The sample exam questions provided are derived from the 2004 and 2005 Recertification examinations. Not all question categories are represented, largely because those exams contained more than 50% of Type B questions, which are no longer being used on certification examinations. Happy practiciing, and good luck! PART A SAMPLE QUESTIONS 1. The major toxic effect of hydrogen cyanide exposure is
A) lung damage
B) hemoglobin alteration
C) hemolysis of RBCs
D) inhibition of mitochondrial respiration
E) lipid peroxidation 2. Which of the following ionizing radiations has the shortest range (i.e., travels the shortest distance in tissue) for the same initial energy?
A) alpha particle
B) beta particle
C) gamma ray
D) x ray
E) cosmic ray 3. Which of the following agents would NOT likely produce reactive airways dysfunction syndrome (RADS)?
A) carbon monoxide
B) chlorine
C) ammonia
D) toluene diisocyanate
E) acetic acid 4. Exposure to fumes of which of the following metals is most likely to cause acute chemical pneumonitis and pulmonary edema?
A) lead
B) zinc
C) cadmium
D) copper
E) magnesium 5. An individual exposed to 10 rads (0.1 Gy) of whole body x-irradiation would be expected to
A. have a severe bone marrow depression
B. die
C. be permanently sterilized
D. exhibit no symptoms
E. vomit 6. Benzene is similar to toluene
A) in its metabolism to redox active metabolites
B) regarding covalent binding of its metabolites to proteins
C) in its ability to produce CNS depression
D) in its ability to produce acute myelogenous leukemia
E) in its ability to be metabolized to benzoquinone 7. Consumption of milk from goats which have grazed on lupine plants containing the alkaloid, anagyrine, may cause
A) birth defects when ingested by women during early pregnancy
B) severe liver damage characterized by centrilobular necrosis
C) dizziness, nausea, headaches and hallucinations
D) numbness of the extremities
E) aphrodisia and a general increase in sexual awareness 8. Sorbitol and other sugar alcohols have been associated with
A) respiratory distress syndrome
B) osmotic diarrhea
C) hepatotoxicity
D) immediate hypersensitivity reaction
E) CNS depression
9. Which of the following is NOT true regarding Amanita phalloides mushrooms?
A) toxic components are phalloidin and amatoxins
B) produces liver and gastroiintestinal toxicity
C) cardiovascular toxicity is responsible for mortality
D) common name is "death cap"
E) no specific antidotal treatment of poisoning is available 10. Chloroform is NOT
A) a central nervous system depressant
B) hepatotoxic
C) metabolized to phosgene
D) a peroxisome proliferator
E) a contaminant of chlorinated water 11. Increasing the casein content of a partially purified diet up to a level of 36%
A) reduces the spontaneous hepatoma incidence below background in mice
B) increases the spontaneous hepatoma incidence above background in mice
C) has no effect on the incidence of mouse hepatomas
D) reduces the spontaneous incidence of kidney tumors below background in mice
E) reduces the spontaneous incidence of lung tumors below background in mice 12. All of the following may cause metabolic acidosis EXCEPT
A) renal failure
B) salicylates
C) methanol
D) diuretics
E) diarrhea 13. A patient is admitted to the emergency room with the following symptoms: dry mouth and skin; weak, rapid pulse (130 beats/min); elevated body temperature (103 degrees F); and mydriasis. He is excited and disoriented. In his pocket is a bottle of pills labelled: "take one as necessary for stomach pain". This patient is most likely to be suffering from an overdose of
A) a narcotic analgesic
B) a non-narcotic analgesic
C) an antacid
D) an antimuscarinic agent
E) a benzodiazepine tranquilizer 14. Each of the following solvents is paired with a correct target organ of toxicity EXCEPT
A) methanol:retina
B) ethylene glycol:kidney
C) ethylene glycol monomethyl ether:kidney
D) dichloromethane:central nervous system
E) carbon tetrachloride:liver 15. Which of the following is NOT true about arsine?
