological investigations will be reviewed to place the potential carcinogenic and mutagenic hazards frequently associated with drinking water into perspective. First, evidence for the carcinogenicity of certain volatile organic compounds such as trichloroethylene, tetrachloroethylene and carbon tetrachloride is considered. Second, the carcinogenic activity that can be ascribed to various by-products of chlorination is reviewed in some detail. Finally, recent evidence that other chemicals derived from the treatment and distribution of drinking water is highlighted as an area requiring move systematic attention. 72 references.

Radiation risks in pregnancy

International Nuclear Information System (INIS)

Mossman, K.L.; Hill, L.T.

1982-01-01

A major contraindication of radiodiagnostic procedures is pregnancy. Approximately 1% of all pregnant women are given abdominal x-rays during the first trimester of pregnancy. Evaluation of radiation exposure should involve consideration of the types of examinations performed and when performed, as well as radiation dose and risk estimation. This information is then weighed against other possible risks of the pregnancy as well as personal factors. In the authors' experiences, radiation exposures usually result in doses to the embryo of less than 5 cGy (rad); the resulting radiation risks are usually small compared with other risks of pregnancy. Procedures to minimize diagnostic x-ray exposure of the fetus are also discussed

Carcinogenic risk of chromium, copper and arsenic in CCA-treated wood

International Nuclear Information System (INIS)

Ohgami, Nobutaka; Yamanoshita, Osamu; Thang, Nguyen Dinh; Yajima, Ichiro; Nakano, Chihiro; Wenting, Wu; Ohnuma, Shoko

2015-01-01

We showed that 2.1% of 233 pieces of lumber debris after the Great East Japan Earthquake was chromated copper arsenate (CCA)-treated wood. Since hexavalent chromium (Cr), copper (Cu) and pentavalent arsenic (As) in the debris may be diffused in the air via incineration, we exposed human lung normal (BEAS-2B) and carcinoma (A549) cells to Cr, Cu and As at the molar ratio in a representative CCA-treated wood. Co-exposure to 0.10 μM Cr and 0.06 μM As, which solely had no effect on colony formation, synergistically promoted colony formation in BEAS-2B cells, but not A549 cells, with activation of the PI3K/AKT pathway. Sole exposure and co-exposure to Cu showed limited effects. Since previous reports showed Cr and As concentrations to which human lungs might be exposed, our results suggest the importance to avoid diffusion of Cr and As in the air via incineration of debris including CCA-treated wood after the disaster. - Highlights: • CCA-treated wood was found in debris after the Great East Japan Earthquake in 2011. • Carcinogenic risk of CCA-treated woods was evaluated with human lung cell lines. • Co-exposure to Cr and As synergistically promoted colony formation. • Co-exposure to Cr and As synergistically activated the PI3/AKT pathway. • Effects of sole exposure and co-exposure to Cu on colony formation were limited. - Co-exposure to Cr and As, but not Cu, in CCA-treated wood debris from the Great East Japan Earthquake showed carcinogenicity in vitro.

Risks for radiation workers

International Nuclear Information System (INIS)

Rotblat, J.

1978-01-01

The following topics are discussed: recommendations of the International Commission on Radiological Protection; methods for determining dose limits to workers; use of data from survivors of Hiroshima and Nagasaki for estimating risk factors; use of data from survivors of nuclear explosions in Marshall Islands, uranium miners, and patients exposed to diagnostic and therapeutic radiation; risk factors for radioinduced malignancies; evidence that risk factors for persons exposed to partial-body radiation and Japanese survivors are too low; greater resistance of A-bomb survivors to radiation; and radiation doses received by U.K. medical workers and by U.K. fuel reprocessing workers. It is suggested that the dose limit for radiation workers should be reduced by a factor of 5

Science, politics, and health in the brave new world of pharmaceutical carcinogenic risk assessment: technical progress or cycle of regulatory capture?

Science.gov (United States)

Abraham, John; Ballinger, Rachel

2012-10-01

The carcinogenicity (cancer-inducing potential) of pharmaceuticals is an important risk factor for health when considering whether thousands of patients on drug trials or millions/billions of consumers in the marketplace should be exposed to a new drug. Drawing on fieldwork involving over 50 interviews and documentary research spanning 2002-2010 in Europe and the US, and on regulatory capture theory, this article investigates how the techno-regulatory standards for carcinogenicity testing of pharmaceuticals have altered since 1998. It focuses on the replacement of long-term carcinogenicity tests in rodents (especially mice) with shorter-term tests involving genetically-engineered mice (GEM). Based on evidence regarding financial/organizational control, methodological design, and interpretation of the validation and application of these new GEM tests, it is argued that regulatory agencies permitted the drug industry to shape such validation and application in ways that prioritized commercial interests over the need to protect public health. Boundary-work enabling industry scientists to define some standards of public-health policy facilitated such capture. However, as the scientific credibility of GEM tests as tools to protect public health by screening out carcinogens became inescapably problematic, a regulatory resurgence, impelled by reputational concerns, exercised more control over industry's construction and use of the tests, The extensive problems with GEM tests as public-health protective regulatory science raises the spectre that alterations to pharmaceutical carcinogenicity-testing standards since the 1990s may have been boundary-work in which the political project of decreasing the chance that companies' products are defined as carcinogenic has masqueraded as techno-science. Copyright © 2012. Published by Elsevier Ltd.

Comparison of the dose-effect relationship for UV radiation and ionizing radiation

International Nuclear Information System (INIS)

Leenhouts, H.P.; Sijsma, M.J.; Chadwick, K.H.

1990-06-01

Ionizing radiation and ultraviolet radiation (UV) are both physical agents with mutagenic and carcinogenic properties. However, there are some basic differences in the fundamental mechanism of their interaction with biological material that may have consequences for risk assessment. In this paper the dose-effect relationships for gamma radiation and UV at cellular level will be used to demonstrate the different radio-biological effectiveness of both agents. The results will be discussed in the framework of a biophysical model, based on the assumption that DNA doublestranded lesions are crucial for the cytotoxic action. After exposure to ionizing radiation, the lesions are fixed immediately following irradiation, but after UV exposure the lethal lesions are recognized only in the next DNA synthesis phase. The combination of this concept with the mechanism of lesion induction and the possibility of repair, leads to different dose and time relationships for the radiation effects of both agents. The possible consequences for risk assessment at low levels will be discussed. (author). 9 refs.; 5 figs

Perception of low dose radiation risks among radiation researchers in Korea

Science.gov (United States)

Seo, Songwon; Lee, Dalnim; Park, Sunhoo; Jin, Young Woo; Lee, Seung-Sook

2017-01-01

Expert’s risk evaluation of radiation exposure strongly influences the public’s risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts’ radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual’s opinions have often exacerbated the public’s confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years’ research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at risk perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects risk perception of radiation exposure. PMID:28166286

Parental Exposure to Workplace Carcinogens and the Risk of Development of Acute Leukemia in Infants. Case-Control Study.

Science.gov (United States)

Pérez-Saldivar, María Luisa; Fajardo-Gutiérrez, Arturo; Sierra-Ramírez, José Alfredo; Núñez-Villegas, Nancy; Pérez-Lorenzana, Héctor; Dorantes-Acosta, Elisa María; Román-Zepeda, Pedro Francisco; Rodríguez-Zepeda, María Del Carmen; González-Ulivarri, Juana Esther; López-Santiago, Norma; Martínez-Silva, Sofía Irene; Paredes-Aguilera, Rogelio; Velázquez-Aviña, Martha Margarita; Flores-Lujano, Janet; Jiménez-Hernández, Elva; Núñez-Enríquez, Juan Carlos; Bekker-Méndez, Vilma Carolina; Mejía-Aranguré, Juan Manuel

2016-11-01

Occupational exposure of parents to carcinogens is of great interest in the etiology of leukemias. Evidence of the impact of such exposure on infants or small children is scarce. Here we estimated whether occupational exposure of parents to carcinogens could be a risk factor for leukemias in their children. Cases of acute leukemia (AL) in infants ≤24 months old diagnosed in Mexico City (1998-2013) were included in a population-based, case-control study. Each of the 195 cases was matched with at least one healthy child (n = 369). For each of four exposure windows studied, the degree of exposure to carcinogens was determined for both parents by using a validated occupational exposure index. An unconditional logistic regression was carried out. Odds ratios (OR) and the 95% confidence intervals (CI) of the overall occupational exposure for parents during the four exposure windows indicated no association with risk of AL in their children. Pre-conception, the OR by the father 0.77 (0.49-1.21), by the mother 1.03 (0.50-2.11); during pregnancy, father 0.66 (0.38-1.15), mother 1.79 (0.46-6.90); during breastfeeding, father 0.75 (0.43-1.30), mother 0.96 (0.21-4.30); and after birth, father 0.74 (0.45-1.22), mother 0.90 (0.24-3.32). The statistical power of the sample size to identify an OR ≥2 and an exposure of ≥10% among controls was 78%. These data support the idea that parents' occupational exposure during any of the periods studied was not a risk factor contributing to the etiology of AL in infants ≤24 months of age. Copyright © 2016 IMSS. Published by Elsevier Inc. All rights reserved.

Historical background and overview of epidemiological studies on the effects of low-level radiation

International Nuclear Information System (INIS)

Upton, A.C.

1983-01-01

Recognition of the carcinogenic effects of ionizing radiation dates from the early part of this century, when an increased frequency of skin cancer and leukemia was first reported in radiologists. In the interim, systematic epidemiological studies have disclosed additional carcinogenic effects in radiation workers, A-bomb survivors, patients exposed to diagnostic or therapeutic radiation, and other groups. The studies have provided sufficient data on dose-incidence relationships, the distribution of cancer in relation to age at irradiation and time after exposure, and organ-variations in susceptibility to enable attempts at quantitative assessment of the risks of low-level irradiation. Such assessments, although tentative and controversial, have exerted an important influence on developments in radiological protection

Cancer risk as a radiation detriment

International Nuclear Information System (INIS)

Servomaa, A.; Komppa, T.; Servomaa, K.

1992-11-01

Potential radiation detriment means a risk of cancer or other somatic disease, genetic damage of fetal injury. Quantative information about the relation between a radiation dose and cancer risk is needed to enable decision-making in radiation protection. However, assessment of cancer risk by means of the radiation dose is controversial, as epidemiological and biological information about factors affecting the origin of cancers show that risk assessment is imprecise when the radiation dose is used as the only factor. Focusing on radiation risk estimates for breast cancer, lung cancer and leukemia, the report is based on the models given in the Beir V report, on sources of radiation exposure and the uncertainty of risk estimates. Risk estimates are assessed using the relative risk model and the cancer mortality rates in Finland. Cancer incidence and mortality rates for men and women are shown in graphs as a function of age and time. Relative risks are shown as a function of time after exposure and lifetime risks as a function of age at exposure. Uncertainty factors affecting the radiation risk are examined from the point of view of epidemiology and molecular biology. (orig.)

Toxic and carcinogenic agents in dry and moist snuff.

Science.gov (United States)

Hoffmann, D; Adams, J D; Lisk, D; Fisenne, I; Brunnemann, K D

1987-12-01

The oral use of snuff is causatively associated with cancer of the oral cavity. Since most epidemiologic studies to date relate to the long-term use of dry snuff, which has dominated the U.S. smokeless tobacco market in the past, the concentrations of several toxic and carcinogenic agents in the three most popular dry snuff brands have been compared with those in the five most popular moist snuff brands sold in the United States. All eight samples were analyzed for nitrate, alkaloids, polyphenols, volatile carbonyl compounds, lead, cadmium, selenium, and the carcinogenic compounds benzo[a]pyrene (CAS: 50-32-8), polonium-210 (CAS: 13981-52-7), volatile N-nitrosamines (VNAs), N-nitrosodiethanolamine (CAS: 1116-54-7), and the tobacco-specific N-nitrosamines (TSNAs). Most of the snuff brands were rich in nitrate (greater than or equal to 1.5%), total polyphenols (greater than 2%), and in nicotine (greater than or equal to 1.5%), which is the habituating factor in tobacco use. Concentrations of the VNAs were significantly above the permissible limits set for some food products; the concentrations of the TSNAs in both snuff types exceeded the levels of nitrosamines in other consumer products by at least two to three orders of magnitude. The extremely high levels of the TSNAs in snuff have remained unchanged during the last decade and present the major carcinogenic risk factor for the oral use of snuff. Polonium-210 contributes further to the carcinogenic risk associated with snuff. The chemical-analytical data presented in this study do not indicate marked differences in the carcinogenic potential of moist snuff compared to dry snuff.

Radiation toxicology

International Nuclear Information System (INIS)

Fry, R.J.M.; Storer, J.B.; Ullrich, R.L.

1979-01-01

Extensive studies on both human and experimental animal populations have provided information that allow radiation protection standards to be set with greater confidence than for most if not all other carcinogenic agents. Furthermore, both international and national advisory bodies are continually updating the risk estimates and the standards as new information is available. However, it is clear that models are needed that take into account the multistage nature of carcinogenesis. Studies in both ionizing and ultraviolet radiation carcinogenesis are more valuable to the general problem of elucidating the mechanisms involved in cancer than is indicated by the amount of work or support for this field of research

Radiation toxicology

International Nuclear Information System (INIS)

Fry, R.J.M.; Storer, J.B.; Ullrich, R.L.

1979-01-01

The extensive studies on both human and experimental animal populations have provided information that allows radiation protection standards to be set with greater confidence than for most if not all other carcinogenic agents. Furthermore, both international and national advisory bodies are continually updating the risk estimates and the standards as new information is available. However, it is clear that we need models that take into account the multistage nature of carcinogenesis. Studies in both ionizing and ultraviolet radiation carcinogenesis are more valuable to the general problem of elucidating the mechanisms involved in cancer than is indicated by the amount of work or support for this field of research

Usefulness and reliability of available epidemiological study results in assessments of radiation-related risks of cancer. Pt. 4

International Nuclear Information System (INIS)

Martignoni, K.; Elsasser, U.

1990-05-01

Carcinomas occurring in the thyroid gland as a result of radiation generally affect the papillary and, to a slightly lesser extent, follicular parts of this organ, while the available body of evidence hardly gives any indications of anaplastic and medullary neoplasms. Radiation has, however, mostly been associated with multicentric tumours. Among the survivors of the nuclear assaults on Hiroshima and Nagasaki, there are no known cases of anaplastic carcinomas of the thyroid. The papillary carcinoma, which is the prevailing type of neoplasm after radiation exposure, has less malignant potential than the follicular one and is encountered in all age groups. Malignant carcinomas of the thyroid are predominantly found in the middle and high age groups. It was calculated that high Gy doses and dose efficiencies are associated in children with a risk coefficient of 2.5 in 10 4 person-years. This rate is only half as high for adults. Studies performed on relevant cohorts point to latency periods of at least five years. Individuals exposed to radiation are believed to be at a forty-year or even life-long risk of developing cancer. The cancer risk can best be described on the basis of a linear dose-effect relationship. The mortality rate calculated for cancer of the thyroid amounts to approx. 10% of the morbidity rate. The carcinogenic potential of iodine-131 in the thyroid is only one-third as great as that associated with external radiation of high dose efficiency. (orig./MG) [de

Effects of combined exposure of F344 rats to radiation and chronically inhaled cigarette smoke

International Nuclear Information System (INIS)

Finch, G.L.; Nikula, K.J.; Barr, E.B.

1995-01-01

Nuclear workers may be exposed to radiation in various forms, such as low-LET γ-irradiation or α-irradiation from inhaled 239 PuO 2 particles. These workers may then have increased risk for lung cancer compared to the general population. Of additional concern is the possibility that interactions between radiation and other carcinogens may increase the risk of cancer induction, compared to the risks from either type of agent alone. An important and common lung carcinogen is cigarette smoke. The purpose of this project is to better determine the combined effects of chronically inhaled cigarette smoke and either inhaled 239 PuO 2 or external, thoracic X-irradiation on the induction of lung cancer in rats. Histologic and dosimetric evaluations of rats in the CS + 239 PuO 2 study continue, and the study of CS + X rays is beginning

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-01

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

Radiation risk and radiation protection concepts

International Nuclear Information System (INIS)

Doerschel, B.

1989-01-01

The revised dosimetry for the survivors of Hiroshima and Nagasaki implies an increased risk from low LET radiation compared with that currently used. During its meeting in 1987 the ICRP stated that the new data at present do not require any change in the dose limits. However, two other factors can cause larger changes in the present risk estimates. Firstly, for some types of cancer the relative risk model seems to describe the observed data better than the absolute risk model currently used by the ICRP. Secondly, the shape of the dose-response relationship considerably influences the derived risks. In the present paper the factor causing a substantial increase in radiation risk are analyzed. Conclusions are drawn in how far a change in the currently recommended dose limits seems to be necessary. (author)

New radiobiological, radiation risk and radiation protection paradigms

International Nuclear Information System (INIS)

Goodhead, Dudley T.

2010-01-01

The long-standing conventional paradigm for radiobiology has formed a logical basis for the standard paradigm for radiation risk of cancer and heritable effects and, from these paradigms, has developed the internationally applied system for radiation protection, but with many simplifications, assumptions and generalizations. A variety of additional radiobiological phenomena that do not conform to the standard paradigm for radiobiology may have potential implications for radiation risk and radiation protection. It is suggested, however, that the current state of knowledge is still insufficient for these phenomena, individually or collectively, to be formulated systematically into a new paradigm for radiobiology. Additionally, there is at present lack of direct evidence of their relevance to risk for human health, despite attractive hypotheses as to how they might be involved. Finally, it remains to be shown how incorporation of such phenomena into the paradigm for radiation protection would provide sufficient added value to offset disruption to the present widely applied system. Further research should aim for better mechanistic understanding of processes such as radiation-induced genomic instability (for all radiation types) and bystander effects (particularly for low-fluence high-LET particles) and also priority should be given to confirmation, or negation, of the relevance of the processes to human health risks from radiation.

World Health Organization, radiofrequency radiation and health - a hard nut to crack (Review)

OpenAIRE

Hardell, Lennart

2017-01-01

In May 2011 the International Agency for Research on Cancer (IARC) evaluated cancer risks from radiofrequency (RF) radiation. Human epidemiological studies gave evidence of increased risk for glioma and acoustic neuroma. RF radiation was classified as Group 2B, a possible human carcinogen. Further epidemiological, animal and mechanistic studies have strengthened the association. In spite of this, in most countries little or nothing has been done to reduce exposure and educate people on health...

Radiation exposure and radiation risk of the population

International Nuclear Information System (INIS)

Jacobi, W.; Paretzke, H.G.; Ehling, U.H.

1981-02-01

The major scientifically founded results concerning the assessment of the radiation exposure and the analysis and evaluation of the radiationhazards for the population, particularly in the range of low doses, are presented. As to the risk analysis special attention is paid to the rays with low ionization density (X-, γ-, β- and electronrays). Contents: 1) Detailed survey of the results and conclusions; 2) Data on the radiation load of the population; 3) Results to epidemiological questioning on the risk of cancer; 4) Genetical radiation hazards of the population. For quantification purposes of the risk of cancer by γ-radiation the observations with the a-bomb survivors in Japan are taken as a basis, as the available dosimetrical data have to be revised. Appendices: 1) German translation of the UNSCEAR-Report (1977); 2) BEIR-Report (1980); 3) Comments from the SSK on the comparability of the risks of natural-artificial radiation exposure; 4) Comments from the SSK on the importance of synergistical influences for the radiation protection (23.9.1977). (HP) [de

Cancer risk assessments and environmental regulation

International Nuclear Information System (INIS)

Scroggin, D.G.

1990-01-01

Governmental regulation of toxic substances, such as carcinogens and radiation, prompts both legal and scientific controversies. Industry, environmental activist groups, government regulators, and the general public are all concerned with the question of how environmental risk to public health is to be measured and what level of risk warrants government action under the environmental laws. Several recent events shed light on the fundamental scientific and legal problems inherent in such regulation, and these events may affect the direction of future developments. These events include implementation of generic Risk Assessment Guidelines by the US EPA, litigation challenging EPA's regulation of carcinogenic substances, new scientific understanding of the relative risks from human exposure to natural and man-made sources, and the continuing growth of toxic tort litigation in which victims of cancer seek large damages from industrial emitters of pollution

Radiation risk estimation

International Nuclear Information System (INIS)

Schull, W.J.; Texas Univ., Houston, TX

1992-01-01

Estimation of the risk of cancer following exposure to ionizing radiation remains largely empirical, and models used to adduce risk incorporate few, if any, of the advances in molecular biology of a past decade or so. These facts compromise the estimation risk where the epidemiological data are weakest, namely, at low doses and dose rates. Without a better understanding of the molecular and cellular events ionizing radiation initiates or promotes, it seems unlikely that this situation will improve. Nor will the situation improve without further attention to the identification and quantitative estimation of the effects of those host and environmental factors that enhance or attenuate risk. (author)

Ionizing radiation: benefits vs. risks

International Nuclear Information System (INIS)

Wagner, H.N. Jr.

1986-01-01

No one has been identifiably injured by radiation within the levels set by the NCRP and ICRP in 1934. This fact and the level of natural radiation (average dose 102 millirems/year) help provide standards against which the authors can view the relative increases in exposure from manmade sources of radiation. Because one person in five in the US will die of cancer from all causes, it is impossible to detect small increases in some types of cancer from radiation. A valid assumption is that any exposure to radiation carries some possibility of harm and should be kept below the level of the expected benefits. More is known about radiation toxicity than about any other potentially toxic substances. An obstacle to progress in the use of radioactive materials in biology and medicine is an exaggerated impression by the public of the risk of radiation. Several studies indicate that the public perceives the risk of radiation to be the greatest of all societal risks and at times does not distinguish peaceful from military uses of radiation. It behooves scientists and physicians to inform the public about the benefits as well as the risks of procedures involving radiation

Perception of low dose radiation risks among radiation researchers in Korea.

Science.gov (United States)

Seong, Ki Moon; Kwon, TaeWoo; Seo, Songwon; Lee, Dalnim; Park, Sunhoo; Jin, Young Woo; Lee, Seung-Sook

2017-01-01

Expert's risk evaluation of radiation exposure strongly influences the public's risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts' radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual's opinions have often exacerbated the public's confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years' research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects perception of radiation exposure.

Red tattoos, ultraviolet radiation and skin cancer in mice

DEFF Research Database (Denmark)

Lerche, Catharina M.; Heerfordt, Ida M.; Serup, Jørgen

2017-01-01

Ultraviolet radiation (UVR) induces skin cancer. The combination of UVR and red tattoos may be associated with increased risk of skin cancer due to potential carcinogens in tattoo inks. This combination has not been studied previously. Immunocompetent C3.Cg/TifBomTac hairless mice (n=99) were...

Asian Americans and disproportionate exposure to carcinogenic hazardous air pollutants: A national study.

Science.gov (United States)

Grineski, Sara E; Collins, Timothy W; Morales, Danielle X

2017-07-01

Studies have demonstrated disparate exposures to carcinogenic hazardous air pollutants (HAPs) in neighborhoods with high densities of Black and Hispanic residents in the US. Asians are the fastest growing racial/ethnic group in the US, yet they have been underemphasized in previous studies of environmental health and injustice. This cross-sectional study investigated possible disparities in residential exposure to carcinogenic HAPs among Asian Americans, including Asian American subgroups in the US (including all 50 states and the District of Columbia, n = 71,208 US census tracts) using National Air Toxics Assessment and US Census data. In an unadjusted analysis, Chinese and Korean Americans experience the highest mean cancer risks from HAPs, followed by Blacks. The aggregated Asian category ranks just below Blacks and above Hispanics, in terms of carcinogenic HAP risk. Multivariate models adjusting for socioeconomic status, population density, urban location, and geographic clustering show that an increase in proportion of Asian residents in census tracts is associated with significantly greater cancer risk from HAPs. Neighborhoods with higher proportions (as opposed to lower proportions) of Chinese, Korean, and South Asian residents have significantly greater cancer risk burdens relative to Whites. Tracts with higher concentrations of Asians speaking a non-English language and Asians that are US-born have significantly greater cancer risk burdens. Asian Americans experience substantial residential exposure to carcinogenic HAPs in US census tracts and in the US more generally. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physical dosimetry and biological indicators of carcinogenic risk in a cohort of persons exposed to unhealthy ecological factors following the Chernobyl Nuclear Power Plant accident.

Science.gov (United States)

Orel, V E; Tereschenki, V M; Czyatkovskaya, N N; Mazepa, M G; Buzunov, V A

1998-01-01

The April 1986 Chernobyl Nuclear Power Plant accident caused ecological changes in the Ovruch State forests in the Zhytomir oblast in the Ukraine. The highest radioactivity existed in moss, followed by the pine-forest substrate and soil. During 1984-1985, the pine needles were primarily surface contaminated, whereas during 1986-1988, they were contaminated secondarily. Radioactivity in air was highest (1.07+/-0.185 Bq/l) during dry and sunny weather and when trees were felled; the lowest levels (0.196+/-0.044 Bq/l) occurred during periods of stable snow coverage. Between 1987 and 1989 (i.e., after the Chernobyl accident), the caesium levels in forestry employees exceeded by 13.9-fold the average levels found in the Ukrainian Polessje population. Ovruch forest guards and woodcutters had the highest effective equivalent doses of radiation, and they therefore exhibited the highest carcinogenic risk.

Management of radiation risk

International Nuclear Information System (INIS)

Hubert, P.

1996-01-01

The need to control the risk from ionizing radiation can be tracked back to the eve of the twentieth century. However, as knowledge improved and practices expanded, the approaches to this control have evolved. No longer is the mere respect of some forms of exposure limits or safety related standards sufficient. Rather, it is widely admitted that there is a need for managing radiation risk, both by balancing the advantages and disadvantages of enhancing protection and by setting up a proper organization that allows handling of the risk. This paper describes the multiple aspects of radiation risk management and points out the main related issues. It critically analyzes ALARA and ICRP recommendations. 74 refs, 8 figs, 5 tabs

Risk Factors for Breast Cancer, Including Occupational Exposures

Directory of Open Access Journals (Sweden)

Elisabete Weiderpass

2011-03-01

Full Text Available The knowledge on the etiology of breast cancer has advanced substantially in recent years, and several etiological factors are now firmly established. However, very few new discoveries have been made in relation to occupational risk factors. The International Agency for Research on Cancer has evaluated over 900 different exposures or agents to-date to determine whether they are carcinogenic to humans. These evaluations are published as a series of Monographs (www.iarc.fr. For breast cancer the following substances have been classified as “carcinogenic to humans” (Group 1: alcoholic beverages, exposure to diethylstilbestrol, estrogen-progestogen contraceptives, estrogen-progestogen hormone replacement therapy and exposure to X-radiation and gamma-radiation (in special populations such as atomic bomb survivors, medical patients, and in-utero exposure. Ethylene oxide is also classified as a Group 1 carcinogen, although the evidence for carcinogenicity in epidemiologic studies, and specifically for the human breast, is limited. The classification “probably carcinogenic to humans” (Group 2A includes estrogen hormone replacement therapy, tobacco smoking, and shift work involving circadian disruption, including work as a flight attendant. If the association between shift work and breast cancer, the most common female cancer, is confirmed, shift work could become the leading cause of occupational cancer in women.

Fundamental matters on radiation risk communication

International Nuclear Information System (INIS)

Shinohara, Kunihiko; Nagai, Hiroyuki; Yonezawa, Rika; Ohuchi, Hiroko; Chikamoto, Kazuhiko; Taniguchi, Kazufumi; Morimoto, Eriko

2009-01-01

In the field of atomic energy and radiation utilization, radiation risk is considered as one of the social uneasy factors. About the perception of risks, there is a gap between experts and general public (non-experts). It is said that the general public tends to be going to judge risk from intuitive fear and a visible concrete instance whereas the experts judge it scientifically. A company, an administration or experts should disclose relating information about the risks and communicate interactively with the stakeholders to find the way to solve the problem with thinking together. This process is called 'risk communication'. The role of the expert is important on enforcement of risk communication. They should be required to explain the information on the risks with plain words to help stakeholders understand the risks properly. The Japan Health Physics Society (JHPS) is the largest academic society for radiation protection professionals in Japan, and one of its missions is supposed to convey accurate and trustworthy information about the radiation risk to the general public. The expert group on risk communication of ionizing radiation of the JHPS has worked for the purpose of summarizing the fundamental matters on radiation risk communication. 'Lecture on risk communication for the members of the JHPS.' which has been up on the JHPS web-site, and the symposium of 'For better understanding of radiation risk.' are a part of the activities. The expert group proposes that the JHPS should enlighten the members continuously for being interested in and practicing risk communication of radiation. (author)

Carcinogenicity assessment of water-soluble nickel compounds.

