The Definition of Medical Surveillance

Definition of Medical Surveillance

Medical surveillance is the systematic, ongoing health monitoring of workers who are exposed to specific workplace hazards, such as noise, chemicals, dust, metals or radiation. It uses medical exams, questionnaires and tests to detect early signs of work-related illness, so that exposure can be reduced and the worker treated before serious harm develops.

Medical surveillance is different from general health promotion or wellness programs. It is targeted at particular hazards and is meant to check whether workplace controls are actually protecting workers. If several workers show similar early changes, such as hearing loss or rising blood lead levels, that is a sign the controls need to improve.

Many OSHA standards require medical surveillance for workers exposed above set levels. Examples include lead, respirable crystalline silica, asbestos, benzene, cadmium, formaldehyde, bloodborne pathogens and noise. Respirator users also need a medical evaluation before they are fit tested and use a respirator.

Common Medical Surveillance Programs

• Hearing: baseline and annual audiometric testing as part of a hearing conservation program for workers exposed to noise at or above 85 dBA averaged over 8 hours.
• Lead: blood lead level and zinc protoporphyrin testing for workers exposed to lead.
• Silica and dusts: chest X-rays, lung function tests and tuberculosis screening for workers with significant silica exposure.
• Respirator users: medical evaluation to confirm workers can safely wear a respirator. See respiratory protection.
• Hazardous chemicals: blood or urine tests for specific substances, such as benzene or certain solvents.
• Hazardous waste and emergency response: periodic exams for HAZWOPER workers.

Key Elements of a Program

1. Exposure assessment: use air monitoring and industrial hygiene data to decide who needs surveillance.
2. Baseline exam: test workers before or at the start of exposure to create a reference point.
3. Periodic exams: repeat testing at set intervals, often annually.
4. Exit exams: test workers when they leave the job or the exposure ends, where required.
5. Action on results: notify workers of results, review trends and improve controls when problems are found. Some standards require medical removal from exposure.
6. Confidentiality and records: keep medical records confidential and retain them for the required time, often for the duration of employment plus 30 years under OSHA.

Example of Medical Surveillance

A metal fabrication company enrolled its grinders and welders in a hearing conservation program. Annual audiograms showed that three workers in the same shop had developed a standard threshold shift, a measurable drop in hearing, within one year.

The company investigated and found that a new grinding station had raised noise levels and that workers were wearing earplugs incorrectly. It added acoustic panels, provided fit testing for hearing protection and retrained the crew. Follow-up audiograms showed no further shifts in the group.

Frequently Asked Questions: Medical Surveillance

Who pays for medical surveillance?

Under OSHA standards, employers must provide required medical surveillance at no cost to workers, at a reasonable time and place.

Can employers see workers' medical results?

Employers usually receive a written opinion from the physician on fitness for work and any limits, but detailed medical findings unrelated to the exposure are generally kept confidential.

What is the difference between medical surveillance and medical screening?

Screening looks for disease in an individual at a single point in time. Surveillance tracks health over time, often across groups of workers, to see whether workplace exposures are causing harm.