Occupational Health, Industrial Hygiene, and Health Surveillance
Industrial hygiene
Industrial hygiene follows anticipation, recognition, evaluation, and control of workplace exposures. Identify agents such as noise, dust, solvents, metals, heat, and biological hazards. Evaluate exposure using sampling and occupational exposure limits such as TLVs or PELs. Control exposures using the hierarchy of controls before relying on PPE.
Health surveillance
Health surveillance is targeted to specific hazards: audiometry for noise, spirometry for dust, blood lead for lead exposure, and skin checks for dermatitis. It includes pre-employment, periodic, and exit examinations as appropriate. Results are confidential and used to detect work-related health effects and fitness-to-work issues. Health surveillance does not replace exposure control.
Worked example
A worker is exposed to 95 dBA. Baseline audiometry is followed by periodic testing. Noise controls should come first: engineering changes, enclosures, and maintenance; administrative controls and hearing protection follow. If audiometry shows a shift, reassess exposure and controls. The reasoning is that surveillance detects harm but does not prevent it.
Traps that cost marks
Treating health surveillance as a substitute for control, breaching confidentiality, doing only pre-employment tests, and ignoring non-occupational causes are common errors. Do not assume an exposure limit means zero risk.