Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Environmental Protection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63Linked to original sources
PubMed2001

The future of benefit-cost analyses of the Clean Air Act.

This review examines the first two studies conducted pursuant to a Congressional mandate that the U.S. Environmental Protection Agency analyze the effects of the Clean Air Act on the "public health, economy, and the environment of the United States." While these studies indicate that overall, the nation received good value for the resources it invested in improving air quality over the past three decades, we don't know if even higher value could have been obtained by changing or eliminating certain potentially inefficient elements. The review focuses on the critical policy and technical choices made in the analyses, including the selection of the appropriate baseline and the level of disaggregation for the studies. It is proposed that a potential third analysis focus on potential new policies not yet mandated by law or regulation. It is also proposed that the next study fill in key information gaps, expand the benefit categories, and incorporate new research on topics such as mortality and morbidity benefits, cost uncertainties, and others.

Air Pollution↗
PubMed1991

A survey and analysis of states' methodologies for deriving drinking water guidelines for chemical contaminants.

Data from a national survey questionnaire regarding the development of guidelines for chemical contaminants in drinking water were collected from all 50 states. Twenty-three states develop at least some of their own guidelines; the other 27 states rely on guidelines previously developed by the U.S. Environmental Protection Agency (USEPA) or by other states. States which derive guidelines generally employ toxicological criteria and risk assessment methodologies developed by the USEPA. Fourteen of the twenty-three states that develop their own guidelines depend on cancer potency factors derived by the USEPA to establish risk-based concentrations for carcinogens. Most of the states develop guidelines based on preventing possible excess cancer risk greater than one in one million. Seventeen of these twenty-three states rely on oral reference doses (RfDs) to derive guidelines for noncarcinogens. Examination and clarification of the states' approaches to guideline derivation reveal that although similar risk assessment techniques are generally employed, differences in assumptions, chemical classifications, and uncertainty factors may lead to variation in resultant guidance levels. Improved communication and coordination between states and the federal government may help reduce the variations and inconsistencies among the states in establishing drinking water guidelines for chemical contaminants.

Carcinogens↗
PubMed2002

Laboratory evaluation of amalgam separators.

BACKGROUND: Amalgam in dental wastewater is receiving increasing scrutiny from regulators because of national, state and local initiatives to reduce or virtually eliminate the discharge of mercury and mercury-containing items into the environment. Amalgam separators are considered to be one means of reducing the amount of amalgam that dental offices discharge into sewers. The purpose of this study was to evaluate the amalgam removal efficiency of commercially available amalgam separators and the total mercury concentration in the effluent from laboratory testing. METHODS: The authors evaluated the amalgam removal efficiency of 12 amalgam separators according to International Organization for Standardization, or ISO, Standard 11143 for Amalgam Separators. Total mercury concentration in the effluent was calculated using the mass of amalgam particles larger than 1.2 micrometers and the volume of effluent, together with U.S. Environmental Protection Agency, or EPA, Method 245.1 for amalgam particles smaller than 1.2 microm. Total dissolved mercury also was determined. RESULTS: The results show that all 12 amalgam separators exceeded the ISO 11143 requirement of 95 percent amalgam removal efficiency. Statistical differences were found in the efficiencies of the separators. Both the total mercury concentration and total dissolved mercury concentration in the effluent demonstrated large variations. CONCLUSIONS AND CLINICAL IMPLICATIONS: This laboratory evaluation shows that amalgam separators removed at least 96.09 percent of the amalgam in samples with particle-size distribution as specified in ISO 11143. Total mercury concentration and total dissolved mercury concentration in the effluent varied widely for each amalgam separator. Additional research is needed to develop test methods to evaluate the efficiency of amalgam separators in removing small amalgam particles, colloidal amalgam particles and ionic mercury in solution.

Dental Amalgam↗
PubMed1994

Asbestos in New York City public school buildings--public policy: is there a scientific basis?