A) it is a gas at room temperature
B) it produces acute intravascular hemolysis
C) it has a garlic-like odor
D) acute renal failure is a common manifestation of arsine poisoning
E) significant hepatotoxicity often occurs as part of arsine poisoning 16. No specific antidote is available for poisoning by
A) sodium fluoroacetate
B) warfarin
C) chlorinated hydrocarbon insecticides
D) rotenone
E) cyanide 17. Which of the following is NOT commonly associated with mercury vapor poisoning?
A) acute, corrosive bronchitis
B) interstitial pneumonitis
C) tremor
D) increased excitability
E) vomiting and bloody diarrhea 18. Compounds containing beryllium are NOT readily absorbed from the gastrointestinal tract because
A) they form insoluble phosphate precipitates at the pH of the intestinal tract
B) they are chelated by bile salts in the small intestine
C) their size prevents passage through cell membranes
D) they are converted to an oxide form
E) exposures rarely occur to the soluble metallic form 19. Which of the following is NOT associated with spermatotoxicity in rats?
F) ethylene glycol monomethyl ether
G) ethylene glycol monoethyl ether
H) ethoxy acetic acid
I) methoxy acetic acid
J) propylene glycol monomethyl ether 20. Which form of mercury was the predominant cause of Minamata Bay disease?
A) metallic mercury
B) mercuric salts
C) mercurous salts
D) organic mercury compounds
E) mercury was not the causative agent 21. Methyl bromide (CH3Br)
A) is a liquid used primarily as a fumigant
B) has essentially no warning properties, even at physiologically hazardous concentrations
C) is extremely flammable
D) is of greater concern from its oral toxicity than from its inhalation toxicity
E) would not be expected to be readily absorbed through the lungs 22. The chloronicotinyl compound imidacloprid demonstrates a high insecticidal potency and exceptionally low mammalian toxicity due to
A) its high affinity for insect nicotinic acetylcholine receptors and low affinity for mammalian nicotinic acetylcholine receptors
B) the blood-brain barrier in mammals
C) the first pass effect in the liver in mammals
D) the low pH in the stomach of monogastric mammals
E) the presence of true acetylcholinesterase in mammals 23. The most commonly used pyrethroid synergist is
A) silica
B) piperonyl butoxide
C) methyl butyl ether
D) n-octyl bicyloheptene dicarboximide
E) toluene 24. Paraquat and diquat differ substantially in their
A) metabolism to a free radical
B) ability to initiate lipid peroxidation in vivo
C) uptake by the lung
D) generation of superoxide anion in vivo
E) mechanism of cytotoxicity PART A ANSWERS 1. D
2. A
3. A
4. C
5. D
6. C
7. A
8. B
9. C
10. D
11. B
12. D
13. D
14. C
15. E
16. C
17. E
18. A
19. E
20. D
21. B
22. A
23. B
24. C PART B SAMPLE QUESTIONS 1. Which of the following leads to deposition of oxalate crystals in the urinary tract?
A) Dieffenbachia (dumbcane)
B) propylene glycol
C) methoxyflurane
D) philodendron
E) ethylene glycol 2. A target organ of streptomycin-induced toxicity is
A) lung
B) heart
C) reproductive system
D) kidney
E) liver 3. Which of the following is characteristic of a nongenotoxic carcinogen?
A) has no influence on the promotional stage of carcinogenesis
B) would be expected to produce positive responses in in vitro assays for mutagenic potential
C) typically exerts other forms of toxicity and/or disrupts cellular homeostasis
D) generally shows little structural diversity
E) typically has little effect on cell turnover 4. A single large dose of N-nitrosodimethylamine fails to induce cancer in rats, but repeated dosing induces cancer because
A) the single large dose is lethal, while the threshold for cancer induction can be exceeded by repeated smaller doses
B) the main DNA lesion from a single large dose can be repaired readily by methyltransferase, while repeated smaller doses can deplete the available repair enzyme, induce mutations in DNA, and effectively induce cancer
C) the enzyme system involved in detoxification of N-nitrosodimethylamine is depleted after repeated doses, allowing N-nitrosodimethylamine to build up and exceed the threshold for cancer induction
D) the enzyme system involved in conversion of N-nitrosodimethylamine to the active carcinogen is induced and on subsequent repeated doses more active carcinogen is produced
E) the initial dose of N-nitrosodimethylamine causes cell damage and, thus, high mitotic rates; subsequent small doses induce mutations in DNA and effectively induce cancer 5. Based on the available data, cyclosporin A-induced cholestasis is most likely explained by which of the following?
