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PubMed1996

Industry response to SARA Title III: pollution prevention, risk reduction, and risk communication.

This paper reports results from a survey designed to: (1) evaluate changes in industrial pollution prevention practices since the passage of the landmark environmental legislation, the Emergency Planning and Community Right-to-Know Act of 1986, also known as SARA Title III, and (2) identify those factors that may contribute to an industrial facility engaging in pollution prevention and risk communication activities. The survey was conducted under a Cooperative Agreement between the U.S. Environmental Protection Agency and the Columbia University Center for Risk Communication. Evidence from the survey indicates that a wide variety of waste and pollution reduction activities have been undertaken since passage of the Act. Virtually all facilities surveyed in the pulp and paper, chemical, and petroleum and refining industries reported that they had reduced pollutants or wastes on at least one of ten measures, including reducing toxic air emissions. Most facilities indicated paying more attention to pollution prevention activities as a result of SARA Title III and half reported that their communication activities have also increased.

Communication↗
PubMed2006

Mercury concentrations in fish from Lake Meredith, Texas: implications for the issuance of fish consumption advisories.

We examined how length of fish is related to mercury concentrations in muscle tissue of seven species of fish from Lake Meredith, Texas and determined how sex and growth rate are related to mercury concentration in walleye (Sander vitreus). Flathead catfish (Pylodictis olivaris), walleye and white bass (Morone chrysops) had the highest concentrations of mercury and channel catfish (Ictalurus punctatus), common carp (Cyprinus carpio), river carpsucker (Carpiodes carpio) and gizzard shad (Dorosoma cepedianum) had the lowest concentrations of mercury. Mercury concentrations were positively correlated with total length (TL) of fish for all species except gizzard shad, which exhibited a negative correlation between mercury concentration and TL. Male walleye grew more slowly than females, and males had higher concentrations of mercury than females. We also assessed the differences in fish consumption advisories that would be issued using Texas Department of State Health Services (DSHS) guidelines versus United States Environmental Protection Agency (USEPA) recommendations. Using DSHS guidelines, no fish species in Lake Meredith would be issued a fish consumption advisory. Nevertheless, DSHS has issued an advisory for walleye in Lake Meredith, possibly due to an inadequate sample size of fish. Using USEPA guidelines, a fish consumption advisory would be issued for the largest size class of flathead catfish but no advisory exists for flathead catfish in Lake Meredith. We suggest that when fish in a lake may be contaminated with mercury, all game fish in the lake should be assessed, and mercury advisories should take fish size into account.

Animals↗
PubMedDate not supplied

Regional health assessment relating to mercury content of fish caught in the Yukon-Kuskokwim Delta rivers system.

Seven species of fish were surveyed for muscle tissue mercury content across a broad area of western Alaska. Total mercury levels were determined by cold vapor atomic fluorescence spectroscopy in 66 fish sampled during 1997. Methylmercury in sampled fish amounted to 97 to 100% of total mercury values. Using mercury consumption risk levels derived from U.S. Environmental Protection Agency hazard assessment models, mean total mercury was determined to be above the human critical value of 0.2 g/g (ppm) in 29% of the fish species, and 62% of the fish species contained mercury exceeding the wildlife critical value for piscivorous mammals. Overall, 24% of the fish exceed the critical value for human consumption and 58% the wildlife critical value. Similarly 31% of sites sampled exceeded the human consumption critical value. Based on the mean of all fish sampled and a small number of river otters, a biomagnification factor of 12 was calculated for the Yukon-Kuskokwim Delta Region of Alaska.

Alaska↗
PubMed1991

Standard setting processes and regulations for environmental contaminants in drinking water: state versus federal needs and viewpoints.