Science.gov (United States)

Goodman, Julie E; Prueitt, Robyn L; Dodge, David G; Thakali, Sagar

2009-01-01

IARC is reassessing the human carcinogenicity of nickel compounds in 2009. To address the inconsistencies among results from studies of water-soluble nickel compounds, we conducted a weight-of-evidence analysis of the relevant epidemiological, toxicological, and carcinogenic mode-of-action data. We found the epidemiological evidence to be limited, in that some, but not all, data suggest that exposure to soluble nickel compounds leads to increased cancer risk in the presence of certain forms of insoluble nickel. Although there is no evidence that soluble nickel acts as a complete carcinogen in animals, there is limited evidence that suggests it may act as a tumor promoter. The mode-of-action data suggest that soluble nickel compounds will not be able to cause genotoxic effects in vivo because they cannot deliver sufficient nickel ions to nuclear sites of target cells. Although the mode-of-action data suggest several possible non-genotoxic effects of the nickel ion, it is unclear whether soluble nickel compounds can elicit these effects in vivo or whether these effects, if elicited, would result in tumor promotion. The mode-of-action data equally support soluble nickel as a promoter or as not being a causal factor in carcinogenesis at all. The weight of evidence does not indicate that soluble nickel compounds are complete carcinogens, and there is only limited evidence that they could act as tumor promoters.

Radiation carcinogenesis: Epidemiology and biological significance

International Nuclear Information System (INIS)

Boice, J.D.; Fraumeni, J.F.

1984-01-01

Epidemiologic studies of populations exposed to radiation have led to the identification of a preventable cause of cancer, but in the long run perhaps the most important contribution of radiation studies will be to provide insights into the basic processes of human carcinogenesis. In this volume, key investigators of major epidemiologic projects summarize their observations to date, including information to help assess the effects of low-level exposures. Experimentalists and theorists emphasize the relevance of laboratory and epidemiologic data in elucidating carcinogenic risks and mechanisms in man. This volume was prepared with several objectives in mind: (a) organize and synthesize knowledge on radiation carcinogenesis through epidemiologic and experimental approaches; (b) illustrate and explore ways of utilizing this information to gain insights into the fundamental mechanisms of cancer development; (c) stimulate the formation of hypotheses suited to experimental or epidemiologic testing, theoretical modeling, and multidisciplinary approaches; and (d) identify recent advances that clarify dose-response relationships and the influence of low-dose exposures, provide leads to carcinogenic mechanisms and host-environmental interactions, and suggest strategies for future research and preventive action

Current features on risk perception and risk communication of radiation

International Nuclear Information System (INIS)

Kusama, Tomoko

1997-01-01

Health effects and risks of radiation and radionuclides are being misunderstood by many members of general public. Many peoples have fear and anxieties for radiation. So far, the health effects from radiation at low dose and low dose rate have not been cleared on biological aspects. Then, we have quantitatively estimated health risks of low-dose radiation on the basis of linear dose response relationship without threshold from the viewpoints of radiation protection by using both epidemiological data, such as atomic bomb survivors, and some models and assumptions. It is important for researchers and relevant persons in radiation protection to understand the process of risk estimation of radiation and to communicate an exact knowledge of radiation risks of the public members. (author)

How many food additives are rodent carcinogens?

Science.gov (United States)

Johnson, F M

2002-01-01

One generally assumes that chemical agents added to foods are reasonably free of risks to human health, and practically everyone consumes some additives in his or her food daily throughout life. In the United States, the 1958 Food Additives Amendment to the Federal Food, Drug and Cosmetic Act of 1938 requires food manufacturers to demonstrate the safety of food additives to the Food and Drug Administration (FDA). The Amendment contains a provision that prohibits approval of an additive if it is found to cause cancer in humans or animals. In the present study, data from the National Toxicology Program rodent bioassay (NTPRB) were used to identify a sample of approximately 50 rodent-tested additives and other chemicals added to food that had been evaluated independently of the FDA/food industry. Surprisingly, the sample shows more than 40% of these food chemicals to be carcinogenic in one or more rodent groups. If this percentage is extrapolated to all substances added to food in the United States, it would imply that more than 1000 of such substances are potential rodent carcinogens. The NTP and FDA test guidelines use similar, though not necessarily identical, rodent test procedures, including near lifetime exposures to the maximum tolerated dose. The FDA specifies that test chemicals should be administered by the oral route. However, the oral route includes three methods of delivering chemicals, that is, mixed in the food or water or delivered by stomach tube (gavage). The NTP data show only 1 of 18 food chemicals mixed in the food are rodent carcinogens, but 16 of 23 gavage-administered food chemicals are carcinogenic to rodents. The distribution suggests that among orally delivered chemicals, those administered in the feed will more likely prove to be noncarcinogens than chemicals given by gavage. The rodent data also reveal that effects may vary according to dose and genotype, as well as by route of administration, to further complicate extrapolation to humans

Proposed changes in the classification of carcinogenic chemicals in the work area.

Science.gov (United States)

Neumann, H G; Thielmann, H W; Filser, J G; Gelbke, H P; Greim, H; Kappus, H; Norpoth, K H; Reuter, U; Vamvakas, S; Wardenbach, P; Wichmann, H E

1997-12-01

Carcinogenic chemicals in the work area are currently classified into three categories in Section III of the German List of MAK and BAT Values. This classification is based on qualitative criteria and reflects essentially the weight of evidence available for judging the carcinogenic potential of the chemicals. It is proposed that these Categories--IIIA1, IIIA2, and IIIB--be retained as Categories 1, 2, and 3, to conform with EU regulations. On the basis of our advancing knowledge of reaction mechanisms and the potency of carcinogens, it is now proposed that these three categories be supplemented with two additional categories. The essential feature of substances classified in the new categories is that exposure to these chemicals does not convey a significant risk of cancer to man, provided that an appropriate exposure limit (MAK value) is observed. It is proposed that chemicals known to act typically by nongenotoxic mechanisms and for which information is available that allows evaluation of the effects of low-dose exposures be classified in Category 4. Genotoxic chemicals for which low carcinogenic potency can be expected on the basis of dose-response relationships and toxicokinetics and for which risk at low doses can be assessed will be classified in Category 5. The basis for a better differentiation of carcinogens is discussed, the new categories are defined, and possible criteria for classification are described. Examples for Category 4 (1,4-dioxane) and Category 5 (styrene) are presented. The proposed changes in classifying carcinogenic chemicals in the work area are presented for further discussion.

Effects of combined exposure of F344 rats to radiation and chronically inhaled cigarette smoke

Energy Technology Data Exchange (ETDEWEB)

Finch, G.L.; Nikula, K.J.; Barr, E.B. [and others

1995-12-01

Nuclear workers may be exposed to radiation in various forms, such as low-LET {gamma}-irradiation or {alpha}-irradiation from inhaled {sup 239}PuO{sub 2} particles. These workers may then have increased risk for lung cancer compared to the general population. Of additional concern is the possibility that interactions between radiation and other carcinogens may increase the risk of cancer induction, compared to the risks from either type of agent alone. An important and common lung carcinogen is cigarette smoke. The purpose of this project is to better determine the combined effects of chronically inhaled cigarette smoke and either inhaled {sup 239}PuO{sub 2} or external, thoracic X-irradiation on the induction of lung cancer in rats. Histologic and dosimetric evaluations of rats in the CS + {sup 239}PuO{sub 2} study continue, and the study of CS + X rays is beginning.

Risks associated with utilization of radiation

International Nuclear Information System (INIS)

Matsuoka, Satoshi; Kumazawa, Shigeru; Aoki, Yoshiro; Nakamura, Yuji; Takeda, Atsuhiko; Kusama, Tomoko; Inaba, Jiro; Tanaka, Yasumasa.

1993-01-01

When mankind decides action, the conveniences and the risks obtained by the action are weighed up. When socially important judgement is done, the logical discussion based on objective data is indispensable. The utilization of radiation spread from industrial circles to general public, accordingly the circumstances changed from the recognition of its risks by professionals to that by general public. The radiation exposure dose of public has increased rapidly by medical treatment. The global radioactivity contamination accompanying nuclear explosion experiment and the Chernobyl accident raised the psychological risk recognition of public. Now, the fear of the potential radioactivity which may be released from nuclear power plants and nuclear fuel cycle facilities expanded. The radiation exposure due to its utilization in recent years is mostly at the level below natural radiation. The acute radiation syndrome by whole body exposure is shown, and the effect is probabilistic. The evaluation of the risks due to radiation in the early effect, the hereditary effect and the delayed effect including canceration is explained. The risks in general human activities, the concept of risks in radiation protection, the effect of Chernobyl accident and the perception of general public on radiation risks are reported. (K.I.)

Relations between radiation risks and radiation protection measuring techniques

International Nuclear Information System (INIS)

Herrmann, K.; Kraus, W.

Relations between radiation risks and radiation protection measuring techniques are considered as components of the radiation risk. The influence of the exposure risk on type and extent of radiation protection measurements is discussed with regard to different measuring tasks. Based upon measuring results concerning the frequency of certain external and internal occupational exposures in the GDR, it has been shown that only a small fraction of the monitored persons are subjected to a high exposure risk. As a consequence the following recommendations are presented: occupationally exposed persons with small exposure risk should be monitored using only a long-term desimeter (for instance a thermoluminescence desimeter). In the case of internal exposure, the surface and air contamination levels should be controlled so strictly that routine measurements of internal contamination need not be performed

North American Magazine Coverage of Skin Cancer and Recreational Tanning Before and After the WHO/IARC 2009 Classification of Indoor Tanning Devices as Carcinogenic.

Science.gov (United States)

McWhirter, Jennifer E; Hoffman-Goetz, Laurie

2015-09-01

The mass media is an influential source of skin cancer information for the public. In 2009, the World Health Organization's International Agency for Research on Cancer classified UV radiation from tanning devices as carcinogenic. Our objective was to determine if media coverage of skin cancer and recreational tanning increased in volume or changed in nature after this classification. We conducted a directed content analysis on 29 North American popular magazines (2007-2012) to investigate the overall volume of articles on skin cancer and recreational tanning and, more specifically, the presence of skin cancer risk factors, UV behaviors, and early detection information in article text (n = 410) and images (n = 714). The volume of coverage on skin cancer and recreational tanning did not increase significantly after the 2009 classification of tanning beds as carcinogenic. Key-related messages, including that UV exposure is a risk factor for skin cancer and that indoor tanning should be avoided, were not reported more frequently after the classification, but the promotion of the tanned look as attractive was conveyed more often in images afterwards (p skin cancer risk factors, other UV behaviors, or early detection information over time. The classification of indoor tanning beds as carcinogenic had no significant impact on the volume or nature of skin cancer and recreational tanning coverage in magazines.

Effective doses and standardised risk factors from paediatric diagnostic medical radiation exposures: Information for radiation risk communication

International Nuclear Information System (INIS)

Bibbo, Giovanni

2018-01-01

In the paediatric medical radiation setting, there is no consistency on the radiation risk information conveyed to the consumer (patient/carer). Each communicator may convey different information about the level of risk for the same radiation procedure, leaving the consumer confused and frustrated. There is a need to standardise risks resulting from medical radiation exposures. In this study, paediatric radiographic, fluoroscopic, CT and nuclear medicine examination data have been analysed to provide (i) effective doses and radiation induced cancer risk factors from common radiological and nuclear medicine diagnostic procedures in standardised formats, (II) awareness of the difficulties that may be encountered in communicating risks to the layperson, and (iii) an overview of the deleterious effects of ionising radiation so that the risk communicator can convey with confidence the risks resulting from medical radiation exposures. Paediatric patient dose data from general radiographic, computed tomography, fluoroscopic and nuclear medicine databases have been analysed in age groups 0 to <5 years, 5 to <10 years, 10 to <15 years and 15 to <18 years to determine standardised risk factors. Mean, minimum and maximum effective doses and the corresponding mean lifetime risks for general radiographic, fluoroscopic, CT and nuclear medicine examinations for different age groups have been calculated. For all examinations, the mean lifetime cancer induction risk is provided in three formats: statistical, fraction and category. Standardised risk factors for different radiological and nuclear medicine examinations and an overview of the deleterious effects of ionising radiation and the difficulties encountered in communicating the risks should facilitate risk communication to the patient/carer.

The risk philosophy of radiation protection

International Nuclear Information System (INIS)

Lindell, B.

1996-01-01

The processes of risk assessment and risk evaluation are described. The assumptions behind current radiation risk assessments, which are focused on the probability of attributable death from radiation-induced cancer, are reviewed. These assessments involve projection models to take account of future cancer death in irradiated populations, the transfer of risk estimates between populations and the assumptions necessary to derive risk assessments for low radiation doses from actual observations at high doses. The paper ends with a presentation of the basic radiation protection recommendations of the International Commission on Radiological Protection (ICRP) in the context of a risk philosophy. (author)

Nanodosimetry and nanodosimetric-based models of radiation action for radon alpha particles. Final performance technical report

International Nuclear Information System (INIS)

Zaider, M.

1997-01-01

The goal of this project was to develop theoretical/computational tools for evaluating the risks incurred by populations exposed to radon alpha particles. Topics of concern include the following: compound dual radiation action (general aspects); a mathematical formalism describing the yield of radiation induced single-and double-strand DNA breaks, and its dependence on radiation quality; a study of the excited states in cytosine and guanine stacks in the Hartree-Fock and exciton approximations; nanodosimetry of radon alpha particles; application of the HSEF to assessing radiation risks in the practice of radiation protection; carcinogenic risk coefficients at environmental levels of radon exposures: a microdosimetric approach; and hit-size effectiveness approach in radiation protection

Competing risk theory and radiation risk assessment

International Nuclear Information System (INIS)

Groer, P.G.

1980-01-01

New statistical procedures are applied to estimate cumulative distribution functions (c.d.f.), force of mortality, and latent period for radiation-induced malignancies. It is demonstrated that correction for competing risks influences the shape of dose response curves, estimates of the latent period, and of the risk from ionizing radiations. The equivalence of the following concepts is demonstrated: force of mortality, hazard rate, and age or time specific incidence. This equivalence makes it possible to use procedures from reliability analysis and demography for radiation risk assessment. Two methods used by reliability analysts - hazard plotting and total time on test plots - are discussed in some detail and applied to characterize the hazard rate in radiation carcinogenesis. C.d.f.'s with increasing, decreasing, or constant hazard rate have different shapes and are shown to yield different dose-response curves for continuous irradiation. Absolute risk is shown to be a sound estimator only if the force of mortality is constant for the exposed and the control group. Dose-response relationships that use the absolute risk as a measure for the effect turn out to be special cases of dose-response relationships that measure the effect with cumulative incidence. (H.K.)

Cancer and environment. Tobacco, pesticides, radiations, diet: a document for the World Meeting on Ecology

International Nuclear Information System (INIS)

Lopes, E.R.; Mendonca, G.A.S.; Goldfarb, L.M.C.S.

1992-01-01

A detailed evaluation concerning the cancer etiology is presented. Several aspects on chemical agents role are described, as the relationship between tobacco and disease development, active and passive smoking, environmental pollution, occupational diseases, soil use and pesticides. The radiation exposure is studied, including solar radiation and risk factors for cutaneous malignant melanoma, ionizing radiations, radiological accidents, procedures of radioactive control in Brazil. Mutagens, carcinogens and tumor promoters in daily food are discussed as well as factors for reducing the risk of cancer development. (M.A.C.)

Novel approach to analyzing the carcinogenic effect of ionizing radiations.

Science.gov (United States)

Gregoire, O; Cleland, M R

2006-01-01

Cancer incidence of ionizing radiations exposure is considered to be proportional to the absorbed dose. However, there are disagreements between substantial amounts of epidemiological studies. In this study, we question the basic relationship of the risk estimate with total accumulated dose, and reanalyse available data on the basis of a daily dose concept. The data analysed were relative mortality risk from all cancers vs. total-body dose on a daily basis. References have been selected on the basis of objective criteria. We found that this relationship removes major discrepancies. It revises estimates of low-level exposures, with consequences regarding nuclear power plants safety, wastes management, medical applications or homeland security. The idea that the dose rate may have a significant impact on health effects of ionizing radiations is not new, but has always been considered as a parameter in models based on integrated dose. The novel approach in this paper is to consider the primary relevant parameter as an average of dose rate over a time period of one day. This is an argument to revise the whole philosophy in radioprotection, and place regulatory limits on specific locations instead of annual limits relevant to individual persons.

Carcinogenicity assessments of biotechnology-derived pharmaceuticals: a review of approved molecules and best practice recommendations.

Science.gov (United States)

Vahle, John L; Finch, Gregory L; Heidel, Shawn M; Hovland, David N; Ivens, Inge; Parker, Suezanne; Ponce, Rafael A; Sachs, Clifford; Steigerwalt, Ronald; Short, Brian; Todd, Marque D

2010-06-01

An important safety consideration for developing new therapeutics is assessing the potential that the therapy will increase the risk of cancer. For biotherapeutics, traditional two-year rodent bioassays are often not scientifically applicable or feasible. This paper is a collaborative effort of industry toxicologists to review past and current practice regarding carcinogenicity assessments of biotherapeutics and to provide recommendations. Publicly available information on eighty marketed protein biotherapeutics was reviewed. In this review, no assessments related to carcinogenicity or tumor growth promotion were identified for fifty-one of the eighty molecules. For the twenty-nine biotherapeutics in which assessments related to carcinogenicity were identified, various experimental approaches were employed. This review also discusses several key principles to aid in the assessment of carcinogenic potential, including (1) careful consideration of mechanism of action to identify theoretical risks, (2) careful investigation of existing data for indications of proliferative or immunosuppressive potential, and (3) characterization of any proliferative or immunosuppressive signals detected. Traditional two-year carcinogenicity assays should not be considered as the default method for assessing the carcinogenicity potential of biotherapeutics. If experimentation is considered warranted, it should be hypothesis driven and may include a variety of experimental models. Ultimately, it is important that preclinical data provide useful guidance in product labeling.

Mobile phone use and the risk of skin cancer

DEFF Research Database (Denmark)

Poulsen, Aslak Harbo; Friis, Søren; Johansen, Christoffer

2013-01-01

The International Agency for Research on Cancer has classified radiofrequency radiation as possibly carcinogenic. Previous studies have focused on intracranial tumors, although the skin receives much radiation. In a nationwide cohort study, 355,701 private mobile phone subscribers in Denmark from......% confidence interval: 0.54, 2.00). A similar risk pattern was seen among women, though it was based on smaller numbers. In this large, population-based cohort study, little evidence of an increased skin cancer risk was observed among mobile phone users....

Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

International Nuclear Information System (INIS)

Fabrikant, J.I.

1981-01-01

The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain, for problems and difficulties in extrapolation from data obtained at high doses to low doses, and from animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy

Validity of the linear no-threshold theory of radiation carcinogenesis at low doses

International Nuclear Information System (INIS)

Cohen, B.L.

1999-01-01

A great deal is known about the cancer risk of high radiation doses from studies of Japanese A-bomb survivors, patients exposed for medical therapy, occupational exposures, etc. But the vast majority of important applications deal with much lower doses, usually accumulated at much lower dose rates, referred to as 'low-level radiation' (LLR). Conventionally, the cancer risk from LLR has been estimated by the use of linear no-threshold theory (LNT). For example, it is assumed that the cancer risk from 0 01 Sr (100 mrem) of dose is 0 01 times the risk from 1 Sv (100 rem). In recent years, the former risk estimates have often been reduced by a 'dose and dose rate reduction factor', which is taken to be a factor of 2. But otherwise, the LNT is frequently used for doses as low as one hundred-thousandth of those for which there is direct evidence of cancer induction by radiation. It is the origin of the commonly used expression 'no level of radiation is safe' and the consequent public fear of LLR. The importance of this use of the LNT can not be exaggerated and is used in many applications in the nuclear industry. The LNT paradigm has also been carried over to chemical carcinogens, leading to severe restrictions on use of cleaning fluids, organic chemicals, pesticides, etc. If the LNT were abandoned for radiation, it would probably also be abandoned for chemical carcinogens. In view of these facts, it is important to consider the validity of the LNT. That is the purpose of this paper. (author)

Effects of low doses of ionizing radiation

International Nuclear Information System (INIS)

Anon.

2008-01-01

Ionizing radiation of cosmic or terrestrial origin is part of the environment in which all living things have evolved since the creation of the universe. The artificial radioactivity generated by medical diagnostic and treatment techniques, some industrial activities, radioactive fallout, etc. has now been added to this natural radioactivity. This article reviews the biological effects of the low doses of ionizing radiation to which the population is thus exposed. Their carcinogenic risk cannot simply be extrapolated from what we know about high-dose exposure. (author)

Comparative statistical analysis of carcinogenic and non-carcinogenic effects of uranium in groundwater samples from different regions of Punjab, India

International Nuclear Information System (INIS)

Saini, Komal; Singh, Parminder; Bajwa, Bikramjit Singh

2016-01-01

LED flourimeter has been used for microanalysis of uranium concentration in groundwater samples collected from six districts of South West (SW), West (W) and North East (NE) Punjab, India. Average value of uranium content in water samples of SW Punjab is observed to be higher than WHO, USEPA recommended safe limit of 30 µg l −1 as well as AERB proposed limit of 60 µg l −1 . Whereas, for W and NE region of Punjab, average level of uranium concentration was within AERB recommended limit of 60 µg l −1 . Average value observed in SW Punjab is around 3–4 times the value observed in W Punjab, whereas its value is more than 17 times the average value observed in NE region of Punjab. Statistical analysis of carcinogenic as well as non carcinogenic risks due to uranium have been evaluated for each studied district. - Highlights: • Uranium level in groundwater samples have been assessed in different regions of Punjab. • Comparative study of carcinogenic and non carcinogenic effects of uranium has been done. • Wide variation has been found for different geological regions. • It has been found that South west Punjab is worst affected by uranium contamination in its water. • For west and north east regions of Punjab, uranium levels in groundwater laid under recommended safe limits.

Critical effective methods to detect genotoxic carcinogens and neoplasm-promoting agents.

OpenAIRE

Weisburger, J H; Williams, G M

1991-01-01

Neoplasia in fish can result from contamination of waters with carcinogens and promoters. Cancer in fish, therefore, is a possible indicator of cancer risk to man and serves as a guide to the need for preventive approaches involving improved means of waste disposal and environmental hygiene. Moreover, cancer in fish indicates that this important food source may be contaminated. Detection of genotoxic carcinogens to which fish are exposed can be achieved quickly and efficiently by carefully se...

Methods for estimating the probability of cancer from occupational radiation exposure

International Nuclear Information System (INIS)

1996-04-01

The aims of this TECDOC are to present the factors which are generally accepted as being responsible for cancer induction, to examine the role of radiation as a carcinogen, to demonstrate how the probability of cancer causation by radiation may be calculated and to inform the reader of the uncertainties that are associated with the use of various risk factors and models in such calculations. 139 refs, 2 tabs

Radiation. Doses, effect, risk

International Nuclear Information System (INIS)

Vapirev, E.; Todorov, P.

1994-12-01

This book outlines in a popular form the topic of ionizing radiation impacts on living organisms. It contains data gathered by ICRP for a period of 35 years. The essential dosimetry terms and units are presented. Natural and artificial sources of ionizing radiation are described. Possible biological radiation effects and diseases as a consequence of external and internal irradiation at normal and accidental conditions are considered. An assessment of genetic risk for human populations is presented and the concept of 'acceptable risk' is discussed

Effects of Ionizing Radiation on Cellular Structures, Induced Instability, and Carcinogenesis

International Nuclear Information System (INIS)

Resat, Marianne S.; Arthurs, Benjamin J.; Estes, Brian J.; Morgan, william F.

2006-01-01

According to the American Cancer Society, the United States can expect 1,368,030 new cases of cancer in 2004 [1]. Among the many carcinogens Americans are exposed to, ionizing radiation will contribute to this statistic. Humans live in a radiation environment. Ionizing radiation is in the air we breathe, the earth we live on, and the food we eat. Man-made radiation adds to this naturally occurring radiation level thereby increasing the chance for human exposure. For many decades the scientific community, governmental regulatory bodies, and concerned citizens have struggled to estimate health risks associated with radiation exposures, particularly at low doses. While cancer induction is the primary concern and the most important somatic effect of exposure to ionizing radiation, potential health risks do not involve neoplastic diseases exclusively but also include somatic mutations that might contribute to birth defects and ocular maladies, and heritable mutations that might impact on disease risks in future generations. Consequently it is important we understand the effect of ionizing radiation on cellular structures and the subsequent long-term health risks associated with exposure to ionizing radiation

Blood proteins as carcinogen dosimeters

International Nuclear Information System (INIS)

Tannenbaum, S.R.; Skipper, P.L.

1986-01-01

The problem of quantifying exposure to genotoxins in a given individual represents a formidable challenge. In this paper methods which rely on the covalent binding of carcinogens and their metabolites to blood proteins are described. That carcinogens interact with proteins as well as with DNA has been established, although whether protein-carcinogen adducts can result in genetic damage has not been established. It has been shown, however, that the amount of a protein carcinogen adduct formed may be used as a quantitative measure of exposure to a carcinogen. Such a measure presumably is reflective of the absorption, metabolism, and excretion of the compound in an exposed individual. Protein adduction may reflect exposure in a time-frame of weeks to months. Thus, protein adduct measurement is a form of human chemical dosimetry. Hemoglobin and albumin are promising candidates for such dosimeters. Hemoglobin has a lifetime of about 120 days in humans; thus, circulating levels of carcinogen-modified hemoglobin will reflect the level of carcinogen exposure during a period of nearly four months. It also possesses some metabolic competence, particularly, the ability to oxidize aromatic hydroxylamines to nitroso compounds which react quite efficiently with sulfhydryl groups. Albumin has a half-life of 20 to 25 days in man. This protein does not possess metabolic capacity other than, perhaps, some esterase activity. In contrast to hemoglobin, though, it is not protected by the erythrocyte membrane and might be the target for a greater number of carcinogens. It is present and is synthesized in the same cells in which the reactive metabolic intermediates of carcinogens are mostly formed - the hepatocytes. Also, albumin has a number of high-affinity binding sites for a broad spectrum of xenobiotics and endobiotics. 25 refs., 1 tab

Assessment of risk from radiation sources

International Nuclear Information System (INIS)

Subbaratnam, T.; Madhvanath, U.; Somasundaram, S.

1976-01-01

Assessment of risk from exposure to ionizing radiations from man-made radiation sources and nuclear installations has to be viewed from three aspects, namely, dose-effect relationship (genetic and somatic) for humans, calculation of doses or dose-commitments to population groups, assessment of risk to radiation workers and the population at large from the current levels of exposure from nuclear industry and comparison of risk estimates with other industries in a modern society. These aspects are discussed in brief. On the basis of available data, it is shown that estimated incidence of genetic diseases and cancers due to exposure of population to radiation from nuclear industry is negligible in comparison with their natural incidence, and radiation risks to the workers in nuclear industry are much lower than the risks in other occupations. (M.G.B.)

Mutagenic and carcinogenic structural alerts and their mechanisms of action.

Science.gov (United States)

Plošnik, Alja; Vračko, Marjan; Dolenc, Marija Sollner

2016-09-01

Knowing the mutagenic and carcinogenic properties of chemicals is very important for their hazard (and risk) assessment. One of the crucial events that trigger genotoxic and sometimes carcinogenic effects is the forming of adducts between chemical compounds and nucleic acids and histones. This review takes a look at the mechanisms related to specific functional groups (structural alerts or toxicophores) that may trigger genotoxic or epigenetic effects in the cells. We present up-to-date information about defined structural alerts with their mechanisms and the software based on this knowledge (QSAR models and classification schemes).

