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Waste and Cleanup Risk Assessment

RCRA Risk Assessment: Ecological: Stressor Response and Exposure Analysis

RCRA Ecological Risk

Planning and Scoping

Problem Formulation

Stressor Response and
Exposure Analysis

Risk Characterization

RCRA Additional Risk Assessment Topics:

Risk Management

Risk Communication


View resources related to this topic from other Waste and Cleanup Risk Assessment Programs:
(note - programs not linked do not have content for this topic)

Chemical Accident Prevention

Federal Facilities Restoration and Reuse

Underground Storage Tanks

Resource and Conservation Recovery Act


Additional RCRA Information:

Corrective Action

Vapor Intrusion


Hazardous Waste Identification

Industrial Waste

Calculation of Stressor Response and Exposure Estimates is the quantitative (statistical) determination of what plants and animals are exposed and to what degree they are exposed and if that level of exposure is likely or not to cause harmful ecological effects.

The calculations of risk and estimated exposure involve the calculation of hazard quotients (the ratio of chemical contaminant concentration to a selected screening benchmark) for the former; and, for the latter, the use of various parameters (area use, food ingestion rates, bioaccumulation rates, bioavailability, life-stage, body weight, and dietary composition) to determine the levels of exposure to a chemical contaminant by a selected plant or animal (receptor).

Documents | EPA Links | External Links


  1. Ecological Assessment of Superfund Sites: An Overview (PDF) (8 pp, 67K,   About PDF) Eco Update, December 1991
    This EcoUpdate bulletin describes the components of the ecological risk assessment process and how they fit into the Remedial Investigation/Feasibility Study process.

  2. Ecological Risk Assessment and Risk Management Principles for Superfund Sites, (Issuance of Final Guidance) (PDF) (9 pp, 1MB,   About PDF) October 7, 1999
    Guidance intended to help Superfund project managers to make ecological assessment decisions that are consistent across the United States and are transparent to the public.

  3. Ecological Risk Assessment Guidance for Superfund: Process for Designing and Conducting Ecological Risk Assessments - Interim Final June 1997, EPA 540-R-97-006
    These proposed guidelines are EPA's first Agency-Wide Ecological Risk Assessment Guidelines. They are broad in scope, providing general principles and providing numerous examples to show how ecological risk assessment can be applied to a wide range of systems, stressors, and biological spatial/temporal scales.

  4. ECO Update Bulletin Series
    EcoUpdates are a series of bulletins which provide information on various aspects of Ecological Risk Assessments, including toxicity testing, the role of the Biological Technical Assistance Group (BTAG), field studies, and screening level risk assessments.

  5. Guidelines for Ecological Risk Assessment
    These Agency-wide guidelines are provided to improve the quality and consistency of EPA's ecological risk assessments. The Guidelines expand on and replace the 1992 report Framework for Ecological Risk Assessment.

  6. NOAA Screening Quick Reference Tables
    NOAA has developed a set of Screening Quick Reference Tables, or Squirts, that present screening concentrations for inorganic and organic contaminants in various environmental media (water, sediment, and soil). The Squirts also include guidelines for preserving samples and analytical technique options.

  7. Peer Review Workshop Report on) Ecological Soil Screening Levels (PDF) (52 pp, 103K,   About PDF) Eco Update, (Guidance document dated August 31, 2000.)
    This document is a summary of the Peer Review Workshop on Ecological Soil Screening Levels.

  8. Preliminary Remediation Goals for Ecological Endpoints (PDF) (41 pp, 140K,   About PDF)
    Preliminary Remediation Goals are upper concentration limits of specific chemicals that are expected to be protective of human health or the environment and are useful in risk assessment and decision making at Superfund sites.

  9. Region 5 RCRA Corrective Action Ecological Data Quality Levels
    These are concentration levels that can be used in screening level ecological risk assessments.

  10. Role of Screening Level ERAs and Refining Contaminants of Concern in Baseline Ecological Risk Assessments. (PDF) (4 pp, 364K,   About PDF)
    This EcoUpdate bulletin describes the process and purpose of the screening level ecological risk assessment, which is the first steps in a ecological risk assessment at a site, and how the list of COCs can be refined to include only those contaminants that may pose a risk.

  11. Role of the Ecological Risk Assessment in the Baseline Risk Assessment (PDF) (2 pp, 180K,   About PDF) OSWER Directive 9285.7-17, dated August 12, 1994
    Describes the process and purpose of baseline ecological risk assessments, which, if required, come after screening level risk assessments.