A) interaction with the cytoplasmic receptor, cyclophilin
B) inhibition of transcription of message (mRNA) for critical cytokines
C) induction of programmed cell death in centrilobular hepatocytes
D) inhibition of ATP-dependent transporter(s) in the bile canalicular membrane
E) depolarization of the mitochondrial membrane potential 6. In regard to chemically-induced adverse effects on the eye,
A) no chemical has been shown to cause glaucoma
B) nonionic detergents damage the eye more that cationic detergents
C) 2,4-dinitrophenol, corticosteroids and naphthalene are known to cause cataracts in humans
D) methanol produces blindness by rendering the cornea and lens opaque
E) acids usually produce late-appearing ocular toxicity as contrasted to alkalis which produce immediate damage 7. Allergic contact dermatitis is
A) a non-immune response caused by a direct action of an agent on the skin
B) an immediate type I hypersensitivity reaction
C) a delayed type IV hypersensitivity reaction
D) characterized by the intensity of reaction being proportional to the elicitation dose
E) not involved in photo-allergic reactions 8. Which of the following is the correct xenobiotic:toxicity pair?
A) adriamycin : tubular proteinuria
B) polyvinyl alcohol : disseminated intravascular coagulation
C) hydralazine : renal papillary necrosis
D) maleic acid : mesangial fibrosis
E) gold : glomerulonephritis 9. The primary site of kidney damage resulting from acute exposure to inorganic mercury salts is the
A) glomerulus
B) proximal tubule
C) loop of Henle
D) renal papilla
E) entire nephron 10. The fertility index
A) is calculated as (number of pups alive at 4 days/number of pups born alive) x 100
B) represents the number of live fetuses per liter x 100
C) represents the percent of copulations that result in pregnancies
D) is calculated as (number of fetuses at 14 days/total number of implantations) x 100
E) can be calculated as early fetal deaths/total implantations x 100 11. Which substance has been identified as a respiratory tract carcinogen in humans?
A) kaolin
B) hydrogen fluoride
C) arsenic
D) cotton dust
E) vanadium 12. Chloracne is associated with
A) prominent hyperkeratosis of the follicular canal
B) production of excessive sebum
C) exposure to halogenated aliphatic hydrocarbons
D) exposure to chlorine gas
E) increases in serum androgen levels 13. Which of the following statements is NOT true?
A) arsenic, benzene and vinyl chloride are known human carcinogens
B) many peroxisome proliferators cause hepatic tumors in rats and are promoting agents for hepatocarcinogenesis
C) benzidine, beta-naphthylamine, and derived dyes have caused urinary bladder tumors in exposed workers
D) short asbestos fibers (<2 um long) are thought to be predominately responsible for the induction of mesotheliomas
E) butylated hydroxyanisole (BHA) acts as a nonmutagenic carcinogen in the forestomach of rats 14. Which of the following assumptions is NOT correct regarding risk assessment for male reproductive effects in the absence of mechanistic data?
A) an agent that produces an adverse reproductive effect in experimental animals is assumed to pose a potential reproductive hazard to humans
B) in general, a non-threshold is assumed for the dose-response curve for male reproductive toxicity
C) effects of xenobiotics on male reproduction are assumed to be similar across species unless demonstrated otherwise
D) the most sensitive species should be used to estimate human risk
E) reproductive processes are similar across mammalian species 15. Acidic drugs accumulate in the fetus because of which of the following?
