CEP Environmental Risk Assessment & Management 3 — Questions and Answers
Question 1: The 'hazard quotient' (HQ) in non-cancer risk assessment is calculated as:
- Exposure dose divided by the reference dose (Correct answer)
- Reference dose divided by the exposure dose
- Cancer slope factor multiplied by exposure dose
- Lethal dose 50 divided by daily intake
Correct answer: Exposure dose divided by the reference dose
HQ = exposure dose / reference dose (RfD); an HQ greater than 1 indicates potential non-cancer risk concern.
Question 2: Which EPA tier approach is used when site-specific data are insufficient and relies on conservative default assumptions?
- Tier 3 – Site-Specific Risk Assessment
- Tier 2 – Intermediate Risk Assessment
- Tier 1 – Screening-Level Risk Assessment (Correct answer)
- Tier 0 – Baseline Assessment
Correct answer: Tier 1 – Screening-Level Risk Assessment
Tier 1 screening-level assessments use conservative default values and generic assumptions to identify sites that may require further investigation.
Question 3: Under the EPA's Risk-Based Corrective Action (RBCA) framework, cleanup standards are determined by:
- Technology feasibility alone
- Site-specific risk calculations linked to future land use (Correct answer)
- Federal maximum contaminant levels only
- State background concentration levels
Correct answer: Site-specific risk calculations linked to future land use
RBCA ties cleanup standards to site-specific risk calculations that account for actual or reasonably anticipated land use and exposure conditions.
Question 4: What does a 'slope factor' (SF) quantify in cancer risk assessment?
- The probability of developing cancer per unit dose of a carcinogen (Correct answer)
- The maximum safe daily intake of a carcinogen
- The soil-to-air volatilization rate of a contaminant
- The bioavailability of a carcinogen in food
Correct answer: The probability of developing cancer per unit dose of a carcinogen
The cancer slope factor represents the upper-bound probability of developing cancer per unit of lifetime average daily dose of a carcinogen.
Question 5: A 'natural attenuation' remedy is most appropriate when:
- Contamination poses acute risk to current receptors
- Monitored natural processes can degrade contaminants to acceptable levels within a reasonable timeframe (Correct answer)
- Regulatory agencies mandate active remediation
- The contamination plume is expanding rapidly
Correct answer: Monitored natural processes can degrade contaminants to acceptable levels within a reasonable timeframe
Monitored Natural Attenuation (MNA) is appropriate when natural processes (biodegradation, dilution, sorption) can reduce contamination to protective levels without posing unacceptable risk.
Question 6: The 'precautionary principle' applied to environmental risk management means that:
- Regulation requires proof of harm before action is taken
- Lack of full scientific certainty is not a reason to postpone protective measures when threats are serious (Correct answer)
- Cost-benefit analysis must precede any environmental intervention
- Risk assessors should use the lowest available toxicity values
Correct answer: Lack of full scientific certainty is not a reason to postpone protective measures when threats are serious
The precautionary principle holds that when activities raise threats of serious environmental harm, precautionary measures should be taken even if some cause-effect relationships are not fully established scientifically.
Question 7: Environmental stress testing in ESG context evaluates:
- Soil bearing capacity under industrial loads
- A company's financial resilience to physical and transition climate risks under adverse scenarios (Correct answer)
- Maximum pollutant discharge under storm conditions
- Chemical stability of waste under heat exposure
Correct answer: A company's financial resilience to physical and transition climate risks under adverse scenarios
In ESG, environmental stress testing models how a company's financial performance would be affected by climate-related physical risks (floods, heat) and transition risks (carbon pricing, regulation) under adverse scenarios.
CEP Environmental Risk Assessment & Management 3
The 'hazard quotient' (HQ) in non-cancer risk assessment is calculated as: