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PubMed2006

Body surface area in normal-weight, overweight, and obese adults. A comparison study.

Values for body surface area (BSA) are commonly used in medicine, particularly to calculate doses of chemotherapeutic agents and index cardiac output. Various BSA formulas have been developed over the years. The DuBois and DuBois (Arch Intern Med 1916;17:863-71) BSA equation is the most widely used, although derived from only 9 subjects. More recently, Mosteller (N Engl J Med 1987;317:1098) produced a simple formula, [weight (kg) x height (cm)/3600](1/2), which could be easily remembered and evaluated on a pocket calculator, but validation data in adults are rare. The purpose of the present study was to examine the BSA based on Mosteller's formula in normal-weight (body mass index [BMI], 20-24.9 kg/m(2)), overweight (BMI, 25-29.9 kg/m(2)), and obese (BMI, >/=30 kg/m(2)) adults (>18 years old) in comparison with other empirically derived formulas (DuBois and DuBois, Boyd [The growth of the surface area of the human body. Minneapolis: University of Minnesota Press; 1935], Gehan and George [Cancer Chemother Rep 1970;54:225-35], US Environmental Protection Agency [Development of statistical distributions or ranges of standard factors used in exposure assessments Washington, EPA/600/8-85-010. Office of Health and Environmental Assessment; 1985), Haycock et al [J Pediatr 1978;93:62-6], Mattar [Crit Care Med 1989;17:846-7], Livingston and Scott [Am J Physiol Endocrinol Metab 2001;281:E586-91]) and with the new 3-dimensional-derived formula of Yu et al (Appl Ergon. 2003;34:273-8). One thousand eight hundred sixty-eight patients were evaluated (397 normal weight [BMI, 23 +/- 1 kg/m(2); age, 50 +/- 14 years; M/F, 289/108], 714 overweight [BMI, 27 +/- 1 kg/m(2); age, 52 +/- 11 years; M/F, 594/120], and 757 obese [BMI, 36 +/- 6 kg/m(2); age, 53 +/- 11 years; M/F, 543/215]). The overall BSA was 2.04 +/- 0.24 m(2): 1.81 +/- 0.19 m(2) in normal-weight, 1.99 +/- 0.16 m(2) in overweight, and 2.21 +/- 0.22 m(2) in obese subjects. These values were significantly higher in overweight and obese patients compared with the values using the DuBois-DuBois formula (overall, 2.00 +/- 0.22 m(2), P < .01; normal weight, 1.81 +/- 0.19 m(2), P = .93; overweight, 1.97 +/- 0.16 m(2), P < .01; obese, 2.14 +/- 0.21 m(2), P < .001). We could show an excellent correlation between the results obtained from each formula, with all correlations of 0.97 or higher (between 0.971 and 0.999). Body surface area prediction with the commonly used DuBois formula underestimated BSA in obese patients by as much as 3% (male) to 5% (female). Based on the formula of Yu et al, however, BSA is overestimated when these traditional formulas are used. Although Mosteller's formula is recommended based on its simplicity and suitability for laboratory and clinical work in adults, accuracy studies in whites with 3-dimensional one-pass whole-body scanning are needed.

Adult↗
PubMed2006

The carcinogenicity of WHO fibers of silicon carbide: SiC whiskers compared to cleavage fragments of granular SiC.