The primary objective of a standard setting process is to arrive at a drinking water concentration at which exposure to a contaminant would result in no known or potential adverse health effect on human health. The drinking water standards also serve as guidelines to prevent pollution of water sources and may be applicable in some cases as regulatory remediation levels. The risk assessment methods along with various decision making parameters are used to establish drinking water standards. For carcinogens classified in Groups A and B by the United States Environmental Protection Agency (USEPA) the standards are set by using nonthreshold cancer risk models. The linearized multistage model is commonly used for computation of potency factors for carcinogenic contaminants. The acceptable excess risk level may vary from 10(-6) to 10(-4). For noncarcinogens, a threshold model approach based on application of an uncertainty factor is used to arrive at a reference dose (RfD). The RfD approach may also be used for carcinogens classified in Group C by the USEPA. The RfD approach with an additional uncertainty factory of 10 for carcinogenicity has been applied in the formulation of risk assessment for Group C carcinogens. The assumptions commonly used in arriving at drinking water standards are human life expectancy, 70 years; average human body weight, 70 kg; human daily drinking water consumption, 2 liters; and contribution of exposure to the contaminant from drinking water (expressed as a part of the total environmental exposure), 20%. Currently, there are over 80 USEPA existing or proposed primary standards for organic and inorganic contaminants in drinking water. Some of the state versus federal needs and viewpoints are discussed.

Carcinogens, Environmental↗
PubMed2006

Daily intake of di(2-ethylhexyl)phthalate (DEHP) by German children -- A comparison of two estimation models based on urinary DEHP metabolite levels.

Di(2-ethylhexyl)phthalate (DEHP) is a general-purpose plasticizer for polyvinyl chloride (PVC) and has become a ubiquitous environmental contaminant. It is suspected to be an endocrine disrupting/modulating substance in humans. Children are of special concern due to their developmental state. In our study we estimated the daily DEHP intake of 239 children aged 2-14 years by extrapolating from their urinary levels of the DEHP metabolites mono-(2-ethyl-5-hydroxyhexyl)phthalate (5OH-MEHP), mono-(2-ethyl-5-oxohexyl)phthalate (5oxo-MEHP) and mono-(2-ethylhexyl)phthalate (MEHP). We applied two calculation models based upon the volume and the creatinine-related urinary metabolite concentrations. Applying the volume- or the creatinine-based calculation model we determined a median daily DEHP intake of 7.8 or 4.3 microg/kgbody weight (bw)/day and a 95th percentile of 25.2 or 15.2 microg/kgbw/day. Three children (1%) exceeded the value of the tolerable daily intake (TDI) of the European Food Safety Authority of 50 microg/kgbw/day, while 7.5% or 3% (depending on the calculation model) exceeded the reference dose (RfD) of 20 microg/kgbw/day of the US Environmental Protection Agency. In general, DEHP exposure was decreasing with increasing age and boys had higher exposures than girls. Our findings suggest that the majority of the children in the general population is exposed to quantities of DEHP below the TDI and the RfD. However, many children scoop out the preventive limit values to a considerable degree and in individual cases we observed substantial transgressions. Younger children seem to be more severely burdened, which may be due to a higher food consumption related to their bw, mouthing behaviour and/or playing near the ground.

Adolescent↗
PubMed2006

Strategies for eliminating and reducing persistent bioaccumulative toxic substances: common approaches, emerging trends, and level of success.

This paper reviews nine of the best-known strategies for eliminatine and reducing substances in the category known as "persistent bioaccumulative toxic substances" (PBTSs). The nine strategies are as follows: 1) Ontario's Candidate Substances List for Bans and Phase-outs (1992), 2) Canada's ARET Program (1994), 3) Canada's Toxic Substances Management Policy (1995), 4) the Commission for Environmental Cooperation's Sound Management of Chemicals Initiative (1995), 5) the Great Lakes Binational Toxics Strategy (1997), 6) the U.S. Environmental Protection Agency's (U.S. EPA's) draft National PBT Strategy (1998), 7) U.S. EPA's Waste Minimization Program (1998), 8) the U.N. Stockholm Convention on Persistent Organic Pollutants (2001), and 9) Washington State's Rule on Persistent Bioaccumulative Toxins (2006). The review describes the commonalities among the strategies, including their goals and principles, design approaches, and other common elements. It also discusses several emerging trends, such as the increasing importance of economic considerations, human health information, and nonregulatory management approaches. The paper concludes with a discussion of how effective the strategies have been at achieving their goals of elimination and reduction of persistent bioaccumulative toxic substances.