Radiation doses in pediatric radiology: influence of regulations and standards

International Nuclear Information System (INIS)

Suleiman, O.H.

2004-01-01

The benefits of X-ray examinations contribute to the quality of modern medicine; however the risk of using X-rays, a carcinogen, has always been a concern. This concern is heightened for pediatric patients, who have a much greater sensitivity to the carcinogenic effects of radiation than adults. The principle of as low as reasonably achievable, or ALARA, is essential for minimizing the radiation dose patients receive, especially for pediatric patients. In order to keep radiation doses ALARA, one must know the dose patients receive. The determination of radiation dose in a standard way is therefore necessary so that these doses can be compared with practice, and for meaningful comparison against voluntary standards. In extreme situations, where public health needs may require mandatory standards, or regulations, the quantitative measurement and calculation of radiation dose becomes essential. How some radiation dose metrics and standards have evolved, including the value of different metrics such as entrance air kerma, organ dose, and effective dose will be presented. Recent pediatric X-ray studies, whether or not dedicated pediatric equipment is necessary, and recent initiatives by the Food and Drug Administration for pediatric population will be discussed. (orig.)

Perception of risk from radiation

International Nuclear Information System (INIS)

Slovic, P.

1996-01-01

Perceptions of risk from radiation have been studied systematically for about 20 years. This paper summarises the key findings and conclusions from this research with regard to the nature of risk perceptions, the impacts of these perceptions, and the need for communication about radiological hazards. Perhaps the most important generalisation from research in this area is that there is no uniform or consistent perception of radiation risks. Public perception and acceptance is determined by the context in which the radiation is used -and the very different reactions to different uses provide insight into the nature of perception and the determinants of acceptable risk. (author)

[The identification of viruses of human papilloma of high carcinogenic risk and evaluation of physical status of viral DNA using technique of polymerase-chain reaction under affection of cervical epithelium].

Science.gov (United States)

Viazovaia, A A; Kuevda, D A; Trofimova, O B; Shipulina, O Iu; Ershov, V A; Lialina, L V; Narvskaia, O V

2013-08-01

The DNA of virus of human papilloma of high carcinogenic risk was detected in 116 cervical samples. At that, the morphological symptoms of background processes are detected in 19 samples, CIN 1 in 9, CIN 2 in 23, CIN 3 in 54 (and out of them carcinoma in situ in 13), epidermoid cancer (squamous cell carcinoma) in 11 cases. The viral load of human papilloma of high carcinogenic risk in all samples of DNA exceeded threshold of clinical value (3 lg copies of DNA of human papilloma/105 cells). The genetic typing of human papilloma of high carcinogenic risk revealed the dominance of human papilloma of type 16 in 49.7%, type 33 in 15.3%, type 31 in 12.3% and type 45 in 5.5%. In women with background processes in cervix of the uterus DNA of human papilloma type 16 was detected more often in episome form. In case of dysplastic alterations of epithelium and cervical cancer DNA of human papilloma type 16 is detected in mixt form with different degree of integration into cell genome.

Solar ultraviolet radiation from cancer induction to cancer prevention: solar ultraviolet radiation and cell biology.

Science.gov (United States)

Tuorkey, Muobarak J

2015-09-01

Although decades have elapsed, researchers still debate the benefits and hazards of solar ultraviolet radiation (UVR) exposure. On the one hand, humans derive most of their serum 25-hydroxycholecalciferol [25(OH)D3], which has potent anticancer activity, from solar UVB radiation. On the other hand, people are more aware of the risk of cancer incidence associated with harmful levels of solar UVR from daily sunlight exposure. Epidemiological data strongly implicate UV radiation exposure as a major cause of melanoma and other cancers, as UVR promotes mutations in oncogenes and tumor-suppressor genes. This review highlights the impact of the different mutagenic effects of solar UVR, along with the cellular and carcinogenic challenges with respect to sun exposure.

Radiation equivalency: For the radiation recall phenomenon

International Nuclear Information System (INIS)

Stevens, R.H.; Cole, D.A.

1983-01-01

Experimental and clinico-epidemiological investigations have unequivocally established the risk of an offspring in later years developing cancer after experiencing an in utero carcinogenic insult. The present studies have focused upon identifying whether the biological effects of iodine-131 and the colon carcinogen 1,2-dimethylhydrazine (DMH) when administered during pregnancy in the Fischer F344 inbred rat are remembered in the offsprings at a later age. The investigations have been based upon the premise that after exposure to a carcinogen ''foreign-like'' tumor cells develop which result in the host mounting active antitumor immune responses. The authors have now measured at 2 to 3 months post-exposure, the antitumor cell-mediated immunity (CMI) induced by intraperitoneal administration of the radionuclide or chemical at 16-18 days of gestation. Their findings indicate a positive sex relationship existing in those offsprings exposed to the radioiodine with the female being much less sensitive. In contrast, no such difference was observed between responsiveness of the males and females born from dams exposed to the DMH. Significantly, the dams exposed to either the radionuclide or DMH expressed no measurable CMI suggesting that either the fetus acted as a carcinogen trap or else the state of pregnancy altered the mother's immune system in such a fashion to no longer respond to the insult. A Radiation Equivalency value has now been determined for the transplacental DMH exposures with the calculations suggesting the fetus is significantly more sensitive (over 10 times) than the adult animals. The results of this study now demonstrate that carcinogenic memory remains for exposures to both the iodine-131 and DMH in the first offspring generation and suggest that the effects may be recalled at a later age with the expected overt results being the development of cancer

Epistemological problems in assessing cancer risks at low radiation doses

International Nuclear Information System (INIS)

Walinder, G.

1987-01-01

Historically, biology has not been subjected to any epistemological analysis as has been the case with mathematics and physics. Our knowledge of the effects in biological systems of various stimuli proves to be dualistic in a complementary (although not mutually exclusive) way, which bears resemblance to the knowledge of phenomena in quantum physics. The dualistic limbs of biological knowledge are the action of stimuli and the response of the exposed, biological system. With regard to radiogenic cancer, this corresponds to the action of the ionizations and the response of the exposed mammal to that action, respectively. The following conclusions can be drawn from the present analysis: Predictions as to radiogenic cancer seem often if not always to have neglected the response variability (variations in radiosensitivity) in individuals or among individuals in populations, i.e. the predictions have been based exclusively on radiation doses and exposure conditions. The exposed individual or population, however, must be considered an open statistical system, i.e. a system in which predictions as to the effect of an agent are only conditionally possible. The knowledge is inverse to the size of the dose or concentration of the active agent. On epistemological grounds, we can not gain knowledge about the carcinogenic capacity of very low (non-dominant) radiation doses. Based on the same principle, we can not predict cancer risks at very low (non-dominant) radiation doses merely on the basis of models, or otherwise interpolated or extrapolated high-dose effects, observed under special exposure conditions

Risk management of radiation therapy. Survey by north Japan radiation therapy oncology group

International Nuclear Information System (INIS)

Aoki, Masahiko; Abe, Yoshinao; Yamada, Shogo; Hareyama, Masato; Nakamura, Ryuji; Sugita, Tadashi; Miyano, Takashi

2004-01-01

A North Japan Radiation Oncology Group (NJRTOG) survey was carried out to disclose the risk management of radiation therapy. During April 2002, we sent questionnaires to radiation therapy facilities in northern Japan. There were 31 replies from 27 facilities. Many incidents and accidents were reported, including old cases. Although 60% of facilities had a risk management manual and/or risk manager, only 20% had risk management manuals for radiation therapy. Eighty five percent of radiation oncologists thought that incidents may be due to a lack of manpower. Ninety percent of radiation oncologists want to know the type of cases happened in other facilities. The risk management system is still insufficient for radiation therapy. We hope that our data will be a great help to develop risk management strategies for radiation therapy for all radiation oncologists in Japan. (author)

Breast cancer induced by radiation. Relation to mammography and treatment of acne

International Nuclear Information System (INIS)

Simon, N.

1977-01-01

A report is given of cases of 16 women in whom cancer of the breast developed after radiation therapy for acne or hirsutism, suggesting another group at higher risk than is generally expected for cancer of the breast. It is prudent to regard the carcinogenic effect of radiation on the breast as proportional to dose without a threshold. Mammography in young women should be ordered only selectively, not for screening

Shall we be afraid by ionizing radiations?

International Nuclear Information System (INIS)

Gerard, P.

1996-01-01

A conference about ionizing radiations and the frighten they provoke was organised on the 30 May 1996 at Lyon in France. A responsible of the radiotherapy-oncology service, of the hospital center of Lyon, answered. The low doses are without effects on organs, for pregnant women if the dose is higher than 200 milli sieverts, abortion is advised; in fact the principle frighten is the carcinogens risk; the norms recommended by ICRP are to maintain the radiations doses in the a level as low as reasonably achievable. (ALARA principle)

A mode-of-action approach for the identification of genotoxic carcinogens.

Directory of Open Access Journals (Sweden)

Lya G Hernández

Full Text Available Distinguishing between clastogens and aneugens is vital in cancer risk assessment because the default assumption is that clastogens and aneugens have linear and non-linear dose-response curves, respectively. Any observed non-linearity must be supported by mode of action (MOA analyses where biological mechanisms are linked with dose-response evaluations. For aneugens, the MOA has been well characterised as disruptors of mitotic machinery where chromosome loss via micronuclei (MN formation is an accepted endpoint used in risk assessment. In this study we performed the cytokinesis-block micronucleus assay and immunofluorescence mitotic machinery visualisation in human lymphoblastoid (AHH-1 and Chinese Hamster fibroblast (V79 cell lines after treatment with the aneugen 17-β-oestradiol (E₂. Results were compared to previously published data on bisphenol-A (BPA and Rotenone data. Two concentration-response approaches (the threshold-[Td] and benchmark-dose [BMD] approaches were applied to derive a point of departure (POD for in vitro MN induction. BMDs were also derived from the most sensitive carcinogenic endpoint. Ranking comparisons of the PODs from the in vitro MN and the carcinogenicity studies demonstrated a link between these two endpoints for BPA, E₂ and Rotenone. This analysis was extended to include 5 additional aneugens, 5 clastogens and 3 mutagens and further concentration and dose-response correlations were observed between PODs from the in vitro MN and carcinogenicity. This approach is promising and may be further extended to other genotoxic carcinogens, where MOA and quantitative information from the in vitro MN studies could be used in a quantitative manner to further inform cancer risk assessment.

Radiation risk in space exploration

International Nuclear Information System (INIS)

Schimmerling, W.; Wilson, J.W.; Cucinotta, F.; Kim, M.H.Y.

1997-01-01

Humans living and working in space are exposed to energetic charged particle radiation due to galactic cosmic rays and solar particle emissions. In order to keep the risk due to radiation exposure of astronauts below acceptable levels, the physical interaction of these particles with space structures and the biological consequences for crew members need to be understood. Such knowledge is, to a large extent, very sparse when it is available at all. Radiation limits established for space radiation protection purposes are based on extrapolation of risk from Japanese survivor data, and have been found to have large uncertainties. In space, attempting to account for large uncertainties by worst-case design results in excessive costs and accurate risk prediction is essential. It is best developed at ground-based laboratories, using particle accelerator beams to simulate individual components of space radiation. Development of mechanistic models of the action of space radiation is expected to lead to the required improvements in the accuracy of predictions, to optimization of space structures for radiation protection and, eventually, to the development of biological methods of prevention and intervention against radiation injury. (author)

Mutagens and carcinogens in foods. Epidemiologic review.

OpenAIRE

Hislop, T. G.

1993-01-01

Evidence that diet contributes to the development of cancer is strengthening. This paper examines mutagens and carcinogens, such as naturally occurring substances, products of cooking and food processing, intentional and unintentional additives, and contaminants, found in foods. Such substances are present in minute quantities in the diets of average Canadians. Indication of health risk is largely limited to experimental laboratory evidence.

Mutagens and carcinogens in foods. Epidemiologic review.

Science.gov (United States)

Hislop, T. G.

1993-01-01

Evidence that diet contributes to the development of cancer is strengthening. This paper examines mutagens and carcinogens, such as naturally occurring substances, products of cooking and food processing, intentional and unintentional additives, and contaminants, found in foods. Such substances are present in minute quantities in the diets of average Canadians. Indication of health risk is largely limited to experimental laboratory evidence. PMID:8499796

Detection and impact on cancer causation of persons exhibiting abnormal susceptibility to carcinogenic agents

International Nuclear Information System (INIS)

Gentner, N.E.; Morrison, D.P.

1988-01-01

The so-called 'late biological effects', like cancer and genetic consequences and cytotoxic effects (cell killing, at higher doses), were once thought to be an inevitable consequence of a given level of exposure, whether to background radiation, to chemicals in our biosphere, or form spontaneous damage, the 'wear and tear' of living. The measurement of exposure, which results in living organisms in the formation of a related amount of DNA damage, became a surrogate for the end-effects that constitute risk. This may not be entirely appropriate. The concept of 'equal exposure -- equal risk' assumes a homogeneous response of individuals. However, there are subgroups within the human population of persons whose cultured cells exhibit abnormal sensitivity to specific carcinogenic agents and who may be at increased risk of cancer induced by these of similar agents. Modern molecular biology has shown that the majority of the damage in DNA is repaired by enzymatic DNA repair processes that restitute or ameliorate the lesions and restore normal DNA structure and function. In this view, it is not the initial damage that is of consequence but rather the residual damage left after the repair processes have acted. Since the vast majority of the initial DNA damage undergoes repair normally, variation in the efficiency of these processes in different persons may affect the actual risk of exposure. The human side of the cancer causation formula, that is, considerable importance. To understand how human DNA repair processes function, our laboratories at Chalk River have studied 'mutant' human cell strains in tissue culture. Generally, these DNA repair-defective cell strains are derived from individual donors with heritable disorders that are associated with carcinogen-hypersensitivity and cancer-proneness. Such studies, together with related epidemiological research, have highlighted the importance of this new 'human' factor in carcinogenesis

Risk factors for neoplasms

International Nuclear Information System (INIS)

Brachner, A.; Grosche, B.

1991-06-01

A broad survey is given of risk factors for neoplasms. The main carcinogenic substances (including also ionizing radiation and air pollution) are listed, and are correlated with the risk factors for various cancers most frequently explained and discussed in the literature. The study is intended to serve as a basis for a general assessment of the incidence of neoplasms in children, and of cancer mortality in the entire population of Bavaria in the years 1983-1989, or 1979-1988, respectively, with the principal idea of drawing up an environment-related health survey. The study therefore takes into account not only ionizing radiation as a main risk factor, but also other risk factors detectable within the ecologic context, as e.g. industrial installations and their effects, refuse incineration plants or waste dumps, or the social status. (orig./MG) [de

Generalized indices for radiation risk analysis

International Nuclear Information System (INIS)

Bykov, A.A.; Demin, V.F.

1989-01-01

A new approach to ensuring nuclear safety has begun forming since the early eighties. The approach based on the probabilistic safety analysis, the principles of acceptable risk, the optimization of safety measures, etc. has forced a complex of adequate quantitative methods of assessment, safety analysis and risk management to be developed. The method of radiation risk assessment and analysis hold a prominent place in the complex. National and international research and regulatory organizations ICRP, IAEA, WHO, UNSCEAR, OECD/NEA have given much attention to the development of the conceptual and methodological basis of those methods. Some resolutions of the National Commission of Radiological Protection (NCRP) and the Problem Commission on Radiation Hygiene of the USSR Ministry of Health should be also noted. Both CBA (cost benefit analysis) and other methods of radiation risk analysis and safety management use a system of natural and socio-economic indices characterizing the radiation risk or damage. There exist a number of problems associated with the introduction, justification and use of these indices. For example, the price, a, of radiation damage, or collective dose unit, is a noteworthy index. The difficulties in its qualitative and quantitative determination are still an obstacle for a wide application of CBA to the radiation risk analysis and management. During recent 10-15 years these problems have been a subject of consideration for many authors. The present paper also considers the issues of the qualitative and quantitative justification of the indices of radiation risk analysis

Evaluation of carcinogenic potential of the herbicide glyphosate, drawing on tumor incidence data from fourteen chronic/carcinogenicity rodent studies.

Science.gov (United States)

Greim, Helmut; Saltmiras, David; Mostert, Volker; Strupp, Christian

2015-03-01

Abstract Glyphosate, an herbicidal derivative of the amino acid glycine, was introduced to agriculture in the 1970s. Glyphosate targets and blocks a plant metabolic pathway not found in animals, the shikimate pathway, required for the synthesis of aromatic amino acids in plants. After almost forty years of commercial use, and multiple regulatory approvals including toxicology evaluations, literature reviews, and numerous human health risk assessments, the clear and consistent conclusions are that glyphosate is of low toxicological concern, and no concerns exist with respect to glyphosate use and cancer in humans. This manuscript discusses the basis for these conclusions. Most toxicological studies informing regulatory evaluations are of commercial interest and are proprietary in nature. Given the widespread attention to this molecule, the authors gained access to carcinogenicity data submitted to regulatory agencies and present overviews of each study, followed by a weight of evidence evaluation of tumor incidence data. Fourteen carcinogenicity studies (nine rat and five mouse) are evaluated for their individual reliability, and select neoplasms are identified for further evaluation across the data base. The original tumor incidence data from study reports are presented in the online data supplement. There was no evidence of a carcinogenic effect related to glyphosate treatment. The lack of a plausible mechanism, along with published epidemiology studies, which fail to demonstrate clear, statistically significant, unbiased and non-confounded associations between glyphosate and cancer of any single etiology, and a compelling weight of evidence, support the conclusion that glyphosate does not present concern with respect to carcinogenic potential in humans.

Assessment of predictivity of volatile organic compounds carcinogenicity and mutagenicity by freeware in silico models.

Science.gov (United States)

Guerra, Lília Ribeiro; de Souza, Alessandra Mendonça Teles; Côrtes, Juliana Alves; Lione, Viviane de Oliveira Freitas; Castro, Helena Carla; Alves, Gutemberg Gomes

2017-12-01

The application of in silico methods is increasing on toxicological risk prediction for human and environmental health. This work aimed to evaluate the performance of three in silico freeware models (OSIRIS v.2.0, LAZAR, and Toxtree) on the prediction of carcinogenicity and mutagenicity of thirty-eight volatile organic compounds (VOC) related to chemical risk assessment for occupational exposure. Theoretical data were compared with assessments available in international databases. Confusion matrices and ROC curves were used to evaluate the sensitivity, specificity, and accuracy of each model. All three models (OSIRIS, LAZAR and Toxtree) were able to identify VOC with a potential carcinogenicity or mutagenicity risk for humans, however presenting differences concerning the specificity, sensitivity, and accuracy. The best predictive performances were found for OSIRIS and LAZAR for carcinogenicity and OSIRIS for mutagenicity, as these softwares presented a combination of negative predictive power and lower risk of false positives (high specificity) for those endpoints. The heterogeneity of results found with different softwares reinforce the importance of using a combination of in silico models to occupational toxicological risk assessment. Copyright © 2017 Elsevier Inc. All rights reserved.

Critical effective methods to detect genotoxic carcinogens and neoplasm-promoting agents.

Science.gov (United States)

Weisburger, J H; Williams, G M

1991-01-01

Neoplasia in fish can result from contamination of waters with carcinogens and promoters. Cancer in fish, therefore, is a possible indicator of cancer risk to man and serves as a guide to the need for preventive approaches involving improved means of waste disposal and environmental hygiene. Moreover, cancer in fish indicates that this important food source may be contaminated. Detection of genotoxic carcinogens to which fish are exposed can be achieved quickly and efficiently by carefully selected batteries of complementary in vitro and in vivo bioassays. One such battery consists of the Ames test, a reverse mutation assay in prokaryotic Salmonella typhimurium, and the Williams test, involving DNA repair in freshly explanted metabolically highly competent liver cells from diverse species, including humans. Determination of DNA-carcinogen adducts by varied techniques, including 32P-postlabeling, as well as DNA breakage, mammalian cell mutagenicity, chromosome aberrations, sister chromatid exchange, or cell transformation represent additional approaches, each with its own advantages and disadvantages. More research is needed on systems to apprehend neoplasm promoters, but tests to determine interruption of intercellular communications through gap junctions appear promising. Other approaches rely on measurement of enzymes such as ornithine decarboxylase and protein kinase C. Approaches to the definition of risk to fish or humans require characterization of the genotoxic or nongenotoxic properties of a chemical, relative potency data obtained in select, limited rodent bioassays, and knowledge of prevailing environmental concentrations of specific carcinogens.

Participation of IPEN in the international program of information about occupational exposure to carcinogen risks; Participacion del IPEN en el programa internacional de informacion sobre exposicion ocupacional de riesgos cancerigenos (CAREX-Peru)

Energy Technology Data Exchange (ETDEWEB)

Osores, Jose; Gonzales, Susana [Direccion de Servicios, Instituto Peruano de Energia Nuclear, Lima (Peru)

2014-07-01

During 2014, the Peruvian Nuclear Energy Institute participated in the mapping of risks to carcinogens due to occupational exposure for our country through CAREX program because all radioactive substances are considered by the International Agency for Research Cancer as type 1 carcinogens (high risk) and the presence of these substances in the work environment are unknown to professionals from other institutions. This occasion allowed the incorporation of Natural Occurring Radioactive Materials (NORM) as indicators in all work activities that were not considered by the Energy and Mining Sector. (authors).

Exploring gamma radiation effect on exoelectron emission properties of bone

International Nuclear Information System (INIS)

Zakaria, M.; Dekhtyar, Y.; Bogucharska, T.; Noskov, V.

2006-01-01

Gamma radiation is used for radiation therapy to treat carcinogenic diseases including bone cancer. Ionising radiation kills carcinogenic calls. However, there are side effects of the gamma radiation on the bone surface electron structure. One of the effects is in the form of altering electron density of states of bone that, with time, influences biomedical reactions on bone life condition. (authors)

Exploring gamma radiation effect on exoelectron emission properties of bone

Energy Technology Data Exchange (ETDEWEB)

Zakaria, M.; Dekhtyar, Y.; Bogucharska, T.; Noskov, V. [Riga Technical Univ., Biomedical Engineering and Nanotechnology Institute (Latvia)

2006-07-01

Gamma radiation is used for radiation therapy to treat carcinogenic diseases including bone cancer. Ionising radiation kills carcinogenic calls. However, there are side effects of the gamma radiation on the bone surface electron structure. One of the effects is in the form of altering electron density of states of bone that, with time, influences biomedical reactions on bone life condition. (authors)

Radiation risk of diagnostical procedures

International Nuclear Information System (INIS)

Pohlit, W.

1986-01-01

The environmental radiation burden of man in Germany is about 1 mGy (Milligray) per year. This is, of course, also valid for children. Due to diagnostical procedures this burden is increased to about 1.3 mGy. The question arises wether this can be neglected, or important consequences have to be drawn. To give a clear answer, the action of ionizing radiation in living cells and in organisms is explained in detail. Many of the radiation actions at the DNA can soon be repaired by the cell, if the radiation dose was small. Some damage, however will remain irreparable for the cell and consequently leads to cell death, to mutations or to cell transformation. The number of these lesion increases or decreases linearily with radiation dose. Therefore, it must be expected that the risk of tumour induction is increased to above the normal background even by the smallest doses. This small but not negligible risk has to be compared with other risks of civilization or with other medical risks. But also the benefit and the efficacy of diagnostic procedures have to be considered. (orig./HSCH) [de

Minimising the risk: reducing breast tissue dose in an adolescent female

International Nuclear Information System (INIS)

Thompson, Ann; Toe, Aimee; Ungureanu, Elena; Wolf, M.; Wirth, Andrew

2005-01-01

Breast cancer is amongst the leading radiation-associated, second malignancies that develop in patients after treatment for Hodgkin's disease. This risk is affected by two main factors: 1. The age of the patient at the time of radiotherapy; and 2. The dose received by the breast tissue The adolescent female thus faces an exceptionally high risk, as breast tissue at this age is undergoing rapid developmental growth and small doses of radiation exposure could be carcinogenic. This case report of a fifteen-year-old girl who received radiotherapy for Hodgkin's disease demonstrates how radiation therapists worked together with the radiation oncologists and medical physicists to provide an optimal treatment plan for a high-risk patient. Copyright (2005) Australian Institute of Radiography

Respiratory carcinogenicity assessment of soluble nickel compounds.

OpenAIRE

Oller, Adriana R

2002-01-01

The many chemical forms of nickel differ in physicochemical properties and biological effects. Health assessments for each main category of nickel species are needed. The carcinogenicity assessment of water-soluble nickel compounds has proven particularly difficult. Epidemiologic evidence indicates an association between inhalation exposures to nickel refinery dust containing soluble nickel compounds and increased risk of respiratory cancers. However, the nature of this association is unclear...

Tobacco smoking, polymorphisms in carcinogen metabolism enzyme genes, and risk of localized and advanced prostate cancer: results from the California Collaborative Prostate Cancer Study

International Nuclear Information System (INIS)

Shahabi, Ahva; Corral, Román; Catsburg, Chelsea; Joshi, Amit D; Kim, Andre; Lewinger, Juan Pablo; Koo, Jocelyn; John, Esther M; Ingles, Sue A; Stern, Mariana C

2014-01-01

The relationship between tobacco smoking and prostate cancer (PCa) remains inconclusive. This study examined the association between tobacco smoking and PCa risk taking into account polymorphisms in carcinogen metabolism enzyme genes as possible effect modifiers (9 polymorphisms and 1 predicted phenotype from metabolism enzyme genes). The study included cases (n = 761 localized; n = 1199 advanced) and controls (n = 1139) from the multiethnic California Collaborative Case–Control Study of Prostate Cancer. Multivariable conditional logistic regression was performed to evaluate the association between tobacco smoking variables and risk of localized and advanced PCa risk. Being a former smoker, regardless of time of quit smoking, was associated with an increased risk of localized PCa (odds ratio [OR] = 1.3; 95% confidence interval [CI] = 1.0–1.6). Among non-Hispanic Whites, ever smoking was associated with an increased risk of localized PCa (OR = 1.5; 95% CI = 1.1–2.1), whereas current smoking was associated with risk of advanced PCa (OR = 1.4; 95% CI = 1.0–1.9). However, no associations were observed between smoking intensity, duration or pack-year variables, and advanced PCa. No statistically significant trends were seen among Hispanics or African-Americans. The relationship between smoking status and PCa risk was modified by the CYP1A2 rs7662551 polymorphism (P-interaction = 0.008). In conclusion, tobacco smoking was associated with risk of PCa, primarily localized disease among non-Hispanic Whites. This association was modified by a genetic variant in CYP1A2, thus supporting a role for tobacco carcinogens in PCa risk

Meat intake, cooking methods, dietary carcinogens, and colorectal cancer risk: findings from the Colorectal Cancer Family Registry.

Science.gov (United States)

Joshi, Amit D; Kim, Andre; Lewinger, Juan Pablo; Ulrich, Cornelia M; Potter, John D; Cotterchio, Michelle; Le Marchand, Loic; Stern, Mariana C

2015-06-01

Diets high in red meat and processed meats are established colorectal cancer (CRC) risk factors. However, it is still not well understood what explains this association. We conducted comprehensive analyses of CRC risk and red meat and poultry intakes, taking into account cooking methods, level of doneness, estimated intakes of heterocyclic amines (HCAs) that accumulate during meat cooking, tumor location, and tumor mismatch repair proficiency (MMR) status. We analyzed food frequency and portion size data including a meat cooking module for 3364 CRC cases, 1806 unaffected siblings, 136 unaffected spouses, and 1620 unaffected population-based controls, recruited into the CRC Family Registry. Odds ratios (OR) and 95% confidence intervals (CI) for nutrient density variables were estimated using generalized estimating equations. We found no evidence of an association between total nonprocessed red meat or total processed meat and CRC risk. Our main finding was a positive association with CRC for pan-fried beefsteak (P(trend) carcinogens relevant for CRC risk. © 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Radiation in space: risk estimates

International Nuclear Information System (INIS)

Fry, R.J.M.

