Human Exposure to Mercury Through Fish Consumption: Risk Assessment of Riverside Inhabitants of the Urrá Reservoir,Colombia

This study evaluated the risk to human health from mercury exposure through fish consumption in three riverside populations: Children (CH, 2–15 years old), women of childbearing age (WCHA, 16–49 years old), and the rest of the population (RP) from the Urrá reservoir area, Colombia. Questionnaire-based surveys were used to collect data and information about the weekly amount of fish consumed (WAFC) and the relative importance of each fish species in the diet of the study participants. There were no significant differences in WAFC between population groups. CH recorded the highest weekly intake of total Hg (WIT-Hg) (0.6–55.4 μg/kg bodyweight/week), with significant differences (p < .05) from WCHA (0.2–26.7 μg/kg bw/w) and RP (0.1–23.6 μg/kg bw/w). A high percentage (90%) of estimated WIT-Hg values exceeded the provisional tolerable weekly intake (PTWI) established in order to protect the embryo and fetus. Results suggested that sensitive subgroups, such as pregnant women or those who may become pregnant and young children should limit or avoid consumption of certain fish of higher trophic levels due to their high total Hg (T-Hg) concentrations (up to 2.73 μg/g). In sum, the high values of WIT-Hg in children and women of childbearing age revealed a worrying situation, which should be reviewed carefully in order to prevent a potential public health crisis.     

Approaches for Integrated Risk Assessment

Recognizing the need to enhance the effectiveness and efficiency of risk assessments globally, the World Health Organization's International Programme on Chemical Safety, the U.S. Environmental Protection Agency, the European Commission, and the Organization for Economic Cooperation and Development developed a collaborative partnership to foster integration of assessment approaches used to evaluate human health and ecological risks. The objectives of this effort included: improving understanding of the benefits of integration, identifying obstacles to the integration process, and engaging key agencies, organizations, and scientific societies to promote integration. A framework with supporting documentation was developed to describe an approach for integration. Four case studies were constructed to illustrate how integrated risk assessments might be conducted for chemical and nonchemical stressors. The concepts and approaches developed in the project were evaluated in an international workshop. The goal of this effort was international acceptance of guidance for integrated risk assessment.     

Integrated Risk Assessment — Results from an International Workshop

The World Health Organization's International Programme on Chemical Safety and international partners have developed a framework for integrated assessment of human health and ecological risks and four case studies. An international workshop was convened to consider how ecological and health risk assessments might be integrated, the benefits of and obstacles to integration, and the research and mechanisms needed to facilitate implementation of integrated risk assessment. Using the case studies, workshop participants identified a number of opportunities to integrate the assessment process. Improved assessment quality, efficiency, and predictive capability were considered to be principal benefits of integration. Obstacles to acceptance and implementation of integrated risk assessment included the disciplinary and organizational barriers between ecological and health disciplines. A variety of mechanisms were offered to overcome these obstacles. Research recommendations included harmonization of exposure characterization and surveillance methods and models, development of common risk endpoints across taxa, improved understanding of mechanisms of effect at multiple scales of biological organization, and development of methods to facilitate comparison of risks among endpoints.     

Extrapolation in Human Health and Ecological Risk Assessments: Proceedings of a Symposium

A symposium was conducted in April 1998 by the U.S. Environmental Protection Agency's National Health and Environmental Effects Research Laboratory (NHEERL) to explore issues of extrapolation in human health and ecological risk assessments. Over the course of three and one half days, leading health and ecology experts presented and discussed research methods and approaches for extrapolating data among taxa and across levels of biological organization, through time, and across spatial scales. The intended result of this symposium was enhanced interaction among a diverse array of scientists, policymakers, and risk assessors to promote identification of approaches for reducing the uncertainties of extrapolation in risk assessment.     

The Concept of Data Utility in Health Risk Assessment: A Multi-Disciplinary Perspective

Human and ecological health risk assessments and the decisions that stem from them require the acquisition and analysis of data. In agencies that are responsible for health risk decision-making, data (and/or opinions/judgments) are obtained from sources such as scientific literature, analytical and process measurements, expert elicitation, inspection findings, and public and private research institutions. Although the particulars of conducting health risk assessments of given disciplines may be dramatically different, a common concern is the subjective nature of judging data utility. Often risk assessors are limited to available data that may not be completely appropriate to address the question being asked. Data utility refers to the ability of available data to support a risk-based decision for a particular risk assessment. This article familiarizes the audience with the concept of data utility and is intended to raise the awareness of data collectors (e.g., researchers), risk assessors, and risk managers to data utility issues in health risk assessments so data collection and use will be improved. In order to emphasize the cross-cutting nature of data utility, the discussion has not been organized into a classical partitioning of risk assessment concerns as being either human health- or ecological health-oriented, as per the U.S. Environmental Protection Agency's Superfund Program.     

