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REHS Exam Questions with 100% Correct
Answers | Latest Version 2026 | Verified.
1. A factor or agent which increases the risk of cancer is known as a
a. teratogen
b. mutagen
c. carcinogen
d. fomite - ANSWER-carcinogen
2. The four major causes of death among all age groups of Americans
include all of the following
except.
a. homicide
b. accidents
c. malignant neoplasms
d. heart disease - ANSWER-homicide
3. In recent years, the largest number of rabies cases were associated
with
a. skunks
b. bats
c. dogs
d. raccons. - ANSWER-skunks
4. Asbestosis is caused by fine silicate fibers retained in the
a. kidneys
b. lungs
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c. colon
d. abdomen - ANSWER-lungs
5. An illness due to a specific infectious agent or its toxic product which
is transmitted from a
reservoir to a susceptible host either directly or indirectly is called
a. an infectious disease
b. a communicable disease
c. a genetic disease
d. a noncommunicable disease - ANSWER-a communicable disease
6. Rocky mountain spotted fever is spread by
a. flies
b. spiders
c. cockroaches
d. ticks - ANSWER-ticks
7. Mycotoxins are poisonous chemicals produced by
a. bacteria
b. vertebrates
c. viruses
d. fungi - ANSWER-fungi
8. The study of the occurrence, frequency, and distribution of disease is
a. entomology
b. biology
c. endocrinology
d. epidemiology - ANSWER-epidemiology
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9. Which of the following organisms are most resistant to unfavorable
environmental conditions and indicate past or possibly intermittent
pollution? a. fecal streptococci
b. escherichia coli
c. aerobacter aerogenes
d. clostridium sporulates - ANSWER-clostridium sporulates
10. Engineering controls are
a. controls that isolate or remove hazards from the work place
b. less effective than good training
c. the last option that should be considered
d. less effective than personal protection processes - ANSWER-controls
that isolate or remove hazards from the workplace
11. Which of the following is not considered a satisfactory solution to
the problem of chemical contamination in
Well systems?
a. abandoning the well
b. boiling the water
c. building a new, properly constructed, drilled well - ANSWER-
boiling the water
12. Which of the following chemicals is most widely used to destroy
microorganisms?
a. chlorine
b. copper sulfate
c. chloramine
d. hydrogen sulfate - ANSWER-chlorine
13. Which of the following is not a practical method for removal of
cadmium?
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a. ion exchange
b. lime softening
c. reverse osmosis
d. iron coagulation - ANSWER-reverse osmosis
14. Which of the following is not a commonly accepted method of
device to prevent backsiphonage? a. vacuum breakers
b. cross-connections
c. air gap separation
d. back pressure units - ANSWER-cross-connections
15. This substance is the first product of the decomposition of organic
matter. Its presence in water usually
Indicates "fresh pollution" of sanitary significance. What is it?
a. ammonia
b. sugar
c. carbon dioxide
d. hydrogen sulfide - ANSWER-ammonia
16. One of the most common reasons for the contamination of wells
drilled through rock, clay, or hardpan is a. seepage of pollutants
through soil
b. failure to seal well casings properly
c. porosity of the rock
d. use of inferior quality well casings - ANSWER-failure to seal well
casings properly
17. In emergencies, small quantities of water can be disinfected by
boiling or using
a. aluminum salts
b. tincture of iodine
c. salt tablets
REHS Exam Questions with 100% Correct
Answers | Latest Version 2026 | Verified.
1. A factor or agent which increases the risk of cancer is known as a
a. teratogen
b. mutagen
c. carcinogen
d. fomite - ANSWER-carcinogen
2. The four major causes of death among all age groups of Americans
include all of the following
except.
a. homicide
b. accidents
c. malignant neoplasms
d. heart disease - ANSWER-homicide
3. In recent years, the largest number of rabies cases were associated
with
a. skunks
b. bats
c. dogs
d. raccons. - ANSWER-skunks
4. Asbestosis is caused by fine silicate fibers retained in the
a. kidneys
b. lungs
,2|Page
c. colon
d. abdomen - ANSWER-lungs
5. An illness due to a specific infectious agent or its toxic product which
is transmitted from a
reservoir to a susceptible host either directly or indirectly is called
a. an infectious disease
b. a communicable disease
c. a genetic disease
d. a noncommunicable disease - ANSWER-a communicable disease
6. Rocky mountain spotted fever is spread by
a. flies
b. spiders
c. cockroaches
d. ticks - ANSWER-ticks
7. Mycotoxins are poisonous chemicals produced by
a. bacteria
b. vertebrates
c. viruses
d. fungi - ANSWER-fungi
8. The study of the occurrence, frequency, and distribution of disease is
a. entomology
b. biology
c. endocrinology
d. epidemiology - ANSWER-epidemiology
,3|Page
9. Which of the following organisms are most resistant to unfavorable
environmental conditions and indicate past or possibly intermittent
pollution? a. fecal streptococci
b. escherichia coli
c. aerobacter aerogenes
d. clostridium sporulates - ANSWER-clostridium sporulates
10. Engineering controls are
a. controls that isolate or remove hazards from the work place
b. less effective than good training
c. the last option that should be considered
d. less effective than personal protection processes - ANSWER-controls
that isolate or remove hazards from the workplace
11. Which of the following is not considered a satisfactory solution to
the problem of chemical contamination in
Well systems?
a. abandoning the well
b. boiling the water
c. building a new, properly constructed, drilled well - ANSWER-
boiling the water
12. Which of the following chemicals is most widely used to destroy
microorganisms?
a. chlorine
b. copper sulfate
c. chloramine
d. hydrogen sulfate - ANSWER-chlorine
13. Which of the following is not a practical method for removal of
cadmium?
, 4|Page
a. ion exchange
b. lime softening
c. reverse osmosis
d. iron coagulation - ANSWER-reverse osmosis
14. Which of the following is not a commonly accepted method of
device to prevent backsiphonage? a. vacuum breakers
b. cross-connections
c. air gap separation
d. back pressure units - ANSWER-cross-connections
15. This substance is the first product of the decomposition of organic
matter. Its presence in water usually
Indicates "fresh pollution" of sanitary significance. What is it?
a. ammonia
b. sugar
c. carbon dioxide
d. hydrogen sulfide - ANSWER-ammonia
16. One of the most common reasons for the contamination of wells
drilled through rock, clay, or hardpan is a. seepage of pollutants
through soil
b. failure to seal well casings properly
c. porosity of the rock
d. use of inferior quality well casings - ANSWER-failure to seal well
casings properly
17. In emergencies, small quantities of water can be disinfected by
boiling or using
a. aluminum salts
b. tincture of iodine
c. salt tablets
