Health Effects and Medical Surveillance
Domain focus
The exam tests how asbestos exposure causes disease and when OSHA medical surveillance is triggered. Expect latency, dose-response, smoking interaction, and surveillance content.
Core rules
- Inhaled fibers deposit in the lung; disease usually appears 15-40 years after exposure. Higher cumulative dose increases asbestosis and lung cancer risk, but mesothelioma can occur at low doses.
- Asbestosis is diffuse interstitial fibrosis; lung cancer risk is multiplicative with smoking; mesothelioma is a malignancy of the pleura or peritoneum and is not caused by smoking.
- Under OSHA 29 CFR 1926.1101(m), medical surveillance is required for employees doing Class I, II, or III work for 30 or more days per year, or exposed above the PEL/STEL for that many days. Baseline and annual exams are required, with termination examination available under the standard.
- Surveillance includes work and medical history, physical exam, chest X-ray, and pulmonary function tests; the physician gives a written opinion without unrelated findings.
Worked example
A 58-year-old smoker who installed pipe insulation for 25 years without respiratory protection has dyspnea and a chest X-ray showing diffuse opacities. The findings fit asbestosis, but the same exposure also raises lung cancer risk. His smoking multiplies the lung cancer risk; it does not cause mesothelioma. He needs medical evaluation, and the employer must determine whether surveillance was required.
Traps
Do not confuse latency with incubation; do not say smoking causes mesothelioma; do not use a chest X-ray alone to rule out disease; surveillance is not exposure monitoring.