The most recent of New York City's asbestos emergencies occurred in the late summer of 1993. It prevented schools from opening that fall, precipitated much media excitement, and caused a flurry of widespread abatement activities. This resulted in large measure from the U.S. Environmental Protection Agency's subjective school building inspection policy concerning identification of asbestos hazards in buildings and the subsequent Asbestos Hazard Emergency Response Act mandate for inspection. Data on concentrations of asbestos in the air, important for the calculation of risk to building occupants, were not required and therefore not obtained, as part of the abatement strategy or priority setting. Based on fiber-in-air measurements obtained elsewhere, the calculated risk to NYC school children, using the most pessimistic models, was less than six excess cancer deaths per million lifetimes equivalent to smoking less than a dozen cigarettes in a lifetime. The NYC administration responded to pressure from parent groups concerned with perceived asbestos risks to their children by closing the schools. The hysteria occurred because much of EPA's policy lacked a scientific basis for risk evaluation and assessment.

Air Pollution, Indoor↗
PubMedDate not supplied

Lead-based paint testing technologies: summary of an EPA/HUD field study.

The U.S. Environmental Protection Agency and the U.S. Department of Housing and Urban Development sponsored a field study of portable technologies for testing for lead in paint in three U.S. cities in 1993. Six chemical test kits and six X-ray fluorescence instruments, which represented the two main types of portable technologies available for residential lead testing at that time, were evaluated. Painted building components in single-family and multifamily housing units were selected to assess the performance of these products under real-world conditions. The study found that the chemical test kits were not effective in distinguishing lead-based paint, as defined by federal standards, from nonlead based paint. The X-ray fluorescence instruments were, under certain circumstances, found to be effective. The study filled an informational gap about the accuracy and precision of the portable lead-testing technologies. This article describes the design of the study and its major findings.

Environmental Monitoring↗
PubMed1998

Targeting lead in the multimedia environment in the continental United States.

The U.S. Environmental Protection Agency's (EPA) lead attainment strategy for air is being expanded to address geographic areas with the potential for multimedia, multipathway exposures to lead. Geographic Information Systems (GIS) technology is used to coordinate information from various databases to identify areas of potential concern. The data retrieval and decision processes used in identifying priority sources from each medium and in evaluating identified areas of concern are described in this paper. Only EPA databases with reliable locational information were used to facilitate accurate mapping and allow correlation with other data sources. The sources of lead loadings to air, water, and soils were mapped using either latitude and longitude or zip code, or county centroids for data lacking longitudinal and latitudinal coordinates (such as the drinking water data). A multimedia cluster of lead sources was identified at the county level, since all the facility data in the five databases could be mapped to this level. An impact factor and weighting system was devised to combine the information on the number of facilities and their relative size in developing a ranking of the multimedia lead clusters of concern in each region. The counties with the highest number of points were considered clusters of highest concern for multimedia lead sources. Two separate lists of the clusters were developed according to a point system. One identified 10 multimedia lead clusters in each of the 10 EPA regions, and the other identified the 100 clusters of highest concern in the country as a whole. The project is designed to be a first step in targeting future efforts to identify potential environmental problems associated with lead. The analyses presented in this paper provide a first look at the areas in the country where there is a potential for multimedia exposure to lead. A more refined analysis at the zip code level was subsequently developed to provide a good understanding of the issues pertaining to potential exposure at the neighborhood level. The results of this analysis will ultimately help the EPA and the states to target implementation and enforcement in areas of high potential lead exposures.

Databases, Factual↗
PubMed1995

Development of structure-activity relationship rules for predicting carcinogenic potential of chemicals.

Since the inception of Section 5 (Premanufacturing/Premarketing Notification, PMN) of the Toxic Substances Control Act (TSCA), structure-activity relationship (SAR) analysis has been effectively used by U.S. Environmental Protection Agency's (EPA) Structure Activity Team (SAT) in the assessment of potential carcinogenic hazard of new chemicals for which test data are not available. To capture, systematize and codify the Agency's predictive expertise in order to make it more widely available to assessors outside the TSCA program, a cooperative project was initiated to develop a knowledge rule-based expert system to mimic the thinking and reasoning of the SAT. In this communication, we describe the overall structure of this expert system, discuss the scientific bases and principles of SAR analysis of chemical carcinogens used in the development of SAR knowledge rules, and delineate the major factors/rules useful for assessing the carcinogenic potential of fibers, polymers, metals/metalloids and several major classes of organic chemicals. An integrative approach using available short-term predictive tests and non-cancer toxicological data to supplement SAR analysis has also been described.