2002-01-01

The complexity of radiation environments in space makes estimation of risks more difficult than for the protection of terrestrial population. In deep space the duration of the mission, position of the solar cycle, number and size of solar particle events (SPE) and the spacecraft shielding are the major determinants of risk. In low-earth orbit missions there are the added factors of altitude and orbital inclination. Different radiation qualities such as protons and heavy ions and secondary radiations inside the spacecraft such as neutrons of various energies, have to be considered. Radiation dose rates in space are low except for short periods during very large SPEs. Risk estimation for space activities is based on the human experience of exposure to gamma rays and to a lesser extent X rays. The doses of protons, heavy ions and neutrons are adjusted to take into account the relative biological effectiveness (RBE) of the different radiation types and thus derive equivalent doses. RBE values and factors to adjust for the effect of dose rate have to be obtained from experimental data. The influence of age and gender on the cancer risk is estimated from the data from atomic bomb survivors. Because of the large number of variables the uncertainties in the probability of the effects are large. Information needed to improve the risk estimates includes: (1) risk of cancer induction by protons, heavy ions and neutrons; (2) influence of dose rate and protraction, particularly on potential tissue effects such as reduced fertility and cataracts; and (3) possible effects of heavy ions on the central nervous system. Risk cannot be eliminated and thus there must be a consensus on what level of risk is acceptable. (author)

Polymorphisms in genes related to activation or detoxification of carcinogens might interact with smoking to increase renal cancer risk: Results from The Netherlands Cohort Study on diet and cancer

NARCIS (Netherlands)

Smits, K.M.; Schouten, L.J.; Dijk, B.A.C. van; Houwelingen, K. van; Hulsbergen-Kaa, C.A. van de; Kiemeney, L.A.L.M.; Houwelingen, K. van; Goldbohm, R.A.; Oosterwijk, E.; Brandt, P.A. van den

2008-01-01

Metabolic gene polymorphisms have previously been suggested as risk factors for renal cell carcinoma (RCC). These polymorphisms are involved in activation or detoxification of carcinogens in cigarette smoke which is another RCC risk factor. We evaluated gene-environment interactions between CYP1A1,

The carcinogenic effects of aspartame: The urgent need for regulatory re-evaluation.

Science.gov (United States)

Soffritti, Morando; Padovani, Michela; Tibaldi, Eva; Falcioni, Laura; Manservisi, Fabiana; Belpoggi, Fiorella

2014-04-01

Aspartame (APM) is an artificial sweetener used since the 1980s, now present in >6,000 products, including over 500 pharmaceuticals. Since its discovery in 1965, and its first approval by the US Food and Drugs Administration (FDA) in 1981, the safety of APM, and in particular its carcinogenicity potential, has been controversial. The present commentary reviews the adequacy of the design and conduct of carcinogenicity bioassays on rodents submitted by G.D. Searle, in the 1970s, to the FDA for market approval. We also review how experimental and epidemiological data on the carcinogenic risks of APM, that became available in 2005 motivated the European Commission (EC) to call the European Food and Safety Authority (EFSA) for urgent re-examination of the available scientific documentation (including the Searle studies). The EC has further requested that, if the results of the evaluation should suggest carcinogenicity, major changes must be made to the current APM specific regulations. Taken together, the studies performed by G.D. Searle in the 1970s and other chronic bioassays do not provide adequate scientific support for APM safety. In contrast, recent results of life-span carcinogenicity bioassays on rats and mice published in peer-reviewed journals, and a prospective epidemiological study, provide consistent evidence of APM's carcinogenic potential. On the basis of the evidence of the potential carcinogenic effects of APM herein reported, a re-evaluation of the current position of international regulatory agencies must be considered an urgent matter of public health. © 2014 Wiley Periodicals, Inc.

Mammalian cell transformation: Mechanisms of carcinogenesis and assays for carcinogens

International Nuclear Information System (INIS)

Barrett, J.C.; Tennant, R.W.

1985-01-01

This book contains nine sections, each consisting of several papers. The section titles are: Molecular Changes in Cell Transformation; Differentiation, Growth Control, and Cell Transformation; Mutagenesis and Cell Transformation; Tumor Promotion and Cell Transformation; Mechanisms of Transformation of Human Fibroblasts; Mechanisms of Transformation of Epithelial Cells; Mechanisms of C 3 H 10T12 Cell Transformation; Mechanisms of Radiation-Induced Cell Transformation; and Use of Cell Transformation Assays for Carcinogen Testing

Assessing carcinogenic risks associated with ingesting arsenic in farmed smeltfish (Ayu, Plecoglossus altirelis) in aseniasis-endemic area of Taiwan

International Nuclear Information System (INIS)

Lee, J.-J.; Jang, C.-S.; Liang, C.-P.; Liu, C.-W.

2008-01-01

This study spatially analyzed potential carcinogenic risks associated with ingesting arsenic (As) contents in aquacultural smeltfish (Plecoglossus altirelis) from the Lanyang Plain of northeastern Taiwan. Sequential indicator simulation (SIS) was adopted to reproduce As exposure distributions in groundwater based on their three-dimensional variability. A target cancer risk (TR) associated with ingesting As in aquacultural smeltfish was employed to evaluate the potential risk to human health. The probabilistic risk assessment determined by Monte Carlo simulation and SIS is used to propagate properly the uncertainty of parameters. Safe and hazardous aquacultural regions were mapped to elucidate the safety of groundwater use. The TRs determined from the risks at the 95th percentiles exceed one millionth, indicating that ingesting smeltfish that are farmed in the highly As-affected regions represents a potential cancer threat to human health. The 95th percentile of TRs is considered in formulating a strategy for the aquacultural use of groundwater in the preliminary stage

Environmental carcinogens in human target tissues in culture: Progress report

International Nuclear Information System (INIS)

Hsu, I.C.

1987-01-01

We have accumulated more experimental evidences that demonstrated the comparative approaches with human cells will allow us to predict human risk with good accuracy following exposure to toxic chemicals. We also synthesized several carcinogenic DNA adducts, i.e., the major benzo[a]pyrene DNA adduct, 0 6 -methyldeoxyguanosine, 7-methyl- deoxyguanosine and 2-methyl-deoxyguanosine to be used as standards for quantitating DNA adduct formation in carcinogen exposed cells. A simple synthetic method was developed for preparation of the major B[a]p DNA adduct with yields better than those reported. The main accomplishments related to the originally stated objectives are summarized. 8 refs., 2 figs., 1 tab

Radiation exposure and risk of death

International Nuclear Information System (INIS)

Hongo, Syozo

1979-01-01

By using the risk factor given in ICRP publication 26 and an assumption of linear relationship between risk and dose, death rate and death number which correspond to radiation dose level and collective dose level of Japanese are estimated and they are compared with vital statistics of Japanese in 1975 to get out some ideas about radiation risk relative to the risks of everyday life. (author)

Repair of DNA treated with lambda-irradiation and chemical carcinogens. Progress report, 1984-1985

International Nuclear Information System (INIS)

Goldthwait, D.A.

1985-01-01

Research progress is reported in the following areas: (1) DNA repair in HeLa cells; (2) a search for human transposable elements; (3) the effect of radiation and carcinogens on the activation of LTR sequences; and (4) studies on oncogenes of central nervous system tumors

Population variability in biological adaptive responses to DNA damage and the shapes of carcinogen dose-response curves

International Nuclear Information System (INIS)

Conolly, Rory B.; Gaylor, David W.; Lutz, Werner K.

2005-01-01

Carcinogen dose-response curves for both ionizing radiation and chemicals are typically assumed to be linear at environmentally relevant doses. This assumption is used to ensure protection of the public health in the absence of relevant dose-response data. A theoretical justification for the assumption has been provided by the argument that low dose linearity is expected when an exogenous agent adds to an ongoing endogenous process. Here, we use computational modeling to evaluate (1) how two biological adaptive processes, induction of DNA repair and cell cycle checkpoint control, may affect the shapes of dose-response curves for DNA-damaging carcinogens and (2) how the resulting dose-response behaviors may vary within a population. Each model incorporating an adaptive process was capable of generating not only monotonic dose-responses but also nonmonotonic (J-shaped) and threshold responses. Monte Carlo analysis suggested that all these dose-response behaviors could coexist within a population, as the spectrum of qualitative differences arose from quantitative changes in parameter values. While this analysis is largely theoretical, it suggests that (a) accurate prediction of the qualitative form of the dose-response requires a quantitative understanding of the mechanism (b) significant uncertainty is associated with human health risk prediction in the absence of such quantitative understanding and (c) a stronger experimental and regulatory focus on biological mechanisms and interindividual variability would allow flexibility in regulatory treatment of environmental carcinogens without compromising human health

Estimation of health risks from radiation exposures

International Nuclear Information System (INIS)

Randolph, M.L.

1983-08-01

An informal presentation is given of the cancer and genetic risks from exposures to ionizing radiations. The risks from plausible radiation exposures are shown to be comparable to other commonly encountered risks

Estimation of health risks from radiation exposures

Energy Technology Data Exchange (ETDEWEB)

Randolph, M.L.

1983-08-01

An informal presentation is given of the cancer and genetic risks from exposures to ionizing radiations. The risks from plausible radiation exposures are shown to be comparable to other commonly encountered risks.

Prevention of cancer and the dose-effect relationship: the carcinogenic effects of ionizing radiations; La prevention du cancer et la relation dose-effet: l'effet cancerogene des rayonnements ionisants

Energy Technology Data Exchange (ETDEWEB)

Tubiana, M. [Centre Antoine-Beclere, Faculte de Medecine, 75 - Paris (France)

2009-07-15

Cancer prevention has to be based on robust biological and epidemiological data, therefore its reappraisal becomes mandatory in view of recent progress in the understanding of carcinogenesis. The first phase of the carcinogenic process, that of initiation, is generally associated with mutation; however the role of extrinsic mutagens is less critical than was thought two decades ago. During intracellular oxygen metabolism, reactive oxygen species (R.O.S.) are made which are potent mutagens. Defense mechanisms against these intrinsic mutagens include scavenger and enzymatic systems which destroy them (catalase, superoxide dismutase). When the radiation dose is low, DNA repair is very effective as well as the elimination of cells with unrepaired or bad repaired DNA. Therefore a small increase in the number of R.O.S., such as that caused by a small dose of radiation has most probably no significant effect on the risk of DNA damage. These conclusions are consistent with the concept of a practical threshold. The second phase, that of promotion, appears to be the key one. During the promotion phase, initiated cells must acquire new properties (immortalization, release of angiogenic factors, resistance to hypoxia, etc.) in order to become pre-cancerous. This evolution is due to the accumulation in the genome of 6 to 10 new alteration defects. In the clone of initiated cells, the occurrence in one cell of a mutation or an epigenetic event gives birth to a sub clone. There is a Darwinian type competition between the sub clones and those with the more rapid growth because dominant (the acceleration of the growth rate can be due to shorter cell cycles or to an alleviation of cell proliferation exerted by the neighboring cells or the microenvironment). In the dominant sub clones new genomic events provoke the appearance of new sub clones growing more rapidly and having greater autonomy. The process is very slow because the specific genetic events that favour this evolution

Approaches to radiation guidelines for space travel

International Nuclear Information System (INIS)

Fry, R.J.M.

1984-01-01

There are obvious risks in space travel that have loomed larger than any risk from radiation. Nevertheless, NASA has maintained a radiation program that has involved maintenance of records of radiation exposure, and planning so that the astronauts' exposures are kept as low as possible, and not just within the current guidelines. These guidelines are being reexamined currently by NCRP Committee 75 because new information is available, for example, risk estimates for radiation-induced cancer and about the effects of HZE particles. Furthermore, no estimates of risk or recommendations were made for women in 1970 and must now be considered. The current career limit is 400 rem. The appropriateness of this limit and its basis are being examined as well as the limits for specific organs. There is now considerably more information about age-dependency for radiation and this will be taken into account. Work has been carried out on the so-called microlesions caused by HZE particles and on the relative carcinogenic effect of heavy ions, including iron. A remaining question is whether the fluence of HZE particles could reach levels of concern in missions under consideration. Finally, it is the intention of the committee to indicate clearly the areas requiring further research. 21 references, 1 figure, 7 tables

Sarcoma risk after radiation exposure

Directory of Open Access Journals (Sweden)

Berrington de Gonzalez Amy

2012-10-01

Full Text Available Abstract Sarcomas were one of the first solid cancers to be linked to ionizing radiation exposure. We reviewed the current evidence on this relationship, focusing particularly on the studies that had individual estimates of radiation doses. There is clear evidence of an increased risk of both bone and soft tissue sarcomas after high-dose fractionated radiation exposure (10 + Gy in childhood, and the risk increases approximately linearly in dose, at least up to 40 Gy. There are few studies available of sarcoma after radiotherapy in adulthood for cancer, but data from cancer registries and studies of treatment for benign conditions confirm that the risk of sarcoma is also increased in this age-group after fractionated high-dose exposure. New findings from the long-term follow-up of the Japanese atomic bomb survivors suggest, for the first time, that sarcomas can be induced by acute lower-doses of radiation (

Detection of carcinogen-DNA adducts by radioimmunoassay

International Nuclear Information System (INIS)

Poirier, M.C.; Yuspa, S.H.; Weinstein, I.B.; Blobstein, S.

1977-01-01

Covalent binding of carcinogen to nucleic acids is believed to be an essential component of the carcinogenic process, so it is desirable to have highly sensitive and specific methods for detecting such adducts in cells and tissues exposed to known and suspected carcinogens. A radioimmunoassay is here described capable of detecting nanogram amounts of DNA adducts resulting from the covalent binding of the carcinogen N-2-acetylaminofluorene and its activated N-acetoxy derivative. (author)

Radiation and other risks

International Nuclear Information System (INIS)

Trott, K.-R.

1991-01-01

Examples of occupational cancer and its diagnosis drawn from history are given. These include lung cancer prevalent among cobalt miners at Schneeburg in Sascaria in the nineteenth century. The true agent causing the cancer was not identified until 1955 when it became clear that the cobalt miners of the past and uranium miners currently employed close to the old Schneeburg mines were at risk because of their exposure to the decay products of radon. Radon build up in houses in certain areas became a cause of concern although the significance of the risk has not yet been appropriately investigated. The science of epidemiology has developed new and powerful methods to detect occupational hazards, however, which are being applied to the radon issue and to other cases where the risks are much lower than in the historical examples quoted. The study of occupational cancer at the Sellafield nuclear plant in the United Kingdom is a typical example. This modern research produces results which are much less self-evident and, to the non-specialist, much more difficult to understand. Learning from the past, we may be able to avoid some errors and provide safer working conditions for the future; certainly, over the last twenty years in the UK, occupational exposure to all conceivable carcinogens has decreased considerably. (UK)

Genetic risks from radiation

International Nuclear Information System (INIS)

Selby, P.B.

Two widely-recognized committees, UNSCEAR and BEIR, have reevaluated their estimates of genetic risks from radiation. Their estimates for gene mutations are based on two different approaches, one being the doubling-dose approach and the other being a new direct approach based on an empirical determination of the amount of dominant induced damage in the skeletons of mice in the first generation following irradiation. The estimates made by these committees are in reasonably good agreement and suggest that the genetic risks from present exposures resultng from nuclear power production are small. There is room for much improvement in the reliability of the risk estimates. The relatively new approach of measuring the amount of induced damage to the mouse skeleton shows great promise of improving knowledge about how changes in the mutation frequency affect the incidence of genetic disorders. Such findings may have considerable influence on genetic risk estimates for radiation and on the development of risk estimates for other less-well-understood environmental mutagens. (author)

Quantifying Cancer Risk from Radiation.

Science.gov (United States)

Keil, Alexander P; Richardson, David B

2017-12-06

Complex statistical models fitted to data from studies of atomic bomb survivors are used to estimate the human health effects of ionizing radiation exposures. We describe and illustrate an approach to estimate population risks from ionizing radiation exposure that relaxes many assumptions about radiation-related mortality. The approach draws on developments in methods for causal inference. The results offer a different way to quantify radiation's effects and show that conventional estimates of the population burden of excess cancer at high radiation doses are driven strongly by projecting outside the range of current data. Summary results obtained using the proposed approach are similar in magnitude to those obtained using conventional methods, although estimates of radiation-related excess cancers differ for many age, sex, and dose groups. At low doses relevant to typical exposures, the strength of evidence in data is surprisingly weak. Statements regarding human health effects at low doses rely strongly on the use of modeling assumptions. © 2017 Society for Risk Analysis.

Relations between radiation risks and radiation protection measuring techniques

International Nuclear Information System (INIS)

Herrmann, K.; Kraus, W.

1975-10-01

'Risk of damage' and 'exposure risk' are considered as components of the radiation risk. The influence of the 'exposure risk' on type and extent of radiation protection measurements is discussed with regard to different measuring tasks. Basing upon measuring results concerning the frequency of certain external and internal occupational exposures in the GDR, it has been shown that only a small fraction of the monitored persons are subjected to a high 'exposure risk'. As a consequence the following recommendations are given for discussion: (a) occupationally exposed persons with small 'exposure risk' should be monitored using only a long-term dosimeter (for instance a thermoluminescence dosimeter), (b) in the case of internal exposure the surface and, if necessary, air contamination should be controlled so strictly that routine measurements of internal contamination need not be performed. (author)

Exposure of Finnish population to solar UV radiation and consequent carcinogenic effects

Energy Technology Data Exchange (ETDEWEB)

Huurto, L; Jansen, C [Turku Univ. Hospital, Turku (Finland); Jokela, K [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

1997-12-31

Depletion of stratospheric ozone increases irradiance of terrestrial ultraviolet (UV) radiation at short wavelengths, which may be harmful to the human health. To understand quantitatively the risks caused by increasing UV radiation to the Finnish population, the actual UV exposure of the population has to be assessed. It was shown that the snow reflection increases the UV exposure to the face and eyes particularly in the northern Finland. In 1993 exceptionally low ozone levels persisted up to the end of May, which resulted in a theoretical increase in the annual UV dose ranging from 8 % to 13 % in Finland. The maximal increase in the measured erythemally effective dose rate was 34 % on 23 April, when compared with the theoretical normal value. During this study exposure models have been developed. The models have been combined them with Green`s radiation transfer model to estimate annual facial UV doses received by different groups of Finnish population. Also, an updated estimate for increase in skin cancer incidence due to the ozone depletion is presented. It is estimated that the maximal increase in UV doses caused by the depletion of the stratospheric ozone will be 12 % in the first years of the next century in Finland. This may result in increase in skin carcinomas by 20-30 % if the people do not improve their protection against solar UV radiation. At the moment the annual facial UV dose of the Finnish indoor worker varies from 3 % to 6 % of the annual ambient dose. In the worst case an outdoor worker may receive even 16% of the annual ambient dose. However, the doses received by indoor workers during vacation to an untanned skin may be more harmful due to the increased risk of malignant melanoma.

Exposure of Finnish population to solar UV radiation and consequent carcinogenic effects

Energy Technology Data Exchange (ETDEWEB)

Huurto, L.; Jansen, C. [Turku Univ. Hospital, Turku (Finland); Jokela, K. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

1996-12-31

Depletion of stratospheric ozone increases irradiance of terrestrial ultraviolet (UV) radiation at short wavelengths, which may be harmful to the human health. To understand quantitatively the risks caused by increasing UV radiation to the Finnish population, the actual UV exposure of the population has to be assessed. It was shown that the snow reflection increases the UV exposure to the face and eyes particularly in the northern Finland. In 1993 exceptionally low ozone levels persisted up to the end of May, which resulted in a theoretical increase in the annual UV dose ranging from 8 % to 13 % in Finland. The maximal increase in the measured erythemally effective dose rate was 34 % on 23 April, when compared with the theoretical normal value. During this study exposure models have been developed. The models have been combined them with Green`s radiation transfer model to estimate annual facial UV doses received by different groups of Finnish population. Also, an updated estimate for increase in skin cancer incidence due to the ozone depletion is presented. It is estimated that the maximal increase in UV doses caused by the depletion of the stratospheric ozone will be 12 % in the first years of the next century in Finland. This may result in increase in skin carcinomas by 20-30 % if the people do not improve their protection against solar UV radiation. At the moment the annual facial UV dose of the Finnish indoor worker varies from 3 % to 6 % of the annual ambient dose. In the worst case an outdoor worker may receive even 16% of the annual ambient dose. However, the doses received by indoor workers during vacation to an untanned skin may be more harmful due to the increased risk of malignant melanoma.

Epigenetic mechanism of radiation carcinogenesis

International Nuclear Information System (INIS)

Niwa, Ohtsura

1995-01-01

Carcinogenic action of radiations has long been thought to be due to its mutagenic activity. Since DNA damage is induced and distributes in a stochastic fashion, radiation induction of cancers was also assumed to follow a stochastic kinetics. However, recent progress in radiation research has revealed that some features of radiation carcinogenesis are not explainable by the simple action of radiation as a DNA damaging and mutagenic agent. Firstly, frequencies of radiation-induced transformation in vitro and radiation-induced mammary cancers in rats are too high to be accounted for by the frequency of radiation-induced mutation. Secondly, trans-generation carcinogenesis among F1 mice born to irradiated parents occurs also much more frequently than to be predicted by the frequency of radiation induced germline mutation. Thirdly, multistage carcinogenesis theory predicts that carcinogens give hits to the target cells so as to shorten the latency of cancers. However, latencies of radiation induced solid cancers among atomic bomb survivors are similar to those of the control population. Fourthly, although radiation elevates the frequency of cancers, the induced cancers seem to share the same spectrum of cancer types as in the unirradiated control populations. This suggests that radiation induces cancer by enhancement of the spontaneous carcinogenesis process. These data suggest that the first step of radiation carcinogenesis may not be the direct induction of mutation. Radiation may induce genetic instability which increases the spontaneous mutation rate in the cells to produce carcinogenic mutations. Growth stimulatory effect of radiation may also contribute to the process. Thus, epigenetic, but not genetic effect of radiation might better contribute in the process of carcinogenesis. (author)

Comparative statistical analysis of carcinogenic and non-carcinogenic effects of uranium in groundwater samples from different regions of Punjab, India.

Science.gov (United States)

Saini, Komal; Singh, Parminder; Bajwa, Bikramjit Singh

2016-12-01

LED flourimeter has been used for microanalysis of uranium concentration in groundwater samples collected from six districts of South West (SW), West (W) and North East (NE) Punjab, India. Average value of uranium content in water samples of SW Punjab is observed to be higher than WHO, USEPA recommended safe limit of 30µgl -1 as well as AERB proposed limit of 60µgl -1 . Whereas, for W and NE region of Punjab, average level of uranium concentration was within AERB recommended limit of 60µgl -1 . Average value observed in SW Punjab is around 3-4 times the value observed in W Punjab, whereas its value is more than 17 times the average value observed in NE region of Punjab. Statistical analysis of carcinogenic as well as non carcinogenic risks due to uranium have been evaluated for each studied district. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inconsistency... or why differentiate, where prevention is concerned, between radioactive substances and carcinogenic chemicals

International Nuclear Information System (INIS)

Choquet, R.; Vinit, J.

1982-01-01

Radiotracers, low-activity unsealed radioactive sources, and certain chemical products belong to the list of substances and agents known to promote cancers in humans. The dangers of radiotracers and carcinogenic chemicals being very similar, or even identical, it is inadmissible that preventive measures have not been equally developed and are not viewed in the same way in our country. It should be noted that the International Labour Bureau has long since included radioactive products in the list of carcinogenic substances and agents and treated preventive measures as a whole by proceeding in this way it would be easier to account for the possible combined effects of ionising radiations and chemical molecules. After a review of some facts about cancer the present situation is examined with regard to statutory measures applied on the one hand to radioelements and on the other to chemicals recognised as carcinogenic by international organisations. Proposals are made to remedy this illogical situation [fr

NASA Space Radiation Program Integrative Risk Model Toolkit

Science.gov (United States)

Kim, Myung-Hee Y.; Hu, Shaowen; Plante, Ianik; Ponomarev, Artem L.; Sandridge, Chris

2015-01-01

NASA Space Radiation Program Element scientists have been actively involved in development of an integrative risk models toolkit that includes models for acute radiation risk and organ dose projection (ARRBOD), NASA space radiation cancer risk projection (NSCR), hemocyte dose estimation (HemoDose), GCR event-based risk model code (GERMcode), and relativistic ion tracks (RITRACKS), NASA radiation track image (NASARTI), and the On-Line Tool for the Assessment of Radiation in Space (OLTARIS). This session will introduce the components of the risk toolkit with opportunity for hands on demonstrations. The brief descriptions of each tools are: ARRBOD for Organ dose projection and acute radiation risk calculation from exposure to solar particle event; NSCR for Projection of cancer risk from exposure to space radiation; HemoDose for retrospective dose estimation by using multi-type blood cell counts; GERMcode for basic physical and biophysical properties for an ion beam, and biophysical and radiobiological properties for a beam transport to the target in the NASA Space Radiation Laboratory beam line; RITRACKS for simulation of heavy ion and delta-ray track structure, radiation chemistry, DNA structure and DNA damage at the molecular scale; NASARTI for modeling of the effects of space radiation on human cells and tissue by incorporating a physical model of tracks, cell nucleus, and DNA damage foci with image segmentation for the automated count; and OLTARIS, an integrated tool set utilizing HZETRN (High Charge and Energy Transport) intended to help scientists and engineers study the effects of space radiation on shielding materials, electronics, and biological systems.

Characterising risk - aggregated metrics: radiation and noise

International Nuclear Information System (INIS)

Passchier, W.

1998-01-01

The characterisation of risk is an important phase in the risk assessment - risk management process. From the multitude of risk attributes a few have to be selected to obtain a risk characteristic or profile that is useful for risk management decisions and implementation of protective measures. One way to reduce the number of attributes is aggregation. In the field of radiation protection such an aggregated metric is firmly established: effective dose. For protection against environmental noise the Health Council of the Netherlands recently proposed a set of aggregated metrics for noise annoyance and sleep disturbance. The presentation will discuss similarities and differences between these two metrics and practical limitations. The effective dose has proven its usefulness in designing radiation protection measures, which are related to the level of risk associated with the radiation practice in question, given that implicit judgements on radiation induced health effects are accepted. However, as the metric does not take into account the nature of radiation practice, it is less useful in policy discussions on the benefits and harm of radiation practices. With respect to the noise exposure metric, only one effect is targeted (annoyance), and the differences between sources are explicitly taken into account. This should make the metric useful in policy discussions with respect to physical planning and siting problems. The metric proposed has only significance on a population level, and can not be used as a predictor for individual risk. (author)

Health risk assessment of exposure to ionizing radiation

International Nuclear Information System (INIS)

Ogata, Hiromitsu

2011-01-01

Risk assessment is an essential process for evaluating the human health effects of exposure to ionizing radiation and for determining acceptable levels of exposure. There are two major components of radiation risk assessment: a measure of exposure level and a measure of disease occurrence. For quantitative estimation of health risks, it is important to evaluate the association between exposure and disease occurrence using epidemiological or experimental data. In these approaches, statistical risk models are used particularly for estimating cancer risks related to exposure to low levels of radiation. This paper presents a summary of basic models and methods of risk assessment for studying exposure-risk relationships. Moreover, quantitative risk estimates are subject to several sources of uncertainty due to inherent limitations in risk assessment studies. This paper also discusses the limitations of radiation risk assessment. (author)

Acceptable level of radiation risk and its perception

International Nuclear Information System (INIS)

Kusama, Tomoko; Shinozaki, Motoshi; Yoshizawa, Yasuo

1987-01-01

The acceptable level of radiation risk for public members, that is 10 -5 /y, was proposed by ICRP and other international organizations. We studied to survey basic procedures of deriving this value and to derive an acceptable risk value in Japan by using similar procedures. The basic procedures to derive 10 -5 /y were found as follows; (1) 0.1 percent of annual mortality from all diseases, (2) 0.1 percent of life time risk, (3) one percent of mortality from all causes in each age cohort and (4) corresponding value to 1 mSv annual radiation exposure. From these bases we derived the value of 10 -5 /y as acceptable risk level in Japan. The perception to risk level of 10 -5 /y in conventional life was investigated by means of questionnaires for 1,095 college students living in Tokyo. The risks considered in this study were natural background radiation, coffee, skiing, X-ray diagnosis, spontaneous cancer, passive smoking and air pollution. The most acceptable risk was the risk related with natural background radiation. And the risk of natural background radiation was more easily accepted by the students who had knowledges on natural background radiation. On the other hand, the risk from air pollution or passive smoking was the most adverse one. (author)

Biological effects of radiation and estimation of risk to radiation workers

International Nuclear Information System (INIS)

Murthy, M.S.S.

