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PubMed1999

Ultrasonic extraction and portable anodic stripping voltammetric measurement of lead in paint, dust wipes, soil, and air: an interlaboratory evaluation.

Recent studies have demonstrated the utility of ultrasonic extraction (UE), followed by portable anodic stripping voltammetry (ASV), for the on-site determination of lead in environmental and industrial hygiene samples. The aim of this work was to conduct an interlaboratory evaluation of the UE-ASV procedure, with a goal of establishing estimates of method performance based on results from collaborative interlaboratory analysis. In this investigation, performance evaluation materials (PEMs) with characterized lead concentrations were used for interlaboratory testing of the UE-ASV procedure. The UE-ASV protocol examined has been promulgated in the form of two separate national voluntary consensus standards (one for UE and another for electroanalysis, which includes ASV). The PEMs consisted of characterized and homogenized paints, soils, and dusts (the last of which were spiked onto wipes meeting national voluntary consensus standard specifications), and air filter samples (mixed cellulose ester membrane) generated using characterized paints within an aerosol chamber. The lead concentrations within the PEMs were chosen so as to bracket pertinent action levels for lead in the various sample matrices. The interlaboratory evaluation was conducted so as to comply with an applicable national voluntary consensus standard that can be used to estimate the interlaboratory precision of a given analytical test method. Based on the analytical results reported by the participating laboratories, relative standard deviations (RSDs) for repeatability and reproducibility were computed for three different lead contents of the four PEMs. RSDs for repeatability were 0.019-0.100 for paints; 0.030-0.151 for soils; 0.085-0.134 for dust wipes; and 0.095-0.137 for air filters. RSDs for reproducibility were 0.127-0.213 for paints; 0.062-0.162 for soils; 0.085-0.134 for dust wipes; and 0.114-0.220 for air filters. With the exception of one of the air filter samples and one of the paint samples, the precision estimates were within the +/- 20% precision requirement specified in the US Environmental Protection Agency National Lead Laboratory Accreditation Program (NLLAP). The results of this investigation illustrate that the UE-ASV procedure is an effective method for the quantitative measurement of lead in the matrices evaluated in this study.

Air Pollution, Indoor↗
PubMed2005

The interaction effects of binary mixtures of benzene and toluene on the developing heart of medaka (Oryzias latipes).

The United States Environmental Protection Agency (USEPA) has pursued the estimation of risk of adverse health effects from exposure to chemical mixtures since the early 1980s. Methods used to calculate risk estimates of mixtures were often based on single chemical information that required assumptions of dose-addition or response-addition and did not consider possible changes in response due to interaction effects among chemicals. Full factorial designs for laboratory studies can produce interactions information, but these are expensive to perform and may not provide the information needed to evaluate specific environmentally relevant mixtures. In this research, groups of Japanese medaka (Oryzias latipes) embryos were exposed to binary mixtures of benzene and toluene as well as to each of these chemicals alone. Endpoint specific dose-response models were built for the hydrocarbon mixture under an assumption of dose-additivity, using the single chemical dose-response information on benzene and toluene. The endpoints included heart rate, heart rate progression, and lethality. Results included a synergistic response for heart rate at 72 h of development, and either additivity or antagonism for all other endpoints at 96 h of development. This work uses an established statistical method to evaluate the toxicity of an environmentally relevant mixture to ascertain whether interaction effects are occurring, thus providing additional information on toxicity.

Animals↗
PubMed1999

Effects of ambient air pollution and environmental tobacco smoke on respiratory health of non-smoking women in Hong Kong.