A steep dose-response relationship for tumors was reported after application of 0.05 to 25 mg of whiskers of SiC in 1991 in a chronic intraperitoneal injection study in rats. In contrast, doses of 250 and 1000 mg of granular SiC did not cause tumors. The whiskers contained 107,000,000 fibers longer than 5 mum, per milligram while the granular sample was assumed to be free of such fibers. However, it has since been realized that even granular SiC may contain fibrous fragments that fulfill the definition of WHO fibers. It was the objective of our study to reanalyze the quantity of WHO fibers that were administered with the granular SiC. In addition, we examined whether the potency per WHO fiber was different for the SiC fragments and the SiC whiskers. Samples of the original granular and fibrous SiC were suspended in water and filtered. One half of each filter was analyzed by scanning electron microscopy (SEM, magnification x 2500), and transmission electron microscopy (TEM, x 10,000) was also performed for the SiC whiskers. The concentration of WHO fibers was 58,000 fibers/mg for the granular sample compared to 48,000,000 (SEM) and 42,000,000 (TEM) fibers/mg for the whiskers. The aspect ratio of the WHO fibers exceeded 10/1 for only 3.3% of the fragments but in each analysis for 96% of the whiskers. In addition, 0% of the fragments compared to 44% and 30% of the whiskers were more than 10 mum long. In total, 15 and 58 x 106 WHO fibers were injected with the granular SiC even though only 0.8% and 0% tumors were recorded. However, 20.1% and 43.3% tumors would have been expected if the carcinogenic potency were the same for the fragments and for the whiskers. We therefore conclude that carcinogenic potency is a function of the shapes of the WHO fibers and is much lower for SiC fragments than for whiskers. Hence carcinogenicity mainly is restricted to a subgroup of WHO fibers longer than about 10 and thinner than about 1 mum. This conclusion is in line with the optimal exposure index, which recently has been proposed by the U.S. Environmental Protection Agency (EPA) for asbestos.

Air Pollutants↗
PubMedDate not supplied

[Vinyl chloride and 1,2-dichloroethane: classification and assessment of carcinogenicity, guidelines, threshold values, and standards developed by national and international entities, organizations, and agencies].

International, national and regulatory classification, evaluation, guidelines and occupational exposure values regarding vinyl chloride and 1,2-dichloroethane, carried out by European Union (EU). Environmental Protection Agency (US EPA), International Agency for Research on Cancer (IARC), Italian National Advisory Toxicological Committee (CCTN), Occupational Safety and Health Administration (OSHA), World Health Organization (WHO), National Institute for Occupational Safety and Health (NIOSH), American Conference of Governmental Industrial Hygienists (ACGIH) and other institutions, have been considered with particular reference to the carcinogenic effects. Moreover information is reported in support of classification and evaluation and a short historical review since early 1970s, when first evidence that occupational exposure to VC could lead to angiosarcoma was published.

Carcinogens↗
PubMed2002

Applying ecological risk principles to watershed assessment and management.

Considerable progress in addressing point source (end of pipe) pollution problems has been made, but it is now recognized that further substantial environmental improvements depend on controlling nonpoint source pollution. A watershed approach is being used more frequently to address these problems because traditional regulatory approaches do not focus on nonpoint sources. The watershed approach is organized around the guiding principles of partnerships, geographic focus, and management based on sound science and data. This helps to focus efforts on the highest priority problems within hydrologically-defined geographic areas. Ecological risk assessment is a process to collect, organize, analyze, and present scientific information to improve decision making. The U.S. Environmental Protection Agency (EPA) sponsored three watershed assessments and found that integrating the watershed approach with ecological risk assessment increases the use of environmental monitoring and assessment data in decision making. This paper describes the basics of the watershed approach, the ecological risk assessment process, and how these two frameworks can be integrated. The three major principles of watershed ecological risk assessment found to be most useful for increasing the use of science in decision making are (1) using assessment endpoints and conceptual models, (2) holding regular interactions between scientists and managers, and (3) developing a focus for multiple stressor analysis. Examples are provided illustrating how these principles were implemented in these assessments.

Conservation of Natural Resources↗
PubMed2005

U.S. national response assets for radiological incidents.

