CHAPT 56: ENVIRONMENTAL & OCCUPATIONAL TOXICOLOGY

Question 1

branch of pharmacology that encompasses
the deleterious effects of chemicals on biologic systems

Answer 1

Toxicology

Question 2

air pollutants

Answer 2

CO
SO2
NO2
O3

Question 3

is an odorless, colorless gas that competes avidly with oxygen for hemoglobin

Answer 3

Carbon Monoxide

Question 4

The affinity of CO for hemo-
globin is more than ____-fold greater than that of oxygen.

Answer 4

200

Question 5

The threshold limit value of CO for an 8-h workday is ___ parts per million (ppm);

Answer 5

25

Question 6

Effect of CO

Answer 6

tissue hypoxia

Question 7

Collapse and syncope occur when approximately ___% of hemoglobin has been converted to
_______________.

Answer 7

40; carboxyhemoglobin

Question 8

T or F: Exposure of a pregnant woman to elevated CO levels at critical fetal developmental periods may cause fetal death or serious and irreversible but survivable birth defects.

Answer 8

T

Question 9

__________ _______ accelerates the clearance of carbon monoxide.

Answer 9

Hyperbaric oxygen

Question 10

a colorless, irritating gas formed from the combustion of fossil fuels.

Answer 10

Sulfur Dioxide

Question 11

SO2 forms _________ ______ on contact with moist mucous membranes

Answer 11

Sulfurous Acid

Question 12

Primary sign of SO2 exposure

Answer 12

Conjunctival and bronchial irritation (esp in individuals w/ asthma)

Question 13

Presence of ___-___ ppm of SO2 in the air is enough to cause severe bronchospasm.

Answer 13

5; 10

Question 14

Heavy exposure to SO2 may lead to

Answer 14

delayed pulmonary edema

Question 15

Chronic low-level exposure to SO2 may aggravate:

Answer 15

cardiopulmonary disease

Question 16

a brownish irritant gas, is the principal
member of this group; formed in fires and in silage on farms

Answer 16

Nitrogen Oxide

Question 17

causes deep lung irritation and pulmonary edema.

Answer 17

NO2

Question 18

The most cost common source of human exposure to oxides of nitrogen

Answer 18

automobile and truck traffic emissions

Question 19

a bluish irritant gas produced in air and water purification devices and in electrical fields

Answer 19

Ozone

Question 20

Exposure to ___–___ ppm of O3 may cause irritation and dryness of the mucous membranes.

Answer 20

0.01-0.1

Question 21

The increasing concentration of a substance in the environment as the result of environmental persistence and physical properties (eg, lipid solubility) that leads to accumulation in biologic tissues

Answer 21

Bioaccumulation

Question 22

Although the concentration of a contaminant may be virtually undetectable in water, it may be magnified hundreds or thousands of times as the contaminant passes up the food chain

Answer 22

Biomagnification

Question 23

Study of the toxic effects of chemical and physical agents on populations and communities of living organisms within defined ecosystems

Answer 23

Ecotoxicology

Question 24

Chemicals in the environment that have estrogen-like or antiandrogen activity or disrupt thyroid function.
They may increase reproductive cancers, impair fertility,
and have teratogenic effects

Answer 24

Endocrine disruptors

Question 25

The area of toxicology that deals with the effects of agents found in the environment; regulated by the Environmental Protection Agency (EPA) in the United States

Answer 25

Environmental toxicology

Question 26

The area of toxicology that deals with the toxic effects of chemicals found in the workplace; regulated by the Occupational Safety and Health Administration (OSHA) in the United States

Answer 26

Occupational toxicology

Question 27

The amount of exposure to a given agent that is deemed safe for a stated time period. It is higher for shorter periods than for longer periods

Answer 27

Threshold limit value

Question 28

Aliphatic hydrocarbons are also known as

Answer 28

halohydrocarbons

Question 29

Examples of halohydrocarbons

Answer 29

carbon tetrachloride chloroform trichloroethylene

Question 30

Solvents are potent CNS __________ (stimulants or depressants)

Answer 30

depressants

Question 31

Chronic exposure to aliphatic hydrocarbons leads to

Answer 31

hepatic dysfunction and nephrotoxicity

Question 32

solvents that cause peripheral neuropathy

Answer 32

tetrachloroethylene and trichloroethane

Question 33

important aromatic hydrocarbons

Answer 33

Benzene Toluene Xylene

Question 34

aromatic hydrocarbon associated with hematotoxicity and various types of hematologic cancers like leukemia