1987-01-01

The biological effects of radiation have three stages: physical, chemical and biological. A precise mathematical description of biological effects and of one-to-one correspondence between the initial energy absorption and final effect has not been possible, because several factors are involved in biological effects and their manifestation period varies from less than one second to several years. The mechanism of biological radiation effects is outlined. The two groups of these effects are (1) immediate and (2) delayed. The main aim of radiation protection programme is to eliminate the risk of non-stochastic effects to an acceptable level. The mean annual dose for 30,000 radiation workers in India is 2.7 m Sv. Estimated risk of fatal cancer from this dose is about 50 cases of cancer per year per million workers which is well below the ICRP standard for safe occupation stipulated at fatality rate less than or equal to 100 per year per milion workers. When compared with risk in other occupations, the risk to radiation workers is much less. (M.G.B.)

Space Radiation and Risks to Human Health

Science.gov (United States)

Huff, Janice L.; Patel, Zarana S.; Simonsen, Lisa C.

2014-01-01

The radiation environment in space poses significant challenges to human health and is a major concern for long duration manned space missions. Outside the Earth's protective magnetosphere, astronauts are exposed to higher levels of galactic cosmic rays, whose physical characteristics are distinct from terrestrial sources of radiation such as x-rays and gamma-rays. Galactic cosmic rays consist of high energy and high mass nuclei as well as high energy protons; they impart unique biological damage as they traverse through tissue with impacts on human health that are largely unknown. The major health issues of concern are the risks of radiation carcinogenesis, acute and late decrements to the central nervous system, degenerative tissue effects such as cardiovascular disease, as well as possible acute radiation syndromes due to an unshielded exposure to a large solar particle event. The NASA Human Research Program's Space Radiation Program Element is focused on characterization and mitigation of these space radiation health risks along with understanding these risks in context of the other biological stressors found in the space environment. In this overview, we will provide a description of these health risks and the Element's research strategies to understand and mitigate these risks.

Prediction of Chemical Carcinogenicity in Rodents from in vitro Genetic Toxicity Assays

Science.gov (United States)

Tennant, Raymond W.; Margolin, Barry H.; Shelby, Michael D.; Zeiger, Errol; Haseman, Joseph K.; Spalding, Judson; Caspary, William; Resnick, Michael; Stasiewicz, Stanley; Anderson, Beth; Minor, Robert

1987-05-01

imperative that there be documentation by a substantial set of systematically acquired test results on well-defined rodent carcinogens and noncarcinogens (36). The current study represents a prototype of the evaluative effort needed for such documentation. Results of the current study focus attention on two questions involving discordances between carcinogenicity and genotoxicity test results: (i) Do nongenotoxic rodent carcinogens pose the same carcinogenic risk to humans as those that are genotoxic? (ii) Can the apparent high frequency of in vitro genotoxic rodent noncarcinogens be explained as a combination of artifacts arising from extremely high dosing in in vitro tests or the failure of many bona fide in vitro genotoxins to express their genetic toxicity in whole animals? Until these questions are resolved, chemicals that show mutagenic effects, particularly if such effects are observed in vivo, must be initially considered to pose human health risks as long as the somatic mutation theory of cancer remains a viable explanation for the etiology of some chemically induced cancers.

Epidemiological data and radiation risk estimates

International Nuclear Information System (INIS)

Cardis, E.

2002-01-01

The results of several major epidemiology studies on populations with particular exposure to ionizing radiation should become available during the first years of the 21. century. These studies are expected to provide answers to a number of questions concerning public health and radiation protection. Most of the populations concerned were accidentally exposed to radiation in ex-USSR or elsewhere or in a nuclear industrial context. The results will complete and test information on risk coming from studies among survivors of the Hiroshima and Nagasaki atomic bombs, particularly studies on the effects of low dose exposure and prolonged low-dose exposure, of different types of radiation, and environmental and host-related factors which could modify the risk of radiation-induced effects. These studies are thus important to assess the currently accepted scientific evidence on radiation protection for workers and the general population. In addition, supplementary information on radiation protection could be provided by formal comparisons and analyses combining data from populations with different types of exposure. Finally, in order to provide pertinent information for public health and radiation protection, future epidemiology studies should be targeted and designed to answer specific questions, concerning, for example, the risk for specific populations (children, patients, people with genetic predisposition). An integrated approach, combining epidemiology and studies on the mechanisms of radiation induction should provide particularly pertinent information. (author)

Radiation risk due to occupational exposure

International Nuclear Information System (INIS)

Kargbo, A.A

2012-04-01

Exposure to ionizing radiation occurs in many occupations. Workers can be exposed to both natural and artificial sources of radiation. Any exposure to ionizing radiation incurs some risk, either to the individual or to the individual's progeny. This dissertation investigated the radiation risk due to occupational exposure in industrial radiography. Analysis of the reported risk estimates to occupational exposure contained in the UNSCEAR report of 2008 in industrial radiography practice was done. The causes of accidents in industrial radiography include: Lack of or inadequate regulatory control, inadequate training, failure to follow operational procedures, human error, equipment malfunction or defect, inadequate maintenance and wilful violation have been identified as primary causes of accidents. To minimise radiation risks in industrial radiography exposure devices and facilities should be designed such that there is intrinsic safety and operational safety ensured by establishing a quality assurance programme, safety culture fostered and maintained among all workers, industrial radiography is performed in compliance with approved local rules, workers engaged have appropriate qualifications and training, available safe operational procedures are followed, a means is provided for detecting incidents and accidents and an analysis of the causes and lessons learned. (author)

Risk assessment of hot beta-particles from the Chernobyl fallout in Bulgaria

International Nuclear Information System (INIS)

Uzunov, I.

1993-01-01

Research on hot particles (HP) was carried out in the Laboratory of Dosimetry and Radiation Protection. Field measurements with a Geiger-counter led to early discovery of HP on the ground in May 1986. Laboratory measurements of HP activity followed and their nuclide composition was determined. The carcinogenic risk of HP is discussed on the basis of a computer model assuming the radiation as initiator and all other factors as stimulators for cell proliferation (promoters). It is found that in the case of low radiation dose the probability for cancer is almost directly proportional to the number of cell divisions while at high radiation dose the slope is nearly vertical and reaches saturation point at about 5 cell divisions. An estimation of the number of inhaled HP was made by investigation of air filters. It is concluded that, besides iodine, inhaled HP are the most hazardous factor of the Chernobyl fallout. For some critical groups of the population, engaged in dusty outdoor operations, the carcinogenic risk was estimates as high as 0.1 - 1%. An average activity of 50 Bq per retained particle is proposed. It is stressed that Bulgarian population had not been informed adequately and no protection measures against HP intake had been taken. 3 figs., 12 refs

Risk assessment of hot beta-particles from the Chernobyl fallout in Bulgaria

Energy Technology Data Exchange (ETDEWEB)

Uzunov, I

1994-12-31

Research on hot particles (HP) was carried out in the Laboratory of Dosimetry and Radiation Protection. Field measurements with a Geiger-counter led to early discovery of HP on the ground in May 1986. Laboratory measurements of HP activity followed and their nuclide composition was determined. The carcinogenic risk of HP is discussed on the basis of a computer model assuming the radiation as initiator and all other factors as stimulators for cell proliferation (promoters). It is found that in the case of low radiation dose the probability for cancer is almost directly proportional to the number of cell divisions while at high radiation dose the slope is nearly vertical and reaches saturation point at about 5 cell divisions. An estimation of the number of inhaled HP was made by investigation of air filters. It is concluded that, besides iodine, inhaled HP are the most hazardous factor of the Chernobyl fallout. For some critical groups of the population, engaged in dusty outdoor operations, the carcinogenic risk was estimates as high as 0.1 - 1%. An average activity of 50 Bq per retained particle is proposed. It is stressed that Bulgarian population had not been informed adequately and no protection measures against HP intake had been taken. 3 figs., 12 refs.

Radiation and health: low-level-ionizing radiation exposure and effects

International Nuclear Information System (INIS)

Kant, Krishan

2013-01-01

In the present paper, brief review of the available literature, data and reports of various radiation exposure and protection studies is presented. An in-depth analysis of reports available suggests that the possible beneficial outcomes of exposure to LLIR are: increased Growth rate, Development, Neurogenesis, Memory, Fecundity (Fertility), Immunity (Resistance to diseases due to large doses of radiation) and Lifespan (Longevity) Decreased Cancer deaths, Cardiovascular deaths, Respiratory deaths, Neonatal deaths, Sterility, Infection, Premature deaths. The findings also suggest that the LNT theory is overly stated for assessing carcinogenic risks at low doses. It is not scientifically justified and should be banned as it creates radio phobia thereby blocking the efforts to supply reliable, environmentally friendly nuclear energy and important medical therapies. There is no need for anyone to live in fear of serious health consequences from the radioactivity that comes out from nuclear installations and exposures in the range of background radiation. A linear quadratic model has been given illustrating the validity of radiation hormesis, besides the comparison of the dose rates arising from natural and manmade sources to Indian population

Perception of radiation risks

International Nuclear Information System (INIS)

Brenot, J.

1992-01-01

Perception of risks by people depends on many factors, either characterizing the individuals, or specific to the risk sources. The risk concept, which confuses the issue, is precised first. Second, the perception phenomenon is presented as an interactive process involving the individual, the hazard, and the social context. Third, dimensions of perception are listed and used to describe the perception of radiation risks. Finally, the relation between perception and attitude is clarified. (author) 50 refs

Radiation risks for patients having X rays

International Nuclear Information System (INIS)

Hale, J.; Thomas, J.W.

1985-01-01

In addition to radiation from naturally occurring radioactive materials and cosmic rays, individuals in developed countries receive radiation doses to bone marrow and gonads from the medical diagnostic use of X rays. A brief discussion of radiation epidemiology shows that deleterious effects are low even when doses are high. The concept of acceptable risk is introduced to help evaluate the small, but still existent, risks of radiation dose. Examples of bone marrow and gonadal doses for representative X-ray examinations are presented along with the current best estimates, per unit of X-ray dose, of the induction of leukemia or of genetic harm. The risk to the patient from an examination can then be compared with the normal risk of mortality from leukemia or of the occurrence of genetic defects. The risk increase is found to be very low. The risks to unborn children from radiographic examinations are also discussed. The benefit to the patient from information obtained from the examination must be balanced against the small risks

Perspective on radiation from the nuclear power industry

International Nuclear Information System (INIS)

Cohen, B.L.

1990-01-01

Methods for estimating the risk of radiation induced cancer mortality to members of the public are outlined for each element of the nuclear power industry - reactor accidents, routine releases from nuclear plants, transport, mining and milling of uranium, and escape of buried radioactive waste (high level and low level). The results are compared with mortality risks from the air pollution and chemical carcinogens released into the ground in generating the same amount of electricity by coal burning - the latter are thousands of times larger. Radiation from nuclear power is also 1,000 times smaller than that from radon in homes. The amount of money spent to avert a death from nuclear power radiation is in the billion dollar range, whereas lives could be saved from radon in homes for 0.00001 times that cost. Medical screening and highway safety programs can save lives for a similarly low cost

Predictive Models for Carcinogenicity and Mutagenicity ...

Science.gov (United States)

Mutagenicity and carcinogenicity are endpoints of major environmental and regulatory concern. These endpoints are also important targets for development of alternative methods for screening and prediction due to the large number of chemicals of potential concern and the tremendous cost (in time, money, animals) of rodent carcinogenicity bioassays. Both mutagenicity and carcinogenicity involve complex, cellular processes that are only partially understood. Advances in technologies and generation of new data will permit a much deeper understanding. In silico methods for predicting mutagenicity and rodent carcinogenicity based on chemical structural features, along with current mutagenicity and carcinogenicity data sets, have performed well for local prediction (i.e., within specific chemical classes), but are less successful for global prediction (i.e., for a broad range of chemicals). The predictivity of in silico methods can be improved by improving the quality of the data base and endpoints used for modelling. In particular, in vitro assays for clastogenicity need to be improved to reduce false positives (relative to rodent carcinogenicity) and to detect compounds that do not interact directly with DNA or have epigenetic activities. New assays emerging to complement or replace some of the standard assays include VitotoxTM, GreenScreenGC, and RadarScreen. The needs of industry and regulators to assess thousands of compounds necessitate the development of high-t

Inhibition of trihalomethane formation in city water by radiation-ozone treatment and rapid composting of radiation disinfected sewage sludge

International Nuclear Information System (INIS)

Takehisa, M.; Arai, H.; Arai, M.

1985-01-01

Humic acid and Fulvic acid in natural water are precursors of carcinogenic THM which is formed during chlorine disinfection in city water processing. The radiation-oxidation process in the presence of ozone is effective to remove the precursors. The THM formation was reduced more than the decrease in TOC by the combination treatment. This is mainly due to a change in the chemical structure of the oxidation products. A composting of radiation disinfected sludge cake for agricultural reuse could be achieved within 3 days primary fermentation in a sewage plant. The rapid fermentation with use of radiation is effective to scale down of a fermentor of composting plant and the process reduces a health risk from the workers as well as final users. (author)

Inhibition of trihalomethane formation in city water by radiation-ozone treatment and rapid composting of radiation disinfected sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Takehisa, M; Arai, H; Arai, M

1985-01-01

Humic acid and Fulvic acid in natural water are precursors of carcinogenic THM which is formed during chlorine disinfection in city water processing. The radiation-oxidation process in the presence of ozone is effective to remove the precursors. The THM formation was reduced more than the decrease in TOC by the combination treatment. This is mainly due to a change in the chemical structure of the oxidation products. A composting of radiation disinfected sludge cake for agricultural reuse could be achieved within 3 days primary fermentation in a sewage plant. The rapid fermentation with use of radiation is effective to scale down a fermentor of a composting plant and the process reduces health risk for the workers as well as final users.

Acceptable level of radiation risk and its perception

Energy Technology Data Exchange (ETDEWEB)

Kusama, Tomoko; Shinozaki, Motoshi; Yoshizawa, Yasuo

1987-03-01

The acceptable level of radiation risk for public members, that is 10/sup -5//y, was proposed by ICRP and other international organizations. We studied to survey basic procedures of deriving this value and to derive an acceptable risk value in Japan by using similar procedures. The basic procedures to derive 10/sup -5//y were found as follows; (1) 0.1 percent of annual mortality from all diseases, (2) 0.1 percent of life time risk, (3) one percent of mortality from all causes in each age cohort and (4) corresponding value to 1 mSv annual radiation exposure. From these bases we derived the value of 10/sup -5//y as acceptable risk level in Japan. The perception to risk level of 10/sup -5//y in conventional life was investigated by means of questionnaires for 1,095 college students living in Tokyo. The risks considered in this study were natural background radiation, coffee, skiing, X-ray diagnosis, spontaneous cancer, passive smoking and air pollution. The most acceptable risk was the risk related with natural background radiation. And the risk of natural background radiation was more easily accepted by the students who had knowledges on natural background radiation. On the other hand, the risk from air pollution or passive smoking was the most adverse one.

Hypofractionation does not increase radiation pneumonitis risk with modern conformal radiation delivery techniques

DEFF Research Database (Denmark)

Vogelius, Ivan R; Westerly, David C; Cannon, George M

2010-01-01

To study the interaction between radiation dose distribution and hypofractionated radiotherapy with respect to the risk of radiation pneumonitis (RP) estimated from normal tissue complication probability (NTCP) models.......To study the interaction between radiation dose distribution and hypofractionated radiotherapy with respect to the risk of radiation pneumonitis (RP) estimated from normal tissue complication probability (NTCP) models....

Possibility of use of plat test systems for estimation of degree risk at radiation influence

International Nuclear Information System (INIS)

Gogebashvili, M.E.; Ivanishvili, N.I.

2010-01-01

Full text : Now one of the major problems of radiobiology is studying of degree risks at influence of small doses of an ionizing radiation. It is known, that not tumoral forms of the remote pathology are not stochastic, threshold, reactions of an organism to beam influence, frequency and weight depend on a dose, while carcinogenic and genetic effects (stochastic reactions) - frequency raises with dose increase. Last years the general hypothesis for definition of the raised risk in the irradiated populations, based on the theoretical analysis of extensive researches of various biological objects and epidemiological data, assumes existence of difficult parities between a dose of an irradiation and frequency of investigated effect. In this aspect the special importance is got by biological models with which help reception of quantitative parameters of influence of modifying factors for creation of more exact systems of monitoring of the remote radiobiological effects is possible. One of such systems is reciprocal grows reaction of stamen threads of plant tradescantia. At the heart of action of the given biomodel that growth tradescantia threads occurs from one initial cell is, and level of its radiating damage is shown in number of the subsequent cellular generation during the postradiating period. For an estimation of adequacy of the given model we had been chose two kinds tradescantia - Tradescantia virginiana L. and Tradescantia rosea Vent. It is notes, that at identical quantity of chromosomes their volume interface nucleus composable at Tradescantia virginiana L. 63.7 μ 3 , and at T.rosea Vent. - 38.5 μ 3 . Thus at interpretation of data it was possible to estimate them with the target theory. In work two basic criteria of an estimation of radiating damage - quantity of viable pollen threads and quantity of viable cells in each of threads have been used. The received results have shown strict correlation of reciprocal postradiating effects between used variants

Radiation risk perception in Institute 'Vinca'

International Nuclear Information System (INIS)

Milanovic, S.; Pavlovic, S

1999-01-01

The necessity for research and development of risk analysis methods arise from practical needs for safety for men and environment. Relating to speed of technological development risk is implemented in modern technological achievements. Complexity of approach to the concept of risk presents the essence of risk management. Risk management means to apply risk analysis in order to risk decrease and control. Database for risk management is in technical social, economic and political area. Risk perception is a construction in the field of social psychology i.e. public opinion research. These results are of importance for the risk management. Research presented in this paper has been done on the sample of 240 examines with two basic sub samples: person working with ionizing radiation (140 of them) and persons not working with ionizing radiation (100 of them). Attitudes to risk definition risk acceptance and relation to risk consequences. (author)

Calculating Risk: Radiation and Chernobyl.

Science.gov (United States)

Gale, Robert Peter

1987-01-01

Considers who is at risk in a disaster such as Chernobyl. Assesses the difficulty in translating information regarding radiation to the public and in determining the acceptability of technological risks. (NKA)

Low-level radiation risks in people

International Nuclear Information System (INIS)

Goloman, M.; Filjushkin, V. lgor

1993-01-01

Using the limited human data plus the relationships derived from the laboratory, a leukemia risk model has been developed as well as a suggested model for other cancers in people exposed to low levels of radiation. Theoretical experimental and epidemiological evidence will be presented in an integrated stochastic model for projection of radiation-induced cancer risks

To manage the ionizing radiations risks

International Nuclear Information System (INIS)

Metivier, H.; Romerio, F.

2000-01-01

Mister Romerio's work tackles the problem of controversy revealed by the experts in the field of estimation and management of ionizing radiations risks. The author describes the three paradigms at the base of the debate: the relationship without threshold (typified by the ICRP and its adepts), these ones that think that low doses risks are overestimated ( Medicine Academia for example) or that ones that believe that dose limits are too severe and induce unwarranted costs; then that ones that think that these risks are under-estimated and limits should be more reduced, even stop these practices that lead to public exposure to ionizing radiations. The author details the uncertainties about the risk estimations, refreshes the knowledge in radiation protection with the explanations of the different paradigms. At the end a table summarize the positions of the three paradigms

Indoor air-assessment: Indoor concentrations of environmental carcinogens

International Nuclear Information System (INIS)

Gold, K.W.; Naugle, D.F.; Berry, M.A.

1991-01-01

In the report, indoor concentration data are presented for the following general categories of air pollutants: radon-222, environmental tobacco smoke (ETS), asbestos, gas phase organic compounds, formaldehyde, polycyclic aromatic hydrocarbons (PAH), pesticides, and inorganic compounds. These pollutants are either known or suspect carcinogens (i.e., radon-222, asbestos) or more complex mixtures or classes of compounds which contain known or suspect carcinogens. Concentration data for individual carcinogenic compounds in complex mixtures are usually far from complete. The data presented for complex mixtures often include compounds which are not carcinogenic or for which data are insufficient to evaluate carcinogenicity. Their inclusion is justified, however, by the possibility that further work may show them to be carcinogens, cocarcinogens, initiators or promotors, or that they may be employed as markers (e.g., nicotine, acrolein) for the estimation of exposure to complex mixtures

Cancer risk from inorganics

International Nuclear Information System (INIS)

Swierenga, S.H.; Gilman, J.P.; McLean, J.R.

1987-01-01

Inorganic metals and minerals for which there is evidence of carcinogenicity are identified. The risk of cancer from contact with them in the work place, the general environment, and under conditions of clinical (medical) exposure is discussed. The evidence indicates that minerals and metals most often influence cancer development through their action as cocarcinogens. The relationship between the physical form of mineral fibers, smoking and carcinogenic risk is emphasized. Metals are categorized as established (As, Be, Cr, Ni), suspected (Cd, Pb) and possible carcinogens, based on the existing in vitro, animal experimental and human epidemiological data. Cancer risk and possible modes of action of elements in each class are discussed. Views on mechanisms that may be responsible for the carcinogenicity of metals are updated and analysed. Some specific examples of cancer risks associated with the clinical use of potentially carcinogenic metals and from radioactive pharmaceuticals used in therapy and diagnosis are presented. Questions are raised as to the effectiveness of conventional dosimetry in accurately measuring risk from radiopharmaceuticals. 302 references

Radiation induced cancer risk estimation for contralateral breast in 3D conformal treatments of post mastectomy cancer patients: based on OED

International Nuclear Information System (INIS)

Hemalatha, A.; Athiyaman, M.; Kumar, H.S.; Chougule, Arun

2016-01-01

A global comparison of breast cancer in India with other countries like US/China in 2012 gave a data that collectively the above countries including India account for almost one third of global breast cancer burden. According to this report for every two women newly diagnosed with breast cancer in India, one lady is dying of it. The curative radiotherapy for breast cancer treatment associated with scattered and leakage radiation exposure to critical organs like contralateral breast, lung etc. Radiation is one of the well known carcinogen of breast due its high radiosensititvity. The study done by Stovall et al concluded that the contralateral breast cancer risk is elevated for breast cancer patients of age less than 40 years if dose to health breast is greater than 1 Gy. So its necessary to evaluate dose to Contralateral Breast (ClB) for breast cancer patients for more than 1 Gy. The aim of this study is to compare the risks of secondary breast cancer from conventional wedge field and forward IMRT technique using the concept of OED-Organ Equivalent Dose/for chest wall irradiation of post mastectomy breast cancer patients

Radiation in medicine: Origins, risks and aspirations.

Science.gov (United States)

Donya, Mohamed; Radford, Mark; ElGuindy, Ahmed; Firmin, David; Yacoub, Magdi H

2014-01-01

The use of radiation in medicine is now pervasive and routine. From their crude beginnings 100 years ago, diagnostic radiology, nuclear medicine and radiation therapy have all evolved into advanced techniques, and are regarded as essential tools across all branches and specialties of medicine. The inherent properties of ionizing radiation provide many benefits, but can also cause potential harm. Its use within medical practice thus involves an informed judgment regarding the risk/benefit ratio. This judgment requires not only medical knowledge, but also an understanding of radiation itself. This work provides a global perspective on radiation risks, exposure and mitigation strategies.

Medical interventional procedures--reducing the radiation risks

International Nuclear Information System (INIS)

Cousins, C.; Sharp, C.

2004-01-01

Over the last 40 years, the number of percutaneous interventional procedures using radiation has increased significantly, with many secondary care clinicians using fluoroscopically guided techniques. Many procedures can deliver high radiation doses to patients and staff, with the potential to cause immediate and delayed radiation effects. The challenge for interventionists is to maximize benefit, whilst minimizing radiation risk to patients and staff. Non-radiologist clinicians are often inadequately trained in radiation safety and radiobiology. However, clinical governance and legislation now requires a more rigorous approach to protecting patients and staff. Protection can be ensured, and risks can be controlled, by appropriate design, procurement and commissioning of equipment; quality assurance; and optimal operational technique, backed by audit. Interventionists need knowledge and skills to reduce the risks. Appropriate training should include awareness of the potential for radiation injury, equipment operational parameters, doses measurement and recording methods and dose reduction techniques. Clinical governance requires informed consent, appropriate patient counselling and follow-up

Medical interventional procedures--reducing the radiation risks

Energy Technology Data Exchange (ETDEWEB)

Cousins, C. E-mail: claire.cousins@addenbrookes.nhs.uk; Sharp, C

2004-06-01

Over the last 40 years, the number of percutaneous interventional procedures using radiation has increased significantly, with many secondary care clinicians using fluoroscopically guided techniques. Many procedures can deliver high radiation doses to patients and staff, with the potential to cause immediate and delayed radiation effects. The challenge for interventionists is to maximize benefit, whilst minimizing radiation risk to patients and staff. Non-radiologist clinicians are often inadequately trained in radiation safety and radiobiology. However, clinical governance and legislation now requires a more rigorous approach to protecting patients and staff. Protection can be ensured, and risks can be controlled, by appropriate design, procurement and commissioning of equipment; quality assurance; and optimal operational technique, backed by audit. Interventionists need knowledge and skills to reduce the risks. Appropriate training should include awareness of the potential for radiation injury, equipment operational parameters, doses measurement and recording methods and dose reduction techniques. Clinical governance requires informed consent, appropriate patient counselling and follow-up.

Information from the National Institute of Radiation Protection about radiation doses and radiation risks at x-ray screening

International Nuclear Information System (INIS)

1975-05-01

This report gives a specification of data concerning radiation doses and risks at x-ray investigations of lungs. The dose estimations are principally based on measurements performed in 1974 by the National Institute of Radiation Protection. The radiation doses at x-ray screening are of that magnitude that the risk for acute radiation injuries is non-existent. At these low doses it has not either been able to prove that the radiation gives long-range effects as changes in the genes or cancer of late appearance. At considerable higher doses, more than tens of thousands of millirads, a risk of cancer appearance at a small part of all irradiated persons has been proved, based on the assumption that the cancer risk is proportional to the radiation dose. Cancer can thus occure at low radiation doses too. Because of the mass radiography in Sweden 1974 about twenty cases of cancer may appear in the future. (M.S.)

Approaches to the risk assessment of genotoxic carcinogens in food: a critical appraisal.

NARCIS (Netherlands)

O'Brien, J; Renwick, A G; Constable, A; Dybing, Erik; Müller, D J G; Schlatter, J; Slob, Wout; Tueting, W; Benthem, Jan van; Williams, G M; Wolfreys, A

2006-01-01

The present paper examines the particular difficulties presented by low levels of food-borne DNA-reactive genotoxic carcinogens, some of which may be difficult to eliminate completely from the diet, and proposes a structured approach for the evaluation of such compounds. While the ALARA approach is

Risk assessment and multiple stages in radiation carcinogenesis

International Nuclear Information System (INIS)

Burns, F.J.; Sawey, M.J.; Hosselet, S.; Garte, S.J.