BACKGROUND: Two-thirds of complaints received by the Hong Kong Environmental Protection Department in 1988 were related to poor air quality. In July 1990 legislation was implemented to reduce fuel sulphur levels. The intervention led to a reduction in respiratory symptoms and bronchial hyperresponsiveness of primary school children. The objectives of this study were to investigate the differences in respiratory health between non-smoking women living in the more polluted district (Kwai Tsing) and those living in the less polluted district (Southern); to assess the impact of the government air quality intervention; and to study the effect of environmental tobacco smoke on respiratory health in non-smoking women in both districts. METHOD: A total of 3405 non-smoking women, aged 36.5 years (standard deviation = 3.0), from two districts with good and poor air quality respectively before the intervention were followed yearly from 1989 to 1991. Binary latent variable modelling was used to summarize the six respiratory symptoms and to estimate the effects of risk factors. RESULTS: In 1989, living in the polluted district was associated with poor respiratory health (odds ratio [OR] = 1.55, 95% confidence interval [CI]: 1.11-2.17, P < 0.01). After the intervention, in the polluted district only, sulphur dioxide levels fell by up to 80% and sulphate concentrations in respirable particulates by 38%. Between 1989 and 1990-1991, there was no significantly greater decline (P > 0.241) in the more polluted compared with the less polluted district for poor respiratory health. In 1989, the effects on poor respiratory health for exposure to two or more categories of smokers relative to none in the home (OR = 1.80, 95% CI: 1.15-2.83, P < 0.01) were higher but not significantly than those for living in polluted relative to less polluted district (95% CI of the two effects overlapping each other). CONCLUSIONS: Environmental tobacco smoke (ETS) and outdoor air pollution had independent adverse effects on respiratory health of non-smoking women and improvement in air quality had produced some but non-significant benefits.

Adolescent↗
PubMedDate not supplied

Risk and revisionism in arsenic cancer risk assessment.

Oral exposures of nonoccupational populations to environmental inorganic arsenic are associated with skin and internal cancers as well as various noncarcinogenic effects. Cancer risk assessments have been based largely on epidemiological studies of a large population exposed to inorganic arsenic in well water in Taiwan. Criticisms and skepticism of the use of the Taiwanese data for estimating arsenic cancer risks outside of Taiwan, including potential use by the U.S. Environmental Protection Agency for regulatory purposes, have been expressed on various grounds. The nature and extent of such criticisms have sharpened with recent findings in the exposed Taiwanese of increased incidence of internal cancers (bladder, kidney, liver, and lung), in addition to already-observed skin cancer, coupled with a good likelihood that these findings will produce more stringent arsenic regulation in the United States and elsewhere. These criticisms collectively posit a revisionist view that: 1) cancer incidence among the Taiwanese was amplified by a number of host and environmental factors not applicable elsewhere, 2) the cancer dose-response curve may not be linear at the lower exposures elsewhere, and 3) there is a toxicokinetic and metabolic threshold to cancer risk that was exceeded by the Taiwanese. However, a number of the arguments against wide use of the Taiwanese data are flawed and subject to challenge. We explore some of these arguments and their critical evaluation, particularly as they concern certain exposure, metabolic, and nutritional determinants of the cancer risk of inorganic arsenic in the Taiwanese.

Adult↗
PubMed2001

The development and certification of Standard Reference Materials (SRMs) to assess and ensure accurate measurement of Pb in the environment.

The National Institute of Standards and Technology (NIST) has had a major quality-assurance role in the federal effort to reduce lead poisoning of children in the United States through its mission of ensuring the accuracy of chemical measurements. NIST certifies reference materials (standard reference materials--SRMs) that are used to benchmark measurements by secondary and field methods of analysis--to ensure that decisions of great health and economic impact are soundly based on good measurement science. Over the past 10 years, in cooperation with the US Environmental Protection Agency (EPA), US Department of Housing and Urban Development (HUD), and the United States Geological Survey (USGS), NIST has prepared and certified SRMs for lead content in soil, indoor dust, and paint. The role of these materials in meeting regulatory and abatement needs is described and their certified values are summarized.

Dust↗
PubMed2003

Standardization of procedures and structures for risk evaluation in Germany--the work of the Risk Commission.