A) ion trapping due to reduced intracellular pH in the fetus
B) decreased levels of alpha 1-acid glycoproteins in the fetus
C) placental transport systems favor accumulation in the fetus
D) fetal hepatic uptake and biliary excretion develop early in gestation
E) fetal albumin exhibits a higher affinity than adult albumin 16. The most serious consequence of crude oil or kerosene ingestion by cattle is
A) liver damage
B) kidney damage
C) aspiration pneumonia
D) central nervous system stimulation
E) leukemia 17. Toxic injury to the cell body, axon and surrounding Schwann cells of peripheral nerves are referred to, respectively, as
A) neuropathy, axonopathy and myelopathy
B) neuronopathy, axonopathy and myelinopathy
C) neuropathy, axonopathy and gliosis
D) neuronopathy, dying-back neuropathy and myelopathy
E) chromatolysis, axonopathy and gliosis 18. The conceptus is considered preferentially vulnerable to chemical insult due to all of the following EXCEPT
A) rapid rate of cell proliferation
B) requirement for precise temporal and spatial localization of cells and cell products C) rapid blood flow (heart rate) and increased tissue distribution of the chemical
D) limited drug metabolism capability
E) immaturity of the immune system 19. Which of the following is a nongenotoxic liver carcinogen in rats?
A) aflatoxin
B) vinyl chloride
C) pyrrolizidine alkaloids
D) clofibrate
E) tamoxifen 20. Suppression of NK (natural killer) cell activity produces adverse effects in animals because
A) NK cells play a role in the immune surveillance of tumors and the inhibition of metastases
B) NK cells are precursors to pulmonary macrophages, and suppression of activity results in a decreased ability to combat pulmonary infections
C) NK cells function as a helper cell in erythropoiesis, and suppression of NK cell activity results in anemia
D) NK cells function in the complement-fixation cascade, and reduced NK cell activity causes loss of blood clotting
E) NK cells function directly by phagocytosis of pathogens to protect the host from pathogenic bacteria (acquired cell-mediated immunity) PART B ANSWERS 1. E
2. D
3. C
4. B
5. D
6. C
7. C
8. E
9. B
10. C
11. C
12. A
13. D
14. B
15. A
16. C
17. B
18. C
19. D
20. A PART C SAMPLE QUESTIONS 1. A threshold limit value-time weighted average for a chemical represents
A) an airborne concentration of a chemical that can never be exceeded
B) an airborne concentration of a chemical that is believed to cause no adverse health effect to a worker exposed for 8 hours a day, 40 hours a week
C) an airborne concentration of a chemical that cannot be exceeded for longer than 15 minutes a day
D) a value for an acceptable airborne concentration of a chemical established by the Occupational Safety and Health Administration
E) an airborne concentration which cannot be measured using available technology 2. The reference dose (RfD) is generally determined by applying which of the following default procedures?
A) an uncertainty factor of 100 is applied to the NOAEL in chronic animal studies
B) a risk factor of 1000 is applied to the NOAEL in chronic animal studies
C) a risk factor of 10,000 is applied to the NOAEL in subchronic animal studies
D) an uncertainty factor between 10,000 and 1 million is applied to the NOEL from chronic animal studies
E) multiplying the NOAEL from chronic animal studies by 100 3. Which of the following concerning the use of the "benchmark dose" in risk assessment is NOT correct?
A) can use the full range of doses and responses studied
B) allows use of data obtained from experiments where a clear "no observed adverse effect level" (NOAEL) has been attained
C) may be defined as the lower confidence limit on the 10% effective dose
D) is primarily used for analyses of carcinogenicity data and has limited utility for analyses of developmental and reproduction studies that generate quantal data
E) is not limited to the values of the administered doses 4. Administration by oral gavage of a test compound that is highly metabolized by the liver versus subcutaneous injection will most likely result in
A) less parent compound present in the systemic circulation
B) more local irritation at the site of administration caused by the compound
C) lower levels of metabolites in the systemic circulation
D) more systemic toxicity
E) less systemic toxicity 5. Which of the following is the most significant contributor to air pollution by mass in suburban areas?
A) manufacturing
B) transportation
C) space heaters
D) electric power generation
E) waste disposal 6. Methylation
A) typically increases the water solubility of xenobiotics
B) is a major pathway of xenobiotic metabolism
C) requires S-adenosylmethionine (SAM)
D) requires acetyl coenzyme A
E) requires taurine 7. From 1973 to 1977, the average annual incidence rate of lung cancer in Connecticut was 45.9 per 100,000. The average annual prevalence was 23.0 per 100,000. From these values, what is the average duration of survival after being diagnosed with lung cancer?
