Assessment of exposure to pulmonary toxicants: Use of biological markers

The use of biological markers to determine the extent of prior exposures to a specific chemical and to predict future disease outcome holds great promise. Knowledge of the kinetics of formation and breakdown or clearance used to monitor exposures or to predict adverse health outcomes in a quantitative manner. Also required is more quantitative information on the relationship between the markers and resultant disease. Much of the detailed kinetic information must be obtained from animal studies. The use of PBPK modeling can help to integrate the kinetic data into a useful tool for extrapolation of data from high-to-low dose, between different exposure regimes, and from animal data to expected values in humans.