Animals↗
PubMed1984

Disposal of antineoplastic wastes at the National Institutes of Health.

The process of developing disposal guidelines for antineoplastic wastes at the National Institutes of Health (NIH) is described. Because of the large volume of hazardous wastes generated, NIH must comply with Environmental Protection Agency (EPA) guidelines for disposal. Seven antineoplastic agents are defined by EPA as hazardous wastes. Because of the similar toxicities and pharmacologic drugs, NIH officials elected to dispose of all such agents as hazardous wastes. Available options are presented. The NIH procedure divides antineoplastic wastes into trace- and bulk-contaminated categories. Trace-contaminated wastes contain minimal or trace amounts of drugs and are disposed of by one-site incineration. Bulk-contaminated materials (defined as intravenous solutions or containers whose contents weigh more than 3% of the capacity of the container) are disposed of by land internment and incineration at EPA-approved sites. Syringes and i.v. bottles containing antineoplastic drugs are labeled with bright red-orange labels instructing personnel to return the materials to the pharmacy for disposal. General decision-making procedures for other institutions are recommended.

Antineoplastic Agents↗
PubMedDate not supplied

Applying mode-of-action and pharmacokinetic considerations in contemporary cancer risk assessments: an example with trichloroethylene.

The guidelines for carcinogen risk assessment recently proposed by the U.S. Environmental Protection Agency (U.S. EPA) provide an increased opportunity for the consideration of pharmacokinetic and mechanistic data in the risk assessment process. However, the greater flexibility of the new guidelines can also make their actual implementation for a particular chemical highly problematic. To illuminate the process of performing a cancer risk assessment under the new guidelines, the rationale for a state-of-the-science risk assessment for trichloroethylene (TCE) is presented. For TCE, there is evidence of increased cell proliferation due to receptor interaction or cytotoxicity in every instance in which tumors are observed, and most tumors represent an increase in the incidence of a commonly observed, species-specific lesion. A physiologically based pharmacokinetic (PBPK) model was applied to estimate target tissue doses for the three principal animal tumors associated with TCE exposure: liver, lung, and kidney. The lowest points of departure (lower bound estimates of the exposure associated with 10% tumor incidence) for lifetime human exposure to TCE were obtained for mouse liver tumors, assuming a mode of action primarily involving the mitogenicity of the metabolite trichloroacetic acid (TCA). The associated linear unit risk estimates for mouse liver tumors are 1.5 x 10(-6) for lifetime exposure to 1 microg TCE per cubic meter in air and 0.4 x 10(-6) for lifetime exposure to 1 microg TCE per liter in drinking water. However, these risk estimates ignore the evidence that the human is likely to be much less responsive than the mouse to the carcinogenic effects of TCA in the liver and that the carcinogenic effects of TCE are unlikely to occur at low environmental exposures. Based on consideration of the most plausible carcinogenic modes of action of TCE, a margin-of-exposure (MOE) approach would appear to be more appropriate. Applying an MOE of 1000, environmental exposures below 66 microg TCE per cubic meter in air and 265 microg TCE per liter in drinking water are considered unlikely to present a carcinogenic hazard to human health.

Animals↗
PubMed1991

Comparing alternative approaches to establishing regulatory levels for reproductive toxicants: DBCP as a case study.

This paper compares four alternative approaches for deriving regulatory levels for reproductive toxicants by applying them to the available data on the human spermatotoxicant 1,2-dibromo-3-chloropropane (DBCP). The alternatives examined include the Proposition 65 approach (application of a mandatory 1000-fold uncertainty factor to a no-observed-adverse-effect level [NOAEL]), the Environmental Protection Agency (EPA) approach (application of flexible uncertainty factors to a NOAEL), the Benchmark Dose approach (application of flexible uncertainty factors to a dose associated with a known level of change in a reproductive parameter), and the Quantitative Risk Estimation approach (using low-dose linear extrapolation and a model of the relationship between sperm count and infertility). Applied to DBCP, these approaches do not produce substantially different estimates of allowable exposure levels. However, the approaches do have different data requirements and provide different amounts of information on reproductive hazards to risk managers and the public. Neither the Proposition 65 nor the EPA approach provides information about the extent of health risk remaining at a regulatory level. In contrast, the Benchmark Dose approach can provide estimates of the magnitude of sperm count reduction at a regulatory level, and the Quantitative Risk Estimation approach can provide estimates of exposure-induced infertility.