Comparison of Contaminated Site Human Health Risk Assessment Approaches in Canada: Application of Provincial Methods to a Hypothetical Site

Human health risk assessment, whether at the screening level or more complex phase, is not an exact science. A wide variety of advice and direction is offered by international, national, and provincial/state environmental agencies regarding the conduct of risk assessment, and different risk assessors access and rely on the available regulatory advice and direction differently. This may result in wide variability in the estimates of chemical exposure and risk. A comparison of human health risk assessment approaches practiced at the provincial level in Canada was undertaken, wherein each jurisdiction's approach was applied to a hypothetical contaminated site. Approaches were found to vary both in terms of methodological considerations, and in matters of policy. The exercise yielded results in terms of estimated exposures and predicted hazard quotients/indexes and incremental lifetime cancer risks that were in some cases quite consistent (varying by a factor of less than 1.5 times), and in other cases remarkably different (varying by orders of magnitude). This article reviews the various approaches/frameworks applied and discusses the results of the hypothetical risk assessments, in terms of both the observed variation and the source of this variability.     

Selenium Was a Time Bomb

At high dietary levels, selenium causes adverse effects in animals. Aquatic birds are among the more sensitive wildlife species, because their reproduction can be impaired when dietary selenium levels exceed about 4?µg/g (dry weight basis). Fish can also be adversely affected at similar dietary exposures. Conversely, low dietary levels of selenium (below about 0.1 to 0.5?µg/g) cause nutritional deficiencies in domestic animals, fish, and wildlife. Selenium became recognized as a significant environmental contaminant for wildlife in 1983, with the discovery of developmental abnormalities and excessive embryonic mortality in aquatic birds at Kesterson Reservoir, California. There are a number of environmental settings in which selenium warrants concern and must be considered carefully in relation to potential effects to fish and wildlife, and there may still be surprises in which it unexpectedly becomes a significant ecological issue. However, if selenium is included among the chemicals of potential ecological concern when ecological risk assessments are planned and conducted, there is enough information to thoroughly evaluate its environmental significance in much the same way as other contaminants. The main difference is that it is essential to have a good understanding of selenium's occurrence, complex biogeochemistry, and ecotoxicology to avoid serious errors.     

A Human Health Risk Assessment Software for Facilitating Management of Urban Contaminated Sites: A Case Study: The Massa Site,Tuscany, Italy

The goal of this article is to present the Human Health Risk Assessment (HRA) software developed as one of the NORISC ^{1 1}NORISC is the acronym of the project “Network Oriented Risk assessment by In-situ Screening of Contaminated sites” realized under under the 5th European Union Community Framework Programme for Research, Technological Development and Demonstration Activities. View all notes decision support software system components that could be used as a tool for facilitating management of urban contaminated sites. The NORISC-HRA software provides sufficient technical and procedural support to conduct a simple site-specific risk assessment. The employed HRA methodology is generally based on U.S. Environmental Protection Agency (USEPA) procedures. The software determines the level and spatial distribution of human health risks at a given site and sets up site-specific preliminary Health-Based Remedial Goals (HBRGs)/Risk-Based Concentrations (RBCs) for soil and groundwater. The NORISC-HRA software is recommended for use when national soil and groundwater limit values are exceeded. Exposure pathways considered in this software are associated with three land use patterns—residential, industrial/commercial, and recreational. The aricle also presents the software testing results obtained at one of the NORISC test sites—the Massa site (Avenza-Carrara, Tuscany, Italy). Findings of the HRA indicated that the contaminated soil at the Massa test site might pose potential cancer and non-cancer risks to industrial workers in its present condition. Arsenic was the dominant substance responsible for most of the baseline risk and at the RBC of 1.77 mg/kg it was the primary driver of remedial decisions at the Massa site.     

