EV-595 Fall 1997

Readings:

Chapter 2; "Exposures" of Calculated Risks
Chapter 3; "Into the Body" pp 25 to 31 of Calculated Risks
Chapter 10; "Assessing Risks" of Calculated Risks

Chapter 1; "Introduction" of Risk Assessment Guidance for Superfund (Volume I; Part A)
Chapter 2; "Statutes, Regulations, Guidance, and Studies Relevant to the Human Health Evaluation" of Risk Assessment Guidance for Superfund (Volume I; Part A)
Chapter 6; "Exposure Assessment of Risk Assessment Guidance for Superfund (Volume I; Part A)

Supplemental Reading:

"Guidelines for Exposure Assessment" found in Federal Register; Volume 57; No. 104; pp. 22888-22938; 5/29/92

Basis for Use of Risk Assessment:

* Several fields use risk assessment and have contributed to the methods used in risk assessment. These include:
- Industrial hygiene
- Insurance (actuarial tables)
- Banking (financial risk)
- Toxicology (cancer risk, systemic toxicity)
- Ecology (environmental toxicology)

* Environmental risk assessment is useful because:
- Takes expected effects from exposure to multiple contaminants in multiple media and reduces to one value
- Is an intuitive approach (Not really a "black box")

* Several federal agencies use risk assessment in setting regulation:
- Environmental Protection Agency
- Food and Drug Administration
- Federal Aviation Administration
- Nuclear Regulatory Commission
- Occupational Safety and Health Administration

===> BUT HOW RISK ASSESSMENT IS APPLIED BY AGENCIES DIFFERS <===

* Several federal laws either use risk assessment to set numerical values or direct use of risk assessment
- NEPA (National Environmental Policy Act)
- CAA (Clean Air Act)
- CWA (Clean Water Act)
- SDWA (Safe Drinking Water Act)
- RCRA (Resource Conservation and Recovery Act)
- TSCA (Toxic Substances Control Act)
- CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act)
(as modified by SARA; Superfund Amendments and Reauthorization Act)

*Use of risk assessment discussed in NCP (National Oil and Hazardous Pollution Contingency Plan)
- In 55 FR 8665-8865; Section 300.430 (d)(1); March 8, 1990; have:

Risk assessment to be prepared to "characterize the current and potential threats to human health and the environment that may be posed by contaminants migrating to ground water or surface water, releasing to air, leaching through soil, and bioaccumulating in the food chain.

* Have EPA guidance that elaborates on this and provides specific methods to be followed.

* Primary purpose of completing risk assessment is to:
- determine if action is needed (by comparison to benchmarks)
- assist in selection of appropriate action(s) (formulation of remedial goal options [RGOs], a part of remedial action objectives [RAOs]).

General Risk Assessment Principals:

* Risk Assessment has been around a long time.
- People perform risk assessments all the time as part of living.

* Process used under CERCLA formalized in Risk Assessment in the Federal Government: Managing the Process"
- Produced by National Academy of Science
- Also called "Red Book"
- Four interrelated parts for risk assessment in NAS Risk Assessment Paradigm (bottom of page)
- Hazard Identification
- Dose-Response Assessment
- Exposure Assessment
- Risk Characterization

- Four interrelated parts for risk management
- Risk Characterization
- Control Options
- Non-Risk Analysis
- Regulatory Decisions

- Risk Assessment and Risk Management overlap

* EPA guidance slightly different; RAGS Risk Assessment Paradigm (bottom of page)
- Four interrelated parts
- Slightly different names
- Data Gathering and Evaluation
- Toxicity Assessment
- Exposure Assessment
- Risk Characterization
- Although RAGS paradigm shows only downward flow of information, really have flow of information in both directions

* Paradigms can be related to real world "adventures"

* Advantages of using paradigm - COMMUNICATION AND STRUCTURE
- Common language
- Structured system that can be used to examine information used in risk assessment and risk management
- Structured system that can be used to outline relationships between risk assessment and risk management

NAS Risk Assessment Paradigm

Modified RAGS Risk Assessment Paradigm