Frontier Article
Framework for Metals Risk Assessment

https://doi.org/10.1016/j.ecoenv.2007.03.015Get rights and content

Abstract

EPA recognized that metals present unique risk assessment issues, and saw the need to develop a framework document that puts forth key scientific principles for metals risk assessments to help ensure consistency in metals assessments across EPA programs and regional offices. This framework, called the “Framework for Metals Risk Assessment,” is a science-based document that describes basic principles that address the special attributes and behaviors of metals and metal compounds to be considered when assessing their human health and ecological risks. The Risk Assessment Forum oversaw the development of this document, including input from stakeholders and experts throughout the Agency, and obtained through several expert workshops, followed by peer review by the EPA Science Advisory Board (SAB).

The Framework for Metals Risk Assessment document is intended to serve as a guide for all EPA programs and regional offices to supplement or update the policies, practices and guidance they currently use in their respective metals assessments.

This framework document is not a prescriptive guide on how any particular type of assessment should be conducted within an EPA program office. Rather, it outlines key metal principles and describes how they should be considered in conducting human health and ecological risk assessments to advance our understanding of metals impact and foster consistency across EPA programs and regions.

Although the audience for the framework is primarily intended to be Agency risk assessors, it also will communicate principles and recommendations for metals risk assessment to stakeholders and the public. This framework will be used in conjunction with guidance developed by the programs and regions for site-specific risk assessment, criteria derivation, ranking or categorization and other similar Agency activities related to metals. The Framework for Metals Risk Assessment document is intended to serve as a guide for all EPA programs and regional offices to supplement or update the policies, practices and guidance they currently use in their respective metals assessments.

EPA assessments can vary in level of detail from simple, screening analyses to complex, definitive assessments. More complex scientific tools and metal specific methods should be applied as the complexity of the hazard assessment or risk assessment increases.

Section snippets

Preface

Many US Environmental Protection Agency (EPA or the Agency) programs are designed to develop guidelines on how to regulate metals. In this process, decisions can range from setting environmental release standards, to establishing protective levels in different environmental media, to setting priorities for programmatic or voluntary efforts. A fundamental input to the decision-making process for most EPA programs is an assessment of the potential risks to human health and the environment.

EPA's

Co-chairs

Anne Fairbrother, US EPA, Office of Research and Development, National Health and Environmental Effects Laboratory, Western Ecology Division, Corvallis, OR.

Randall Wentsel, US EPA, Office of Research and Development, Washington, DC.

Steering committee

Stephen DeVito, US EPA, Office of Environmental Information, Washington, DC.

Alexander McBride, US EPA, Office of Solid Waste and Emergency Response, Washington, DC (Retired).

David Mount, US EPA, Office of Research and Development, National Health and Environmental

Executive summary

The Framework for Metals Risk Assessment is a science-based document that addresses the special attributes and behaviors of metals and metal compounds to be considered when assessing their human health and ecological risks. The document describes basic principles to be considered in assessing risks posed by metals and is intended to foster consistency in how these principles are applied across the Agency's programs and regions when conducting these assessments. Although the audience for the

Framework for Metals Risk Assessment

The following discussion addresses issues that are unique to inorganic metals and routinely encountered during the inorganic metals risk assessment process. Discussions of issues generic to any chemical risk assessments are kept to a minimum because these are dealt with in other framework and guidance documents (e.g., US EPA (Environmental Protection Agency), 1998a, EPA, 2000a, US EPA (Environmental Protection Agency), 2003a; http://www.epa.gov/ncea/ and http://www.epa.gov/ncea/raf).

This

Introduction and terminology

A general review of factors pertaining to the chemistry of metals in sediments, soils, waters, and the atmosphere is presented in this section in the context of risk assessment. Because the behavior of metals defies simple generalities, understanding the chemistry of the particular metal and the environment of concern is necessary. However, the factors that control metal chemistry and the environmental characteristics used to produce estimates of metal fate and effects can be generalized.

Human health risk assessment for metals

The National Research Council (NAS/NRC (National Academy of Sciences/National Research Council), 1983, NAS/NRC (National Academy of Sciences/National Research Council), 1994b, NAS/NRC (National Academy of Sciences/National Research Council), 1996), of the National Academy of Sciences (NAS), described four phases to the human health risk assessment paradigm (hazard identification, dose-response assessment, exposure assessment, and risk characterization) and identified risk communication as a

Aquatic ecological risk assessment for metals

This section describes how to incorporate the metals risk assessment principles described in 1 Introduction, 2 Framework for Metals Risk Assessment into ecological risk assessments involving aquatic-based receptors. Specifically, the following discussion focuses on the relationship between each metal principle and components of the EPA's Framework for Ecological Risk Assessment (US EPA, 1992a) and subsequent guidelines (US EPA, 1998a). These components include problem formulation,

Terrestrial ecological risk assessment for metals

This section of the framework provides an overview of how the principles for metals risk assessment apply to ecological risk assessments for terrestrial environments. Receptors typically considered in these assessments include soil invertebrates, plants, and wildlife species. Some assessments also examine effects on microbiota and soil processes. This section of the framework builds on the information presented in Section 2 that lays out issues to be considered during problem formulation and

Disclaimer

This document has been reviewed in accordance with US Environmental Protection Agency policy. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

References (411)

  • E.A. Crecelius et al.

    Copper bioavailability to marine bivalves and shrimp: relationship to cupric ion activity

    Mar. Environ. Res.

    (1982)
  • T. Crommentuijn et al.