The federal government has had the ability to respond to incidents of national significance for decades. Since 11 September 2001, there have been enhancements to existing federal assets and the creation of new federal assets. This presentation will provide an overview of the more significant federal assets. Pivotal to a response of national significance is the U.S. Department of Energy (DOE) Federal Radiological Monitoring and Assessment Center, which organizes and coordinates federal agency monitoring activities during an emergency. DOE manages the Federal Radiological Monitoring and Assessment Center during the emergency phase, and the Environmental Protection Agency (EPA) manages the response during the recovery phase once the emergency is terminated. EPA monitoring teams provide support during both the emergency and recovery phases of an emergency. Other DOE teams are available to respond to major nuclear power plant events, transportation accidents, or terrorism events involving the use of radiological materials, including the Radiological Assistance Program, the Aerial Measuring System, the National Atmospheric Release Advisory Center, and the Radiation Emergency Assistance Center/Training Site. For incidents involving a nuclear weapon, an improvised nuclear device, or a radiological dispersal device, DOE assets such as the Nuclear Emergency Support Team and the Accident Response Group could provide capabilities for weapon or device search, recovery, and removal. The Radiological Triage System harnesses the weapons scientists and engineers at the DOE national laboratories to provide gamma spectroscopy interpretation for agencies responding to an incident. In recent years, National Guard Weapons of Mass Destruction-Civil Support Teams have been created to support state and local response to terrorism events. The Civil Support Teams normally come under direct control of the state and can respond without requiring authorization from the U.S. Department of Defense (DoD). Changes brought about by the events of September 11 also extend to changing federal response policy and planning. Therefore, the Catastrophic Incident Response Annex to the National Response Plan is discussed. DoD also provides specifically designated radiological response capabilities that can be utilized within the guidelines of the National Response Plan. While optimally designed to support military missions, these resources also help provide for a well-equipped set of national assets to temporarily support and augment the local, state, and federal civil agencies that have primary authority and responsibility for domestic disaster assistance. The military's role in domestic emergencies is well defined in military regulations, as well as the national plan.

Civil Defense↗
PubMed2003

Global surveillance of DDT and DDE levels in human tissues.

The organochlorine insecticide dichlorodiphenyltrichloroethane (DDT) was initially introduced for control of vector-borne discases It was banned in the United States by the Environmental Protection Agency in 1972 because of potential harmful effects on humans, wildlife and the environment. Since it is a potential human carcinogen, the United Nations Environmental Program (UNEP) has recently restricted the use of DDT in developing countries until alternative methods of vector control are sought. DDT and its metabolite, dichlorodiphenyltrichloroethylene (DDE) are lipid soluble, and bioaccumulate more in human adipose tissue, than breast milk and serum. This article is a review of DDT and DDE levels in human tissues from different countries in the world. Data on p,p'-DDT and p,p'-DDE levels in human adipose tissue, breast milk and serum were selected from more recent literature. It was discovered that countries in Africa, Asia, and Latin America with more recent exposure to DDT and DDE have higher levels in human tissue than in Europe and the United States. The global concern for DDT and DDE is the environmental spread and persistence in the food chain. Hypothetically, there is a potential risk of harmful effects of DDT and DDE to human health. UNEP has cautiously taken action to protect human health, the environment and the earth from further destruction by persistent organic pollutants. Further exposure to DDT should be prevented to achieve this goal.

Adipose Tissue↗
PubMed1998

A survey of lead-based paint abatement projects performed in public buildings in Erie and Crawford Counties, Pennsylvania, during the time period 1995-1997.

A survey of lead-based paint abatement projects in public buildings of Crawford and Erie Counties, Pennsylvania, was conducted during the time period January 1995 to March 1997. These survey results suggest that few lead abatement projects were performed during this time period. Projects that were performed commonly did not employ proper lead abatement practices as described by the U.S. Occupational Safety and Health Administration, U.S. Environmental Protection Agency, and U.S. Department of Housing and Urban Development. These data suggest that most contractors and public officials have misunderstandings of both environmental regulations and required procedures for safe and effective lead-based paint abatement.

Air Pollution, Indoor↗
PubMed2006

Epigenetic processes and cancer risk assessment.

