Applications of new technology in molecular epidemiology and their relevance to occupational medicine.

Technological advances in molecular biology over the past 2 decades have offered more complex techniques that can be used to study the role of specific exogenous agents and host variables that cause ill health. Increasingly, studies in human populations use this new technology, combined with epidemiological methods, to shed light on the understanding of the biological processes associated with development of disease. This approach has many potential applications in occupational and environmental medicine (OEM), and some aspects of the work in this growing field are reviewed. An understanding of biochemistry and genetics at the molecular level, specific knowledge on metabolism and mechanisms of action, and epidemiology have become increasingly important for the OEM practitioner. This is necessary to consider the major question of validation and relevance of these molecular biomarkers. As end users, OEM practitioners should also consider the impact of these advances on their practices. For example, the availability of genetic tests to identify susceptible workers raises issues of ethics, individual privacy, right to work, and the relevance of such tests. Several studies have presented data on the association of environmental measurements and various biomarkers for internal and biologically effective dose, genetic polymorphisms, and early response markers. Given the limitations of individual molecular biomarkers in assessing risk to health, and the multifactorial nature of environmental disease, it is likely that such an approach will increase our understanding of the complex issue of mechanisms of disease and further refine the process of risk assessment.