Occupational & Environmental Medicine: Exposure, Surveillance, and Fitness for Duty
The specialty core
Occupational medicine questions revolve around the exposure–dose–response–effect chain. Know routes of entry (inhalation, dermal, ingestion), the difference between exposure monitoring (air sampling) and biological monitoring (internal dose, e.g., blood lead, urinary metabolites), and the role of occupational exposure limits (TWA, STEL, ceiling). Understand that limits are not bright lines between safe and unsafe-they are risk-management tools.
Surveillance and fitness for duty
Periodic health surveillance targets workers at risk: audiometry for noise, spirometry for dusts and vapors, skin checks for contact sensitizers, and biological monitoring where absorption occurs. Fitness for duty balances the worker's health against job demands, applying the ADA-style principle that decisions be individualized, based on current medical knowledge, and not on stereotypes. Distinguish pre-placement (baseline and capability) from periodic (detect change) from return-to-work (accommodation).
Environmental and regulatory context
Expect questions on hierarchy of controls (elimination, substitution, engineering, administrative, PPE last), sentinel health events (one case may signal a workplace problem), and reporting obligations. Environmental topics include air and water contaminants, biomagnification, and susceptible populations.
Traps
Watch for questions that equate PPE with primary prevention (it is the least reliable control). Another trap: confusing work-relatedness with compensability-they are different legal and clinical questions. Also, a normal air sample does not rule out dermal absorption.
Rule of thumb
When asked to control a hazard, choose the highest feasible step on the hierarchy-engineering before administrative before PPE-and verify with both exposure and health surveillance.