BIOMARKERS - COMING OF AGE FOR ENVIRONMENTAL-HEALTH AND RISK ASSESSMENT

Biological markers, or biomarkers, reflect molecular and cellular alte rations that occur along the temporal and mechanistic pathways connect ing exposure to toxic chemicals or physical agents and the presence or risk of clinical disease. Biomarkers include a vast array of measurem ents that reflect exposure, effect, and/or susceptibility. The develop ment and validation of potential biomarkers is a long-term endeavor th at proceeds from basic research to pilot human studies to full-scale e pidemiological investigations. The past decade has seen extensive rese arch investigation of biomarkers and the beginnings of their practical application for risk assessment and environmental health management. These potential applications include improved exposure characterizatio n and dose-response assessment, measurement of interindividual variabi lity, and evaluation of causation in toxic tort and environmental liti gation. This paper reviews the biomarker paradigm as applied to xenobi otic exposure in humans, discusses progress toward applying biomarker technology in environmental epidemiology, and summarizes recent biomar ker data for three important environmental and occupational agents, be nzo[a]pyrene, 1,3-butadiene, and acrylamide.