The U.S. Environmental Protection Agency's Guidelines for Carcinogen Risk Assessment encourages the use of mechanistic data in the assessment of human cancer risk at low (environmental) exposure levels. The key events that define a particular mode of action for tumor formation have been concentrated to date more on mutational responses that are broadly the result of induced DNA damage and enhanced cell proliferation. While it is clear that these processes are important in terms of tumor induction, other modes that fall under the umbrella of epigenetic responses are increasingly being considered to play an important role in susceptibility to tumor induction by environmental chemicals and as significant modifiers of tumor responses. Alterations in gene expression, DNA repair, cell cycle control, genome stability and genome reprogramming could be the result of modification of DNA methylation and chromatin remodeling patterns as a consequence of exposure to environmental chemicals. These concepts are described and discussed.

Animals↗
PubMed2002

A process for evaluating adverse environmental impacts by cooling-water system entrainment at a California power plant.

A study to determine the effects of entrainment by the Diablo Canyon Power Plant (DCPP) was conducted between 1996 and 1999 as required under Section 316(b) of the Clean Water Act. The goal of this study was to present the U.S. Environmental Protection Agency (EPA) and Central Coast Regional Water Quality Control Board (CCRWQCB) with results that could be used to determine if any adverse environmental impacts (AEIs) were caused by the operation of the plant's cooling-water intake structure (CWIS). To this end we chose, under guidance of the CCRWQCB and their entrainment technical working group, a unique approach combining three different models for estimating power plant effects: fecundity hindcasting (FH), adult equivalent loss (AEL), and the empirical transport model (ETM). Comparisons of the results from these three approaches provided us a relative measure of confidence in our estimates of effects. A total of 14 target larval fish taxa were assessed as part of the DCPP 316(b). Example results are presented here for the kelp, gopher, and black-and-yellow (KGB) rockfish complex and clinid kelpfish. Estimates of larval entrainment losses for KGB rockfish were in close agreement (FH is approximately equals to 550 adult females per year, AEL is approximately equals to 1,000 adults [male and female] per year, and ETM = larval mortality as high as 5% which could be interpreted as ca. 2,600 1 kg adult fish). The similar results from the three models provided confidence in the estimated effects for this group. Due to lack of life history information needed to parameterize the FH and AEL models, effects on clinid kelpfish could only be assessed using the ETM model. Results from this model plus ancillary information about local populations of adult kelpfish suggest that the CWIS might be causing an AEI in the vicinity of DCPP.

Animals↗
PubMed1999

A risk assessment for exposure to grunerite asbestos (amosite) in an iron ore mine.

The potential for health risks to humans exposed to the asbestos minerals continues to be a public health concern. Although the production and use of the commercial amphibole asbestos minerals-grunerite (amosite) and riebeckite (crocidolite)-have been almost completely eliminated from world commerce, special opportunities for potentially significant exposures remain. Commercially viable deposits of grunerite asbestos are very rare, but it can occur as a gangue mineral in a limited part of a mine otherwise thought asbestos-free. This report describes such a situation, in which a very localized seam of grunerite asbestos was identified in an iron ore mine. The geological occurrence of the seam in the ore body is described, as well as the mineralogical character of the grunerite asbestos. The most relevant epidemiological studies of workers exposed to grunerite asbestos are used to gauge the hazards associated with the inhalation of this fibrous mineral. Both analytical transmission electron microscopy and phase-contrast optical microscopy were used to quantify the fibers present in the air during mining in the area with outcroppings of grunerite asbestos. Analytical transmission electron microscopy and continuous-scan x-ray diffraction were used to determine the type of asbestos fiber present. Knowing the level of the miner's exposures, we carried out a risk assessment by using a model developed for the Environmental Protection Agency.

Asbestos, Amosite↗
PubMed1998

The uptake of radionuclides by beans, squash, and corn growing in contaminated alluvial soils at Los Alamos National Laboratory.