Animals↗
PubMed1992

Risk factors for nonoccupational organophosphate pesticide poisoning.

The 535 reports of nonoccupational/nonagricultural poisoning with malathion in the Pesticide Incident Monitoring System (PIMS), a data base maintained by the Environmental Protection Agency, were coded and classified to describe the occurrence and to determine risk factors for poisoning. Between 1966 and 1980, 335 (63%) of reported incidents were associated with at least one symptomatic person, with a total of 670 persons exposed. Home exposures accounted for 92% of reports and arose from improper use and labeling problems in 61% and 3% of reports, respectively. Seventeen reports (3%) were associated with commercial extermination at home. One third of the 18 fatalities from malathion were unintentional and, therefore, preventable. The relative risks of fatal outcome from suicidal intent and labeling problems were, respectively 41 (P less than 10[-6]) and 4.8 (P = .09). When data from a previously coded data set on diazinon were added, the odds ratios were 20 and 6.7 (both P less than .0003). This suggests that public health measures aimed at safer use of pesticides outside the workplace are needed and that the PIMS data are a valuable source of epidemiological data on pesticide poisoning.

Accidents, Home↗
PubMed1995

Applying the Good Laboratory Practice regulations to studies involving genetically modified plants.

How can the Environmental Protection Agency's Good Laboratory Practice (GLP) regulations, originally written primarily for mammalian toxicology studies, be applied to regulatory studies conducted for genetically modified plants? Do they fit? Can they be applied and still make sense? How is a Quality Assurance Unit (QAU) to interpret the requirements in this new area of biotechnology? The answers to these questions are discussed in this brief presentation of how one team within the Monsanto QAU, along with the researchers, developed am effective and comprehensive compliance program by applying the "traditional approach" to the GLP regulations to a new and important scientific field in regulatory compliance. Topics discussed will address the differences in the approach between traditional toxicity testing and the newer technology and how the differences were resolved, new and innovative definitions of particular phases and other aspects of regulatory studies, and how the draft regulations for pesticidal plants will help this area of technology in the future.

Animals↗
PubMed2000

New methods for detection of potential endocrine disruptors.

It has been hypothesized that recent adverse trends in humans are linked to an increased exposure to potential endocrine disrupting agents. These include widely used compounds that mimic the action of sex hormones, including bisphenol A, phthalates and parabens. Since the chemical structure is not sufficient to determine whether a chemical will act as an oestrogen, there is a need for assays that can determine whether a compound interferes with the endocrine systems. The Environmental Protection Agency has recently suggested a testing scheme, composed of an initial screening followed by a more comprehensive investigation of chemicals that are positive in the screening. The screening will use several short-term assays to screen many thousands of compounds for potential endocrine disrupting properties. However, none of these tests determines compound-induced effects on the expression of endogenous genes, which is the cause of the adverse effects. We propose to use a precise quantification of the expression levels of endogenous oestrogen-regulated genes to test whether a chemical has oestrogenic properties, and describe how an endogenous gene expression assay can be established and conducted. Furthermore, different applications of such an assay are discussed: in cell cultures; in experimental animals; or, optimally, directly in blood samples from exposed humans.

Animals↗
PubMed2000

EPA: airing on the side of caution or pulling standards out of thin Air?

In May 1999, a federal appeals court ruled that the U.S. Environmental Protection Agency (EPA) had violated the Constitution when it strengthened regulations for ground-level ozone and particulate matter (PM). Although the court did not question the validity of the EPA's scientific basis for establishing the PM and ozone standards, it did challenge how the EPA selected the particular levels since the scientific record in both rules did not indicate unequivocally where the standards should be set. The agency failed to identify an "intelligible principle" that would guide such choices, the court said, and thereby exceeded the power it was granted by Congress. Because scientific uncertainty attends so much rule making, the ruling leaves open the question of when the EPA may make what is essentially a policy determination versus when those determinations must be made by Congress. For this reason, observers consider the ruling to have potentially significant implications beyond just the ozone and PM standards that may affect other EPA regulations and regulations by other agencies.

Air Pollution↗
PubMed2003

A cost-effective method for detoxification of sludge containing lead.

