Contribution of biological markers to occupational health.

Occupational diseases are now being assessed at the cellular and molecular levels; this presents new opportunities for prevention and control [Calleman et al., 1978; Ong et al., 1987; Stejskal et al., 1989; Welch and Cullen, 1988; Garry et al., 1989]. The key to these opportunities is the ability to detect biological markers that reflect exposure, response, and susceptibility. Biological markers are not new, however. Biological markers such as blood lead, urinary phenol levels in benzene exposure, and liver function assays have long been used in occupational and public health research and practice. What distinguishes the current generation of markers from previous markers is a greater degree of analytical sensitivity and the ability to describe events that occur earlier in the progression between exposure and clinical disease. There are now new domains of response that were not known to exist 20 years ago. Accompanying this sensitivity is the increased requirement to consider the numerous factors that can influence the appearance of biological markers. It has been observed that all workers with similar exposures do not develop disease or markers indicative of exposure or disease. Various acquired and hereditary host factors are responsible for this variation in responses. The role of assessing the nature and degree of variation between individuals is of paramount importance. Finally, the use of biological markers in occupational health research and practice also brings new ethical and legal considerations into high profile. This paper presents my personal opinions on how biological markers can contribute to occupational health efforts and the new requirements that they bring to the field. As with any technological change, the more we can anticipate the impact, the better our ability to adjust.