Define the following terms: Intervention study
- A. A study where researchers observe natural behaviors.
- B. A study where researchers manipulate variables to assess impact.
- C. A study analyzing past records.
- D. A study based solely on surveys.
Correct Answer: B
Rationale: Intervention studies involve deliberate manipulation of variables by researchers.
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When is initiating surveillance for a new public health problem justified?
- A. If it is a communicable disease with a high case-fatality rate.
- B. If the problem is new and systematically collected data are needed to characterize the disease.
- C. If a program at CDC has recommended its addition to better understand national trends and patterns.
- D. To guide, monitor, and evaluate programs to prevent or control the problem.
Correct Answer: D
Rationale: Surveillance is essential to guide and evaluate prevention and control strategies.
What is meant by the term TTHM, and why is it relevant to water quality?
- A. Trihalomethanes formed during chlorination; potential carcinogens.
- B. Toxic trace heavy metals; cause immediate poisoning.
- C. Total thermal heat management; regulates temperature.
- D. Temporary total hardness measure; affects taste.
Correct Answer: A
Rationale: TTHMs are disinfection byproducts linked to cancer risks, making them critical for water quality monitoring.
First step of epidemic investigation?
- A. Preparing case definition
- B. Mapping the epidemic
- C. Confirmation
- D. Searching for the cases
Correct Answer: C
Rationale: The first step in investigating an epidemic is to confirm the existence of the outbreak through verification of cases.
Discuss the possible health effects that have been associated with exposure to electric and magnetic fields and ionizing radiation.
- A. EMF: unclear evidence; Ionizing: cancer risk.
- B. EMF: immediate death; Ionizing: no known risks.
- C. EMF: improved sleep; Ionizing: enhanced mood.
- D. EMF: faster metabolism; Ionizing: increased energy.
Correct Answer: A
Rationale: Evidence linking EMFs to health effects is inconclusive, while ionizing radiation is a well-established carcinogen.
For the cruise ship scenario, if you suspected ice as a transmission source, how might you display 'place'?
- A. Spot map by assigned dinner seating location
- B. Spot map by cabin
- C. Shaded map of United States by state of residence
- D. Shaded map by whether passenger consumed ship's ice or not
Correct Answer: D
Rationale: Mapping by exposure to ice helps identify potential sources of infection.