Canada↗
PubMed2005

Chromate ion adsorption by agricultural by-products modified with dimethyloldihydroxyethylene urea and choline chloride.

The use of cellulose-containing agricultural by-products modified with the cross-linking reagent dimethyloldihydroxyethylene urea (DMDHEU) and the quaternary amine, choline chloride, as anion exchange resins, has not been reported. The objective of the present study was to convert the readily available by-products, soybean hulls, sugarcane bagasse and corn stover to functional anion exchange resins using DMDHEU and choline chloride. Optimization of the modification method was achieved using soybean hulls as a substrate. The optimized method was additionally used to modify sugarcane bagasse and corn stover. Adsorption efficiency results with chromate ion showed that modification with both DMDHEU and choline chloride was required for the highest efficiencies. Adsorption capacities of the modified by-products were determined using chromate ion and found to be 1.97, 1.61 and 1.12 mmol/g for sugarcane bagasse, corn stover and soybean hulls, respectively. Competitive adsorption studies were conducted at 10 and 50 times US Environmental Protection Agency (US EPA) limits for arsenic, chromium and selenium in a simulated wastewater at pH 7. The results showed preferential adsorption of chromate ion over arsenate or selenate ion. Estimated product costs for the three resins ranged from $0.88/kg to $0.99/kg, which was considerably lower than the market costs for the two commercial anion exchange resins QA-52 and IRA-400 also used in this study. DMDHEU/choline chloride modification of the three by-products produced an anion exchange resin with a high capacity to adsorb chromate ion singly or competitively in the presence of other anions from aqueous solutions.

Adsorption↗
PubMed2002

Respirable particulate matter at an urban and nearby industrial location: concentrations and variability and synoptic weather conditions during high pollution episodes.

Continuous data of the concentration measurements of respirable suspended particulates (PM10, particles with aerodynamic diameter smaller than or equal to 10 pm) were analyzed. These measurements were carried out at an urban and nearby industrial location in northern Greece for the 5-year period 1996-2000. The time series concentration trend was examined, the seasonal and diurnal variations were identified, and the lognormality of the daily mean concentration data sets was tested. Over the 5-year data-gathering period, the days on which the U.S. Environmental Protection Agency (EPA) 24-hr PM10 standard was exceeded (episode days) were identified and their relation to prevailing synoptic-scale meteorological conditions was studied. The analysis led to useful information concerning the air quality levels, the contribution of the main pollution sources in this area, as well as some of the mechanisms that influence the PM10 concentrations. It also was proved that the measured PM10 concentrations are a result of a combination of processes including local anthropogenic sources, mesoscale transport, and resuspension. A complex system of sources and meteorological conditions modulate the heavy particulate pollution in the area of interest.

Air Pollutants↗
PubMed1998

Exposures from indoor spraying of chlorpyrifos pose greater health risks to children than currently estimated.