Answer 34

Benzene

Question 35

aromatic hydrocarbon that is a known human carcinogen

Answer 35

benzene

Question 36

aka methylbenzene

Answer 36

Toluene

Question 37

aka dimethylbenzene

Answer 37

Xylene

Question 38

3 major classes of pesticides

Answer 38

Chlorinated hydrocarbons Acetylcholinesterase inhibitors Botanical agents

Question 39

persistent, poorly metabolized, lipophilic chemicals that exhibit significant bioaccumulation

Answer 39

Chlorinated Hydrocarbons

Question 40

Chlorinated hydrocarbons block physiologic inactivation in the _______ channels of nerve membranes

Answer 40

sodium

Question 41

usually the first sign of acute chlorinated hydrocarbon toxicity

Answer 41

Tremor

Question 42

T or F: Chronic exposure of animals to chlorinated hydrocarbon pesticides is tumorigenic.

Answer 42

T

Question 43

associated with non-Hodgkin’s lymphoma and testicular cancer

Answer 43

Chlorinated Hydrocarbons

Question 44

effective pesticides with short environmental half-lives

Answer 44

Carbamates

Question 45

T or F: Carbamates are cholinesterase inhibitors

Answer 45

T

Question 46

________ _________ increase muscarinic and nicotinic cholinergic activity.

Answer 46

Cholinesterase inhibitors

Question 47

The signs and symptoms include pinpoint pupils, sweating, salivation, bronchoconstriction, vomiting and diarrhea, CNS stimulation followed by depression, and muscle fasciculations, weakness, and paralysis.

Answer 47

Cholinesterase inhibitors

Question 48

most common cause of death of cholinesterase inhibitors

Answer 48

respiratory failure

Question 49

used in large doses to control muscarinic excess

Answer 49

Atropine

Question 50

used to regenerate cholinesterase

Answer 50

Pralidoxime

Question 51

Botanical insecticides

Answer 51

Nicotine Rotenone Pyrethrum

Question 52

has the same effects on nicotinic cholinoceptors in insects as in mammals and probably kills by the same mechanism

Answer 52

Nicotine

Question 53

plant alkaloid pesticide that causes gastrointestinal distress when ingested and conjunctivitis and dermatitis after direct contact

Answer 53

Rotenone

Question 54

plant alkaloids that can cause contact dermatitis as well as CNS excitation and peripheral neurotoxicity in large quantities

Answer 54

Pyrethrum

Question 55

The compound in Agent Orange

Answer 55

2,4,5-trichlorophenoxyacetic acid

Question 56

2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid are members of

Answer 56

Chlorophenoxy Acid (herbicide)

Question 57

the principle ingredient in Roundup brand weed killer

Answer 57

Glyphosate

Question 58

the most widely used herbicide in the world

Answer 58

Glyphosate

Question 59

a key enzyme involved in aromatic amino acid biosynthesis in plants

Answer 59

5-enolpyruvylshikimate-3-phosphate synthase,

Question 60

a bipyridyl herbicide used extensively to kill weeds on farms and for highway maintenance

Answer 60

Paraquat

Question 61

herbicide that is relatively nontoxic unless ingested

Answer 61

Paraquat

Question 62

the initial effect is gastrointestinal irritation with hematemesis and bloody stools

Answer 62

Paraquat

Question 63

prompt prevention of absorption of Paraquat is done by

Answer 63

activated charcoal, Fuller's earth

Question 64

Chemical compounds that contribute to environmental pollution

Answer 64

polychlorinated biphenyls dioxins asbestos heavy metals

Question 65

were used extensively in manufacturing electrical equipment until their potential for environmental damage was recognized

Answer 65

Polychlorinated Biphenyls

Question 66

are among the most stable organic compounds known

Answer 66

PCBs

Question 67

poorly metabolized and lipophilic, therefore highly persistent in the environment; accumulate in the food chain

Answer 67

PCB and Asbestos

Question 68

most common effect of PCB exposure among workers

Answer 68

dermatoxicity

Question 69

Used in insulation and fire retardancy

Answer 69

PCBs

Question 70

aka dioxins

Answer 70

polychlorinated dibenzo-p-dioxins

Question 71

most important dioxin

Answer 71

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

Question 72

causes a wasting syndrome, hepatotoxicity, immune dysfunction, teratogenicity, and cancer

Answer 72

TCDD

Question 73

cause cystic acneiform lesions

Answer 73

Dioxins

Question 74

is a group of naturally occurring long, flexible mineral fibers, most commonly containing silicon

Answer 74

Asbestos

Question 75

can cause a fibrotic lung disorder

Answer 75

inhalation of Asbestos fiber

Question 76

a lung disorder characterized by shortness of breath

Answer 76

asbestosis

Question 77

associated with mesothelioma

Answer 77

Asbestos