Dioxin risk assessment

Ravo VR, Unger A. 1995. A novel application of a competitive binding model in dioxin risk assessment. Reg Toxicol Pharmacol 21 108-116. 

An evaluation of human health hazards posed by dioxin-contaminated soil in certain areas of Missouri illustrates specific uncertainties in dioxin risk assessment. These uncertainties include the relationship of studies in animals to effects in humans, the level and extent of contamination in the soil, the level of exposure to humans, and the character of the dose-response curve. Uncertainties in assessing risks posed by toxic substances in general are viewed from the standpoint of a 1985 report prepared by the Task Force on Risk Assessment and Risk Management for the Secretary, Department of Health and Human Services. The Task Force listed nine commonly used assumptions—which may also be called uncertainties. 

The uncertainties in dioxin risk assessment in Missouri are many—and there are many in the risk assessment and risk management of any toxic substance anywhere. But, we are working to reduce these uncertainties and, as this is done, our assessments of risks and our management of risks should continue to improve. 

Information is also needed on the toxicological interactions of groups of polychlorinated chemicals (such as certain biphenyls, biphenylenes, and dibenzofurans) known to be isosteric with 2,3,7,8-TCDD and that frequently coexist with 2,3,7,8-TCDD in environmental samples. Acquisition of these data should provide the basis of a risk assessment analysis for dioxin and fishery and wildlife resources. 

Andersen, M.E., J.J. Mills, M.L. Gargas, L. Kedderis, L.S. Bimbaum, D. Neubert, and W.F. Greenlee. 1993. Modeling receptor-mediated processes with dioxin implications for pharmacokinetics and risk assessment. Risk Analysis 13 25-36. 

Cook, P.M., RJ. Erickson, R.L. Spehar, S.P. Bradbury, and G.T. Ankley. 1993. Interim Report on Data and Methods for Assessment of 2,3,7,8-tetrachlorodibenzo-p-dioxin Risks to Aquatic Life and Associated Wildlife. U.S. Environ. Protection Agen. EPA/600/R-93/055. 156 pp. 

During the last two decades, a number of different risk assessments of dioxins and related compounds have been performed. Since the mid-1990s, coplanar PCBs have often been included in the assessments. In 1997, WHO established an expert group on dioxins and related compounds. 

This voluntary risk assessment programme started in 1995 and concerned a list of 25 chemicals dichloromethane, chloroform, tetrachloromethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, vinyl chloride, trichloroethene, tetra-chloroethene, hexachlorobutadiene, monochlorobenzene, 1,4-dichlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, tetrachlorobenzene, hexachlorobenzene, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, pentachlorophenol, hexachloro-cyclohexane, dioxins, PCB, DDT, and elemental mercury. 

There are several problems in using the TEF approach in the risk assessment of PAH in food. The use of the TEF approach requires that the compounds in question exert the toxicological effect by the same mechanism of action, such as is the case for the polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, which act through binding to the Ah-receptor. Although a number of... 

This thesis focuses on the applicability of in vitro, in vivo bioassays and bioindicators as tools for evaluating the effects of complex chemical mixtures in the process of deciding whether dredged harbour sediments can be disposed of at sea without serious adverse effects on marine ecosystem and human health. It considers the North Sea delta area in order to determine a comprehensive approach for the application of both in vitro and in vivo bioassays for hazard assessment, advanced risk assessment, and location-specific ecological impact assessment for dredged harbour sediments. To aid in the selection of appropriate, robust and reliable in vitro and in vivo bioassay and bioindication methods for these specific purposes, the uneertainty, predictability and specificity of the bioassays have been explored and the applieability in eombination with other analyses is discussed. The focus of the chosen examples is on bioassays and bioindicators for the relatively well studied dioxin-like contaminants and TBT. 

Factor Approach for Risk Assessment of Dioxins and Related Compounds. Journal of Animal Science 76 134-41. 

European Commission, Scientific Committee on Food, Opinion of the Scientific Committee on Food on the Risk Assessment of Dioxins and Dioxin-Like PCBs in Food, Adopted on May 50, 2001. http //europa.eu.int/ comm/food/fs/sc/scf/out90 en.pdf. 

Remarkably, Portier has provided some of the risk assessments for EPA s efforts to label dioxin as a human cancer risk and to calculate risks from environmental exposures to dioxin. I don t know why he dismisses the IOM committee s very similar opinions about the health effects of Agent Orange as political, but I agree with him. 

H. R. Pohl et al., Public Health Perspectives on Dioxin Risks Two Decades of Evaluations, Human and Ecological Risk Assessment 8 (2002) 255-50. 

Safe S (1991) Polychlorinated dibenzo-p-dioxins and related compounds sources, environmental distribution and risk assessment. Environ Carcinog Ecotoxicol Rev 9 261-302... 

NORTH ATLANTIC TREATY ORGANISATION, COMMITTEE ON THE CHALLENGES of MODERN SOCIETY. International Toxicity Equivalency Factor (I-TEF) method of risk assessment for complex mixtures of dioxins and related compounds. Pilot study on international information exchange on dioxins and related compounds . CCMS Report Number 176, Environmental Protection Agency, Washington D.C., 1988. 

SIELKEN, R.L. (1987). Quantitative cancer risk assessments for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), Food Chem. Toxicol. 25, 257—267. 

Kang, Y.-S., Park, J.-S., Min, B.-Y., 2002. Residue and risk assessment of polychlorinated dibenzo-p-dioxin/dibenzofurans in the Korean population. Anal. Sci. Tehcnol. 15(2),... 

Lee, H.-M., 2002. Risk assessment and the latest trend of management in food dioxins. In International symposium in Korean society of environmental toxicology, 2002, Issues in Environmental toxicology. The Society of Environmental Toxicology (in Korean), pp. 21M8. 

---