Recent findings of indoor exposure studies of chlorpyrifos indicate that young children are at higher risks to the semivolatile pesticide than had been previously estimated [Gurunathan et al., Environ Health Perspect 106:9-16 (1998)]. The study showed that after a single broadcast use of the pesticide by certified applicators in apartment rooms, chlorpyrifos continued to accumulate on children's toys and hard surfaces 2 weeks after spraying. Based on the findings of this and other research studies, the estimated chlorpyrifos exposure levels from indoor spraying for children are approximately 21-119 times above the current recommended reference dose of 3 microg/kg/day from all sources. A joint agreement reached between the U.S. Environmental Protection Agency and the registrants of chlorpyrifos-based products will phase out a number of indoor uses of the pesticide, including broadcast spraying and direct uses on pets. While crack and crevice treatment of insects (such as cockroaches and termites) by chlorpyrifos will still continue, it appears prudent to explore other insect control options, including the use of baits, traps, and insect sterilants and growth regulators. To ensure global protection, adequate dissemination of appropriate safety and regulatory information to developing regions of the world is critical, where importation and local production of chlorpyrifos-based products for indoor uses may be significant.

Air Pollution, Indoor↗
PubMedDate not supplied

Noncancer inhalation toxicology of crystalline silica: exposure-response assessment.

Silicosis from inhalation of silica has long been recognized as an occupational hazard. Concern has arisen regarding the potential risk of silicosis from ambient silica (primarily quartz dust). This presentation reviews available data regarding ambient silica levels and estimates of the risk of silicosis at low exposure levels as they relate to the current U.S. Environmental Protection Agency National Ambient Air Quality Standards (NAAQS) for particulate matter. Current data indicate that for individuals not compromised by other respiratory ailments and for ambient environments expected to sustain 10% or less silica fraction in particulate matter with a mean aerodynamic diameter of < or = 10 microns (PM10), maintenance of the 50 micrograms/m3 annual NAAQS for PM10 is adequate to protect against fibrotic effects from ambient silica exposures. Issues such as the large divergence of risk estimates within the occupational setting (particularly at high cumulative exposures) and factors to consider for extrapolating risk in an occupational setting to risk from ambient exposure are discussed.

Air Pollutants↗
PubMed1999

A review of the effects of hazardous waste on reproductive health.

Approximately 1 in 4 Americans lives within 4 miles of a hazardous waste site according to the Environmental Protection Agency. In light of this large proportion and the public's high level of concern that hazardous waste causes health problems, it is important for primary care physicians and other health care providers to know that residential proximity to some kinds of hazardous waste sites is associated with adverse reproductive effects. Findings from both state-based surveillance programs and studies of individual hazardous waste sites have shown increased risk of congenital malformations and reductions in birth weight among infants born to parents living near hazardous waste sites. This article summarizes salient literature on human health effects of hazardous waste and suggests actions for primary care providers to consider.

Canada↗
PubMed2005

Application of photoassisted electrochemical detection to explosive-containing environmental samples.

High-performance liquid chromatography (HPLC) with ultraviolet (UV) absorbance and photoassisted electrochemical detection (PAED) is applied to the determination of explosives in groundwater and soil samples. On-line, solid-phase extraction minimizes sample pretreatment, enabling direct analysis of groundwater samples and soil extracts. Soils are extracted using pressurized fluid extraction, which is compared to the Environmental Protection Agency (EPA) sonication method. Limits of detection for explosives in the matrixes of interest are equivalent or superior (i.e., <10 parts-per-trillion for HMX) to those achieved using the EPA method 8330. HPLC-UV-PAED is also shown here to be more broadly applicable, as it is capable of determining nitro compounds of interest (e.g., nitroglycerin) that have poor UV chromophores. Additional selectivity of amine-substituted nitroaromatic explosives is achieved by using a photochemical reactor with a 366-nm wavelength lamp. By coupling reversed-phase columns of different selectivities together, baseline resolution of all 14 standard explosives is demonstrated.

Chromatography, High Pressure Liquid↗
PubMed1998

Methylcyclopentadienyl manganese tricarbonyl: health risk uncertainties and research directions.