  12. Screening Level Ecological Risk Assessment Protocol 1999
    This is a guidance document that describes the process used in conducting ecological risk assessments at Hazardous Waste Combustion Facilities.

  13. Using Toxicity Tests in Ecological Risk Assessment (PDF) (12 pp, 455K,   About PDF) March 1994 Eco Update
    An EcoUpdate Bulletin that describes the purpose and process of toxicity testing in ecological risk assessments.

  14. Wildlife Exposure Factors Handbook (PDF) (43 pp, 388K,   About PDF) December 1993, EPA/600/R-93/187
    The bulk of this document summarizes literature information on exposure factors for wildlife, including homerange sizes, food and water intake rates, types of food consumed, body weights, etc.

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EPA Links

  1. ECOTOX Database System
    The ECOTOX (ECOTOXicology) database provides single chemical toxicity information for aquatic and terrestrial life. ECOTOX is a useful tool for examining impacts of chemicals on the environment.

  2. Ecotox Thresholds (software, released by Jan 1996 Eco Update, EPA 540/F-95/038
    Web site containing information on EPA's Ecotox Thresholds, which are benchmark values for chemicals commonly found in surface water, sediments, and soil.

  3. EPA National Center for Environmental Assessment, Guide to Current Literature on Exposure Factors
    Web site summarizing sources of latest information on exposure factors.

  4. EPA Region 3 RBCs
    Website with information on cancer risk, and screening for human health risk assessment.

  5. EPA Region 4 Supplements to RAGS
    Information on regional risk assessment (human health and ecological) as well as regional contacts and screening values.

  6. EPA Region 5 Ecology Technical Center Ecological Risk Assessment
    Overview of ecological risk assessment process in Superfund, regional case studies, toxicity profiles, and regional contacts.

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External Links

  1. Biological and Ecotoxicological Characteristics of Terrestrial Vertebrates from Barnett Rattner
    Summary information in the database includes species, collection date, site coordinates, estuary name, hydrologic unit catalog code, sample matrix, contaminant concentrations, biomarker and bioindicator responses, and reference source.

  2. BSAF Database from WES
    Information on Biota-to-Sediment Accumulation Factors and lipids from the Army Corps of Engineers.

  3. Canadian National Guidelines and Standards Link to EPA's External Link Disclaimer
    Web site source for Canada's benchmark screening values for surface water, sediment, soil, and tissue.

  4. DOE Standard, A Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota (PDF) (48 pp, 374K, About PDF)
    and the RAD-BCG Calculator
    Link to Department of Energy’s procedure for investigating radiation exposure to aquatic and land plants and animals.

  5. Guidelines for Interpretation of Residues in Biota, Water, and Sediments from USGS-BRD
    National Irrigation Water Quality Program, U.S. Department of the Interior

  6. Oak Ridge National Laboratory: Toxicology and Risk Analysis Section
    This EcoUpdate bulletin describes the components of the ecological risk assessment process and how they fit into the Remedial Investigation/Feasibility Study process.

  7. Oak Ridge National Laboratory - Ecological Risk Analysis: Tools and Applications
    Link to guidance, screening benchmarks for various categories of plants and wildlife, and examples of completed ecological risk assessments.

  8. Spatial Analysis and Decision Assistant Link to EPA's External Link Disclaimer
    A software (freeware) tool designed to aid in ecological risk assessments with a spatial component.

  9. USACE Environmental Residue Effects Database
    A compilation of data, taken from the literature, where biological effects (e.g., reduced survival, growth, etc.) and tissue contaminant concentrations were simultaneously measured in the same organism.

  10. USGS Acute Toxicity Database
    This database summarizes the results from aquatic acute toxicity tests conducted by the USGS Columbia Environmental Research Center located in Columbia, Missouri. The acute toxicity test provides a relative starting point for hazard assessment of contaminants and is required for federal chemical registration programs.

  11. USGS - Contaminant Reviews
    Contains the 35 reports in the Contaminant Hazard Reviews (CHR) originally published between 1985 and 1999 in the U.S. Dept. of the Interior Biological Report series, which include information on selected inorganic and organic chemicals and ionizing radiation.

  12. USGS Upper Miss/IL Sediment Database
    Contains sediment-contaminant data (44 data sets from a total of 3950 analyzed sediment samples collected from 1974 through 2000 from the Upper Mississippi and Illinois Rivers and their tributaries) of known quality in a readily accessible format

  13. Wildlife Exposure and Toxicity Factors for California Wildlife (searchable) Link to EPA's External Link Disclaimer
    A compilation of exposure factors (i.e., ecological and physiological data) and toxicity data for a number of California mammals, birds, amphibians and reptiles.

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