Workplace health surveillance

The concept of workplace health surveillance is new to occupational health and is frequently confused with medical screening. Health screening refers to the early detection and treatment of diseases associated with particular occupations, while workplace health surveillance refers to the removal of the causative factors.

NIOSH defines occupational health surveillance as “the tracking of occupational injuries, illnesses, hazards, and exposures.” The Joint ILO/WHO Committee on Occupational Health at its 12th Session in 1995 defined an occupational health surveillance system as “a system which includes a functional capacity for data collection, analysis and dissemination linked to occupational health programmes”.

Indicators
The workgroup constituted by the Centers for Disease Control and Prevention and NIOSH defined three indicators of workplace health surveillance programme.
 * 1) Availability of easily obtainable statewide data
 * 2) Public health importance of the occupational health effect or exposure to be measured
 * 3) Potential for intervention activities

These indicators are useful in assessing the ongoing policies and preventive measures but they also have some limitations. Among the major limitations are the underreporting of occupational health disorders (very common in most of the undeveloped and developing countries), inability to diagnose the etiology by the occupational health care workers and availability of the data such as municipal death records.

Tools
The most important tool is biomonitoring, which indicates the total body burden of a hazardous chemical in a worker by means of the laboratory investigations using biological specimens like urine or blood. The best practice is to use non-invasive procedures as far as possible for this purpose.

Other tools for workplace health surveillance include physical examinations and epidemiological cohort and case control studies. The pulmonary function testing is the mainstay of early detection occupational lung diseases. This test gives information about severity and staging of asthma and other restrictive lung diseases. The FEV1 is an important screening test. Pulmonary function testing combined with plathysmography reflects a very clear picture of status of lung functions of the subject.

Audiometry remains the mainstay of diagnosis of noise-induced hearing loss which is the most common reported occupational disease in all parts of the world.

Hand arm assessment and dermatological assessments are other important tools for workplace health surveillance.

Confidentiality of information
Most countries have specific regulations for individual health data, which require that the worker be informed if this information is ever shared with any third party. Workers should have the right to access this information whenever they wish.