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