CIH Occupational Health Hazards 3 — Questions and Answers
Question 1: The dose-response relationship in toxicology assumes which fundamental principle?
- All chemicals are toxic at any dose
- The severity of effect increases with dose above a threshold (Correct answer)
- Low doses always produce beneficial hormetic effects
- Toxic effects are independent of exposure duration
Correct answer: The severity of effect increases with dose above a threshold
The dose-response relationship holds that effect severity increases with dose, typically above a threshold level, which is foundational to toxicological risk assessment.
Question 2: Which NIOSH concept describes a level of airborne contaminant above which a worker's escape is impaired or irreversible health effects occur within 30 minutes?
- TLV-STEL
- IDLH (Immediately Dangerous to Life or Health) (Correct answer)
- Action Level
- REL-C (Ceiling)
Correct answer: IDLH (Immediately Dangerous to Life or Health)
IDLH (Immediately Dangerous to Life or Health) defines the maximum concentration from which a worker could escape within 30 minutes without escape-impairing symptoms.
Question 3: Beryllium sensitization differs from chronic beryllium disease (CBD) in that sensitization:
- Always progresses to CBD within two years
- Is detected by the beryllium lymphocyte proliferation test (BeLPT) without clinical disease (Correct answer)
- Causes irreversible lung fibrosis
- Requires a beryllium air concentration above the OSHA PEL
Correct answer: Is detected by the beryllium lymphocyte proliferation test (BeLPT) without clinical disease
Beryllium sensitization is an immunological response detectable by BeLPT in the absence of clinical disease, and not all sensitized workers develop CBD.
Question 4: A worker develops wheezing exclusively at work that resolves on weekends. This pattern is most consistent with:
- Hypersensitivity pneumonitis
- Occupational asthma (Correct answer)
- Byssinosis
- Reactive airways dysfunction syndrome (RADS)
Correct answer: Occupational asthma
Work-related wheezing that resolves on days away from work is the hallmark presentation of occupational asthma.
Question 5: Which biological monitoring specimen is preferred for assessing recent inorganic mercury vapor exposure?
- Whole blood mercury
- Urine mercury (creatinine-adjusted) (Correct answer)
- Hair mercury
- Fingernail mercury
Correct answer: Urine mercury (creatinine-adjusted)
Urine mercury, adjusted for creatinine, reflects inorganic mercury body burden and is the preferred biomarker for occupational mercury vapor exposure.
Question 6: In the hierarchy of controls, which approach provides the most reliable long-term protection against occupational health hazards?
- Administrative controls
- Personal protective equipment
- Engineering controls (elimination or substitution) (Correct answer)
- Work practice controls
Correct answer: Engineering controls (elimination or substitution)
Engineering controls, especially elimination and substitution, are at the top of the hierarchy because they physically remove or reduce the hazard rather than relying on worker behavior.
Question 7: Which condition results from repetitive low-level trauma causing compression of the median nerve at the wrist?
- Epicondylitis
- Carpal tunnel syndrome (Correct answer)
- Trigger finger
- De Quervain's tenosynovitis
Correct answer: Carpal tunnel syndrome
Carpal tunnel syndrome involves compression of the median nerve within the carpal tunnel, commonly associated with repetitive hand/wrist motions and forceful gripping.
CIH Occupational Health Hazards 3
The dose-response relationship in toxicology assumes which fundamental principle?