Volatile toxicants may be present in emissions from mobile and stationary sources as well as in ambient air. Methods for collecting and concentrating volatiles from air samples have been developed. Solid-phase adsorbents were compared in their trapping efficiencies for dichloromethane (DCM), ethylene dibromide (EDB), 4-nitroblphenyl (4-NB), 2-nitrofluorene (2-NF), and fluoranthene (FI). Charcoal and Carbosieve were the most efficient media for retaining DCM, while XAD-4 was the best adsorbent for EDB and the aromatic compounds. Extraction of direct spikes of compounds from adsorbents using supercritical carbon dioxide resulted in greater than 90% recovery of EDB and 60-92% recovery of the aromatics. Integration of trapping and desorption methods with the Salmonella microsuspension bioassay was demonstrated with EDB and 4-NB recoveries from air; chemical analysis and bioassay gave comparable results (within 10%).

The transplacental cytogenetic effects of benzene were studied by using the micronucleus test of polychromatic erythrocytes (PCE) found in both fetal liver and fetal peripheral blood, and were compared with PCE from maternal bone marrow. Timed-pregnant mice received single intraperitoneal doses of benzene (0, 109, 219, 437, or 874 mg/kg bw) on the 14th day of gestation and were sacrificed 21 hr after injection. Benzene elicited a significant increase (P less than 0.01) in the frequency of micronucleated polychromatic erythrocytes (MNPCE) in fetal liver blood cells (0.55 to 1.36%, control 0.18%) at doses of 219 to 874 mg/kg, and in fetal peripheral blood cells (0.49 to 0.58%, control 0.25%) and maternal bone marrow cells (0.53 to 0.70%, control 0.10%) at doses of 437 and 874 mg/kg. The data demonstrate that benzene is a moderate transplacental clastogenic agent, and that the mouse transplacental micronucleus test using fetal liver blood cells is a potentially more sensitive indicator of the genotoxicity of benzene than either fetal peripheral blood or maternal bone marrow cells.

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