Environmental and Occupational Health
Core concepts
Understand exposure pathways (air, water, soil, food), dose-response, and risk assessment steps (hazard identification, dose-response, exposure assessment, risk characterisation). Know air pollutants (PM2.5, ozone, SO2, NO2), water quality and sanitation, food safety, and waste management. For occupational health, master hierarchy of controls (elimination, substitution, engineering, administrative, PPE), occupational exposure limits (TWA, STEL, ceiling), and common occupational diseases (pneumoconioses, noise-induced hearing loss, dermatitis, musculoskeletal disorders). Understand surveillance, notification, and workers' compensation principles.
Traps
- Placing PPE above engineering controls-PPE is last resort.
- Confusing TWA (8-hour average) with STEL (short-term) and ceiling (never exceed).
- Assuming low-dose always means no risk-many pollutants lack a threshold.
- Confusing biological monitoring with environmental monitoring.
Worked example / rule of thumb
Hierarchy of controls, from most to least effective: elimination, substitution, engineering, administrative, PPE. Rule of thumb: if a question describes a control that relies on worker behaviour (e.g., training, PPE), it is lower in the hierarchy than a control that removes the hazard at source.