Pinto beans (Phaselous vulgaris), sweet corn (Zea mays), and zucchini squash (Cucurbita pepo) were grown in a field pot study using alluvial floodplain soils contaminated with various radionuclides within Los Alamos Canyon (LAC) at Los Alamos National Laboratory, New Mexico. Soils as well as washed edible (fruit) and nonedible (stems and leaves) crop tissues were analyzed for tritium (3H), cesium (137Cs), strontium (90Sr), plutonium (238Pu and 239,240Pu), americium (241Am), and total uranium (totU). Most radionuclides, with the exception of 3H and totU, in soil and crop tissues from LAC were detected in significantly higher concentrations (p < 0.05) than in soil or crop tissues collected from regional background locations. Significant differences in radionuclide concentrations among crop species (squash were generally higher than beans or corn) and plant parts (nonedible tissue were generally higher than edible tissue) were observed. Most soil-to-plant concentration ratios for radionuclides in edible and nonedible crop tissues grown in soils from LAC were within default values in the literature commonly used in dose and risk assessment models. Overall, the maximum net positive committed effective dose equivalent (CEDE)--the CEDE plus two sigma for each radioisotope minus background and then all positive doses summed--to a hypothetical 50-year resident that ingested 352 lb ([160 kg]; the maxiumum ingestion rate per person per year) of beans, corn, and squash in equal proportions was 74 mrem y-1 (740 microS y-1). This upper bound dose was below the International Commission on Radiological Protection permissible dose limit of 100 mrem y-1 (1000 microS y-1) from all pathways and corresponds to a risk of an excess cancer fatality of 3.7 x 10(-5) (37 in a million), which is also below the U.S. Environmental Protection Agency's guideline of 10(-4).

Environmental Health↗
PubMed2002

Performance of poly(vinyl alcohol) gel columns on the ion chromatographic determination of perchlorate in fertilizers.

Interest in possible sources of perchlorate (ClO4) that could lead to environmental release has been heightened since the Environmental Protection Agency placed this anion on its Contaminant Candidate List for drinking water. Although recent investigations have suggested that fertilizers are minor contributors to environmental perchlorate contamination overall, there is still interest in screening commercial products for possible contamination and quantitating perchlorate when it is found. Ion chromatography (IC) has been used for this application owing to its speed, low detection limits, widespread availability, and moderate ruggedness relative to other techniques. However, fertilizer matrixes complicate the IC analysis relative to potable water matrixes. In this study, the performance of poly(vinyl alcohol) gel resin IC columns (100 mm and 150 mm) was evaluated for fertilizer matrixes using method EPA/600/R-01/026. The NaOH eluent included an organic salt, sodium 4-cyanophenoxide. Detection was by suppressed conductivity. A set of 55 different field samples representing 48 products and previously used by the EPA to assess occurrence of perchlorate in fertilizers (EPA/600/R-01/049) was reanalyzed on the 150 mm column. The 100 mm column was used to further investigate the positive hits. Both columns gave satisfactory performance in fertilizer matrixes, with spike recoveries (+/- 15%), assured reporting levels (0.5-225 microg g(-1) except for one at 1,000 microg g(-1)), accuracy (relative error < 30% always and most < 15%), and precision [injection-to-injection reproducibility < 3% relative standard deviation (RSD)] comparable to those reported in other studies. Performance did not vary substantially between column lengths. Lastly, the results of this investigation provided further evidence in support of the conclusions that had been reached previously by the EPA on the occurrence of perchlorate in fertilizers.

Chromatography, Ion Exchange↗
PubMed1998

The integrated exposure uptake biokinetic model for lead in children: independent validation and verification.

The U.S. Environmental Protection Agency employs a model, the integrated exposure biokinetic (IEUBK) model for lead in children, for the assessment of risks to children posed by environmental lead at hazardous waste sites. This paper describes results of an effort to verify the consistency of the documentation with the computer model and to test the computer code using a group that is independent from those involved in the model development. This review concluded that the IEUBK model correctly calculates the equations specified in the IEUBK model theory documentation. However, several issues were identified on model documentation, model performance, and the C++ programming language code (i.e., IEUBK model source code) documentation. These issues affect the ability of an independent reviewer to understand the workings of the IEUBK model but not the model's reliability. As a result of these findings, recommendations have been provided for updating documentation to the model as well as associated adjustments to the model documentation.

Child↗
PubMed2003

[Report of the "Health and Environment" commission of the National Academy of pharmacy. Carbon monoxide and environmental health: are carbon monoxide levels in urban areas a health hazard?].