Risk evaluation in Germany is characterized by the uncoordinated involvement of various governmental and non-governmental institutions, by lacking transparency, by mingling of scientific risk assessment and political risk management, and by unsatisfactory public participation. Within the frame of the German Environmental Health Action Program the Ministers of Health and the Environment established a commission to develop recommendations for the reorganization of procedures and structures for risk evaluation within health-orientated environmental protection in the Federal Republic of Germany. The Risk Commission recently published its first report. It recommends strict separation of risk assessment and risk management; implementation of a clear procedural framework, risk communication as an integrated element of the whole process of risk evaluation and finally the establishment of two permanent co-ordinating institutions.

Communication↗
PubMed2006

Ecological health assessment and remediation of the stream impacted by acid mine drainage of the Gwangyang mine area.

Ecological health in a temperate stream impacted by acid mine drainage (AMD) was evaluated by using a multimetric approach of the Index of Biological Integrity (IBI) based on natural fish assemblage. Recently, this approach has been widely used in many developed countries as a tool for ecological risk assessments of water environments. We used 10 metric systems, instead of 12 metrics suggested by Barbour, M. T., Gerritsen, J., Snyder, B. D., & Stribling, J. B. (1999). Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers: Periphyton, benthic Macroinvertebrates and Fish, 2nd edn. EPA 841-B-99-002. Washington, DC: U.S. Environmental Protection Agency, Office of Water, for a development of the regional IBI model, and used trophic guilds, habitat guilds, and richness variables for the calculation of IBI values. In the model, the attributes of four of 11 metrics were modified for the regional application. IBI values in the stream averaged 20.6 (n = 5), indicating a "poor condition" in terms of ecological health according to the modified criteria of U.S. EPA (1993). Fish Field and Laboratory Methods for Evaluating the Biological Integrity of Surface Waters. EPA 600-R-92-111. Environmental Monitoring systems Laboratory - Cincinnati office of Modeling, Monitoring systems, and quality assurance Office of Research Development, U.S. EPA, Cincinnati, Ohio, 45268. In particular, mean IBI values in the impacted areas of sites 2 and 3 were 13, and this health condition was categorized as "very poor condition." IBI values in the impacted sites were significantly lower than the values found in the control. Also, we found that fishes in site sites 2 and 3 were not present during the study, and morphological deformity of Rhynchocypris oxycephalus was observed in site 4, influenced directly by sites 2 and 3, indicating a chemical impact in the sites. From the results of experiments in which AMD was treated with marine shells at stagnant condition, pH increased up to 6.0 from 3.1, and Fe and Al were removed up to 99% within 6 h. In the reactor experiment considering field application, pH of effluent maintained around 7.0. In addition, concentrations of Fe, Al, and heavy metals decreased remarkably in the effluents, and bottom-opened screen between neutralizer basins showed high effectiveness in the treatment of AMD.

Acids↗
PubMed2001

Neurotoxicity and molecular effects of methylmercury.

The neurotoxicity of high levels of methylmercury (MeHg) and the high susceptibility of the developing brain are well established both in humans and experimental animals. Prenatally poisoned children display a range of effects varying from severe cerebral palsy to subtle developmental delays. Still unknown is the lowest dose that impairs neurodevelopment. The primary source of human exposure is the fish. The data obtained so far from epidemiological studies on fish-eating populations are not consistent. A reference dose of 0.1 microg MeHg/kg per day has been established by the U.S. Environmental Protection Agency based on a study on Iraqi children exposed to MeHg in utero. However, these exposures occurred at high level for a limited period of time, and consequently were not typical of lower chronic exposure levels associated with fish consumption. Major obstacles for estimation of a threshold dose for MeHg include the delayed appearance of the neurodevelopmental effects following prenatal exposure and limited knowledge of cellular and molecular processes underlying these neurological changes. In this respect, a strategy which aims at identifying sensitive molecular targets of MeHg at environmentally relevant levels may prove particularly useful to risk assessment. Here some examples of MeHg molecular effects occurring at low doses/concentrations are presented.