    Bioavailability and ecological effects of cadmium on Folsomia candida (Willem) in an artificial soil substrate as influenced by pH and organic matter

    Appl. Soil Ecol.

    (1997)
  • K.A.C. De Schamphelaere et al.

    Refinement and field validation of a biotic ligand model predicting acute copper toxicity to Daphnia magna. Special issue: the biotic ligand model for metals current research, future directions, regulatory implications

    Comp. Biochem. Physiol. C

    (2002)
  • C.O. Abernathy et al.

    Essentiality versus toxicity, some considerations in the risk assessment of essential trace elements

  • W.J. Adams et al.

    Analysis of field and laboratory data to derive selenium toxicity thresholds for birds

    Environ. Toxicol. Chem.

    (2003)
  • H.E. Allen

    Bioavailability of Metals in Terrestrial Ecosystems: Importance of Partitioning for Bioavailability to Invertebrates, Microbes and Plants

    (2002)
  • J.D. Allison et al.

    MINTEQA2/PRODEFA2, A Geochemical Assessment Model for Environmental Systems: Version 3.0, User's Manual

    (1991)
  • G.T. Ankley et al.

    Acid-volatile sulfide as a factor mediating cadmium and nickel bioavailability in contaminated sediments

    Environ. Toxicol. Chem.

    (1991)
  • G.T. Ankley et al.

    Technical basis and proposal for deriving sediment quality criteria for metals

    Environ. Toxicol. Chem.

    (1996)
  • ANZECC and ARMCANZ (Australian and New Zealand Environment and Conservation Council and Agriculture and Resource...
  • P.T. Arnold et al.

    Comparative uptake kinetics and transport of cadmium and phosphate in Phleum pratenseGlomus deserticolum associations

    Environ. Toxicol. Chem.

    (1993)
  • Toxicological Profile for Nickel, Draft for Public Comment

    (2003)
  • Evaluation of the Toxicology of Chemical Mixtures Commonly Found at Hazardous Waste Sites

    (2004)
  • AWWA (American Water Works Association). (1999) Water quality and treatment. A Handbook Of Community Water Supplies,...
  • L.G.M. Baas-Becking et al.

    Limits of the natural environment in terms of pH and oxidation–reduction potentials

    J. Geol.

    (1960)
  • Y. Babukutty et al.

    Chemical partitioning and bioavailability of lead and nickel in an estuarine system

    Environ. Toxicol. Chem.

    (1995)
  • R.G. Bailey

    Delineation of ecosystem regions

    Environ. Manage.

    (1983)
  • Bailey, R.G., Avers, P.E., King, T., McNab, W.H. (Eds.), 1994. Ecoregions and subregions of the United States (map) US...
  • S.B. Baines et al.

    Assimilation and retention of selenium and other trace elements from crustacean food by juvenile striped bass (Morone saxatilis)

    Limnol. Oceanogr.

    (2002)
  • N. Ballatori

    Transport of toxic metals by molecular mimicry

    Environ. Health Perspect.

    (2002)
  • Barak, P., 1999. Essential elements for plant growth. Department of Soil Science, University of Wisconsin-Madison....
  • S.A. Barber

    Soil Nutrient Bioavailability: A Mechanistic Approach

    (1995)
  • R.M. Barnes

    Childhood soil ingestion: how much dirt do kids eat?

    Anal. Chem.

    (1990)
  • J. Barnhart

    Chromium chemistry and implications for environmental fate and toxicity

    J. Soil Contam.

    (1997)
  • N.T. Basta et al.

    Path analysis of heavy metal adsorption by soil

    Agron. J.

    (1993)
  • P.F. Bell et al.

    Residual effects of land applied municipal sludge on tobacco, I: effects on heavy metals concentrations in soils and plants

    Tobacco Sci.

    (1988)
  • M. Berglund et al.

    Intestinal absorption of dietary cadmium in women depends on body stores and fiber intake

    Environ. Health Perspect.

    (1994)
  • W.J. Berry et al.

    Predicting the toxicity of metal-spiked laboratory sediments using acid-volatile sulfide and interstitial water normalizations

    Environ. Toxicol. Chem.

    (1996)
  • W.N. Beyer et al.

    Environmental Contaminants in Wildlife: Intepreting Tissue Concentrations

    (1996)
  • W.N. Beyer et al.

    Lead exposure of waterfowl ingesting Coeur d’Alene River Basin sediments

    J. Environ. Qual.

    (1998)
  • F.T. Bingham et al.

    The effect of sulfate on the availability of cadmium

    Soil Sci.

    (1986)
  • P. Bjerregaard et al.

    Accumulation and retention of 237Pu and 241Am in the mussel Mytilus edulis

    Mar. Ecol. Prog. Ser.

    (1985)
  • L.J. Blus et al.

    Lead toxicosis in tundra swans near a mining and smelting complex in northern Idaho

    Arch. Environ. Contam. Toxicol.

    (1991)
  • H.L. Bohn et al.

    Soil Chemistry

    (1985)
  • P.M. Bolger et al.

    Identification and reduction of sources of dietary lead in the United States

    Food Additives Contam.

    (1996)
  • A. Bose et al.

    Azarcón por empacho—another cause of lead toxicity

    Pediatrics

    (1983)
  • T.S. Bowers et al.

    Assessing the relationship between environmental lead concentrations and adult blood lead levels

    Risk Anal.

    (1994)
  • Bradham, K.D., 2002. Effect of soil properties on the bioavailability and toxicity of metals to Eisenia andrei. Ph.D....
  • Cited by (357)

    View all citing articles on Scopus
    View full text