Environmental Toxicology Flashcards

Which environmental fate parameter describes the tendency of a chemical to partition between octanol and water?

Answer: Octanol-water partition coefficient (Kow)

The octanol-water partition coefficient (Kow or P) is used as a surrogate for lipophilicity and predicts a chemical's tendency to bioaccumulate in fatty tissues.

Endocrine-disrupting chemicals (EDCs) can mimic or block hormones. Which effect describes a chemical that binds estrogen receptors without activating them?

Answer: Estrogen receptor antagonism

An estrogen receptor antagonist binds to estrogen receptors but does not activate transcription, effectively blocking endogenous estrogen from exerting its effects.

Under CERCLA, which term describes the party legally responsible for cleanup costs at a Superfund site?

Answer: Potentially Responsible Party (PRP)

CERCLA defines Potentially Responsible Parties (PRPs) as current or former owners/operators, transporters, and generators who may be liable for cleanup costs at hazardous waste sites.

Which route of exposure is most significant for volatile organic compounds (VOCs) at contaminated sites?

Answer: Inhalation of vapors (vapor intrusion)

Vapor intrusion — the migration of VOC vapors from contaminated soil and groundwater into overlying buildings — is often the dominant exposure pathway for volatile contaminants.

The concept of 'hormesis' in environmental toxicology describes:

Answer: A biphasic dose-response with low-dose stimulation and high-dose inhibition

Hormesis is a biphasic dose-response phenomenon where low doses produce a stimulatory or beneficial effect and higher doses produce an inhibitory or toxic effect.

Beryllium is classified as a Group 1 carcinogen by IARC and is associated with which occupational lung disease?

Answer: Chronic beryllium disease (berylliosis)

Chronic beryllium disease (berylliosis) is a granulomatous lung disease caused by sensitization to beryllium, predominantly seen in aerospace and nuclear industries.