Health Surveillance and Occupational Medicine
Health surveillance is a secondary prevention tool that detects early signs of work-related ill health when exposure cannot be adequately controlled. Understand the difference between surveillance (ongoing, exposure-linked monitoring such as audiometry for noise or spirometry for respiratory hazards) and pre-employment or fitness-for-work assessment. Know that surveillance must be proportionate to risk, voluntary where legally permitted, confidential, and used to trigger workplace action rather than to blame individuals. Familiarize yourself with biological monitoring (measuring the substance or its metabolite in blood or urine) and its advantage in capturing total absorbed dose across routes.
Traps: using health surveillance as a substitute for exposure control; treating a pre-placement medical as surveillance; breaching confidentiality by sharing diagnoses with managers rather than fitness conclusions; and ignoring the need for baseline results before exposure begins.
Rule of thumb: surveillance is indicated when there is a known work-related disease, valid detection methods exist, and early detection benefits the worker. Worked example: noise-exposed workers show a standard threshold shift on audiometry. The correct response is to review the exposure assessment and noise controls and refit hearing protection, not merely to counsel the worker.