A Preliminary Human Health Risk Assessment of Organochlorine Pesticide Residues Associated with Aquatic Organisms from the Rangsit Agricultural Area,Central Thailand

Food consumption is one of the main routes of human exposure to organochlorine pesticide residues (OCPRs). To assess the potential health risks associated with OCPRs contaminants due to freshwater organism consumption, a number of vegetables, prawn, snail, and fish were collected from Khlong 7 (canal), Rangsit agricultural area, Pathum-Thani Province, Thailand. The samples were extracted using a multiresidue extraction method and then analyzed by gas chromatography with microelectron capture detector (μ -ECD). The results show that low concentrations of OCPRs were detected in parts per billion (ppb) levels. Based on a plausible worst-case scenario, the local population could be at risk for cancer due to consumption of fish contaminated by α -, β -HCH, heptachlor, heptachlor epoxide, aldrin, dieldrin, DDD, DDE, and DDT. Likewise, individuals may be at risk from consumption of Lanchester's freshwater prawn Macrobrachium lanchesteri, freshwater snail Filopaludina mertensi, swamp morning-glory Ipomomea aquatica, neptunia Neptunia oleracea, and water lily Nymphaea lotus because these species all contained elevated concentrations of α -, β -HCH, heptachlor, heptachlor epoxide, aldrin, and dieldrin.     

Risk Assessment for Dermal Exposure of Organochlorine Pesticides for Local Fishermen in the Rangsit Agricultural Area,Central Thailand

Organochlorine pesticides (OCPs) used in agriculture and for public health purposes were banned in Thailand over the past decade; however, their persistent residues have been found in several agricultural areas of the country. This may result in adverse effects to human populations. This study investigated the concentration of organochlorine pesticides residues (OCPRs) in surface water and evaluated the potential cancer risk associated with dermal contact of the local fisherman fishing in the Khlong 7 canal, Rangsit agricultural area, central Thailand. Water samples were extracted using liquid-liquid extraction (LLE) and then analyzed by gas chromatography with microelectron capture detector (μ -ECD). The results show that low concentrations of OCPRs were detected in parts per billion (ppb or ng/ml) levels, that is, ∑ Endosulfan (α -, β -, and -sulfate) 0.082 ng/ml > DDT and derivatives 0.019 ng/ml > ∑ HCH (α -, γ -, β -, and δ -HCH) 0.014 ng/ml > aldrin and dieldrin 0.007 ng/ml > heptachlor and heptachlor epoxide 0.0068 ng/ml > endrin and endrin aldehyde 0.005 ng/ml > methoxychlor 0.001 ng/ml, respectively. Using the worst-case scenario defined as the reasonable maximum exposure (RME) to assess the potential cancer risk, five OCPs (dieldrin, 4,4′ -DDT, β -HCH, heptachlor, and heptachlor epoxide) may pose a risk of concern on a lifetime human carcinogenesis greater than one in a million.     

Human health risk assessment of trace elements in shallow groundwater of the Linhuan coal-mining district,Northern Anhui Province,China

Enrichment of trace elements in groundwater poses considerable risks to human health. The concentrations of seven trace elements (Cr, Mn, Ni, Cu, Zn, Cd, and Pb) in 34 samples of shallow groundwater from the study area were estimated. We assessed the concentrations of the trace elements and health risks with statistical analysis and the US Environment Protection Agency (USEPA) model. The results showed that the mean concentrations of trace elements decreased as follows: Mn > Zn > Ni > Cr > Cu > Cd > Pb. Apart from Mn at one sampling point, the concentrations of all trace elements were below the guideline values of the World Health Organization for drinking water. Correlation and cluster analysis indicated that the trace elements fell into groups, with Ni and Cu in one group, and Mn, Zn, and Cd in another, which suggested that the trace elements grouped together had similar sources. The total non-carcinogenic risk values ranged from 8.52 × 10^?4 to 1.27 × 10^?1. The total carcinogenic risk caused by Cr and Cd averaged 1.62 × 10^?6, which exceeded the acceptable level of 1 × 10^?6 recommended by the USEPA. The carcinogenic risk of Cr accounted for 75.93% of R_total.     

美国、加拿大环境和健康风险管理方法

对目前美国和加拿大多个部门使用的风险评价与风险管理方法进行了全面回顾和综合分析,论述各种不同方法的特征,深入探讨各种管理方法的基础、利弊、使用经验,辨识环境、人类健康和职业健康风险综合方法中应该包含的要素,阐述风险管理目标的确定方法,以期为中国的环境风险管理提供经验。