With the way cleared for increased use of the fuel additive methylcyclopentadienyl manganese tricarbonyl (MMT) in the United States, the issue of possible public health impacts associated with this additive has gained greater attention. In assessing potential health risks of particulate Mn emitted from the combustion of MMT in gasoline, the U.S. Environmental Protection Agency not only considered the qualitative types of toxic effects associated with inhaled Mn, but conducted extensive exposure-response analyses using various statistical approaches and also estimated population exposure distributions of particulate Mn based on data from an exposure study conducted in California when MMT was used in leaded gasoline. Because of limitations in available data and the need to make several assumptions and extrapolations, the resulting risk characterization had inherent uncertainties that made it impossible to estimate health risks in a definitive or quantitative manner. To support an improved health risk characterization, further investigation is needed in the areas of health effects, emission characterization, and exposure analysis.

Administration, Inhalation↗
PubMed2003

Health risk assessment for sulfur dioxide pollution in South Durban, South Africa.

Concern about health risks from sulfur dioxide (SO2) pollution prompted a health risk assessment for residents of the heavily polluted industrial region of South Durban, South Africa. The U.S. Environmental Protection Agency health risk assessment model was used to evaluate health effects for individuals in 4 age groups on the basis of data for a 3-yr period, from 1997-1999. Under normal exposure conditions, the level of risk was low (Hazard Quotient < 1); only under the worst-case scenario (exposure 24 hr/day) was there a significant risk of developing health effects. Inasmuch as these results are contrary to the popularly held belief that residents have a high risk of developing SO2-related respiratory diseases under normal exposure conditions, future studies should more thoroughly investigate exposure patterns and verify the authors' assumption that indoor SO2 levels are zero.

Air Pollutants↗
PubMed2002

Development of an agricultural job-exposure matrix for British Columbia, Canada.

Farmers in British Columbia (BC), Canada have been shown to have unexplained elevated proportional mortality rates for several cancers. Because agricultural exposures have never been documented systematically in BC, a quantitative agricultural Job-exposure matrix (JEM) was developed containing exposure assessments from 1950 to 1998. This JEM was developed to document historical exposures and to facilitate future epidemiological studies. Available information regarding BC farming practices was compiled and checklists of potential exposures were produced for each crop. Exposures identified included chemical, biological, and physical agents. Interviews with farmers and agricultural experts were conducted using the checklists as a starting point. This allowed the creation of an initial or 'potential' JEM based on three axes: exposure agent, 'type of work' and time. The 'type of work' axis was determined by combining several variables: region, crop, job title and task. This allowed for a complete description of exposures. Exposure assessments were made quantitatively, where data allowed, or by a dichotomous variable (exposed/unexposed). Quantitative calculations were divided into re-entry and application scenarios. 'Re-entry' exposures were quantified using a standard exposure model with some modification while application exposure estimates were derived using data from the North American Pesticide Handlers Exposure Database (PHED). As expected, exposures differed between crops and job titles both quantitatively and qualitatively. Of the 290 agents included in the exposure axis; 180 were pesticides. Over 3000 estimates of exposure were conducted; 50% of these were quantitative. Each quantitative estimate was at the daily absorbed dose level. Exposure estimates were then rated as high, medium, or low based on comparing them with their respective oral chemical reference dose (RfD) or Acceptable Daily Intake (ADI). This data was mainly obtained from the US Environmental Protection Agency (EPA) Integrated Risk Information System database. Of the quantitative estimates, 74% were rated as low (< 100%) and only 10% were rated as high (>500%). The JEM resulting from this study fills a void concerning exposures for BC farmers and farm workers. While only limited validation of assessments were possible, this JEM can serve as a benchmark for future studies. Preliminary analysis at the BC Cancer Agency (BCCA) using the JEM with prostate cancer records from a large cancer and occupation study/survey has already shown promising results. Development of this JEM provides a useful model for developing historical quantitative exposure estimates where is very little documented information available.

Agricultural Workers' Diseases↗
PubMed1995

Teratogenesis induced by short- and long-term exposure of Xenopus laevis progeny to lead.

