Question 1 : In environmental health, the term toxin refers to a toxic substance that _______________.

is naturally produced by a plant or animal

occurs in the occupational setting

results from human activity

a man-made product introduced into the environment due to human activity

Question 2 : In toxicity testing in rodents, the LD50 is a dose that is _______________.

acutely fatal to 50 percent of test animals

fatal to 50 percent of test animals within a 90-day period

fatal to 50 percent of test animals after lifetime bioaccumulation

Question 3 : Which of the following is not characteristic of a health impact assessment?

It evaluates a site or activity as it is, rather than looking forward in time

It includes social and economic factors in the assessment

It incorporates input from community members

Question 4 : An exposure pathway connects _______________ to _______________.

an exposure / a change in tissue structure or function

inhalation / absorption

the environmental source of a contaminant / the point of exposure

Question 5 : The three major routes of human exposure to environmental contaminants are _______________.

by air, water, and soil

environmental, occupational, and residential

ingestion, inhalation, and dermal contact

Question 6 : The phrase contact with the human envelope is a common definition of _______________.

absorption

disposition

exposure

Question 7 : The quantity of a toxicant (or its breakdown product) that is available to interact with some vulnerable tissue in the body is called the _______________.

absorbed dose

biologically effective dose

body burden

Question 8 : The body burden of a chemical in the body reflects the net effect of _______________.

absorption and biological effectiveness

synergism and antagonism

the processes of toxicokinetics

Question 9 : Bioaccumulation is the _______________.

gradual building up of a chemical in the tissue of an organism

increase of concentrations of a chemical at higher levels of a food pyramid

movement of a chemical from water to living tissue

Question 10  : Which of the following is an example of a biomarker?

Body mass index calculated from measured height and weight

Concentration of a pesticide in blood

Inhalation rate in liters per hour

Question 11 : The Ames test is a test of a chemical's _______________.

acute lethality, and is conducted in rodents

mutagenicity, and is conducted in bacteria

teratogenic potential, and is conducted mammalian cells

Question 12 : Exposure modeling is used to estimate the _______________.

biologically effective dose of a toxicant

fate and transport of a toxicant

ingestion of, inhalation of, or dermal contact with a toxicant

Question 13 : Conceptually, a reference dose is a dose that has no adverse effects in _______________.

sensitive subpopulations over a long-term exposure

sensitive subpopulations over a short-term exposure

the general population over a long-term exposure

the general population over a short-term exposure

Question 14 : Which of the following is one of the major processes which together make up toxicokinetics?

Bioconcentration

Distribution

Mutation

Synergism

Question 15 : In doing a risk assessment for a chemical, the usual assumption is that _______________.

carcinogenicity has a threshold; non-cancer effects do not

non-cancer effects have a threshold; carcinogenicity does not

both carcinogenicity and non-cancer effects have thresholds

neither carcinogenicity nor non-cancer effects has a threshold