The industrial wastewater treatment plant discussed in this paper generates sludge containing heavy metals, including lead. Occasionally, the concentration of lead in the Toxic Characteristics Leaching Procedure (TCLP) extract from the sludge exceeded the U.S. Environmental Protection Agency (EPA) regulatory limit of 5 mg/l and resulted in the solid waste exhibiting the characteristic of toxicity. The technical and economic feasibility of a process for conditioning the lead-containing sludge was investigated. The results revealed that the lead-laden sludge could be made non-hazardous by chemical conditioning. The lead reduction efficiency of triple super phosphate (TSP) is higher than that of either calcium carbonate or magnesium hydroxide. The laboratory and pilot-scale tests indicated that the conditioning system consistently reduced the lead in the TCLP extract below the regulatory limit of 5 mg/l. The economic feasibility evaluation demonstrated that more than 450,000 US dollars could be saved annually by conditioning the sludge with TSP and disposing it as a non-hazardous material in a landfill. The results obtained from the laboratory as well as from the pilot-scale operation are described and discussed in this paper.

Calcium Carbonate↗
PubMed1999

On intergenerational equity and its clash with intragenerational equity and on the need for policies to guide the regulation of disposal of wastes and other activities posing very long-term risks.

This article begins with some history of the derivation of 40 CFR Part 191, the U.S. Environmental Protection Agency (EPA) standard that governs the geologic disposal of spent nuclear fuel and high-level and transuranic radioactive wastes. This is followed by criticisms of the standard that were made by a Sub-Committee of the EPA Science Advisory Board, by the staff of the U.S. Nuclear Regulatory Commission, and by a panel of the National Academies of Science and Engineering. The large disparity in the EPA approaches to regulation of disposal of radioactive wastes and disposal of hazardous, long-lived, nonradioactive chemical waste is illustrated. An examination of the intertwined matters of intergenerational equity and the discounting of future health effects follows, together with a discussion of the conflict between intergenerational equity and intragenerational equity. Finally, issues related to assumptions in the regulations concerning the future state of society and the biosphere are treated, as is the absence of any national philosophy or guiding policy for how to deal with societal activities that pose very long-term risks.

History, 20th Century↗
PubMed1996

Factors in standardizing automated cholinesterase assays.

A scientific panel assembled by the U.S. Environmental Protection Agency (EPA) determined that variability in cholinesterase (ChE) activities in the agency's pesticide/animal study database likely was due to a lack of accepted guidelines for ChE methodology. A series of trials was held in which participating laboratories measured ChE activity in blood and brain samples from untreated and pesticide-treated rats using a colorimetric assay method. The degree of inhibition of ChE activity in plasma and brain samples compared to controls was consistent among most of the laboratories. The ChE activity in erythrocyte samples differed more between laboratories due to a high blank, low erythrocyte AChE activity and hemoglobin absorption at the wavelength of the assay. Strategies are suggested for minimizing the variability of ChE activity in hemoglobin-rich samples.

Acetylcholinesterase↗
PubMed2004

Quality and quantity of suspended particles in rivers: continent-scale patterns in the United States.

Suspended solids or sediments can be pollutants in rivers, but they are also an important component of lotic food webs. Suspended sediment data for rivers were obtained from a United States-wide water quality database for 622 stations. Data for particulate nitrogen, suspended carbon, discharge, watershed area, land use, and population were also used. Stations were classified by United States Environmental Protection Agency ecoregions to assess relationships between terrestrial habitats and the quality and quantity of total suspended solids (TSS). Results indicate that nephelometric determinations of mean turbidity can be used to estimate mean suspended sediment values to within an order of magnitude (r(2) = 0.89). Water quality is often considered impaired above 80 mg TSS L(-1), and 35% of the stations examined during this study had mean values exceeding this level. Forested systems had substantially lower TSS and somewhat higher carbon-to-nitrogen ratios of suspended materials. The correlation between TSS and discharge was moderately well described by an exponential relationship, with the power of the exponent indicating potential acute sediment events in rivers. Mean sediment values and power of the exponent varied significantly with ecoregion, but TSS values were also influenced by land use practices and geomorphological characteristics. Results confirm that, based on current water quality standards, excessive suspended solids impair numerous rivers in the United States.

Carbon↗