Short-term (96-h) tests on Xenopus laevis embryos are advocated for rapid screening of teratogens, as an alternative to the use of mammals. The objective of the present investigation was to determine whether extending the short-term tests beyond 96 h would detect the teratogenicity of chemicals that would otherwise be missed by the short-term tests. Lead teratogenicity was examined in Xenopus, using lead concentrations of 0.02, 0.05, 0.1, 0.5, 1.0, and 3.0 mg/L, which bracket the U.S. Environmental Protection Agency (EPA) maximum allowable concentration of 0.05 mg/L in water. Short-term exposure times were 72 or 96 h, starting on d 1, 2, or 3 postfertilization, while long-term exposure covered d 1 through metamorphosis. Short-term exposure resulted in neural tube defects (when exposure included d 1 and/or d 2) and tail curvatures, but only at the higher lead concentrations (1 and 3 mg/L). Lower lead concentrations produced no malformations upon short-term exposure, and this corresponded with the absence of tissue lead uptake. On the other hand, long-term exposure to lead (> 3 wk) resulted in the delayed appearance of lordoscoliosis at low lead concentrations (0.02-0.1 mg/L). The delayed appearance of lordoscoliosis corresponded roughly with the attainment of stable lead tissue levels, and this malformation persisted after metamorphosis. Thus, short-term observation tests alone may fail to detect the teratogenicity of low concentrations of environmental chemicals, and may result in the setting of inappropriately liberal exposure standards.

Animals↗
PubMed2002

Derivation of risk based wipe surface screening levels for industrial scenarios.

The environmental characterization of building interiors and other surfaces has generally been performed with wipe-sampling because it is a non-destructive technique. There is no consensus, however, as to the interpretation of the results of wipe-sampling. Specifically, there is not a standardized method to determine if chemicals found at sampled levels pose a threat to human health. A methodology was developed, based on acceptable health risk levels, to derive screening levels for evaluating wipe-sampling results pertaining to industrial scenarios. The methodology was based on the United States Environmental Protection Agency (USEPA) Region IX Preliminary Remediation Goal (PRG) approach; a multi-exposure methodology commonly used for evaluating soil concentrations. PRGs are the USEPA determined health based goals for soil preliminary remediation efforts. Probabilistic techniques were used to conduct a sensitivity analysis of the methodology to determine which variables drive the ultimate screening levels. Discrete values were then selected based on standard industrial scenarios common to the US Army. The wipe surface screening levels reported are for use as preliminary guidelines which help to determine whether further sampling or cleanup are necessary. The levels are not meant as cleanup or compliance criteria.

Administration, Cutaneous↗
PubMed1998

Safe drinking water: a public health challenge.

Disinfection of drinking water through processes including filtration and chlorination was one of the major achievements of public health, beginning in the late 1800s and the early 1900s. Chloroform and other chlorination disinfection by-products (CBPs) in drinking water were first reported in 1974. Chloroform and several other CBPs are known to cause cancer in experimental animals, and there is growing epidemiologic evidence of a causal role for CBPs in human cancer, particularly for bladder cancer. It has been estimated that 14 16% of bladder cancers in Ontario may be attributable to drinking water containing relatively high levels of CBPs; the US Environmental Protection Agency has estimated the attributable risk to be 2 17%. These estimates are based on the assumption that the associations observed between bladder cancer and CBP exposure reflect a cause-effect relation. An expert working group (see Workshop Report in this issue) concluded that it was possible (60% of the group) to probable (40% of the group) that CBPs pose a significant cancer risk, particularly of bladder cancer. The group concluded that the risk of bladder and possibly other types of cancer is a moderately important public health problem. There is an urgent need to resolve this and to consider actions based on the body of evidence which, at a minimum, suggests that lowering of CBP levels would prevent a significant fraction of bladder cancers. In fact, given the widespread and prolonged exposure to CBPs and the epidemiologic evidence of associations with several cancer sites, future research may establish CBPs as the most important environmental carcinogens in terms of the number of attributable cancers per year.

Animals↗