Environmental and Occupational Health
Environmental and Occupational Health
This domain tests how environmental exposures cause disease and how workplaces and communities reduce risk. Expect questions on exposure pathways, risk assessment, air and water quality, sanitation, and the hierarchy of controls.
Core rules and concepts
- Risk assessment has four steps: hazard identification, dose-response assessment, exposure assessment, and risk characterization. Risk management then weighs control options with costs, feasibility, and equity.
- Exposure occurs through inhalation, ingestion, dermal contact, and sometimes injection. Dose depends on concentration, duration, frequency, and individual susceptibility.
- The occupational hierarchy of controls is elimination, substitution, engineering controls, administrative controls, and personal protective equipment. PPE is last because it depends on fit and behavior.
- Environmental health interventions include safe water, sanitation, hand hygiene, vector control, clean cookstoves, air-quality standards, and waste management.
- Occupational health includes hazard surveillance, exposure monitoring, health surveillance, injury prevention, and worker participation.
Worked example
Workers in a small furniture workshop are exposed to solvent vapor. The manager proposes respirators for everyone. The better reasoning is to apply the hierarchy: eliminate the solvent, substitute a safer product, install local exhaust ventilation, adjust work practices and exposure time, and then use fit-tested respirators as a last layer. Respirators do not remove the hazard from the workplace and may fail if worn incorrectly.
Traps that cost marks
Do not start with PPE when engineering controls are feasible. Do not confuse environmental protection with occupational safety. Do not treat a hazard as a risk without considering exposure and dose. Remember the healthy-worker effect can make exposed workers look healthier than the general population.