CES Environmental Health & Toxicology Flashcards
6 cards from real CES practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CES Environmental Health & Toxicology flashcards as text
Which principle in toxicology, attributed to Paracelsus, states that 'the dose makes the poison'?
Answer: Dose-response relationship
The dose-response relationship, rooted in Paracelsus's principle, establishes that any substance can be toxic at a sufficient dose—the effect depends on the amount of exposure.
What does the term 'bioaccumulation' mean in environmental toxicology?
Answer: The buildup of a contaminant in an organism's tissues over time at a higher concentration than in the environment
Bioaccumulation occurs when an organism absorbs a contaminant faster than it can metabolize or excrete it, leading to tissue concentrations higher than environmental levels.
Which of the following best defines 'biomagnification'?
Answer: The increase in a contaminant's concentration as it moves up successive trophic levels in a food chain
Biomagnification describes the progressive increase in contaminant concentrations at each successive trophic level, so apex predators accumulate the highest concentrations.
The Reference Dose (RfD) established by EPA for non-carcinogens represents:
Answer: An estimate of daily exposure that is unlikely to cause adverse effects in humans over a lifetime
The EPA's Reference Dose (RfD) is a daily oral exposure estimate, derived from animal or human studies with uncertainty factors applied, below which adverse effects are unlikely over a lifetime.
Which route of exposure typically results in the fastest absorption of a toxic chemical into the bloodstream?
Answer: Inhalation (breathing)
Inhalation generally produces the fastest systemic absorption because the large surface area of the lungs and thin alveolar membranes allow rapid transfer directly into the bloodstream.
What is the difference between 'acute' and 'chronic' toxicity?
Answer: Acute toxicity involves a single high-dose exposure with rapid effects; chronic toxicity involves repeated low-dose exposure over a long period
Acute toxicity results from a single or short-term high-dose exposure producing rapid effects, while chronic toxicity results from prolonged or repeated low-dose exposure causing effects over months or years.