title: Risk-based concentrations: prioritizing environmental problems using limited data.
abstract: A difficult task faced by regulatory agencies is that of choosing, on the basis of limited data, which environmental problems to address. This paper incorporates USEPA risk assessment methods into a quantitative approach for prioritizing locations, contaminants and media according to potential health risk. USEPA has developed either a reference dose (a chronic dose without adverse effect) or slope factor (upper bound lifetime cancer risk per mg.kg-1.d-1) for many substances. This work combines these 'toxicological constants' with predetermined risk levels (either a 10(-6) cancer risk or a chronic intake equal to the reference dose) and protective human exposure assumptions (e.g. 70-kg body mass, 30-year exposure, 2-1.d-1 drinking water ingestion, etc.) to produce risk-based concentrations for 596 contaminants in air, drinking water, edible fish and soil. Because USEPA designed its methods to estimate upper bound risks, these risk-based concentrations are likely to be protective of human health. Regulatory officials can use this information to calculate numerical ratios between measured environmental levels and risk-based concentrations. These ratios serve as a surrogate for potential health impacts and can be used to prioritize problems for attention. Ratio calculation and ranking can be automated for searches of computerized environmental databases.
authors.affiliation: U.S. Environmental Protection Agency, Philadelphia, PA 19107, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Smith
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects; D002273:Carcinogens; D002648:Child; D003627:Data Interpretation, Statistical; D004781:Environmental Exposure; D004784:Environmental Monitoring; D015386:Hazardous Substances / Q000009:adverse effects*; D006292:Health Priorities; D006801:Humans; D018570:Risk Assessment; D012989:Soil Pollutants / Q000009:adverse effects; D018675:Toxicity Tests; D014481:United States; D014484:United States Environmental Protection Agency; D014873:Water Pollutants / Q000009:adverse effects
chemical_list: D000393:Air Pollutants; D002273:Carcinogens; D015386:Hazardous Substances; D012989:Soil Pollutants; D014873:Water Pollutants