CIH Occupational Health Hazards 4 — Questions and Answers
Question 1: Carbon monoxide (CO) exerts its primary toxic effect by:
- Dissolving in plasma to lower blood pH
- Binding hemoglobin with ~240 times the affinity of oxygen (Correct answer)
- Inhibiting cytochrome oxidase in mitochondria
- Displacing oxygen from alveolar air
Correct answer: Binding hemoglobin with ~240 times the affinity of oxygen
CO binds hemoglobin ~240 times more avidly than oxygen, forming carboxyhemoglobin and impairing oxygen delivery to tissues.
Question 2: What does the ACGIH Biological Exposure Index (BEI) represent?
- The maximum allowable blood level set by OSHA regulation
- A reference value for biological media corresponding to TLV exposure (Correct answer)
- The IDLH concentration expressed as a urine metabolite level
- A worker's baseline measurement before chemical exposure begins
Correct answer: A reference value for biological media corresponding to TLV exposure
BEIs are reference values for biological specimens corresponding to exposure at the TLV, used as a supplement to air monitoring rather than a regulatory limit.
Question 3: Which agricultural pesticide class is associated with inhibition of acetylcholinesterase, leading to cholinergic toxidrome?
- Pyrethroids
- Organophosphates and carbamates (Correct answer)
- Organochlorines
- Neonicotinoids
Correct answer: Organophosphates and carbamates
Organophosphates and carbamates inhibit acetylcholinesterase, causing accumulation of acetylcholine and a cholinergic toxidrome (SLUDGE symptoms).
Question 4: OSHA's Hazard Communication Standard (HazCom 2012) requires Safety Data Sheets to follow which internationally harmonized format?
- NFPA 704 diamond system
- Globally Harmonized System (GHS) (Correct answer)
- ISO 11014 format
- WHMIS 1988 format
Correct answer: Globally Harmonized System (GHS)
HazCom 2012 aligned U.S. requirements with the Globally Harmonized System (GHS), standardizing 16-section SDS format and pictograms globally.
Question 5: Which type of hearing loss is primarily associated with occupational noise exposure?
- Conductive hearing loss
- Sensorineural hearing loss at high frequencies (4000 Hz notch) (Correct answer)
- Mixed conductive and sensorineural loss
- Low-frequency sensorineural loss
Correct answer: Sensorineural hearing loss at high frequencies (4000 Hz notch)
Noise-induced hearing loss (NIHL) is sensorineural, characterized by a 4000 Hz notch on audiogram from damage to outer hair cells in the cochlea.
Question 6: Heat stroke differs from heat exhaustion primarily in that heat stroke:
- Is characterized by heavy sweating and pale skin
- Involves core temperature above 40°C with central nervous system dysfunction (Correct answer)
- Is treated with oral fluid replacement alone
- Does not require emergency medical intervention
Correct answer: Involves core temperature above 40°C with central nervous system dysfunction
Heat stroke is defined by a core temperature >40°C (104°F) accompanied by CNS dysfunction (confusion, seizures), requiring immediate cooling and emergency care.
Question 7: What is the primary health concern associated with occupational exposure to asbestos fibers with high aspect ratios?
- Kidney toxicity and nephropathy
- Pulmonary fibrosis (asbestosis), lung cancer, and mesothelioma (Correct answer)
- Hepatotoxicity and liver cirrhosis
- Peripheral neuropathy
Correct answer: Pulmonary fibrosis (asbestosis), lung cancer, and mesothelioma
Asbestos exposure causes asbestosis (pulmonary fibrosis), lung cancer (synergistic with smoking), and malignant mesothelioma of the pleura and peritoneum.
CIH Occupational Health Hazards 4
Carbon monoxide (CO) exerts its primary toxic effect by: