AMBIENT AIR CONCENTRATIONS OF PCDDS, PCDFS, COPLANAR PCBS, AND PAHS AT THE MISSISSIPPI SANDHILL CRANE NATIONAL-WILDLIFE-REFUGE, JACKSON COUNTY, MISSISSIPPI

Our objective was to determine the levels of selected airborne contami nants in ambient air at the Mississippi Sandhill Crane National Wildli fe Refuge, Mississippi, that might be affecting the health of endanger ed cranes living there. Two high-volume air samplers were operated at separate locations on the Refuge during May-September 1991. The sampli ng media were micro-quartz filters in combination with polyurethane fo am plugs. Composite bimonthly samples from each station were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (PCBs), and polycyclic aromatic hyd rocarbons (PAHs). Overall, residue concentrations were low. The toxic PCDD isomer 2,3,7,8-tetra-CDD was not detected, nor was penta-CDD. The re was no difference (P > 0.05) in residue concentrations between stat ions or over time and meteorological parameters were not correlated wi th residue concentrations. Because contaminant levels and patterns may differ seasonally, we recommend that air samples collected during win ter months also be analyzed for these same chemical groups.