Exposure to hazard and individual risk: when occupational medicine gets personal

Occupational medicine is grounded on a scientific foundation that blends toxicology and epidemiology. Epidemiologic studies are often less helpful than they could be, both because the variation in response is seldom addressed and because exposure estimates are crude. Biologic variation has usually been treated as "noise" in the system but it is a more basic problem that lends itself to investigation and quantification. To investigate sources of variation requires personal information on factors that may modify the response in individual workers. For research, collection of selected data on nonoccupational personal characteristics of workers has become essential. The collection of personal data is also required for many legitimate functions of an occupational health service that benefit the worker, among them employee assistance, health promotion, health surveillance, and, in many cases, fitness to work evaluation. Collecting important personal data will ultimately benefit the worker and workers in general by better services, better management of individual cases, and better understanding of exposure-related disorders.