In an urban environment, carbon monoxide is produced by incomplete combustion, particularly in motor vehicles. Air pollution caused by CO produced by motor vehicles is controlled by legislation. Legal regulations have considerably lowered emission levels authorized for new vehicles and total CO emission levels. CO levels in the environment (urban environment in general and zones close to motorways) have thus declined. CO remains a public health concern both as a pollutant and as an indicator of air quality. We recall here the more recent approaches used to assess CO-related hazards developed by the Environmental Protection Agency in the United States and pertinent conclusions backing up previously defined reference levels. We then report recent French data concerning CO emission, environmental levels and evaluation procedures for different situations of human exposure: geographical situations, mode of transportation, police force, air sentinels. The third part of this article is devoted to biological data (interaction between CO and hemo-proteins, CO neurotransmitter?) and epidemiological data (serial surveys). The discussion centers on the limitations of epidemiological data and on the difficulty in evaluating hazards solely on the basis of a carboxyhemoglobin threshold. This latter point is particularly important because carboxyhemoglobin is only one of many indicators of air quality. Finally recommendations are proposed concerning weather-related aspects, evaluation of human exposure, and ways of improving biological and epidemiological data.

Air Pollutants↗
PubMedDate not supplied

ATSDR evaluation of health effects of chemicals. IV. Polycyclic aromatic hydrocarbons (PAHs): understanding a complex problem.

Polycyclic Aromatic Hydrocarbons (PAHs) are a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances, such as tobacco and charbroiled meat. There are more than 100 PAHs. PAHs generally occur as complex mixtures (for example, as part of products such as soot), not as single compounds. PAHs are found throughout the environment in the air, water, and soil. As part of its mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares toxicological profiles on hazardous chemicals, including PAHs (ATSDR, 1995), found at facilities on the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priorities List (NPL) and which pose the most significant potential threat to human health, as determined by ATSDR and the Environmental Protection Agency (EPA). These profiles include information on health effects of chemicals from different routes and durations of exposure, their potential for exposure, regulations and advisories, and the adequacy of the existing database. Assessing the health effects of PAHs is a major challenge because environmental exposures to these chemicals are usually to complex mixtures of PAHs with other chemicals. The biological consequences of human exposure to mixtures of PAHs depend on the toxicity, carcinogenic and noncarcinogenic, of the individual components of the mixture, the types of interactions among them, and confounding factors that are not thoroughly understood. Also identified are components of exposure and health effects research needed on PAHs that will allow estimation of realistic human health risks posed by exposures to PAHs. The exposure assessment component of research should focus on (1) development of reliable analytical methods for the determination of bioavailable PAHs following ingestion, (2) estimation of bioavailable PAHs from environmental media, particularly the determination of particle-bound PAHs, (3) data on ambient levels of PAHs metabolites in tissues/fluids of control populations, and (4) the need for a critical evaluation of current levels of PAHs found in environmental media including data from hazardous waste sites. The health effects component should focus on obtaining information on (1) the health effects of mixtures of PAHs particularly their noncarcinogenic effects in humans, and (2) their toxicokinetics. This report provides excerpts from the toxicological profile of PAHs (ATSDR, 1995) that contains more detailed information.

Animals↗
PubMedDate not supplied

Design and implementation of a collaborative study of the mutagenicity of complex mixtures in Salmonella typhimurium.