A) 2 years
B) 6 months
C) 1 year
D) 8 years
E) 4 years 8. Of the more than 40 cytochrome P450 isozymes, which 6 account for the majority of xenobiotic metabolism in humans?
A) CYP1E1, CYP2B1, CYP2B19, CYP2F1, CYP3A7, CYP4A6
B) CYP1A1, CYP2A6, CYP2B6, CYP2D6, CYP2F2, CYP4B2
C) CYP1B2, CYP2C6, CYP2F2, CYP3A2, CYP3A4, CYP4A2
D) CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4
E) CYP1A1, CYP2C8, CYP2F2, CYP3A7, CYP4A2, CYP4A6 9. Which of the following conditions represents a manifestation of moderate chronic fluoride toxicity?
A) osteomalacia
B) osteosclerosis
C) osteopetrosis
D) osteopenia
E) osteolysis 10. Intoxication from consumption of wild cherry or apricot pits would best be treated by
A) hyperbaric oxygen
B) artificial respiration
C) inhalation of amyl nitrite
D) intravenous sodium nitrite and sodium thiosulfate
E) oral sodium nitrate 11. Drug X is available as a 2.5% solution for intravenous administration. The desired dosage of this drug is 5 mg/kg. What volume of drug should be injected if the patient weighs 50 kg?
A) 0.2 ml
B) 1.0 ml
C) 2.0 ml
D) 10 ml
E) 20 ml 12. The phrase that best defines "toxicodynamics" is the
A) linkage between exposure and dose
B) linkage between dose and response
C) dynamic nature of toxic effects among various species
D) dose range between desired biological effects and adverse health effects
E) loss of dynamic hearing range due to a toxic exposure 13. Which of the following was banned under the Delaney clause of the Food Additive Amendment of 1958?
A) butylated hydroxytoluene
B) sulfamethazine
C) cyclamate
D) phytoestrogens
E) aflatoxin 14. Which of the following is NOT a characteristic of active transport?
A) blocked by saxitoxin
B) movement against a concentration gradient
C) exhibits a transport maximum
D) energy dependent
E) selectivity 15. Which of the following is NOT an initiating event in carcinogenesis?
A) DNA adduct formation
B) DNA strand breakage
C) mutation of proto-oncogenes
D) oxidative damage of DNA
E) mitogenesis 16. Which of the following does NOT inhibit electron transport?
A) rotenone
B) succinate
C) antimycin-A
D) formate
E) azide 17. Reabsorption of toxicants does NOT occur through
A) entero-hepatic recirculation
B) glomerular filtration
C) diffusion
D) active transport
E) carriers for physiologic oxyanions 18. Which of the following does NOT uncouple oxidative phosphorylation?
A) pentachlorophenol
B) dinitrophenol
C) aconitase
D) salicylate
E) gramacidin 19. Which of the following is NOT true regarding peroxisome proliferators?
A) they are a structurally diverse group of chemicals
B) they cause marked induction of lipid metabolizing enzymes
C) they often are non-genotoxic hepatocarcinogens in rodents
D) they induce hepatic CYP1A which is indicative of peroxisome proliferation
E) they operate via the peroxisome proliferator activated receptor 20. Permissible Exposure Limits are
A) promulgated by the Occupational Safety and Health Administration and have the force of law
B) identical to and interchangeable with Short Term Exposure Limits
C) authorized under the Toxic Substances Control Act
D) promulgated by the Environmental Protection Agency
E) are directly adopted from the American Conference of Governmental Industrial Hygienists Threshold Limit Value list 21. Which of the following has NOT been linked to human lung cancer?
A) arsenic
B) nickel
C) silica
D) chromium
E) antimony PART C ANSWERS 1. B
2. A
3. D
4. A
5. B
6. C
7. B
8. D
9. B
10. D
11. D
12. B
13. C
14. A
15. E
16. B
17. B
18. C
19. D
20. A
21. E |