1988-01-01

Epithelial cancers are induced in rat skin by ionizing radiation in a manner that is consistent with the dual action (i.e., 2 alterations) hypothesis of radiation effects on DNA. This hypothesis states that 2 initial alterations are necessary to start a normal cell on the pathway to career. The expected cancer yield, Y(D,t), as a function of dose, D, and time, t, has the form Y(D,t) = C(aLD + BD 2 )t,/sup n/, where L is the average LET, D is the radiation dose, a, B are constants and n is an integer. In accordance with multistage theory, n was assumed to be 2 on the basis of the best fit to cancer onset data. Values for a and B were estimated from cancer induction experiments in rat skin exposed to monoenergetic electrons (LET = 0.34 keV/μ) or argon ions (LET = 125 keV/μ). The repair halftime for carcinogenic alterations was found in split dose protocols to be 3.5 +- 1.0 hrs for electron radiation and >24 hrs for argon ions. As an approach to identifying cancer-relevant DNA alterations, skin tumor DNA was analyzed for oncogene activation. K-ras and c-myc oncogenes were activated in highly anaplastic rat skin cancers, whereas only one of these oncogenes, usually c-myc, was activated in squamous cell carcinomas and in comparatively benign basal cell carcinomas. 18 refs., 6 figs

Occupational radiation exposure risks: a review

Energy Technology Data Exchange (ETDEWEB)

Besar, Idris [PUSPATI, Selangor (Malaysia)

1984-06-01

This paper presents a review of the health risk as a result of exposure to ionizing radiation. A comparison of occupational risk among workers exposed to radiological and nonradiological harms are also presented. This comparison shows that radiation workers exposed to the current nuclear industry average of 3.4 mSv. per year are among the safest of all industry groupings.

Occupational radiation exposure risks: a review

International Nuclear Information System (INIS)

Idris Besar

1984-01-01

This paper presents a review of the health risk as a result of exposure to ionizing radiation. A comparison of occupational risk among workers exposed to radiological and nonradiological harms are also presented. This comparison shows that radiation workers exposed to the current nuclear industry average of 3.4 mSv. per year are among the safest of all industry groupings. (author)

Possibility of use of plant test systems for estimation of degree risk at radiation influence

International Nuclear Information System (INIS)

Gogebashvili, M.E; Ivanishvili, N.I.

2011-01-01

Full tex:Now one of the major problems of radiobiology is studying of degree risks at influence of small doses of an ionizing radiation. It is known, that not tumoral forms of the remote pathology are not stochastic, threshold, reactions of an organism to beam influence, frequency and weight depend on a dose, while carcinogenic and genetic effects (stochastic reactions) - frequency raises with dose increase. Last years the general hypothesis for definition of the raised risk in the irradiated populations, based on the theoretical analysis of extensive researches of various biological objects and epidemiological data, assumes existence of difficult parities between a dose of an irradiation and frequency of investigated effect. In this aspect the special importance is got by biological models with which help reception of quantitative parameters of influence of modifying factors for creation of more exact systems of monitoring of the remote radiobiological effects is possible.One of such systems is reciprocal grows reaction of stamen threads of plant tradescantia. At the heart of action of the given biomodel that growth tradescantia threads occurs from one initial cell is, and level of its radiating damage is shown in number of the subsequent cellular generation during the postradiating period. For an estimation of adequacy of the given model we had been chose two kinds tradescantia - Tradescantia virginiana L. and Tradescantia rosea Vent.In work two basic criteria of an estimation of radiating damage - quantity of viable pollen threads and quantity of viable cells in each of threads have been used. The received results have shown strict correlation of reciprocal postradiating effects between used variants.It is known, that at studying of influence of damaging factors of environment, including radiating, on live organisms the concept r iskcharacterizes degree of danger of influence expressed in quantity indicators. Thus, in most general case this includes probability

Cancer risks after radiation exposures

International Nuclear Information System (INIS)

Voelz, G.L.

1980-01-01

A general overview of the effects of ionizing radiation on cancer induction is presented. The relationship between the degree of risk and absorbed dose is examined. Mortality from radiation-induced cancer in the US is estimated and percentages attributable to various sources are given

Nonionising radiation and risk of human cancer: comparison of ultraviolet and radiofrequency radiation

International Nuclear Information System (INIS)

Green, A.

2003-01-01

Human exposure to ultraviolet radiation (UVR) comes largely from sunlight, although a small proportion of people receive high dose UVR from artificial sources. The causal link between solar UVR and the keratinocyte cancers, basal cell carcinomas and squamous cell carcinomas of the skin, is well-established based on a large body of observational and experimental evidence. UVR damages molecules such as DNA directly and this is the principal mechanism of carcinogenesis, though other mechanisms such as immunosuppression and interaction with viruses may also be involved. People are also exposed to another form of nonionising radiation, radiofrequency radiation (RFR), through occupation, the community environment from base stations, and through use of cellular telephones and related communications devices. However, unlike UVR, the relationship between RFR and cancer is far from clear. The main tumours that have been investigated to date are brain tumours and leukaemia but assessing the RFR exposure pathway to such cancers poses many methodological challenges for epidemiologists. Refinements to measurement of exposure are the major urgent need, and the lack of evidence regarding carcinogenic effects of RFR in experimental settings complicates the assessment. Further insights into the links between RFR and chronic disease such as cancer are likely in the next few years however when results of several large-scale epidemiological studies now in train around the world become available

Radiation-associated breast tumors display a distinct gene expression profile

DEFF Research Database (Denmark)

Broeks, Annegien; Braaf, Linde M; Wessels, Lodewyk F A

2010-01-01

PURPOSE: Women who received irradiation for Hodgkin's lymphoma have a strong increased risk for developing breast cancer. Approximately 90% of the breast cancers in these patients can be attributed to their radiation treatment, rendering such series extremely useful to determine whether a common...... radiation-associated cause underlies the carcinogenic process. METHODS AND MATERIALS: In this study we used gene expression profiling technology to assess gene expression changes in radiation-associated breast tumors compared with a set of control breast tumors of women unexposed to radiation, diagnosed...... at the same age. RNA was obtained from fresh frozen tissue samples from 22 patients who developed breast cancer after Hodgkin's lymphoma (BfHL) and from 20 control breast tumors. RESULTS: Unsupervised hierarchical clustering of the profile data resulted in a clustering of the radiation-associated tumors...

Radiation and human health

International Nuclear Information System (INIS)

Sagan, L.

1979-01-01

The growing controversy over low-level radiation risks stems from challenges to the assumptions that had been made about dose rate, linear theory, and total-body exposure. The debate has focused on whether there is a risk threshold or whether linearity overstates low-level risks, both theories being consistent with the available data. The generally accepted consensus on the risks of cancer and genetic effects are examined for several occupational groups and compared with recent studies which use different methodologies and reach conflicting conclusions. The weaknesses of the more recent studies are noted and the conclusion is reached that adherence to the earlier assumptions is probably the conservative position. Since the relationship of exposure to small doses of carcinogenic agents to cancer is a weak link and difficult to verify statistically, the prognosis is poor for resolving the question of linearity. It is important that the costs of reducing the risks be carefully balanced with the available evidence

Radiation risk estimation

International Nuclear Information System (INIS)

Roberts, P.B.

1981-11-01

This report outlines the major publications between 1976 and 1981 that have contributed to the evolution of the way in which radiation risks (cancer and hereditary birth defects) are assessed. The publications include the latest findings of the UNSCEAR, BEIR and ICRP committees, epidemiological studies at low doses and new assessments of the doses received by the Japanese A-bomb survivors. This report is not a detailed critique of those publications, but it highlights the impact of their findings on risk assessment

Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish

Energy Technology Data Exchange (ETDEWEB)

Lin, Chun-Hung [Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan (China); Chou, Pei-Hsin [Department of Environmental Engineering, National Cheng-Kung University, Tainan, Taiwan (China); Chen, Pei-Jen, E-mail: chenpj@ntu.edu.tw [Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan (China)

2014-07-30

Highlights: • We assess ecotoxicological impact of azole fungicides in the aquatic environment. • Carcinogenic and non-carcinogenic azoles show different CYP activities in medaka. • We compare azole-induced CYP expression and carcinogenesis between fish and rodents. • Liver CYP-enzyme induction is a key event in conazole-induced tumorigenesis. • We suggest toxicity evaluation methods for azole fungicides using medaka fish. - Abstract: Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish

Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish

International Nuclear Information System (INIS)

Lin, Chun-Hung; Chou, Pei-Hsin; Chen, Pei-Jen

2014-01-01

Highlights: • We assess ecotoxicological impact of azole fungicides in the aquatic environment. • Carcinogenic and non-carcinogenic azoles show different CYP activities in medaka. • We compare azole-induced CYP expression and carcinogenesis between fish and rodents. • Liver CYP-enzyme induction is a key event in conazole-induced tumorigenesis. • We suggest toxicity evaluation methods for azole fungicides using medaka fish. - Abstract: Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish

Potential for occupational and environmental exposure to ten carcinogens in Toronto

Energy Technology Data Exchange (ETDEWEB)

Muller, P. [ToxProbe Inc., Toronto, ON (Canada)

2002-03-01

A study was conducted in which several contaminants were assessed for their toxicological properties, potencies and occupational and environmental exposures in the city of Toronto. The contaminants included 1,3-butadiene, asbestos, benzene, cadmium, chromium, dioxins, formaldehyde, polycyclic aromatic hydrocarbons (PAHs), tetrachloroethylene, and trichloroethylene. The International Agency for Research on Cancer, the United States Environmental Protection Agency, and Health Canada have classified 9 of the 10 substances as human carcinogens. Tetrachloroethylene was classified as a probable human carcinogen. It was noted that there is no level of exposure for these chemicals that is without some risk. The information on the levels of selected contaminants in the workplace were obtained from existing literature. The sectors with the highest number of potentially exposed workers to these contaminants include the textiles industry, footwear manufacturing, wood products manufacturing, rubber products manufacturing, non-metallic mineral products manufacturing, fabricated metal products manufacturing, construction, land transport, and household services. The report discussed sources of emissions, routes and pathways of exposures and environmental levels, including outdoor air levels water concentrations, soil concentrations, and food concentrations. The report does not estimate the actual risk to Toronto residents due to environmental exposure to these carcinogens because data are insufficient to conduct such an assessment. However, some previous studies have indicated that exposure from ambient and indoor air has the greatest impact on human health. It is recommended that the city of Toronto remain up to date on the regulatory status of these chemicals. refs., tabs., figs., appendices.

Occupational radiation risk to radiologists

International Nuclear Information System (INIS)

Schuettmann, W.

1981-01-01

A review is given of the most important publications dealing with attempts to estimate the occupational radiation risk to radiologists by comparing data on their mortality from leukemia and other forms of cancer with respective data for other physicians who were not occupationally exposed to ionizing radiation. (author)

Risks associated with radiation: General information

International Nuclear Information System (INIS)

Baris, D.; Pomroy, C.; Chatterjee, R.M.

1995-07-01

Employers have a general responsibility to explain occupational risks to their workers. This document has been prepared to assist employers in this task. Employers should inform their workers about radiation risks associated with their work by: identifying the source(s) of radiation exposure; identifying the risk of health effects due to exposure to these sources, including the risk to the embryo and foetus of pregnant female workers; explaining the relationship between regulatory dose limits and the risk of health effects; and, explaining a worker's personal dose in terms of risk. This publication provides basic information on these subjects in a form that is clear and easy to understand. For further information, a list of suggested additional reading is included at the end of the text. (author). 15 refs., 5 tabs., 3 figs

Risks associated with radiation: General information

Energy Technology Data Exchange (ETDEWEB)

Baris, D; Pomroy, C; Chatterjee, R M

1995-07-01

Employers have a general responsibility to explain occupational risks to their workers. This document has been prepared to assist employers in this task. Employers should inform their workers about radiation risks associated with their work by: identifying the source(s) of radiation exposure; identifying the risk of health effects due to exposure to these sources, including the risk to the embryo and foetus of pregnant female workers; explaining the relationship between regulatory dose limits and the risk of health effects; and, explaining a worker`s personal dose in terms of risk. This publication provides basic information on these subjects in a form that is clear and easy to understand. For further information, a list of suggested additional reading is included at the end of the text. (author). 15 refs., 5 tabs., 3 figs.

Prediction of rodent carcinogenic potential of naturally occurring chemicals in the human diet using high-throughput QSAR predictive modeling

International Nuclear Information System (INIS)

Valerio, Luis G.; Arvidson, Kirk B.; Chanderbhan, Ronald F.; Contrera, Joseph F.

2007-01-01

Consistent with the U.S. Food and Drug Administration (FDA) Critical Path Initiative, predictive toxicology software programs employing quantitative structure-activity relationship (QSAR) models are currently under evaluation for regulatory risk assessment and scientific decision support for highly sensitive endpoints such as carcinogenicity, mutagenicity and reproductive toxicity. At the FDA's Center for Food Safety and Applied Nutrition's Office of Food Additive Safety and the Center for Drug Evaluation and Research's Informatics and Computational Safety Analysis Staff (ICSAS), the use of computational SAR tools for both qualitative and quantitative risk assessment applications are being developed and evaluated. One tool of current interest is MDL-QSAR predictive discriminant analysis modeling of rodent carcinogenicity, which has been previously evaluated for pharmaceutical applications by the FDA ICSAS. The study described in this paper aims to evaluate the utility of this software to estimate the carcinogenic potential of small, organic, naturally occurring chemicals found in the human diet. In addition, a group of 19 known synthetic dietary constituents that were positive in rodent carcinogenicity studies served as a control group. In the test group of naturally occurring chemicals, 101 were found to be suitable for predictive modeling using this software's discriminant analysis modeling approach. Predictions performed on these compounds were compared to published experimental evidence of each compound's carcinogenic potential. Experimental evidence included relevant toxicological studies such as rodent cancer bioassays, rodent anti-carcinogenicity studies, genotoxic studies, and the presence of chemical structural alerts. Statistical indices of predictive performance were calculated to assess the utility of the predictive modeling method. Results revealed good predictive performance using this software's rodent carcinogenicity module of over 1200 chemicals

Discussions about nuclear and radiation risk information communication

International Nuclear Information System (INIS)

Yang Bo; Wang Erqi; Peng Xianxun

2013-01-01

This paper described the definition and the objective of risk communication and the development of the risk communication research. It stated that how to establish a trustworthy relationship with public and the 8 aspects that should be done for keeping the relationship. With the analysis of the cognition and the influencing of the nuclear and radiation risk, this article figured out the factors which could influence the cognition of public on nuclear and radiation risk. Moreover, it explained the principles for enhancing the efficiency of the risk communication and the specific works in each phase of the risk communication. Finally, the suggestions for the development of the risk communication of the nuclear and radiation in China had been provided. (authors)

Tumorigenic action of beta, proton, alpha, and electron radiation on the rat skin. Progress report, August 1, 1977--January 31, 1979

International Nuclear Information System (INIS)

Burns, F.J.; Albert, R.E.

1979-01-01

Epithelial tumors are induced reproducibly in rat skin exposed to ionizing radiation, ultraviolet light, or polycyclic aromatic hydrocarbons. For these carcinogens, the comparative risk of tumor formation is being examined for clues to the generality of action and the mode of interaction of diverse carcinogens. Molecular lesions, such as, pyrimidine dimers and single-strand breaks in DNA have been measured as a basis for assessment of cellular dose. Dose-response for single doses, time response for multiple doses, and repair or recovery of oncogenic damage are major areas of current interest

Tumorigenic action of beta, proton, alpha and electron radiation on the rat skin. Progress report, August 1, 1977--January 31, 1979

International Nuclear Information System (INIS)

Burns, F.J.; Albert, R.E.

1979-01-01

Epithelial tumors are induced reproducibly in rat skin exposed to ionizing radiation, ultraviolet light, or polycyclic aromatic hydrocarbons. For these carcinogens, the comparative risk of tumor formation is being examined for clues to the generality of action and the mode of interaction of diverse carcinogens. Molecular lesions, such as, pyrimidine dimers and single-strand breaks in DNA have been measured as a basis for assessment of cellular dose. Dose-response for single doses, time-response for multiple doses, and repair or recovery of oncogenic damage are major areas of current interest

Radiation risk and science education

International Nuclear Information System (INIS)

Eijkelhof, H.M.C.

1996-01-01

Almost everywhere the topic of radioactivity is taught in the physics or chemistry classes of secondary schools. The question has been raised whether the common approach of teaching this topic would contribute to a better understanding of the risks of ionising radiation: and, if the answer is negative, how to explain and improve this situation? In a Dutch research programme which took almost ten years, answers to this question have been sought by means of analyses of newspaper reports, curriculum development, consultation with radiation experts, physics textbook analysis, interviews and questionnaires with teachers and pupils, class observations and curriculum development. Th main results of this study are presented and some recommendations given for science teaching and for communication with the public in general as regards radiation risk. (author)

Radiation in perspective applications, risks and protection

International Nuclear Information System (INIS)

1997-01-01

Everyone on earth is exposed to natural radiation. Radiation produced artificially is no different, either in kind or in effect, from that originating naturally. Although radiation has many beneficial applications, throughout medicine, industry and research, it can be harmful to human beings who must be adequately protected from unnecessary or excessive exposures. For this purpose, a thorough system of international principles and standards and stringent national legislations have been put in place. Yet radiation continues to be the subject of much public fear and controversy. This clearly written report, intended for the nonspecialist reader, aims to contribute to an enlightened debate on this subject by presenting the most up-to-date and authoritative material on sources, uses and affects of radiation, and ways in which people are protected from its risks. It discusses the development of radiation protection measures, its internationally agreed principles, and also addresses social and economic issues such as ethical questions, risk perceptions, risk comparisons, public participation in decision-making and the cost of protection. (author)

DNA repair, human cancer and assessment of radiation hazards

International Nuclear Information System (INIS)

Paterson, M.C.; Myers, D.K.

1979-09-01

Cancers, like genetic defects, are thought to be caused primarily by changes in DNA. Part of the evidence in support of this hypothesis derives from the study of certain rare hereditary disorders in man associated with high risk of cancer. Cells derived from patients suffering from at least one of these disorders, ataxia telangiectasia, appear to be defective in their ability to repair the damage caused by radiation and/or certain other environmental agents. Studies of the consequences of DNA repair suggest that currently accepted estimates of the carcinogenic hazards of low level radiation are substantially correct. There would appear to be some margin of safety involved in these risk estimates for the majority of the population, but any major reduction in the currently accepted risk estimates appears inadvisable in view of the existence of potentially radiosensitive subgroups forming a minority in the general population. (author)

Radiation induced cancer: risk assessment and prevention

International Nuclear Information System (INIS)

Shore, R.E.

1984-01-01

A number of factors have to be considered in defining the cancer risk from ionizing radiation. These include the radiation sensitivity of the target tissue(s), the temporal pattern of risk, the shape of the dose-incidence curve, the effects of low dose rates, host susceptibility factors, and synergism with other environmental exposures. For the population as a whole the largest sources of radiation exposure are natural background radiation and medical/dental radiation. Radiation exposures in the medical field make up the largest volume of occupational exposures as well. Although new technologies offer opportunities to lower exposures, worker training, careful exposure monitoring with remedial feedback, and monitoring to prevent unnecessary radiodiagnostic procedures may be even more important means of reducing radiation exposure. Screening of irradiated populations can serve a useful preventive function, but only for those who have received very high doses

Cooking temperature, heat-generated carcinogens, and the risk of stomach and colorectal cancers.

Science.gov (United States)

Ngoan, Le Tran; Thu, Nguyen Thi; Lua, Nguyen Thi; Hang, Lai Thi Minh; Bich, Nguyen Ngoc; Hieu, Nguyen Van; Quyet, Ha Van; Tai, Le Thi; Van, Do Duc; Khan, Nguyen Cong; Mai, Le Bach; Tokudome, Shinkan; Yoshimura, Takesumi

2009-01-01

Food change due to cooking temperature and unrecognized heat-formed chemical carcinogens may impact on the risk of stomach and colo-rectal cancers. To test this hypothesis a case-control study was performed. A total of 670 cases of stomach and colo-rectal cancers matched with 672 hospital controls for sex and -/+5 years age admitted to three hospitals in Hanoi city in the North Viet Nam from October 2006 to September 2007 were the subjects. Five levels of food change due to cooking temperature were based on food color; white, pale yellow, yellow, dark yellow, and burnt. We asked study subjects to themselves report which of these five colors was their preferable intake before the onset of disease. The present study included; fried fishes-meats-eggs-potato-tofu; grilled foods; roasted foods; sugar, bread, heated wheat, and biscuits. These were cooked at temperatures as high as from 165 to 240 degrees C, based on the literature. Adjusted estimation of odds ratio was conducted controlling for possible confounding factors using STATA 8.0. A high intake of roasted meats, bread and biscuit significantly increased the risk of cancer as much as OR= 1.63, 95%CI= 1.04-2.54; OR= 1.40, 95%CI= 1.03-1.90; OR= 1.60, 95%CI= 1.03-2.46 with probabilities for trend = 0.029, 0.035, and 0.037, respectively. For exposure among controls: 529 (79%) were not exposed at all to roasted meats; 449 (67%) were not exposed at all to bread; and 494 (74%) were not exposed at all to biscuit. Observation of food change due to cooking temperature based on color is practically feasible for detecting associations with risk of developing cancer.

Radiation carcinogenesis in mouse thymic lymphomas

International Nuclear Information System (INIS)

Kominami, Ryo; Niwa, Ohtsura

2006-01-01

Ionizing radiation is a well-known carcinogen for various human tissues and a complete carcinogen that is able to initiate and promote neoplastic progression. Studies of radiation-induced mouse thymic lymphomas, one of the classic models in radiation carcinogenesis, demonstrated that even the unirradiated thymus is capable of developing into full malignancy when transplanted into the kidney capsule or subcutaneous tissue of irradiated mice. This suggests that radiation targets tissues other than thymocytes to allow expansion of cells with tumorigenic potential in the thymus. The idea is regarded as the ''indirect mechanism'' for tumor development. This paper reviews the indirect mechanism and genes affecting the development of thymic lymphomas that we have analyzed. One is the Bcl11b/Rit1 tumor suppressor gene and the other is Mtf-1 gene affecting tumor susceptibility. (author)

Human health risk due to consumption of vegetables contaminated with carcinogenic polycyclic aromatic hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Khan, Sardar [Chinese Academy of Sciences, Xiamen (China). Inst. of Urban Environment; Peshawar Univ. (Pakistan). Dept. of Environmental Science; Cao, Qing [Chinese Academy of Sciences, Beijing (China). Research Center for Eco-Environemntal Sciences

2012-02-15

Polycyclic aromatic hydrocarbons (PAH) are persistent, toxic, and carcinogenic contaminants present in soil ecosystem globally. These pollutants are gradually accumulating in wastewater-irrigated soils and lead to the contamination of vegetables. Food chain contamination with PAH is considered as one of the major pathways for human exposure. This study was aimed to investigate the concentrations of PAH in soils and vegetables collected from wastewater-irrigated fields from metropolitan areas of Beijing, China. Origin of PAH, daily intake, and health risks of PAH through consumption of contaminated vegetables were studied. Soil samples were collected from the upper horizon (0-20 cm) of both wastewater-irrigated and reference sites and sieved (<2 mm mesh) and then followed by freeze-drying at -50 C and 123 {+-} 2 Pa. Standing vegetables were also collected from the same sites used for soil sampling and divided into roots and shoots, thoroughly washed with deionized water, and freeze-dried. PAH were extracted using the Soxhlet method with 200 mL DCM for 24 h, and the extracts were cleaned with silica adsorption chromatography prepared with silica gel, alumina, and capped with anhydrous sodium. The final concentrated extracts (soil and vegetable) were analyzed using gas chromatography-mass spectrometry (Agilent 6890). Bioaccumulation factors, daily intake of PAH, and carcinogenicity of PAH were calculated by different statistical equations. Results indicate that the soils and grown vegetables were contaminated with all possible carcinogenic PAH (declared by USEPA 2002) except indeno[1,2,3-c,d]pyrene. The highest concentration (242.9 {mu}g kg{sup -1}) was found for benzo(k)fluoranthene (BkF), while lowest (79.12 {mu}g kg{sup -1}) for benzo[a]pyrene (BaP). The emission sources of PAH were both pyrogenic and petrogenic in nature. However, the total concentrations of PAH were lower than the permissible limits set by different countries like Canada, Denmark and Germany

Approaches to radiation guidelines for space travel

International Nuclear Information System (INIS)

Fry, R.J.M.

1984-01-01

There are obvious risks in space travel that have loomed larger than any risk from radiation. Nevertheless, NASA has maintained a radiation program that has involved maintenance of records of radiation exposure, and planning so that the astronauts' exposures are kept as low as possible, and not just within the current guidelines. These guidelines are being reexamined currently by NCRP Committee 75 because new information is available, for example, risk estimates for radiation-induced cancer and about the effects of HZE particles. The current career limit is 400 rem to the blood forming organs. The appropriateness of this limit and its basis are being examined as well as the limits for specific organs. There is now considerably more information about age-dependency for radiation effects and this will be taken into account. In 1973 a committee of the National Research Council made a separate study of HZE particle effects and it was concluded that the attendant risks did not pose a hazard for low inclination near-earth orbit missions. Since that time work has been carried out on the so-called microlesions caused by HZE particles and on the relative carcinogenic effect of heavy ions, including iron. A remaining question is whether the fluence of HZE particles could reach levels of concern in missions under consideration. Finally, it is the intention of the committee to indicate clearly the areas requiring further research. 26 references, 1 figure, 7 tables

Quantitative risk in radiation protection standards

International Nuclear Information System (INIS)

Bond, V.P.

1978-01-01

The bases for developing quantitative assessment of exposure risks in the human being, and the several problems that accompany the assessment and introduction of the risk of exposure to high and low LET radiation into radiation protection, will be evaluated. The extension of the pioneering radiation protection philosophies to the control of other hazardous agents that cannot be eliminated from the environment will be discussed, as will the serious misunderstandings and misuse of concepts and facts that have inevitably surrounded the application to one agent alone, of the protection philosophy that must in time be applied to a broad spectrum of potentially hazardous agents. (orig.) [de

Meat intake, cooking methods, dietary carcinogens, and colorectal cancer risk: findings from the Colorectal Cancer Family Registry

International Nuclear Information System (INIS)

Joshi, Amit D; Kim, Andre; Lewinger, Juan Pablo; Ulrich, Cornelia M; Potter, John D; Cotterchio, Michelle; Le Marchand, Loic; Stern, Mariana C

2015-01-01

Diets high in red meat and processed meats are established colorectal cancer (CRC) risk factors. However, it is still not well understood what explains this association. We conducted comprehensive analyses of CRC risk and red meat and poultry intakes, taking into account cooking methods, level of doneness, estimated intakes of heterocyclic amines (HCAs) that accumulate during meat cooking, tumor location, and tumor mismatch repair proficiency (MMR) status. We analyzed food frequency and portion size data including a meat cooking module for 3364 CRC cases, 1806 unaffected siblings, 136 unaffected spouses, and 1620 unaffected population-based controls, recruited into the CRC Family Registry. Odds ratios (OR) and 95% confidence intervals (CI) for nutrient density variables were estimated using generalized estimating equations. We found no evidence of an association between total nonprocessed red meat or total processed meat and CRC risk. Our main finding was a positive association with CRC for pan-fried beefsteak (P trend < 0.001), which was stronger among MMR deficient cases (heterogeneity P = 0.059). Other worth noting associations, of borderline statistical significance after multiple testing correction, were a positive association between diets high in oven-broiled short ribs or spareribs and CRC risk (P trend = 0.002), which was also stronger among MMR-deficient cases, and an inverse association with grilled hamburgers (P trend = 0.002). Our results support the role of specific meat types and cooking practices as possible sources of human carcinogens relevant for CRC risk

Evaluating shielding effectiveness for reducing space radiation cancer risks

International Nuclear Information System (INIS)

Cucinotta, Francis A.; Kim, Myung-Hee Y.; Ren, Lei

2006-01-01

We discuss calculations of probability distribution functions (PDF) representing uncertainties in projecting fatal cancer risk from galactic cosmic rays (GCR) and solar particle events (SPE). The PDFs are used in significance tests for evaluating the effectiveness of potential radiation shielding approaches. Uncertainties in risk coefficients determined from epidemiology data, dose and dose-rate reduction factors, quality factors, and physics models of radiation environments are considered in models of cancer risk PDFs. Competing mortality risks and functional correlations in radiation quality factor uncertainties are included in the calculations. We show that the cancer risk uncertainty, defined as the ratio of the upper value of 95% confidence interval (CI) to the point estimate is about 4-fold for lunar and Mars mission risk projections. For short-stay lunar missions ( 180d) or Mars missions, GCR risks may exceed radiation risk limits that are based on acceptable levels of risk. For example, the upper 95% CI exceeding 10% fatal risk for males and females on a Mars mission. For reducing GCR cancer risks, shielding materials are marginally effective because of the penetrating nature of GCR and secondary radiation produced in tissue by relativistic particles. At the present time, polyethylene or carbon composite shielding cannot be shown to significantly reduce risk compared to aluminum shielding based on a significance test that accounts for radiobiology uncertainties in GCR risk projection

Assessment of the radiation risk from diagnostic radiology

International Nuclear Information System (INIS)

Streffer, C.; Mueller, W.U.

