Question 1

The time period between initial exposure and a measurable response is:

Accepted Answer

A)  threshold. 
B)  latency. 
C)  synergism. 
D)  None of these is correct. B

Question 2

A situation in which the combined effect of several exposures is greater than the sum of the individual effects is:

Accepted Answer

A)  threshold. 
B)  latency. 
C)  synergism. 
D)  None of these is correct. C

Question 3

One must use care in interpreting occupational differences in morbidity and mortality because:

Accepted Answer

A)  good health status may be a factor for selection into a job. 
B)  occupations involving physical activity tend to cause heart attacks among older workers. 
C)  occupational stress, even in extreme situations, is difficult to quantify. 
D)  good health status may be a factor for selection into a job, occupations involving physical activity tend to cause heart attacks among older workers, and occupational stress, even in extreme situations, is difficult to quantify. A

Question 4

The lowest dose at which a particular response may occur is:

Accepted Answer

A)  threshold. 
B)  latency. 
C)  synergism. 
D)  None of these is correct.

Question 5

A sentinel health event refers to:

Accepted Answer

A)  the correlation between daily mortality and increased air pollution. 
B)  the nuclear plant accident in Chernobyl, Ukraine. 
C)  a case of unnecessary workplace disease that serves as a warning signal. 
D)  None of these is correct.

Question 6

Asbestos exposure has been associated with:

Accepted Answer

A)  pesticides from the organochloride family. 
B)  asbestosis, malignant mesothelioma, and lung cancer. 
C)  metallic compounds. 
D)  vinyl chloride.

Question 7

Exposure to electric and magnetic fields has been linked to:

Accepted Answer

A)  childhood leukemia risk. 
B)  lung cancer. 
C)  central nervous system damage. 
D)  All are correct.

Question 8

The healthy worker effect refers to the observation that:

Accepted Answer

A)  exercise on the job causes workers to become healthy and gain years of life. 
B)  healthy persons are more likely to gain employment than unhealthy persons. 
C)  unemployed persons tend to have lower mortality than employed persons. 
D)  All are correct.

Question 9

Recently, two follow-up studies of mortality among licensed pesticide applicators were published in the occupational health literature. One study from Florida found an overall standardized mortality ratio (SMR) of 1.80 and excess deaths due to leukemia, cancers of the brain, and lung cancer. A second study, based in Iowa, found an overall SMR of 1.20 and an elevated SMR for lung cancer only. The mortality statistics for the respective states were used for comparison purposes.
A. Is there reason for concern? Why or why not?
B. Why do you think that there was an elevated SMR for only one specific cause of death in Iowa? Knowing that applicators in both states use similar chemicals in their work, do you think that pesticide workers in Florida should be concerned that they may be at higher risk than their colleagues in Iowa?

Accepted Answer

The answer of Recently, two follow-up studies of mortality among...

Question 10

Investigators conducting a study regarding the effects of water pollution and peptic ulcer disease obtained the following data:
A population of 9000 men and women, aged 45, were examined on January 1, 1985. Of these people, 6000 were exposed to toxins in the local water supply and 3000 were not. At the time of this exam, 90 cases of peptic ulcer disease were discovered; 60 of these cases were among those exposed to toxins in their local water.
All the people at the initial exam who were free from peptic ulcer disease were followed with repeat exams over the following year. This study revealed 268 new cases in the total group; of these, 238 cases were among those exposed to toxins in their local water.
A. Calculate the prevalence per 1000 people of peptic ulcer disease on January 1, 1986:
Among the exposed
Among the nonexposed
B. Calculate the 1985 incidence rate/1000 people of peptic ulcer disease:
Among the exposed
Among the nonexposed

Accepted Answer

The answer of Investigators conducting a study regarding the effects...

Question 11

It has been suggested that occupational exposure to benzene in the petroleum industry increases the risk of developing leukemia. The levels of benzene to which workers in this industry have been exposed were high from 1940 to 1970, but since 1970 have been significantly reduced.
What kind of study design, using petroleum workers, would provide the most useful information on whether benzene affects incidence rates of leukemia in this industry? (You may assume that records of individual worker assignments to jobs involving benzene exposure have been maintained by the industry.)

Accepted Answer

A)  Experimental 
B)  Retrospective cohort 
C)  Prospective cohort 
D)  Case-control 
E)  Cross-sectional

Exam 13: Epidemiologic Aspects of Work and the Environment