CIH Occupational Health Hazards 5 — Questions and Answers
Question 1: Which pathogen causes occupational Q fever, and what is its primary exposure route for workers?
- Brucella abortus via contact with infected animal tissue
- Coxiella burnetii via inhalation of contaminated aerosols from livestock (Correct answer)
- Leptospira interrogans via contact with contaminated water
- Bacillus anthracis via handling of infected animal hides
Correct answer: Coxiella burnetii via inhalation of contaminated aerosols from livestock
Q fever is caused by Coxiella burnetii, a highly infectious bacterium acquired primarily through inhalation of aerosols from infected livestock (cattle, sheep, goats).
Question 2: The concept of 'action level' under OSHA standards typically triggers which employer obligations?
- Immediate evacuation and decontamination of the work area
- Medical surveillance, exposure monitoring, and training programs (Correct answer)
- Mandatory use of supplied-air respirators by all workers
- Posting of IDLH warning signs throughout the facility
Correct answer: Medical surveillance, exposure monitoring, and training programs
At the OSHA action level (typically one-half the PEL), employers must initiate medical surveillance, periodic air monitoring, and worker training.
Question 3: Which type of ventilation system is specifically designed to capture contaminants at or near the point of generation before they enter the worker's breathing zone?
- General dilution ventilation
- Local exhaust ventilation (LEV) (Correct answer)
- Makeup air systems
- Positive-pressure room ventilation
Correct answer: Local exhaust ventilation (LEV)
Local exhaust ventilation (LEV) captures contaminants at the source through hoods, ducts, and fans before they disperse into the workplace air.
Question 4: Ergonomic risk factors for work-related musculoskeletal disorders (WMSDs) include all of the following EXCEPT:
- Repetitive motion and forceful exertion
- Awkward postures and static loading
- Whole-body vibration during vehicle operation
- Low relative humidity in the work environment (Correct answer)
Correct answer: Low relative humidity in the work environment
Low humidity is a comfort/environmental issue but not a recognized primary ergonomic risk factor for WMSDs, unlike repetition, force, posture, and vibration.
Question 5: A chemical with a high vapor pressure and low odor threshold is considered particularly hazardous because:
- It is always a carcinogen under IARC classification
- Workers may be overexposed before detecting it by smell, and it readily vaporizes (Correct answer)
- It penetrates all filter-type respirator cartridges equally
- It does not adsorb onto activated charcoal sampling media
Correct answer: Workers may be overexposed before detecting it by smell, and it readily vaporizes
High vapor pressure means the chemical readily vaporizes to high concentrations, and a low odor threshold (relative to its TLV) provides poor warning of dangerous concentrations.
Question 6: Which blood test is the preferred biomarker for monitoring chronic occupational lead exposure?
- Urine coproporphyrin
- Blood lead level (BLL) and zinc protoporphyrin (ZPP) (Correct answer)
- Serum delta-aminolevulinic acid (ALA)
- Free erythrocyte protoporphyrin (FEP) alone
Correct answer: Blood lead level (BLL) and zinc protoporphyrin (ZPP)
Blood lead level directly measures absorbed lead, while ZPP reflects heme synthesis impairment; together they are the standard biomarkers for chronic occupational lead exposure monitoring.
Question 7: Which respirator protection factor is assigned to a full-facepiece air-purifying respirator (APF) under OSHA 29 CFR 1910.134?
- 10
- 25
- 50 (Correct answer)
- 1000
Correct answer: 50
OSHA assigns an Assigned Protection Factor (APF) of 50 to a full-facepiece air-purifying respirator, meaning it reduces inhalation exposure by a factor of 50.
CIH Occupational Health Hazards 5
Which pathogen causes occupational Q fever, and what is its primary exposure route for workers?