Chromium,Copper, and Arsenic Concentrations in Soil Underneath CCA-Treated Wood Structures

Soils below nine structures (decks and foot bridges) in Florida were examined to evaluate potential impacts from chromated copper arsenate (CCA), a common wood preservative. Eight of the nine structures were confirmed to have been treated with CCA. Soils collected were evaluated for arsenic, chromium, and copper concentrations as well as pH, volatile solids content and particle size distribution. Two types of soil samples were collected: a soil core and surface soil samples (upper 2.5 cm). One soil core was collected from below each deck and one control core was collected from an area removed from one of the structures. Eight or nine surface soil samples were collected in a grid-like fashion from beneath each structure. Equal numbers of surface control samples were collected from areas away from the structures. Metal concentrations were elevated in both the soil cores and surface samples collected from below the CCA-treated structures. Core samples showed elevated concentrations of metals at depths up to 20 cm. The arithmetic mean concentrations of arsenic, chromium, and copper in the 65 surface soil samples collected from below CCA-treated structures were 28.5 mg/kg, 31.1 mg/kg, and 37.2 mg/kg, respectively, whereas the mean concentrations of arsenic, chromium, and copper in the control samples were 1.34 mg/kg, 8.62 mg/kg, and 6.05 mg/kg, respectively. Arsenic concentrations exceeded Florida's risk-based soil cleanup target level (SCTL) for residential settings in all 65 surface soil samples. The industrial setting SCTL was exceeded in 62 of the 65 samples.     

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.     

Human health risks associated with heavy metals in soil in different areas of San Luis Potosí, México

The aim of this study was to develop a health risk assessment in different areas of San Luis Potosí, México. Four heavy metals (arsenic, mercury, cadmium, and lead) were analyzed in soil from communities assessed. The mean arsenic concentration was significantly higher (p < .05) in the city of San Luis Potosí (51.85 mg/kg) compared to the other assessed areas (5.52–8.43 mg/kg). For cadmium, the mean concentration was significantly higher (p < .05) in Santa Maria Picula (7.46 mg/kg) than in the other areas (3.72–4.15 mg/kg). Regarding mercury levels, a significantly higher (p < .05) mean concentration was found in Mezquitic (1.54 mg/kg) compared to other areas (0.56–0.81 mg/kg). Lastly, when comparing the mean lead concentration in the city of San Luis Potosí (108 mg/kg), it was found to be significantly lower (p < .05) than in other areas (219–227 mg/kg). Subsequently, a probabilistic health risk assessment was performed, ingestion was the major exposure pathway for all four metals. Maximum cumulative hazard index (HI) values showed higher risk in all sampled locations (HIs > 1.0), suggesting that these sites can pose a non-carcinogenic risk to the populations (children) living in those areas. This study highlights the necessity of establishing a biomonitoring program for the surveillance of the child populations living in the assessed locations.     

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.     

Assessment of Human Health Risk for an Area Impacted by a Large-Scale Metallurgical Refinery Complex in Hunan,China

Due to accelerated urbanization and reform of industrial structure in China, polluting industries in major cities have been closed or relocated. Consequently, large numbers of industrial sites were generated and the contaminated soils on and around these sites may pose risks to humans. This case study presents an estimation of human health risks for an area that is mainly impacted through air dispersion and deposition from a large-scale metallurgical refinery complex in Zhuzhou city, Hunan Province, China. Carcinogenic and non-carcinogenic risks posed by the contaminants were estimated under future industrial and residential land use scenarios. The result shows that adverse health effects may occur primarily through ingestion of soils contaminated with As, Cd, and Pb. The total carcinogenic risks of multiple contaminants for a large area exceed the acceptable risk level of 1 × 10^?5, and several localized hotspots, where the total hazard index exceeds 1 were identified. Soils in the Tongda site pose the highest carcinogenic risks and non-carcinogenic hazards. It is concluded that potential human health risks exist under the proposed redevelopment scenarios, and development of risk-based remediation strategies is recommended.     

