ABSTRACT

Acknowledgments .........................................................................................................................281

References .....................................................................................................................................281

Biological monitoring is the assessment of exposure to an agent through the measurement of

biomarker(s) that result from contact with the agent(s). Examples are zinc protoporphyrin in

blood, levels of which increase with lead exposure because lead inhibits the biosynthesis of

heme; protein and DNA adducts of aromatic amines in blood that can both reflect the intensity

of exposure and be correlated with the biologically effective dose; antibodies (Abs) produced

against low-molecular-weight molecules-some chemicals, although not immunogenic in their

own right because of small size and other limitations, may bind to constitutive polymers (such

as host proteins) and become immunogenic, causing the production of specific antibody (Ab).

Alternatively, such exposures may lead to the production of new antigenic determinants through

non-adduct-forming reactions between the agent and selected protein-carrier molecules. Abs can be

made to these modified proteins or to the parent hapten-conjugate. In both cases, the Abs may

remain in the human system much longer than the toxicant that initiated their development.