1995-01-01

In any assessment of radiation risks from diagnostic radiology the main concern is the possible induction of cancer. It now appears to be beyond all doubt that ionizing rays invite the development of cancer in humans. The radiation doses encountered in diagnostic radiology generally vary from 1 to 50 mSv. For this dose range, no measured values are available to ascertain cancer risks from ionizing rays. The effects of such doses must therefore be extrapolated from higher dose levels under consideration of given dose-effect relationships. All relevant figures for diagnostic X-ray measures are therefore mathematically determined approximate values. The stochastic radiation risk following non-homogeneous radiation exposure is assessed on the basis of the effective dose. This dose was originally introduced to ascertain the risk from radioactive substances incorporated at the working place. A secondary intention was to trigger further developmental processes in radiation protection. Due to the difficulties previously outlined and the uncertainties surrounding the determination and assessment of the effective dose from diagnostic X-ray procedures, this dose should merely be used for technological refinements and comaprisons of examination procedures. It appears unreasonable that the effective doses determined for the individual examinations are summed up to obtain a collective effective dose and to multiply this with a risk factor so as to give an approximation of the resulting deaths from cancer. A reasonable alternative is to inform patients subjected to X-ray examinations about the associated radiation dose and to estimate form this the magnitude of the probable radiation risk. (orig./MG) [de

Radiation-Induced Second Cancer Risk Estimates From Radionuclide Therapy

Science.gov (United States)

Bednarz, Bryan; Besemer, Abigail

2017-09-01

The use of radionuclide therapy in the clinical setting is expected to increase significantly over the next decade. There is an important need to understand the radiation-induced second cancer risk associated with these procedures. In this study the radiation-induced cancer risk in five radionuclide therapy patients was investigated. These patients underwent serial SPECT imaging scans following injection as part of a clinical trial testing the efficacy of a 131Iodine-labeled radiopharmaceutical. Using these datasets the committed absorbed doses to multiple sensitive structures were calculated using RAPID, which is a novel Monte Carlo-based 3D dosimetry platform developed for personalized dosimetry. The excess relative risk (ERR) for radiation-induced cancer in these structures was then derived from these dose estimates following the recommendations set forth in the BEIR VII report. The radiation-induced leukemia ERR was highest among all sites considered reaching a maximum value of approximately 4.5. The radiation-induced cancer risk in the kidneys, liver and spleen ranged between 0.3 and 1.3. The lifetime attributable risks (LARs) were also calculated, which ranged from 30 to 1700 cancers per 100,000 persons and were highest for leukemia and the liver for both males and females followed by radiation-induced spleen and kidney cancer. The risks associated with radionuclide therapy are similar to the risk associated with external beam radiation therapy.

Biological influence from low dose and low-dose rate radiation

International Nuclear Information System (INIS)

Magae, Junji

2007-01-01

Although living organisms have defense mechanisms for radioadaptive response, the influence is considered to vary qualitatively and quantitatively for low dose and high dose, as well as for low-dose rate and high-dose rate. This article describes the bioresponse to low dose and low-dose rate. Among various biomolecules, DNA is the most sensitive to radiation, and accurate replication of DNA is an essential requirement for the survival of living organisms. Also, the influence of active enzymes resulted from the effect of radiation on enzymes in the body is larger than the direct influence of radiation on the body. After this, the article describes the carcinogenic risk by low-dose radiation, and then so-called Hormesis effect to create cancer inhibition effect by stimulating active physiology. (S.K.)

Environmental radiation standards and risk limitation

International Nuclear Information System (INIS)

Kocher, D.C.

1987-01-01

The Environmental Protection Agency and Nuclear Regulatory Commission have established environmental radiation standards for specific practices which correspond to limits on risk to the public that vary by several orders of magnitude and often are much less than radiation risks that are essentially unregulated, e.g., risks from radon in homes. This paper discusses a proposed framework for environmental radiation standards that would improve the correspondence with limitation of risk. This framework includes the use of limits on annual effective dose equivalent averaged over a lifetime, rather than limits on dose equivalent to whole body or any organ for each year of exposure, and consideration of exposures of younger age groups as well as adults; limits on annual effective dose equivalent averaged over a lifetime no lower than 0.25 mSv (25 mrem) per practice; maintenance of all exposures as low as reasonably achievable (ALARA); and establishment of a generally applicable de minimis dose for public exposures. Implications of the proposed regulatory framework for the current system of standards for limiting public exposures are discussed. 20 refs

A Review of the Carcinogenic Potential of Bisphenol A

Science.gov (United States)

Seachrist, Darcie D; Bonk, Kristen W.; Ho, Shuk-Mei; Prins, Gail S.; Soto, Ana M.; Keri, Ruth A.

2015-01-01

The estrogenic properties of bisphenol A (BPA), a ubiquitous synthetic monomer that can leach into the food and water supply, have prompted considerable research into exposure-associated health risks in humans. Endocrine-disrupting properties of BPA suggest it may impact developmental plasticity during early life, predisposing individuals to disease at doses below the oral reference dose (RfD) established by the Environmental Protection Agency in 1982. Herein, we review the current in vivo literature evaluating the carcinogenic properties of BPA. We conclude that there is substantial evidence from rodent studies indicating that early-life BPA exposures below the RfD lead to increased susceptibility to mammary and prostate cancer. Based on the definitions of “carcinogen” put forth by the International Agency for Research on Cancer and the National Toxicology Program, we propose that BPA may be reasonably anticipated to be a human carcinogen in the breast and prostate due to its tumor promoting properties. PMID:26493093

Susceptibility to radiation-induced mammary carcinoma in genetically resistant Copenhagen rats

International Nuclear Information System (INIS)

Kamiya, Kenji; Nitta, Yumiko; Gould, M.N.

2000-01-01

The objective of this experiment was to compare the cellular basis of mammary cancer induction by a chemical carcinogen with induction by ionizing radiation in three strains of rats (inbred that have different genetic susceptibilities: COP rats, F344 rats, and WF rats). Rats were given a single intraperitoneal injection of 50 mg MNU/kg body weight as a mammary-tumor-inducing chemical carcinogen and were irradiated with a 3.0 Gy dose of 60 Co gamma rays at a dose rate of 26.58±1.19 cGy/min. The rats were inspected weekly, and they were killed and necropsied whenever palpable tumors were detected or they became moribund. The histopathological and immunohistochemical characteristics of the mammary tumors were investigated. A transplantation experiment using selected primary mammary tumors that developed in COP rats exposed to gamma rays was also performed to investigate the transplantability of mammary tumors induced by ionizing radiation. The sensitivity of the WF and F344 rats and the resistance of the COP rats to mammary carcinoma induction by the chemical carcinogen MNU was confirmed. In contrast to the chemical carcinogens, no difference in susceptibility to radiation induction of mammary carcinomas was detected among the three strains of rats, and immunohistochemical examination indicated that the radiation-induced carcinomas consisted of more highly differentiated cells than the MNU-induced cancers. The results of the experiment appear to support the hypothesis that differentiated mammary gland tissue is more resistant to chemical carcinogens than to cancer induction by radiation. The authors conclude that radiation-induced cancers in rats may develop via different pathways or from different cell populations than chemically induced cancers. (K.H.)

Susceptibility to radiation-induced mammary carcinoma in genetically resistant Copenhagen rats

Energy Technology Data Exchange (ETDEWEB)

Kamiya, Kenji; Nitta, Yumiko [Hiroshima Univ. (Japan). Research Inst. for Radiation Biology and Medicine; Gould, M.N.

2000-07-01

The objective of this experiment was to compare the cellular basis of mammary cancer induction by a chemical carcinogen with induction by ionizing radiation in three strains of rats (inbred that have different genetic susceptibilities: COP rats, F344 rats, and WF rats). Rats were given a single intraperitoneal injection of 50 mg MNU/kg body weight as a mammary-tumor-inducing chemical carcinogen and were irradiated with a 3.0 Gy dose of {sup 60} Co gamma rays at a dose rate of 26.58{+-}1.19 cGy/min. The rats were inspected weekly, and they were killed and necropsied whenever palpable tumors were detected or they became moribund. The histopathological and immunohistochemical characteristics of the mammary tumors were investigated. A transplantation experiment using selected primary mammary tumors that developed in COP rats exposed to gamma rays was also performed to investigate the transplantability of mammary tumors induced by ionizing radiation. The sensitivity of the WF and F344 rats and the resistance of the COP rats to mammary carcinoma induction by the chemical carcinogen MNU was confirmed. In contrast to the chemical carcinogens, no difference in susceptibility to radiation induction of mammary carcinomas was detected among the three strains of rats, and immunohistochemical examination indicated that the radiation-induced carcinomas consisted of more highly differentiated cells than the MNU-induced cancers. The results of the experiment appear to support the hypothesis that differentiated mammary gland tissue is more resistant to chemical carcinogens than to cancer induction by radiation. The authors conclude that radiation-induced cancers in rats may develop via different pathways or from different cell populations than chemically induced cancers. (K.H.)

Radiation risk education program - local

International Nuclear Information System (INIS)

Bushong, S.C.; Archer, B.R.

1980-01-01

This article points out the lack of knowledge by the general public and medical profession concerning the true risks of radiation exposure. The author describes an educational program which can be implemented at the local level to overcome this deficiency. The public must understand the enormous extent of benefit derived from radiation applications in our society

Radiation risk - historical perspective and current issues

Energy Technology Data Exchange (ETDEWEB)

Kellerer, Albrecht M. [Strahlenbiologisches Institut, Ludwig-Maximilians-Universitaet, Munich, Germany and Institute for Radiation Biology, GSF-National Research Center for Environment and Health, Neuherberg (Germany)

2002-09-01

The assessment of radiation risk needs to be seen against the background of a historical development that has reversed the initial belief in a general beneficial effect of radiation to apprehension and fear. Numerical risk estimates are, today, based on large epidemiological studies, and the observations on the A-bomb survivors are outlined as the primary source of information. Since the epidemiological findings are obtained from relatively high radiation exposures, extrapolations are required to the much lower doses that are relevant to radiation protection. The evolution of extrapolation procedures up to current attempts at mechanistic modelling is outlined, and some of the open issues are reviewed. (author)

Radiation risk - historical perspective and current issues

International Nuclear Information System (INIS)

Kellerer, Albrecht M.

2002-01-01

The assessment of radiation risk needs to be seen against the background of a historical development that has reversed the initial belief in a general beneficial effect of radiation to apprehension and fear. Numerical risk estimates are, today, based on large epidemiological studies, and the observations on the A-bomb survivors are outlined as the primary source of information. Since the epidemiological findings are obtained from relatively high radiation exposures, extrapolations are required to the much lower doses that are relevant to radiation protection. The evolution of extrapolation procedures up to current attempts at mechanistic modelling is outlined, and some of the open issues are reviewed. (author)

Systematic review on physician's knowledge about radiation doses and radiation risks of computed tomography

International Nuclear Information System (INIS)

Krille, Lucian; Hammer, Gael P.; Merzenich, Hiltrud; Zeeb, Hajo

2010-01-01

Background: The frequent use of computed tomography is a major cause of the increasing medical radiation exposure of the general population. Consequently, dose reduction and radiation protection is a topic of scientific and public concern. Aim: We evaluated the available literature on physicians' knowledge regarding radiation dosages and risks due to computed tomography. Methods: A systematic review in accordance with the Cochrane and PRISMA statements was performed using eight databases. 3091 references were found. Only primary studies assessing physicians' knowledge about computed tomography were included. Results: 14 relevant articles were identified, all focussing on dose estimations for CT. Overall, the surveys showed moderate to low knowledge among physicians concerning radiation doses and the involved health risks. However, the surveys varied considerably in conduct and quality. For some countries, more than one survey was available. There was no general trend in knowledge in any country except a slight improvement of knowledge on health risks and radiation doses in two consecutive local German surveys. Conclusions: Knowledge gaps concerning radiation doses and associated health risks among physicians are evident from published research. However, knowledge on radiation doses cannot be interpreted as reliable indicator for good medical practice.

Radiation and society: Comprehending radiation risk. V. 3. Proceedings of an international conference

International Nuclear Information System (INIS)

1997-01-01

This IAEA international conference on Radiation and Society was the first major international meeting devoted to the comprehension of radiation risk, public attitude towards radiation risk and hazards encountered by the general public in contaminated areas. Volume three of the proceedings contains the speeches, ten introductory papers, summaries of the technical discussion sessions, the key note paper on uncertainties in the health impact of environmental pollutants. Refs, figs, tabs

Aircrew radiation exposure: sources-risks-measurement

International Nuclear Information System (INIS)

Duftschmid, K.E.

1994-05-01

A short review is given on the actual aircrew exposure and its sources. The resulting risks for harmful effects to the health and discuss methods for in-flight measurements of exposure is evaluated. An idea for a fairly simple and economic approach to a practical, airborne active dosimeter for the assessment of individual crew exposure is presented. The exposure of civil aircrew to cosmic radiation, should not be considered a tremendous risk to the health, there is no reason for panic. However, being significantly higher than the average exposure to radiation workers, it can certainly not be neglected. As recommended by ICRP, aircrew exposure has to be considered occupational radiation exposure and aircrews are certainly entitled to the same degree of protection, as other ground-based radiation workers have obtained by law, since long time. (author)

Epidemiology and risk assessment for radiation

International Nuclear Information System (INIS)

Badwe, R.A.

2014-01-01

The hazard and exposures from radiation are known with reasonable accuracy. However, at 'low levels' uncertainty persists as to whether the dose response relationship is linear and whether there is a dose threshold, below which there is no risk. Some have proposed that 'low' exposures to radiation may be beneficial, a hypothesis referred to as 'hormesis'. Over recent decades, various expert groups have adopted linear no-threshold dose-response models for radiation and cancer, based on review of epidemiological and biological evidence. The unexpected epidemic of thyroid cancer among children following the Chernobyl disaster was noticed. The research with epidemiological data and knowledge of the radionuclides to which the children were exposed is needed. Currently a debate concerning potential risks of high frequency electromagnetic radiation from mobile phones illustrates another need for further research

Radiation sources, radiation environment and risk level at Dubna

International Nuclear Information System (INIS)

Komochkov, M.M.

1991-01-01

The overall information about ionizing radiation sources, which form radiation environment and risk at Dubna, is introduced. Systematization of the measurement results is performed on the basis of the effective dose and losses of life expectancy. The contribution of different sources to total harm of Dubna inhabitants has been revealed. JINR sources carry in ∼ 4% from the total effective dose of natural and medicine radiation sources; the harm from them is much less than the harm from cigarette smoking. 18 refs.; 2 tabs

Radiation and Gut

International Nuclear Information System (INIS)

Potten, C.S.; Hendry, J.H.

1995-08-01

Texts on gut with reference to radiation (or other cytotoxic and carcinogenic agents) consist of primary research papers, review articles, or books which are now very out-of-date. With this in mind, the present book was conceived. Here, with chapters by experts in the field, we cover the basic structure and cell replacement process in the gut, the physical situation relevant for gut radiation exposure and a description of some of the techniques used to study radiation effects, in particular the clonal regeneration assay that assesses stem cell functional capacity. Chapters comprehensively cover the effects of radiation in experimental animal model systems and clinical experiences. The effects of radiation on the supportive tissue of the gut is also reviewed. The special radiation situation involving ingested radionuclides is reviewed and the most important late response-carcinogenesis-within the gut is considered. This book follows a volume on 'Radiation and Skin' (1985) and another on 'Radiation and Bone Marrow' is in preparation. The present volume is intended to cover the anatomy and renewal characteristics of the gut, and its response in terms of carcinogenicity and tissue injury in mammalian species including in particular man. The book is expected to be useful to students and teachers in these topics, as well as clinical oncologists (radiotherapists) and medical oncologists, and industrial health personnel. 70 figs., 20 tabs., 869 refs

Radiation risk management at DOE accelerator facilities

International Nuclear Information System (INIS)

Dyck, O.B. van.

1997-01-01

The DOE accelerator contractors have been discussing among themselves and with the Department how to improve radiation safety risk management. This activity-how to assure prevention of unplanned high exposures-is separate from normal exposure management, which historically has been quite successful. The ad-hoc Committee on the Accelerator Safety Order and Guidance [CASOG], formed by the Accelerator Section of the HPS, has proposed a risk- based approach, which will be discussed. Concepts involved are risk quantification and comparison (including with non-radiation risk), passive and active (reacting) protection systems, and probabilistic analysis. Different models of risk management will be presented, and the changing regulatory environment will also be discussed

Dose evaluation and protection of cosmic radiation

International Nuclear Information System (INIS)

Iwai, Satoshi; Takagi, Toshiharu

2004-01-01

This paper explained the effects of cosmic radiation on aircraft crews and astronauts, as well as related regulations. International Commission on Radiological Protection (ICRP) recommends the practice of radiation exposure management for the handling/storage of radon and materials containing natural radioactive substances, as well as for boarding jet aircraft and space flight. Common aircraft crew members are not subject to radiation exposure management in the USA and Japan. In the EU, the limit value is 6 mSv per year, and for the crew group exceeding this value, it is recommended to keep records containing appropriate medical examination results. Pregnant female crewmembers are required to keep an abdominal surface dose within 1 mSv. For astronauts, ICRP is in the stage of thinking about exposure management. In the USA, National Council on Radiation Protection and Measurement has set dose limits for 30 days, 1 year, and lifetime, and recommends lifetime effective dose limits against carcinogenic risk for each gender and age group. This is the setting of the dose limits so that the risk of carcinogenesis, to which space radiation exposure is considered to contribute, will reach 3%. For cosmic radiation environments at spacecraft inside and aircraft altitude, radiation doses can be calculated for astronauts and crew members, using the calculation methods for effective dose and dose equivalent for tissue. (A.O.)

[Health Risk Assessment of Drinking Water Quality in Tianjin Based on GIS].

Science.gov (United States)

Fu, Gang; Zeng, Qiang; Zhao, Liang; Zhang, Yue; Feng, Bao-jia; Wang, Rui; Zhang, Lei; Wang, Yang; Hou, Chang-chun

2015-12-01

This study intends to assess the potential health hazards of drinking water quality and explore the application of geographic information system( GIS) in drinking water safety in Tianjin. Eight hundred and fifty water samples from 401 sampling points in Tianjin were measured according to the national drinking water standards. The risk assessment was conducted using the environmental health risk assessment model recommended by US EAP, and GIS was combined to explore the information visualization and risk factors simultaneously. The results showed that the health risks of carcinogens, non-carcinogens were 3.83 x 10⁻⁵, 5.62 x 10⁻⁹ and 3.83 x 10⁻⁵ for total health risk respectively. The rank of health risk was carcinogen > non-carcinogen. The rank of carcinogens health risk was urban > new area > rural area, chromium (VI) > cadmium > arsenic > trichlormethane > carbon tetrachloride. The rank of non-carcinogens health risk was rural area > new area > urban, fluoride > cyanide > lead > nitrate. The total health risk level of drinking water in Tianjin was lower than that of ICRP recommended level (5.0 x 10⁻⁵), while was between US EPA recommended level (1.0 x 10⁻⁴-1.0 x 10⁻⁶). It was at an acceptable level and would not cause obvious health hazards. The main health risks of drinking water came from carcinogens. More attentions should be paid to chromium (VI) for carcinogens and fluoride for non-carcinogens. GIS can accomplish information visualization of drinking water risk assessment and further explore of risk factors.

Informing people about radiation risks: a review of obstacles to public understanding and effective risk communication

International Nuclear Information System (INIS)

Covello, V.T.

1988-01-01

This paper reviews the literature on informing people about radiation risks. The paper focuses on obstacles to public understanding and effective risk communication. The paper concludes with a set of guidelines for communicating information about radiation risks to the public. The paper also includes an appendix that reviews the literature on one of the most important tools for communicating information about radiation risks: risk comparisons

Radiation and risk in physics education

International Nuclear Information System (INIS)

Eijkelhof, H.M.C.

1990-01-01

The study reported in this thesis deals with physics education, particularly with the teaching and learning of radioactivity and ionizing radiation. It is a follow up of earlier research and development work in the Dutch Physics Curriculum Development Project (PLON) on a unit called Ionizing Radiation. The central theme of this unit was the acceptability of the risks of ionizing radiation. Preliminary evaluation of the effectiveness of the PLON-unit showed that pupils appear to have lay-ideas which seem to be resistant to change. In this study the nature and persistence of these lay-ideas have been explored and a set of recommendations have been developed for writing curriculum materials and for teaching strategies, for physics lessons in secondary high school, in order to promote thoughtful risk analysis and assessment as regards applications of ionizing radiation. (H.W.). 225 refs.; 3 figs.; 41 tabs

Working group 6: Health. 2. Biological radiation effects

International Nuclear Information System (INIS)

Maisin, J.R.

1976-01-01

Health hazards associated with the increasing development of nuclear energy have been evaluated for the Belgian population. Nuclear industry has been shown to be safer than conventional industry, epidemiological and toxicological data connected with the nuclear energy being more complete than those related to the conventional energy. Somatic and genetic effects of small and high doses of ionizing radiations on the Belgian population have been estimated. Small doses of ionizing radiations are expected to promote only carcinogenic effects. The latent period of cancers, the plateau region (period of high risk) and the absolute and relative risk expressed per rem per 10 6 people per year for leukaemia (having the highest risk) and for the ''other cancers'' have been also estimated. These estimations were obtained by linear extrapolation to the 1 rem level from observations made after irradiation at relatively high dose levels and much higher dose rates. Strict protective regulations have been recommended in order to reduce to a minimum the exposure of population to ionizing radiations as well as to get more information on the radioactive genetic and somatic consequences on population. (G.C.)

Environmental exposure to carcinogens in northwestern Cameroon ...

African Journals Online (AJOL)

African Health Sciences ... Humans can prevent themselves from a number of workplace and environmental carcinogens. ... Methods: A structured questionnaire was used to collect information on carcinogen exposure in the workplace and environment through trained field staff from volunteers after gaining informed ...

Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

Science.gov (United States)

Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

2006-01-01

Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low

Prototype Biology-Based Radiation Risk Module Project

Science.gov (United States)

Terrier, Douglas; Clayton, Ronald G.; Patel, Zarana; Hu, Shaowen; Huff, Janice

2015-01-01

Biological effects of space radiation and risk mitigation are strategic knowledge gaps for the Evolvable Mars Campaign. The current epidemiology-based NASA Space Cancer Risk (NSCR) model contains large uncertainties (HAT #6.5a) due to lack of information on the radiobiology of galactic cosmic rays (GCR) and lack of human data. The use of experimental models that most accurately replicate the response of human tissues is critical for precision in risk projections. Our proposed study will compare DNA damage, histological, and cell kinetic parameters after irradiation in normal 2D human cells versus 3D tissue models, and it will use a multi-scale computational model (CHASTE) to investigate various biological processes that may contribute to carcinogenesis, including radiation-induced cellular signaling pathways. This cross-disciplinary work, with biological validation of an evolvable mathematical computational model, will help reduce uncertainties within NSCR and aid risk mitigation for radiation-induced carcinogenesis.

Risk analysis of external radiation therapy

International Nuclear Information System (INIS)

Arvidsson, Marcus

2011-09-01

External radiation therapy is carried out via a complex treatment process in which many different groups of staff work together. Much of the work is dependent on and in collaboration with advanced technical equipment. The purpose of the research task has been to identify a process for external radiation therapy and to identify, test and analyze a suitable method for performing risk analysis of external radiation therapy

QSAR pre-screen of 70,983 substances for genotoxic carcinogenicity, mutagenicity and developmental toxicity in the EU FP7 project ChemScreen

DEFF Research Database (Denmark)

Wedebye, Eva Bay; Dybdahl, Marianne; Nikolov, Nikolai Georgiev

2014-01-01

be performed in REACH on known genotoxic carcinogens or germ cell mutagens with appropriate risk management measures implemented, a QSAR pre-screen for genotoxic carcinogenicity, germ cell mutagenicity and (limited) developmental toxicity was included in the project. Predictions for estrogenic and anti...... algorithms were applied to combine the predictions from the individual models to reach overall predictions for genotoxic carcinogenicity, germ cell mutagenicity and developmental toxicity. Furthermore, the full list of REACH pre-registered substances (143,835) was searched for substances containing certain...

Risks and hazards from conventional and radiation sources

International Nuclear Information System (INIS)

Iyer, P.S.; Ganguly, A.K.

1978-01-01

Beneficial uses of radioisotopes in medicine, industry, agriculture and research are discussed. In absence of adequate safety precautions, uses of radiation may also result in harmful biological effects or genetic effects. Radiation risks and hazards are evaluated by comparing with other risks and hazards which are routinely encountered. The risk of fatality per year by various causes in U.S.A. is given. It is stated with examples and observations that some of the routine habits and necessities and minor luxuries are more risky than radiation risks. Countrywide radiation safety program in India by the Department of Atomic Energy is described in brief. Data are given to show that the risks from radiation are much lower in comparison with many conventional sources. More efficient equipment such as image intensifier is recommended to help to reduce the patient dose. It is stated that caution has to be exercised while handling the X-ray machines which may be harmful not only to patients but to doctors also. As regards, nuclear medicine, it is mentioned that though it is a fast expanding speciality in India, the number of procedures carried out in various centres is small as compared to U.S.A. and France. Some instances are given to show the consequences of the ignorance of the radiation hazards in operating machines in X-ray and gamma ray beam therapy facilities. A survey made by DRP, BARC revealed that some research laboratories lacked basic radiation protection requirements in using X-ray crystallography or analytical equipment. (B.G.W.)

Biological effects of low-level ionizing and non-ionizing radiation

International Nuclear Information System (INIS)

Upton, A.C.

1986-01-01

Early in this century it was recognized that large doses of ionizing radiation could injure almost any tissue in the body, but small doses were generally thought to be harmless. By the middle of the century however it came to be suspected that even the smallest doses of ionizing radiation to the gonads might increase the risk of hereditary disease in subsequently-conceived offspring. Since then the hypothesis that carcinogenic and teratogenic effects also have no threshold has been adopted for purposes of radiological protection. It is estimated nevertheless that the risks that may be associated with natural background levels of ionizing irradiation are too small to be detectable. Hence validation of such risk estimates will depend on further elucidation of the dose-effect relationships and mechanisms of the effects in question, through studies at higher dose levels. In contrast to the situation with ionizing radiation, exposure to natural background levels of ultraviolet radiation has been implicated definitively in the etiology of skin cancers in fair-skinned individuals. Persons with inherited effects in DNA repair capacity are particularly susceptible. Non-ionizing radiations of other types can also affect health at high dose levels, but whether they can cause injury at low levels of exposure is not known

Radiation carcinogenesis: radioprotectors and photosensitizers

International Nuclear Information System (INIS)

Fry, R.J.M.

1982-01-01

This paper outlines 1) some of the salient features of radiation carcinogenesis that are pertinent to the questions of how the carcinogenic effects might be influenced, 2) the effects of radioprotectors on ionizing radiation-induced cancer, and 3) the effect of photosensitizers on UVR-induced skin cancer

Radiation carcinogenesis: radioprotectors and photosensitizers

Energy Technology Data Exchange (ETDEWEB)

Fry, R.J.M.

1982-01-01

This paper outlines 1) some of the salient features of radiation carcinogenesis that are pertinent to the questions of how the carcinogenic effects might be influenced, 2) the effects of radioprotectors on ionizing radiation-induced cancer, and 3) the effect of photosensitizers on UVR-induced skin cancer.

Radiation doses to neonates and issues of radiation protection in a special care baby unit

International Nuclear Information System (INIS)

Armpilia, C.I.; Fife, I.A.J.; Croasdale, P.L.

