Congener-Specific Emissions from Floors and Walls Characterize Indoor Airborne Polychlorinated Biphenyls

To reconcile the federal regulation of material polychlorinatedbiphenyl (PCB) concentrations with recently implemented state regulationsof airborne PCBs, there is a need to characterize the relationshipbetween PCB emissions from surfaces and air concentrations. We hypothesizedthat the magnitude and congener distribution of emissions from floorsand walls fully account for the airborne PCBs measured in rooms constructedduring the height of PCB production and sales. We measured emissionsof PCB congeners from various wall and floor materials using polyurethanefoam passive emission samplers before and after hexane wiping. Ourresults revealed that PCB emissions from flooring adequately predictedthe magnitude and congener distribution of PCBs observed in the roomair. Emissions varied by material within a single building (5 x10(3) ng m(-2) day(-1) fromwood panel walls to 3 x 10(4) ng m(-2) day(-1) from vinyl tile) and within the same room.Yet congener distributions between material emission PCB profilesand room air PCB profiles were statistically similar. Hexane wipingsignificantly reduced PCB emissions (>60%), indicating the importanceof surface films as an ongoing source of airborne PCBs. The magnitudeand congener distribution of material bulk concentrations did notexplain that of material emissions or air concentrations. Passivemeasurements of polychlorinated biphenyl emissions from floors ina university building predict the concentrations of PCBs in room air.

Automated summary

In order to reconcile federal and state regulations for PCB concentrations, the relationship between surface emissions and airborne concentrations needs to be characterized. We found that PCB emissions from flooring materials accurately predicted the magnitude and distribution of PCBs in room air.