CES CES Environmental Health & Toxicology 2

Question 1

Which EPA framework is used to assess the risk that a contaminant in the environment poses to human health?

Accepted Answer

Risk Assessment Guidance for Superfund (RAGS)

Answer

EPA's Risk Assessment Guidance for Superfund (RAGS) provides the standard framework for conducting human health risk assessments at Superfund and other contaminated sites.

Question 2

The four steps of the EPA human health risk assessment framework are, in order:

Accepted Answer

Hazard identification, dose-response assessment, exposure assessment, risk characterization

Answer

The EPA's four-step risk assessment framework proceeds from hazard identification (what can cause harm) through dose-response and exposure assessment to risk characterization (quantifying risk).

Question 3

Which unit is used to express carcinogenic risk in EPA human health risk assessments for individual lifetime excess cancer risk?

Accepted Answer

Probability expressed as a dimensionless number (e.g., 1×10⁻⁶)

Answer

Carcinogenic risk is expressed as a dimensionless probability representing the incremental lifetime probability of developing cancer from exposure (e.g., 1×10⁻⁶ = 1 in a million).

Question 4

What is the Hazard Quotient (HQ) used for in non-carcinogenic risk assessment?

Accepted Answer

To compare estimated exposure to a reference dose—values above 1 suggest potential concern

Answer

The Hazard Quotient is the ratio of estimated daily exposure to the reference dose (RfD); an HQ greater than 1 indicates that the exposure may exceed the level considered safe.

Question 5

Which class of persistent organic pollutants (POPs) was used historically as electrical insulators and is associated with endocrine disruption and carcinogenicity?

Accepted Answer

Polychlorinated biphenyls (PCBs)

Answer

PCBs were widely used as transformer fluids and electrical insulators until banned in 1979 under the Toxic Substances Control Act due to their persistence, bioaccumulation, and links to cancer and endocrine disruption.

(CES) Certified Environmental Scientist Practice Test

(CES) Certified Environmental Scientist Practice Test

CES CES Environmental Health & Toxicology 2