Animals↗
PubMed2002

Implementing GIS to resolve environmental coastal problems in Varna.

The city of Varna, like many other coastal cities along the Black Sea and Mediterranean Sea, has a lot of problems related to the environmental protection for many years, including those with coastal zone management. Recently, the coastal slope problems due to land-slides appeared as very urgent and difficult to be solved. This paper describes a method to solve some of the problems by analysing the data collected. A data layer representing the complete hydrologic network including transport lines through slopes, lakes, streams, rivers, is a necessary component of many hydrologic and coastal applications. The coastal area of the city has significant importance--sea ports, resorts, cargo terminals. Most of them add environmental problems to the Black Sea in adjacent territories and the region as a whole. The attempt described is to solve these problems on the ground. This paper describes a process to analyse the area specific geographical data for a decision. Making a front-end application using ESRI's ArcView 3.0a/Avenue, user-friendly procedures were prepared to automate most of the functions. This application generates maps using data collected during the last two years. The data acquisition is performed according to the Bulgarian standards. Converting procedures are created and tested as well. Finally, a technology for updating data is approved.

Bulgaria↗
PubMed2001

Efficient regional ozone control strategies for the eastern United States.

When environmental regulatory bodies formulate control plans, it is incumbent upon them to try to achieve the stated goals in an economically efficient manner. The US Environmental Protection Agency (EPA) is presently developing regulations to limit the influence of transported ozone on areas that are having difficulty meeting the ambient air quality standard. EPA has proposed stringent control measures for emissions of nitrogen oxides (NOx) in 22 states of the eastern US. The strategy would necessitate the use of selective catalytic reduction or similar high-performance technology on almost all major power plants in the region, as well as extensive controls on industrial sources. This paper suggests several alternative approaches that would achieve equal or better environmental improvement at lower cost. These include focusing control efforts on sources closer to the North-east Corridor, pushing controls on close-in sources to a higher level of technology performance, and relaxing the stringency of requirements for states remote from ozone problem areas. All the approaches examined are two to three times more cost-effective than EPA's proposed approach in the North-east Corridor.

Air Pollutants↗
PubMed1993

The use of the Microtox system for evaluation of toxicity of the wastes in Vítkovice Steelworks, Ostrava (Czechoslovakia).

Ostrava's Industrial Agglomeration is one of the most polluted areas in Czechoslovakia due to an enormous production of wastes and wastewaters from both industry and municipal sources. As most of the wastes are deposited in the environment in a very simple way (usually in landfills) they may cause negative environmental effects and represent a serious hazardous factor for the surroundings. Complex legislative regulations on waste treatment with respect to environmental protection are currently accepted. Many data on the character of produced and deposited wastes which are necessary for classification of wastes are, however, missing. Rapid and reliable estimates of biological effects of wastes were made in one of the biggest steelwork enterprises which belongs to the most significant producers of wastes in the Ostrava region. Typical wastes which are produced in the greatest amount were selected and the leachates of the wastes were tested using the microbial toxicity test, Microtox. The results contribute to a monitoring programme for evaluation of environmental quality.

Czechoslovakia↗
PubMedDate not supplied

Chlorpyrifos (Dursban)-associated birth defects: report of four cases.

Extensive and unusual patterns of birth defects noted in four children included defects of the brain, eyes, ears, palate, teeth, heart, feet, nipples, and genitalia. Brain defects were present in the ventricles, corpus callosum, choroid plexus, and septum pellucidum, and genital defects included the testes (undescended), microphallus, and labia (fused). All children had growth retardation, and three had hypotonia and profound mental retardation. The children were exposed in utero to chlorpyrifos (Dursban). Published literature and unpublished documents by the U.S. Environmental Protection Agency contain reports that identify similarities in defects found in test animals and in children exposed to Dursban. A pattern of defects found in the four children in this study may represent a heretofore unrecognized syndrome that should be considered when Dursban-exposed women have children with birth defects.

Abnormalities, Drug-Induced↗
PubMed2004

Multimedia persistence as an indicator of potential for population-level intake of environmental contaminants.

Although intuitively it is apparent that population-level exposure to contaminants dispersed in the environment must be related to the persistence of the contaminant, there has been little effort to quantify this link formally. In this paper we investigate the relationship between overall persistence and/or overall residence time in a multimedia exposure environment and the population-level intake of contaminants as expressed by intake fraction (iF), the cumulative fraction of chemical emitted to the environment that is taken up by members of the population. We demonstrate that for any given contaminant and emission scenario the definition of iF implies that it is directly proportional to the overall multimedia persistence (Pov), or the overall multimedia residence time (Tov). The proportionality constant has dimensions of time and represents the characteristic time for population intake (CTI) of the chemical from the environment. We then apply the CalTOX fate and exposure model to explore how Tov and CTI combine to determine the magnitude of iF We find that CTI has a narrow range of possible values relative to Tov across multiple chemicals and emissions scenarios. We use data from the Canadian Environmental Protection Act Priority Substance List (PSL1) Assessments and multimedia Pov to show that exposure assessments based on empirical observation are consistent with interpretations from the model. Results indicate that Pov derived from screening-level assessments of persistence, bioaccumulation potential, and toxicity (PBT) is a useful indicator of the potential for population-level exposure.

Environmental Exposure↗
PubMed2006

Evaluation of two new arsenic field test kits capable of detecting arsenic water concentrations close to 10 microg/L.

Millions of people worldwide are exposed to arsenic-contaminated drinking water. Arsenic field test kits may offer a cost-effective approach for measuring these exposures in the field, although the accuracy of some kits used in the past has been poor. In this study, arsenic concentrations were measured in 136 water sources in western Nevada using two relatively new arsenic test kits and compared to laboratory measurements using atomic fluorescence spectroscopy (AFS). Spearman's rank correlation coefficients comparing the Quick Arsenic and Hach EZ kits to laboratory measurements were 0.96 (p < 0.001) and 0.95 (p < 0.001), respectively. When analyzed in seven exposure categories (0-9, 10-19, 20-49, 50-99, 100-199, 200-499, and > or = 500 microg/L), test kit and AFS measurements were in the same category in 71% (Quick Arsenic) and 62% (Hach EZ) of samples, and within one category of each other in 99% (Quick Arsenic) and 97% (Hach EZ) of samples. Both kits identified all water samples with high arsenic concentrations (> 15 microg/L) as being above the United States Environmental Protection Agency's drinking water standard and the World Health Organization's guideline value for arsenic of 10 microg/L. These results suggestthatthese easily portable kits can be used to identify water sources with high arsenic concentrations and may provide an important tool for arsenic surveillance and remediation programs.

Arsenic↗
PubMed2006

Water manganese exposure and children's intellectual function in Araihazar, Bangladesh.

Exposure to manganese via inhalation has long been known to elicit neurotoxicity in adults, but little is known about possible consequences of exposure via drinking water. In this study, we report results of a cross-sectional investigation of intellectual function in 142 10-year-old children in Araihazar, Bangladesh, who had been consuming tube-well water with an average concentration of 793 microg Mn/L and 3 microg arsenic/L. Children and mothers came to our field clinic, where children received a medical examination in which weight, height, and head circumference were measured. Children's intellectual function was assessed on tests drawn from the Wechsler Intelligence Scale for Children, version III, by summing weighted items across domains to create Verbal, Performance, and Full-Scale raw scores. Children provided urine specimens for measuring urinary As and creatinine and were asked to provide blood samples for measuring blood lead, As, Mn, and hemoglobin concentrations. After adjustment for sociodemographic covariates, water Mn was associated with reduced Full-Scale, Performance, and Verbal raw scores, in a dose-response fashion; the low level of As in water had no effect. In the United States, roughly 6% of domestic household wells have Mn concentrations that exceed 300 microg Mn/L, the current U.S. Environmental Protection Agency lifetime health advisory level. We conclude that in both Bangladesh and the United States, some children are at risk for Mn-induced neurotoxicity.

