Toxicology and Human Health Flashcards
6 cards from real Environmental Science practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Toxicology and Human Health flashcards as text
The dose-response relationship in toxicology describes:
Answer: The relationship between the amount of a substance and the magnitude of the biological effect it produces
The dose-response relationship is the fundamental principle that the toxicity of a substance depends on dose - the dose makes the poison (Paracelsus).
Biomagnification refers to the process by which:
Answer: Contaminants become more concentrated at each successive level of a food chain
Lipophilic (fat-soluble) pollutants like PCBs, DDT, and methylmercury accumulate in fatty tissues and increase in concentration with each trophic level because organisms consume many prey items over their lifetime.
Lead poisoning in children is particularly harmful because:
Answer: Lead permanently interferes with neurological development, causing irreversible cognitive and behavioral damage
Lead permanently damages the developing nervous system - reducing IQ, causing learning disabilities, behavioral problems, and reduced hearing - with no safe blood lead level established for children.
Endocrine disruptors are chemicals that pose health risks primarily by:
Answer: Mimicking, blocking, or interfering with the body's hormonal signaling systems
Endocrine disruptors interfere with synthesis, secretion, transport, binding, or elimination of natural hormones, disrupting development, reproduction, and metabolism.
The term synergistic toxicity means that:
Answer: Two chemicals together produce a toxic effect greater than the sum of their individual effects
Synergism occurs when the combined effect of two substances exceeds what would be expected from adding their individual effects (1+1 > 2), making mixtures potentially more dangerous than components alone.
The primary route of human exposure to methylmercury is through:
Answer: Consuming fish and shellfish, particularly large predatory marine fish
Inorganic mercury from industrial sources is methylated by anaerobic bacteria, enters aquatic food chains, and biomagnifies; large predatory fish (tuna, swordfish, shark) accumulate highest concentrations.