CAQ-OccMed cheat sheet

Occupational Medicine: Core Reference

• Hazard–exposure–dose–response chain: identify hazard, characterize exposure route (inhalation, dermal, ingestion, injection), quantify dose, then compare to occupational exposure limits (OELs) such as TLV-TWA, PEL, REL, and STEL.

• Hierarchy of controls, most to least effective: elimination, substitution, engineering controls (local exhaust ventilation, enclosure, isolation), administrative controls (rotation, work-rest schedules), then PPE as the last line of defense.

• Occupational asthma: work-related variable airflow obstruction; distinguish sensitizer-induced (latency after exposure, IgE-mediated for high-molecular-weight agents) from irritant-induced (RADS after a single high exposure); key steps are serial peak flow at and away from work, specific inhalation challenge, and removal from exposure.

• Pneumoconioses: silicosis (upper-lobe nodular, eggshell hilar calcification, risk of TB and lung cancer), coal workers' pneumoconiosis (coal macules, Caplan syndrome), asbestosis (lower-lobe diffuse interstitial fibrosis, latency 15-30 years); asbestos also causes mesothelioma and lung cancer, with synergism from smoking for lung cancer.

• Noise-induced hearing loss: sensorineural, bilateral, symmetric, with a 3-4 kHz notch on audiogram; standard threshold shift defined by OSHA as average shift of 10 dB at 2000, 3000, and 4000 Hz; hearing conservation program triggered at 85 dBA 8-hour TWA.

• Heat stress: measure WBGT; acclimatization takes 1-2 weeks and is a key preventive measure; heat stroke (core temp typically >40 C with CNS dysfunction) is a medical emergency requiring rapid cooling; heat exhaustion shows heavy sweating, weakness, and volume depletion.

• Biological monitoring and medical surveillance: choose biomarkers with known half-life and exposure relationship (e.g., urinary metabolites, blood lead, cholinesterase for organophosphates); surveillance is required when exposure exceeds action levels or when a specific regulation mandates it.

• Occupational cancer and sentinel events: recognize clusters, report notifiable occupational diseases, and use the hierarchy of exposure registries; bladder cancer (aromatic amines), angiosarcoma of liver (vinyl chloride), leukemia (benzene), and mesothelioma (asbestos) are classic occupational associations.

• Return-to-work and fitness-for-duty: assess functional capacity against job demands, consider reasonable accommodation, and document restrictions; opioid or sedative use, uncontrolled seizures, and significant cardiopulmonary limitation are common grounds for restriction in safety-sensitive roles.