Airborne Concentrations and Surface Accumulations of Ionic Substances: Distribution Across an Electronic Equipment Room.

In previous studies we have measured the airborne concentrations and surface accumulation rates of ionic substances at electronic equipment installations. While surface accumulation rate measurements were distributed across the equipment room, the size and cost of air sampling equipment that is required to make a size dependent analysis of concentrations limited such sampling to one indoor location at each site. In this study we have used personal air sampling pumps coupled with cassette mounted Teflon filters to collect total suspended particulates at a location in Newark, NJ. Ten samplers were deployed at locations across the equipment room floor adjacent to equipment frames that were previously shown to have the 5 highest and 5 lowest overall surface accumulation rates of sulfate, nitrate, and chloride among the 25 frames for which measurements were made. The results demonstrate that: (1) the variation in surface accumulation rates cannot be accounted for by the variation in airborne concentrations (the eight examined correlation coefficients ranged from -0. 48 to 0.32 except for one coefficient of 0.73); (2) the size classifying air sampler used previously reasonably represents the airborne concentrations of ionic substances across the entire equipment area.