Biomarkers for assessing body burden from exposure to toxic air pollutants

The body burden of airborne toxic chemicals resulting from all routes of human exposure cannot be determined by traditional techniques, which only measure the concentrations of these chemicals in air. Human exposure has been related to biological endpoints in several studies using biochemical markers. It may be possible to relate human exposure to breath concentrations, biological endpoints, and ultimately body burden, using noninvasive techniques (breath and urine analysis). Preliminary chamber studies in their laboratory have shown that subjects exposed to selected air pollutants at near-normal ambient levels eliminate them in breath at measurable decay rates. This study seeks to determine expired-air decay rates for selected air pollutants and their blood/breath partition coefficients. Such data could lead to correlations with the primary biomarkers directly related to biological endpoints (e.g., DNA or protein adducts, glutathione conjugates, chromosomal damage, immune function impairment). If an association can be established between noninvasive data and primary biomarkers, then an integrated approach should be possible for measuring biological endpoints noninvasively by monitoring human expired breath or urine.