2001-01-01

Radiographs are most commonly taken in the neonatal period to assist in the diagnosis and management of respiratory difficulties. Frequent accurate radiographic assessment is required and a knowledge of the radiation dose is necessary to make the justification of such exposures. A survey of radiation doses to neonates from diagnostic X-ray examinations (chest and abdomen) has been carried out in the special care baby unit (SCBU) of the Royal Free Hospital. Entrance surface dose (ESD) was calculated from Quality Control measurements on the X-ray set itself. Direct measurement of radiation doses was also performed using highly sensitive thermoluminescence dosimeters (LiF:Mg,Cu,P), calibrated and tested for consistency in sensitivity. The mean ESD per radiograph was calculated to be 36μGy (with a standard deviation of 6μGy), averaged over 95 X-ray examinations. The ESD's as derived from the TLD crystals, ranged from 18μGy to 60μGy. The mean energy imparted (EI) and the mean whole body dose per radiograph were estimated to be 14μJ and 10μGy respectively. Assuming that neonates and foetuses are equally susceptible to carcinogenic effects of radiation (it involves an overestimation of risk), the radiation risk of childhood cancer from a single radiograph was estimated to be of the order (0.3-1.3)x10 -6 . Radiation doses compared favourably with the reference value of 80μGy ESD published by CEC in 1996. (author)

Risk and benefits in ionizing radiation uses

International Nuclear Information System (INIS)

2010-08-01

This meeting include: A tribute to Szeinfeld, presentation software for population dose, impact on radiation protection, radiation protection hospital and population exposed workers, regulation and licensing. radiological emergencies, risk, inspection, external radiotherapy and radiation protection with photons, brachytherapy, industrial, environmental monitoring, food irradiation, nuclear power, nuclear medicine.

Predicting carcinogenicity of diverse chemicals using probabilistic neural network modeling approaches

Energy Technology Data Exchange (ETDEWEB)

Singh, Kunwar P., E-mail: kpsingh_52@yahoo.com [Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research, New Delhi (India); Environmental Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001 (India); Gupta, Shikha; Rai, Premanjali [Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research, New Delhi (India); Environmental Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001 (India)

2013-10-15

Robust global models capable of discriminating positive and non-positive carcinogens; and predicting carcinogenic potency of chemicals in rodents were developed. The dataset of 834 structurally diverse chemicals extracted from Carcinogenic Potency Database (CPDB) was used which contained 466 positive and 368 non-positive carcinogens. Twelve non-quantum mechanical molecular descriptors were derived. Structural diversity of the chemicals and nonlinearity in the data were evaluated using Tanimoto similarity index and Brock–Dechert–Scheinkman statistics. Probabilistic neural network (PNN) and generalized regression neural network (GRNN) models were constructed for classification and function optimization problems using the carcinogenicity end point in rat. Validation of the models was performed using the internal and external procedures employing a wide series of statistical checks. PNN constructed using five descriptors rendered classification accuracy of 92.09% in complete rat data. The PNN model rendered classification accuracies of 91.77%, 80.70% and 92.08% in mouse, hamster and pesticide data, respectively. The GRNN constructed with nine descriptors yielded correlation coefficient of 0.896 between the measured and predicted carcinogenic potency with mean squared error (MSE) of 0.44 in complete rat data. The rat carcinogenicity model (GRNN) applied to the mouse and hamster data yielded correlation coefficient and MSE of 0.758, 0.71 and 0.760, 0.46, respectively. The results suggest for wide applicability of the inter-species models in predicting carcinogenic potency of chemicals. Both the PNN and GRNN (inter-species) models constructed here can be useful tools in predicting the carcinogenicity of new chemicals for regulatory purposes. - Graphical abstract: Figure (a) shows classification accuracies (positive and non-positive carcinogens) in rat, mouse, hamster, and pesticide data yielded by optimal PNN model. Figure (b) shows generalization and predictive

Glyphosate rodent carcinogenicity bioassay expert panel review.

Science.gov (United States)

Williams, Gary M; Berry, Colin; Burns, Michele; de Camargo, Joao Lauro Viana; Greim, Helmut

2016-09-01

Glyphosate has been rigorously and extensively tested for carcinogenicity by administration to mice (five studies) and to rats (nine studies). Most authorities have concluded that the evidence does not indicate a cancer risk to humans. The International Agency for Research on Cancer (IARC), however, evaluated some of the available data and concluded that glyphosate probably is carcinogenic to humans. The expert panel convened by Intertek assessed the findings used by IARC, as well as the full body of evidence and found the following: (1) the renal neoplastic effects in males of one mouse study are not associated with glyphosate exposure, because they lack statistical significance, strength, consistency, specificity, lack a dose-response pattern, plausibility, and coherence; (2) the strength of association of liver hemangiosarcomas in a different mouse study is absent, lacking consistency, and a dose-response effect and having in high dose males only a significant incidence increase which is within the historical control range; (3) pancreatic islet-cell adenomas (non-significant incidence increase), in two studies of male SD rats did not progress to carcinomas and lacked a dose-response pattern (the highest incidence is in the low dose followed by the high dose); (4) in one of two studies, a non-significant positive trend in the incidence of hepatocellular adenomas in male rats did not lead to progression to carcinomas; (5) in one of two studies, the non-significant positive trend in the incidence of thyroid C-cell adenomas in female rats was not present and there was no progression of adenomas to carcinomas at the end of the study. Application of criteria for causality considerations to the above mentioned tumor types and given the overall weight-of-evidence (WoE), the expert panel concluded that glyphosate is not a carcinogen in laboratory animals.

Implications of radiation risk for practical dosimetry

International Nuclear Information System (INIS)

Dennis, J.A.

1984-01-01

Radiobiological experiments with animals and cells have led to an expectation that the risks of cancer and hereditary effects are reduced at low doses and low dose rates of low LET radiation. Risk estimates derived from human exposures at high doses and dose rates usually contain an allowance for low dose effects in comparison with high dose effects, but no allowance may have been made for low dose rate effects. Although there are reasons for thinking that leukaemia risks may possibly have been underestimated, the total cancer risk assumed by ICRP for occupational exposures is reasonably realistic. For practical dosimetry the primary dose concepts and limits have to be translated into secondary quantities that are capable of practical realisation and measurement, and which will provide a stable and robust system of metrology. If the ICRP risk assumptions are approximately correct, it is extremely unlikely that epidemiological studies of occupational exposures will detect the influence of radiation. Elaboration of dosimetry and dose recording for epidemiological purposes is therefore unjustified except possibly in relation to differences between high and low LET radiations. (author)

Radiation quality and radiation risks - some current problems

International Nuclear Information System (INIS)

Kellerer, A.M.; Hahn, K.

1989-01-01

The newly evaluated cancer mortality data of the atomic bomb survivors suggest substantially enhanced risk estimates, and the various factors that are involved in the change are considered. The enhanced risk estimates have already led to added restrictions in the dose limits for radiation workers, and there may be a further tightening of regulations in the future. The impending revision of the quality factors in radiation protection may, therefore, lead to practical difficulties, and a careful consideration of the various aspects involved in a revision is required. A liaison group of ICRU and ICRP has proposed a reformulation of the quality factor that is related not to the LET, but to the microdosimetric variably y. The relation leads to increased quality factors for neutrons, but also to a quality factor for γ rays of only 0.5. Alternatives are presented that relate the quality factor to LET and that retain γ- rays as the reference radiation. One option corresponds to different quality factors for γ rays and X-rays, the other option sets the quality factor for photons approximately equal to unity, irrespective of energy. (author)

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

[Use of ionizing radiation sources in metallurgy: risk assessment].

Science.gov (United States)

Giugni, U

2012-01-01

Use of ionizing radiation sources in the metallurgical industry: risk assessment. Radioactive sources and fixed or mobile X-ray equipment are used for both process and quality control. The use of ionizing radiation sources requires careful risk assessment. The text lists the characteristics of the sources and the legal requirements, and contains a description of the documentation required and the methods used for risk assessment. It describes how to estimate the doses to operators and the relevant classification criteria used for the purpose of radiation protection. Training programs must be organized in close collaboration between the radiation protection expert and the occupational physician.

Temporal aspects of tumorigenic response to individual and mixed carcinogens. Progress report, October 1, 1978-September 30, 1979

International Nuclear Information System (INIS)

Albert, R.E.; Burns, F.J.; Altshuler, B.

1979-06-01

The research proposed here is designed to obtain a better understanding of the temporal kinetics of tumor induction when one or more carcinogens are present simultaneously or sequentially for prolonged periods of time. Studies done to date under this contract have shown that carcinogenesis in mouse skin by polycyclic aromatic hydrocarbon carcinogens is consistent with the induction of dependent and autonomous cell transformations by the carcinogen followed by the conversion of autonomous tumor cells into malignancies at a rate which is determined by the level of carcinogen exposure. Dependent cell transformations remain latent in the skin unless expressed by a promoting agent. Dependent neoplasia appears to follow one-hit kinetics while malignancy is a multihit endpoint. Dose-related and time-related aspects of tumor induction are separable in the initiation-promotion system of mouse skin which along with rat skin and hamster lung is being used as a model for testing hypotheses. Results to date provide the basis for a new interpretation of the linear non-threshold extrapolation model. The broad aim of the study is to provide a basis or rationale for estimating risks associated with prolonged exposures to carcinogens found in the environment and to predict how different tissues and species respond to the carcinogens, promoters, and cocarcinogens

Prediction of thyroid C-cell carcinogenicity after chronic administration of GLP1-R agonists in rodents

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Brink, Willem van den; Emerenciana, Annette [Systems Pharmacology, Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden (Netherlands); Medicines Evaluation Board, Utrecht (Netherlands); Bellanti, Francesco [Systems Pharmacology, Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden (Netherlands); Della Pasqua, Oscar [Systems Pharmacology, Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden (Netherlands); Clinical Pharmacology Modelling & Simulation, GlaxoSmithKline, Stockley Park, Uxbridge (United Kingdom); Clinical Pharmacology & Therapeutics, UCL, School of Life and Medical Sciences, London (United Kingdom); Laan, Jan Willem van der, E-mail: jw.vd.laan@cbg-meb.nl [Division of Toxicology, Leiden Academic Centre for Drug Research, Leiden University, Leiden (Netherlands); Medicines Evaluation Board, Utrecht (Netherlands)

2017-04-01

study GLP-1r agonist carcinogenicity. • C-cell carcinogenicity is impacted by both pharmacokinetics and pharmacodynamics. • The relation of GLP-1r stimulation and C-cell hyperplasia appears drug-independent. • Understanding carcinogenic risk needs a pharmacological basis.

Prediction of thyroid C-cell carcinogenicity after chronic administration of GLP1-R agonists in rodents

International Nuclear Information System (INIS)

Brink, Willem van den; Emerenciana, Annette; Bellanti, Francesco; Della Pasqua, Oscar; Laan, Jan Willem van der

2017-01-01

study GLP-1r agonist carcinogenicity. • C-cell carcinogenicity is impacted by both pharmacokinetics and pharmacodynamics. • The relation of GLP-1r stimulation and C-cell hyperplasia appears drug-independent. • Understanding carcinogenic risk needs a pharmacological basis.

Knowledge of medical imaging radiation dose and risk among doctors

International Nuclear Information System (INIS)

Brown, Nicholas; Jones, Lee

2013-01-01

The growth of computed tomography (CT) and nuclear medicine (NM) scans has revolutionised healthcare but also greatly increased population radiation doses. Overuse of diagnostic radiation is becoming a feature of medical practice, leading to possible unnecessary radiation exposures and lifetime-risks of developing cancer. Doctors across all medical specialties and experience levels were surveyed to determine their knowledge of radiation doses and potential risks associated with some diagnostic imaging. A survey relating to knowledge and understanding of medical imaging radiation was distributed to doctors at 14 major Queensland public hospitals, as well as fellows and trainees in radiology, emergency medicine and general practice. From 608 valid responses, only 17.3% correctly estimated the radiation dose from CT scans and almost 1 in 10 incorrectly believed that CT radiation is not associated with any increased lifetime risk of developing cancer. There is a strong inverse relationship between a clinician's experience and their knowledge of CT radiation dose and risks, even among radiologists. More than a third (35.7%) of doctors incorrectly believed that typical NM imaging either does not use ionising radiation or emits doses equal to or less than a standard chest radiograph. Knowledge of CT and NM radiation doses is poor across all specialties, and there is a significant inverse relationship between experience and awareness of CT dose and risk. Despite having a poor understanding of these concepts, most doctors claim to consider them prior to requesting scans and when discussing potential risks with patients.

Skin carcinoma and occupational risk factors

International Nuclear Information System (INIS)

Linares Fernandez, Tomasa Maria; Correa Lozano, Zoila; Ibarra Fernandez de la Vega, Enrique Jose; Bonet Gorbea Mariano

2014-01-01

To identify the relative contribution of different occupational risk factors associated with the occurrence of skin cancer in the provinces of Havana City and Havana, Cuba , in 2006-2007. It was designed a case-control study of hospital base that included 112 cases of non-melanoma skin cancer and 448 witnesses, following the inclusion-exclusion criteria preset. We considered the totality of patients diagnosed with basal cell carcinoma and squamous cell histological study of skin biopsy or surgical excision. Risk factors with possible association with the disease were studied, such as sun exposure, ionizing and non-ionizing radiations and a wide range of chemical and biological substances potentially carcinogenic

Ionizing radiation, genetic risks and radiation protection

International Nuclear Information System (INIS)

Sankaranarayanan, K.

1992-01-01

With one method of risk estimation, designed as the doubling dose method, the estimates of total genetic risk (i.e., over all generation) for a population continuously exposed at a rate of 0.01 Gy/generation of low LET irradiation are about 120 cases of Mendelian and chromosomal diseases/10 6 live births and about the same number of cases for multifactorial diseases (i.e., a total of 240 cases/10 6 ). These estimates provide the basis for risk coefficients for genetic effects estimated by ICRP (1991) in its Publication 60. These are: 1.0%/Sv for the general population (which is 40% of 240/10 6 /0.01 Gy), and 0.6%/Sv for radiation workers (which is 60% of that for the general population). The results of genetic studies carried out on the Japanese survivors of A-bombs have shown no significant adverse effects attributable to parental radiation exposures. The studies of Gardner and colleagues suggest that the risk of leukaemia in children born to male workers in the nuclear reprocessing facility in Sellafield, U.K., may be increased. However, this finding is at variance with the results from the Japanese studies and at present, does not lend itself to a simple interpretation based on radiobiological principles. In the light of recent advances in the molecular biology of naturally-occurring human Mendelian diseases and what we presently know about multifactorial diseases, arguments are advanced to support the thesis that (i) current risk estimates for Mendelian diseases may be conservative and (ii) an overall doubling dose for all adverse genetic effects may be higher than the 1 Gy currently used (i.e., the relative risks are probably lower). (author)

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.

Low-dose extrapolation of radiation health risks: some implications of uncertainty for radiation protection at low doses.

Science.gov (United States)

Land, Charles E

2009-11-01

Ionizing radiation is a known and well-quantified human cancer risk factor, based on a remarkably consistent body of information from epidemiological studies of exposed populations. Typical examples of risk estimation include use of Japanese atomic bomb survivor data to estimate future risk from radiation-related cancer among American patients receiving multiple computed tomography scans, persons affected by radioactive fallout, or persons whose livelihoods involve some radiation exposure, such as x-ray technicians, interventional radiologists, or shipyard workers. Our estimates of radiation-related risk are uncertain, reflecting statistical variation and our imperfect understanding of crucial assumptions that must be made if we are to apply existing epidemiological data to particular situations. Fortunately, that uncertainty is also highly quantifiable, and can be presented concisely and transparently. Radiation protection is ultimately a political process that involves consent by stakeholders, a diverse group that includes people who might be expected to be risk-averse and concerned with plausible upper limits on risk (how bad could it be?), cost-averse and concerned with lower limits on risk (can you prove there is a nontrivial risk at current dose levels?), or combining both points of view. How radiation-related risk is viewed by individuals and population subgroups also depends very much on perception of related benefit, which might be (for example) medical, economic, altruistic, or nonexistent. The following presentation follows the lead of National Council on Radiation Protection and Measurements (NCRP) Commentary 14, NCRP Report 126, and later documents in treating radiation protection from the viewpoint of quantitative uncertainty analysis.

Towards health impact assessment of drinking-water privatization--the example of waterborne carcinogens in North Rhine-Westphalia (Germany).

Science.gov (United States)

Fehr, Rainer; Mekel, Odile; Lacombe, Martin; Wolf, Ulrike

2003-01-01

Worldwide there is a tendency towards deregulation in many policy sectors - this, for example, includes liberalization and privatization of drinking-water management. However, concerns about the negative impacts this might have on human health call for prospective health impact assessment (HIA) on the management of drinking-water. On the basis of an established generic 10-step HIA procedure and on risk assessment methodology, this paper aims to produce quantitative estimates concerning health effects from increased exposure to carcinogens in drinking-water. Using data from North Rhine-Westphalia in Germany, probabilistic estimates of excess lifetime cancer risk, as well as estimates of additional cases of cancer from increased carcinogen exposure levels are presented. The results show how exposure to contaminants that are strictly within current limits could increase cancer risks and case-loads substantially. On the basis of the current analysis, we suggest that with uniform increases in pollutant levels, a single chemical (arsenic) is responsible for a large fraction of expected additional risk. The study also illustrates the uncertainty involved in predicting the health impacts of changes in water quality. Future analysis should include additional carcinogens, non-cancer risks including those due to microbial contamination, and the impacts of system failures and of illegal action, which may be increasingly likely to occur under changed management arrangements. If, in spite of concerns, water is privatized, it is particularly important to provide adequate surveillance of water quality. PMID:12894324

Towards health impact assessment of drinking-water privatization--the example of waterborne carcinogens in North Rhine-Westphalia (Germany).

Science.gov (United States)

Fehr, Rainer; Mekel, Odile; Lacombe, Martin; Wolf, Ulrike

2003-01-01

Worldwide there is a tendency towards deregulation in many policy sectors - this, for example, includes liberalization and privatization of drinking-water management. However, concerns about the negative impacts this might have on human health call for prospective health impact assessment (HIA) on the management of drinking-water. On the basis of an established generic 10-step HIA procedure and on risk assessment methodology, this paper aims to produce quantitative estimates concerning health effects from increased exposure to carcinogens in drinking-water. Using data from North Rhine-Westphalia in Germany, probabilistic estimates of excess lifetime cancer risk, as well as estimates of additional cases of cancer from increased carcinogen exposure levels are presented. The results show how exposure to contaminants that are strictly within current limits could increase cancer risks and case-loads substantially. On the basis of the current analysis, we suggest that with uniform increases in pollutant levels, a single chemical (arsenic) is responsible for a large fraction of expected additional risk. The study also illustrates the uncertainty involved in predicting the health impacts of changes in water quality. Future analysis should include additional carcinogens, non-cancer risks including those due to microbial contamination, and the impacts of system failures and of illegal action, which may be increasingly likely to occur under changed management arrangements. If, in spite of concerns, water is privatized, it is particularly important to provide adequate surveillance of water quality.

Nutrition in adult and childhood cancer: role of carcinogens and anti-carcinogens.

Science.gov (United States)

Mosby, Terezie T; Cosgrove, Maeve; Sarkardei, Samiramis; Platt, Karl L; Kaina, Bernd

2012-10-01

There is no doubt that diet is one of the main modifiable risk factors for many degenerative diseases, including cancer. More than 30% of adult cancers can be prevented or delayed by diet, being physically active and having a healthy body weight. Plant-based foods, including fruit, vegetables, and whole grains, a favorable omega-6/omega-3 polyunsaturated fatty acids ratio, and fish consumption have a protective effect against cancer. On the contrary, a low intake of fruit and vegetables, high intake of red and processed meat, high intake of sodium, alcohol consumption, a diet rich in refined carbohydrates, and a high intake of total fat may increase risk of cancer. Furthermore, calorie restriction and having a body/mass index on the lower end of the normal range can significantly decrease or delay the onset of cancers. Most studies were performed on adults and thus the role of diet in childhood cancer is less well-understood. In the past, diet was not considered to play any role in its etiology in children. However, nowadays there is a growing body of evidence that prolonged and frequent breastfeeding, the maternal diet during pregnancy and vitamin intake during pregnancy, may impart benefit for reduced cancer risk in children. Usually, decades of healthy dietary habits are needed to see significant difference in cancer risk. Therefore, diet choices and diet preparation starting early in life deserve more attention. Here we review data focusing on which dietary factors, including food-borne carcinogens, affect the onset of cancers in adults and stress out the potential role of diet in childhood cancer prevention.

In-vivo studies of mechanisms of haematologic oncogenesis after exposure to ionizing radiation utilizing a model of rats deficient in Potassium 53

International Nuclear Information System (INIS)

Casado, J.A.; Bauluz, C.; Vidania, R. de; Real, A.

1997-01-01

The development of an appropriate radiation protection system is based on the knowledge of health effects of moderate and low radiation. The knowledge of these effects at present is insufficient for determining with exactness the health risks of the said exposure. Epidemiological studies have serious limitations which stand in the way of addressing these problems. Through studies with new experimental models, interesting information can be obtained in this respect and in particular on the oncogenic mechanism of radiation. In this study, rats deficient in Phosphorus 53 have been used to study the impact of haematological cancer after irradiation. For the purpose of characterizing populations potentially implicated in carcinogenic development, cellular morphological analyses and expression of surface markers have been carried out and the content of DNA in haematopoietic cells has been looked into. Rats with Phosphorus 53 develop fundamentally altered lymphomas after irradiation. Leukaemias were also observed, even though the number of rats examined was low. The proposed methodology demonstrates great potential through the study of cellular changes and associated molecules in radiation induced carcinogenic development

Radiation induced cancer risk, detriment and radiation protection

International Nuclear Information System (INIS)

Sinclair, W.K.

1992-01-01

Recommendations on radiation protection limits for workers and for the public depend mainly on the total health detriment estimated to be the result of low dose ionizing radiation exposure. This detriment includes the probability of a fatal cancer, an allowance for the morbidity due to non-fatal cancer and the probability of severe hereditary effects in succeeding generations. In a population of all ages, special effects on the fetus particularly the risk of mental retardation at defined gestational ages, should also be included. Among these components of detriment after low doses, the risk of fatal cancer is the largest and most important. The estimates of fatal cancer risk used by ICRP in the 1990 recommendations were derived almost exclusively from the study of the Japanese survivors of the atomic bombs of 1945. How good are these estimates? Uncertainties associated with them, apart from those due to limitations in epidemiological observation and dosimetry, are principally those due to projection forward in time and extrapolation from high dose and dose rate to low dose and dose rate, each of which could after the estimate by a factor of 2 or so. Recent estimates of risk of cancer derived directly from low dose studies are specific only within very broad ranges of risk. Nevertheless, such studies are important as confirmation or otherwise of the estimates derived from the atomic bomb survivors. Recent U.S. British and Russian studies are examined in this light. (author)

Knowledge of medical imaging radiation dose and risk among doctors.

Science.gov (United States)

Brown, Nicholas; Jones, Lee

2013-02-01

The growth of computed tomography (CT) and nuclear medicine (NM) scans has revolutionised healthcare but also greatly increased population radiation doses. Overuse of diagnostic radiation is becoming a feature of medical practice, leading to possible unnecessary radiation exposures and lifetime-risks of developing cancer. Doctors across all medical specialties and experience levels were surveyed to determine their knowledge of radiation doses and potential risks associated with some diagnostic imaging. A survey relating to knowledge and understanding of medical imaging radiation was distributed to doctors at 14 major Queensland public hospitals, as well as fellows and trainees in radiology, emergency medicine and general practice. From 608 valid responses, only 17.3% correctly estimated the radiation dose from CT scans and almost 1 in 10 incorrectly believed that CT radiation is not associated with any increased lifetime risk of developing cancer. There is a strong inverse relationship between a clinician's experience and their knowledge of CT radiation dose and risks, even among radiologists. More than a third (35.7%) of doctors incorrectly believed that typical NM imaging either does not use ionising radiation or emits doses equal to or less than a standard chest radiograph. Knowledge of CT and NM radiation doses is poor across all specialties, and there is a significant inverse relationship between experience and awareness of CT dose and risk. Despite having a poor understanding of these concepts, most doctors claim to consider them prior to requesting scans and when discussing potential risks with patients. © 2012 The Authors. Journal of Medical Imaging and Radiation Oncology © 2012 The Royal Australian and New Zealand College of Radiologists.

Review of the current status of radiation risk estimates

International Nuclear Information System (INIS)

Charles, M.W.; Little, M.P.

1988-10-01

This report reviews the current status of radiation risk estimation for low linear energy transfer radiation. Recent statements by various national and international organisations regarding risk estimates are critically discussed. The recently published revised population risk estimates from the study of Japanese bomb survivors are also reviewed and used with some unpublished data from Japan to calculate risk figures for a general work force. (author)

Emerging Radiation Health-Risk Mitigation Technologies

International Nuclear Information System (INIS)

Wilson, J.W.; Cucinotta, F.A.; Schimmerling, W.

2004-01-01

Past space missions beyond the confines of the Earth's protective magnetic field have been of short duration and protection from the effects of solar particle events was of primary concern. The extension of operational infrastructure beyond low-Earth orbit to enable routine access to more interesting regions of space will require protection from the hazards of the accumulated exposures of Galactic Cosmic Rays (GCR). There are significant challenges in providing protection from the long-duration exposure to GCR: the human risks to the exposures are highly uncertain and safety requirements places unreasonable demands in supplying sufficient shielding materials in the design. A vigorous approach to future radiation health-risk mitigation requires a triage of techniques (using biological and technical factors) and reduction of the uncertainty in radiation risk models. The present paper discusses the triage of factors for risk mitigation with associated materials issues and engineering design methods

The place of ionizing radiation in the cancer genesis; La place des rayonnements ionisants dans la genese des cancers

Energy Technology Data Exchange (ETDEWEB)

Simon, J. [Societe Francaise d' Energie Nucleaire, 75 - Paris (France)

2009-12-15

Two different fields are considered: the field of high radiation doses (over 1 Sv), the contribution of ionizing radiation in the carcinogenesis is doubtless and the linear dose-effect relationship is unshakable. but this high doses area is rare ( major accident of civil nuclear, radiotherapy, war with use of nuclear weapon) and escapes to usual standards. The field of low dose irradiation (inferior to 100 MSv) we cannot assure the absence of carcinogen risk of ionizing radiation. We can tell that this risk is very low, very inferior to 5% by sievert accepted by the ICRP in conformance with the precautionary principle. In any case, very inferior to the risk in relation with the big causes of cancer that are addiction to smoking, (30% of cancers), food (30% of cancers), chronic diseases (11% of cancers) and hormonal processes (10% of cancers). (N.C.)

Chemical pollution of environment in the cities of Central Siberia: risk for the health of the population

Directory of Open Access Journals (Sweden)

Ludmila Klimatskaya

2015-03-01

Full Text Available pollution in cities including the problem of risk assessment. The aim of the study is to determine carcinogenic and non-carcinogenic risks for the health of the population due to chemical contamination of air, water and food in the cities of the Krasnoyarsk region. Material and methods. The research was conducted in the Center of Hygiene and Epidemiology in the Krasnoyarsk region. 5122 samples of air, 4863 samples of water and 6915 samples of food stuff have been analyzed. Concentration of chemical substances was the base on which individual carcinogenesis risk (ICR and population carcinogenic conventional risks (PCCR and non carcinogenic risks [1] have been calculated. In the industrial cities chemical pollution of air, water and food stuff including carcinogenic substances creates carcinogenic and non-carcinogenic risks of morbidity of the population with the reinforcement of the complex impact, “with” which greatly exceeds the maximum acceptable risks. Results. Chemical pollution of environmental facilities in cities of the Krasnoyarsk region produce complex carcinogenic and non-carcinogenic risks which exceed maximum limit. The greatest shares in structure of complex carcinogenic risks are made in food stuff and water consumption in structure of complex non-carcinogenic risks as a result of air pollution and food stuff pollution. Conclusions. Obtained data could be used to set priorities in preventive measures to preserve health of the population in industrial cities of the Krasnoyarsk region.