ABT Environmental Toxicology

Question 1

Which process describes the increasing concentration of a persistent toxin in successive trophic levels of a food chain?

Accepted Answer

Biomagnification

Answer

Biomagnification refers to the progressive increase in concentration of a substance (e.g., methylmercury, DDT) as it moves up the food chain from prey to predator.

Question 2

The EPA's Superfund program (CERCLA) primarily addresses which environmental concern?

Accepted Answer

Cleanup of hazardous waste sites

Answer

CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act) established the Superfund program to finance cleanup of uncontrolled hazardous waste sites.

Question 3

Polychlorinated biphenyls (PCBs) are classified as persistent organic pollutants primarily because they:

Accepted Answer

Resist environmental degradation and bioaccumulate in fat

Answer

PCBs are highly lipophilic and resistant to biological and chemical degradation, leading to environmental persistence and bioaccumulation in fatty tissues.

Question 4

Which US regulation establishes Maximum Contaminant Levels (MCLs) for chemicals in public drinking water?

Accepted Answer

Safe Drinking Water Act

Answer

The Safe Drinking Water Act (SDWA) authorizes the EPA to set MCLs, which are the legally enforceable maximum concentrations of contaminants allowed in public water supplies.

Question 5

Ground-level ozone is classified as a secondary pollutant because it is formed by:

Accepted Answer

Photochemical reactions between NOx and VOCs in sunlight

Answer

Ground-level ozone is a secondary pollutant formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight.

ABT - American Board of Toxicology Practice Test

ABT - American Board of Toxicology Practice Test

ABT Environmental Toxicology