Arsenic↗
PubMed2006

Assessing water quality in rivers with fuzzy inference systems: a case study.

In recent years, fuzzy-logic-based methods have demonstrated to be appropriated to address uncertainty and subjectivity in environmental problems. In the present study, a methodology based on fuzzy inference systems (FIS) to assess water quality is proposed. A water quality index calculated with fuzzy reasoning has been developed. The relative importance of water quality indicators involved in the fuzzy inference process has been dealt with a multi-attribute decision-aiding method. The potential application of the fuzzy index has been tested with a case study. A data set collected from the Ebro River (Spain) by two different environmental protection agencies has been used. The current findings, managed within a geographic information system, clearly agree with official reports and expert opinions about the pollution problems in the studied area. Therefore, this methodology emerges as a suitable and alternative tool to be used in developing effective water management plans.

Environmental Monitoring↗
PubMedDate not supplied

Gasoline-contaminated ground water as a source of residential benzene exposure: a case study.

In a private residence using gasoline-contaminated ground water (approximately 300 micrograms/l benzene), a series of experiments were performed to assess the potential benzene exposures that may occur in the shower stall, bathroom, master bedroom, and living room as a result of a single 20-min, shower. Integrated fixed site SUMMA TM-polished canister and Tenax GC air samples were collected in the target microenvironments over 20, 60, and 240 min. periods. These results were compared with the long-term personal Tenax GC samples (6 h) and grab samples collected with glass, gas-tight syringes at 0, 10, 18, 20, 25, 25.5, and 30 min. Maximum benzene concentrations occurred in the shower stall (758-1670 micrograms/m3) and bathroom (366-498 micrograms/m3) during and immediately after the shower. Inhalation exposures in the shower stall during the 20-min. shower were 2.1-4.9 times higher than corresponding 20-min, bathroom exposures. The total benzene dose resulting from the shower was estimated to be approximately 281 micrograms, with 40% via inhalation and 60% via the dermal pathway. This total is 2 to 3.5 times higher than the mean inhalation dose received during a concurrent 6 h occupation of the house. These results indicate that domestic use of gasoline-contaminated water can produce relatively high benzene exposures that vary significantly according to an individual's proximity to the water use zone. The information in this document has been funded wholly or in part by the U.S. Environmental Protection Agency. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. The entire experiment was reviewed and approved by the Research Triangle Institute Human Subjects Review Committee.

Air Pollution↗
PubMed2006

Daphnia magna mortality when exposed to titanium dioxide and fullerene (C60) nanoparticles.

Nanoparticles (1-100 nm) comprise the latest technological advances designed to do everything from absorb environmental toxins to deliver drugs to a target organ. Recently, however, they have come under scrutiny for the potential to cause environmental damage. Because compounds in this miniature size range have chemical properties that differ from those of their larger counterparts, nanoparticles deserve special attention. Our main objective was to assess the potential impact that nanoparticles may have on release into aquatic environments. We prepared titanium dioxide (TiO2) and fullerene (C60) nanoparticles by filtration in tetrahydrofuran or by sonication. Daphnia magna were exposed to the four solutions using U.S. Environmental Protection Agency 48-h acute toxicity tests. Images of the particle solutions were recorded using transmission-electron microscopy, and the median lethal concentration, lowest-observable-effect concentration, and no-observable-effect concentration were determined. Exposure to filtered C60 and filtered TiO2 caused an increase in mortality with an increase in concentration, whereas fullerenes show higher levels of toxicity at lower concentrations. Exposure to the sonicated solutions caused varied mortality. Understanding the potential impacts of nanoparticles will help to identify the most appropriate nanotechnology to preserve the aquatic environment while advancing medical and environmental technology.

Animals↗