Human Health Risk Evaluation of ACQ-Treated Wood

Alkaline copper quaternary (ACQ) Type D is one of several compounds currently being used as a chemical preservative to treat wood for prevention of rot and decay. As wood weathers naturally, human exposure to ACQ might occur through dermal contact or incidental ingestion of residues from the wood surface. To understand any potential for health risks from the use of ACQ-treated wood, a health-based evaluation was undertaken on the primary components of ACQ, which are copper, didecyl dimethyl ammonium carbonate, 2-methyl-4-isothiazolin-3-one, and 5-chloro-2-methyl-4-isothiazolin-3-one. For these components, there are no formalized toxicity values in USEPA's Integrated Risk Information System, although extensive toxicity data are available in the scientific literature. Therefore, health-based toxicity benchmarks were derived from a review of existing toxicity data. The exposure assessment was based on methods developed by the Consumer Product Safety Commission in their evaluation of the potential for children's exposure to arsenic from wood treated with chromated copper arsenate. This approach entailed wipe testing the surface of treated wood to determine the amount of chemical that might be removed from the wood, and estimating the amount of chemical that a child might contact via the dermal route or incidental ingestion through hand-to-mouth activities. All calculated exposure estimates were well below toxicity benchmarks.     

Derivation of Risk Management Criteria for Chemicals of Unknown Toxic Potency at Contaminated Sites

Environmental investigations of former industrial sites often detect the presence of chemicals for which no soil criteria exist and for which regulatory agencies have not derived estimates of toxic potency. This poses a considerable problem for making informed risk management decisions involving sites where such chemicals are present. As a result, a methodology has been developed for making risk-based decisions for chemicals of unknown toxic potency in soil at contaminated sites. The method is based on principles and procedures used by the US Food and Drug Administration (USFDA), the US Environmental Protection Agency (USEPA) and the Canadian Council of Ministers of the Environment (CCME). After analyzing the data on hundreds of carcinogenic and non-carcinogenic substances, the USFDA and other leading researchers have concluded that, if no toxicological data is available on a chemical, exposures less than 1.5?µg/person/day (i.e., 0.02?µg/kg body weight/day) are unlikely to result in appreciable health risks even if the substance was later found to be a carcinogen. To develop maximum soil concentrations that will be protective of human health (i.e., Risk Management Criteria or RMC), the above exposure limit of 0.02?µg/kg body weight/day has been assumed to be protective of risks from exposure to chemicals lacking toxicological data. Using a stochastic risk assessment model for estimating exposures to chemicals from contaminated sites, our analyses indicate that a soil concentration of 2?µg/g would be protective of human health for land uses that include residential, commercial, and industrial development provided no major indirect pathways exist at the site. If indirect pathways exists (e.g., vapor infiltration of soil gases, uptake of chemicals into garden produce, etc.), alternate RMC could be developed, that include such indirect pathways, using the methodology provided in this paper. Used by experienced risk assessors, the approach is a scientifically defensible screening method that will preclude many chemicals from unnecessary evaluation, while allowing risk assessors to focus efforts on chemicals of greater concern and make informed risk management decisions.     

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.     

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.     

Arsenic in groundwater and its health risk assessment in drinking water of Mailsi,Punjab, Pakistan

The present study was aimed at assessing drinking water quality regarding arsenic (As) and its impact on health from Mailsi (Punjab), Pakistan. Forty-four groundwater samples were collected from two sites, Sargana and Mailsi. Arsenic and other cations were determined by atomic absorption spectrophotometer, whereas the anions were determined either through titration or spectrophotometer. The results revealed that dominant anions were HCO₃^? and Cl^?, Ca⁺² was the dominant cation, and overall water chemistry of the area was CaMgHCO₃^? type. Arsenic concentrations were high, ranging from 11 to 828 µg/L that crossed the World Health Organization permissible limits. Likewise, higher SO₄^?2 concentrations ranging from 247 to 1053 mg/L were observed. The health risk index was higher in the Sargana site, which employed the differences in terms of higher Average Daily Dose, Hazard Quotient, and Carcinogenic Risk of arsenic, which is unsuitable for drinking purposes. The area seems to be at high risk due to arsenic pollution and wells have never been tested for arsenic concentrations earlier; therefore, necessary measures should be taken to test the wells with respect to arsenic.     

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.