In 1987, the International Programme on Chemical Safety (IPCS) in collaboration with the U.S. Environmental Protection Agency (U.S. EPA) and the U.S. National Institute of Standards and Technology (U.S. NIST) initiated an international collaborative study of the mutagenicity of complex environmental mixtures in the Ames Salmonella typhimurium mutation assay. The objectives of this study were: (1) to estimate the inter- and intra-laboratory variability associated with the extraction of mixtures for bioassay, (2) to estimate the inter- and intra-laboratory variability associated with the Salmonella typhimurium bioassay when applied to complex mixtures, and (3) to determine whether standard reference complex mixtures would be useful in mutagenicity studies and to evaluate whether reference or certified mutagenicity values determined from this collaborative study should be reported. The complex mixtures used in this study were selected from standard reference materials (SRMs) which had previously been issued by the U.S. NIST as SRM 1597 (coal tar), SRM 1649 (diesel particulate matter) and SRM 1650 (urban air particulate matter) with certified values for polycyclic aromatic hydrocarbons. These SRM complex mixtures are available to scientists as reference standards for analytical chemistry research and are under consideration as SRMs for mutagenicity studies of complex environmental mixtures. This paper briefly describes the final study design, protocol, selection of the complex mixtures, and implementation of this international study.

Laboratories↗
PubMed2004

Dose-dependent transitions in mechanisms of toxicity.

Scientists and decision makers from all sectors agree that risk assessments should be based on the best available science. Several years ago, the Health and Environmental Sciences Institute (HESI), a global branch of the International Life Sciences Institute (ILSI), identified the need for better scientific understanding of dose-dependent transitions in mechanisms of toxicity as one avenue by which the best and latest science can be integrated into the decision making process. In July 2001, the HESI Project Committee on Dose-Dependent Transitions in Mechanisms of Toxicity established a group of academic, government, and industry scientists to engage in active technical discourse on the issue of dose-dependent transitions in mechanisms of toxicity. Over the next 18 months, case studies were examined. These case studies included acetaminophen, butadiene, ethylene glycol, formaldehyde, manganese, methylene chloride, the peroxisome proliferator-activated receptor, progesterone/hydroxyflutamide, propylene oxide, vinyl acetate, vinyl chloride, vinylidene chloride, and zinc (Slikker, W., Jr., Andersen, M.E., Bogdanffy, M.S., Bus, J.S., Cohen, S.D., Conolly, R.B., David, R.M., Doerrer, N.G., Dorman, D.C., Gaylor, D.W., Hattis, D., Rogers, J.M., Setzer, R.W., Swenberg, J.A., Wallace, K., 2004. Dose-dependent transitions in mechanisms of toxicity: case studies. Toxicol. Appl. Pharmacol. 201(3), 226-294 (this issue)). The HESI Project Committee sponsored two technical workshops in 2003. The first of these workshops took place on February 12-13, 2003, and was co-sponsored by the Agency for Toxic Substances and Disease Registry, the American Chemistry Council, the National Institute of Environmental Health Sciences, the Society of Toxicology, and the U.S. Environmental Protection Agency. Additional support was provided by Health Canada. Invited experts from government, academia, and industry provided scientific perspectives and recommendations at the workshop. The purpose of the workshop was to examine approaches to dose-response analysis, learn from the case study examples, and gather feedback from invited participants on the impact of dose-dependent transitions on the risk assessment process. The second forum consisted of a workshop in March 2003 at the Society of Toxicology Annual Meeting in Salt Lake City, UT. This paper addresses the issues discussed at both workshops, and presents the consensus conclusions drawn by expert participants.

Animals↗
PubMed2000

Performance evaluation of a method for the determination of bromate in drinking water by ion chromatography (EPA method 317.0) and validation of EPA method 324.0.

The potential carcinogenic nature of bromate has prompted global regulatory agencies, and industrial and academic institutions to publish several methods for the analysis of bromate in both drinking and bottled waters. The United States Environmental Protection Agency (EPA) has reported two methods capable of detecting bromate at or below the promulgated maximum contaminant level of 10.0 microg/l. These methods are EPA Method 300.1 and 317.0. Method 300.1 has been promulgated by EPA for compliance monitoring of bromate under Stage 1 of the Disinfectants/Disinfection By-Products Rule. Due to its sensitivity, selectivity and simplicity, Method 317.0 has been drafted and evaluated for potential use as a future compliance monitoring method. This manuscript describes the performance evaluation work with Method 317.0 and efforts completed at EPA's Technical Support Center that improved the sensitivity of Method 317.0, leading to the development of EPA Method 324.0

Bromates↗