Question 1

Toxicants that cause harm by affecting the immune system include ______________.

Accepted Answer

A)  allergens 
B)  neurotoxins 
C)  hormones 
D)  teratogens 
E)  antibiotics

Question 2

Toxicants that interrupt essential biochemical processes in organisms by blocking one or steps in important biochemical reactions are known as ______________ .

Accepted Answer

A)  mutagens 
B)  insecticides 
C)  neurotoxins 
D)  pathway inhibitors 
E)  carcinogens

Question 3

A naturally occurring substance that seeps up from the ground and that is potentially toxic to people is ______________.

Accepted Answer

A)  Salmonella 
B)  carbon dioxide 
C)  bisphenol A 
D)  DDE 
E)  radon gas

Question 4

Carcinogens may be difficult to identify because ______________.

Accepted Answer

A)  they are the least common toxicants 
B)  they are rare in nature 
C)  there is a long lag time between exposure to the agent and disease 
D)  there is no way to measure the carcinogenic potential of a substance 
E)  most are invisible

Question 5

Choose the one alternative that best completes the statement or answers the question.
-Assume that the scales for graphs (a) and (b) are identical. Compare the graphs. Which of the following statements is true?

Accepted Answer

A)  The toxicant shown in (b) has a lower LD50 compared to the toxicant shown in (a). 
B)  The toxicant shown in (b) has a higher toxicity than the toxicant shown in (a). 
C)  Graphs (a) and (b) show results for the same toxicant, but graph (b) shows a higher dose than graph (a). 
D)  The toxicant shown in (b) has a lower toxicity than the toxicant shown in (a). 
E)  Graphs (a) and (b) show results for the same toxicant, but graph (a) shows a higher dose than graph (b).

Question 6

Read the following scenario and answer the question below.
Mercury is a heavy metal that occurs naturally in minerals and rocks. Release of mercury from natural sources has been relatively constant over time. However, anthropogenic release of mercury has increased significantly in recent years primarily due to increased fossil fuel mining and combustion. Mercury that is released into the air eventually ends up in soils or surface water. Once in water, microbes convert mercury into methyl mercury, which is absorbed quickly and concentrated in the tissues of predatory fish such as shark and swordfish. Large fish typically concentrate more mercury than small fish. People who eat fish with high methyl mercury concentrations can show tremors, deafness, muscle dysfunction, and attention deficits. Pregnant women and children are especially sensitive to methyl mercuryʹs toxic effects. Learning disabilities and developmental delays are common in children who have been exposed to significant levels of methyl mercury.
-Prior to 2005, no rules regulating mercury emissions from coal-fired power plants existed in the United States. This represents the ______________

Accepted Answer

A)  innocent-until-proven-guilty approach 
B)  Ames approach 
C)  case-study approach 
D)  dose-response initiative 
E)  precautionary principle

Question 7

Of the chemicals that fall under the TSCA ______________% have been tested for toxicity and ______________ have been tested for endocrine, nervous, or immune system damage.

Accepted Answer

A)  10; 10% 
B)  50; half 
C)  50; one-quarter 
D)  10; almost none 
E)  25; 10%

Question 8

DDT, DDE, PCBs, and PBDEs are all ______________.

Accepted Answer

A)  approved for use as pesticides by the EPA 
B)  teratogens 
C)  biodegradable and do not persist in the environment 
D)  non-biodegradable and subject to bioaccumulation and/or biomagnification 
E)  toxic at the organism level but not at the ecosystem level

Question 9

Rachel Carsonʹs book Silent Spring primarily focuses on the environmental problems associated with ______________.

Accepted Answer

A)  pesticide toxicity 
B)  overpopulation 
C)  loss of biodiversity 
D)  deforestation 
E)  aquifer depletion

Question 10

Infectious disease accounts for % of deaths globally ______________

Accepted Answer

A)  nearly 25 
B)  almost 50 
C)  40 
D)  less than 1 
E)  30

Question 11

Some indoor chemical hazard(s) are ______________

Accepted Answer

A)  Radon and asbestos 
B)  PCBs 
C)  petroleum and toxic waste tanks tank leaks 
D)  DDT and DDE 
E)  wastewater toxicants

Question 12

The book Our Stolen Future was important because it ______________.

Accepted Answer

A)  focused on the impacts of endocrine-disrupting chemicals on humans 
B)  was the first book that discussed water pollution problems in Lake Apopka 
C)  was the first book to dispute claims in Rachel Carsonʹs book Silent Spring 
D)  is credited with starting the environmental movement in the United States 
E)  was the first book that discussed environmental problems with DDT

Question 13

Choose the item that best matches each item in the following:
-Most widely used herbicide in the United States; an endocrine disruptor

Accepted Answer

A) aldicarb 
B) thalidomide 
C) bisphenol-A 
D) DDT 
E) asbestos
F)nicotine
G)cadmium
H)arsenic
I)mercury
J)atrazine
K)lead

Question 14

Bisphenol A is ______________.

Accepted Answer

A)  produced when fossil fuels are burned 
B)  an estrogen mimic that is used in plastic manufacturing 
C)  a currently used herbicide 
D)  released from aerosol spray cans 
E)  a banned insecticide

Question 15

Choose the one alternative that best completes the statement or answers the question.
-Figures such as these ___________.

Accepted Answer

A)  allow scientists to determine the exact quantity of a toxicant that will harm humans 
B)  are used to report the effects of a toxicant on wildlife populations 
C)  are used by scientists in epidemiological assessment of a toxicantʹs effect 
D)  represent typical dose-response curves for endocrine disruptors 
E)  are used by scientists in risk assessment

Question 16

______________ are best defined as substances that cause birth defects.

Accepted Answer

A)  Carcinogens 
B)  Vectors 
C)  Teratogens 
D)  Neurotoxins 
E)  Allergens

Question 17

The bald eagle, osprey, and peregrine falcon all are ______________.

Accepted Answer

A)  over-hunted for their feathers 
B)  extinct 
C)  found only in Florida 
D)  top consumers susceptible to eggshell damage caused by DDT 
E)  U.S. invasive species

Question 18

Aquatic animals such as fish and frogs are especially good indicators of water pollution because ______________.

Accepted Answer

A)  most chemicals are water soluble so they enter these organisms through drinking or skin absorption 
B)  they are easy to catch 
C)  these organisms are the most abundant on Earth 
D)  the metabolism of these organisms is most like ours 
E)  all chemical toxicants are found in water

Question 19

Suppose that the concentration of DDT in a lake is 0.0000003 ppm (parts per million) and the concentration of DDT in the tissues of an osprey (a fish-eating bird) is 25 ppm. This is an example of ______________.

Accepted Answer

A)  bioremediation 
B)  biomagnification 
C)  bioreduction 
D)  biotruncation 
E)  biodegradation

Question 20

List the properties that determine the rate of degradation of toxicants.

Accepted Answer

The answer of List the properties that determine the rate...

Exam 10: Environmental Health and Toxicology