Indoor/Outdoor Ratios of Ionic Substances: Comparison of Low and High Activity Work Environments

In previous work, the indoor/outdoor ratios and surface accumulation rates of ionic substances contained in fine and coarse particles were determined at low-occupancy office buildings containing electronic equipment. In recently completed work, the indoor/outdoor ratios of ionic substances were determined over a nine month period at an electronics manufacturing plant. In the low-occupancy office building environment the indoor and outdoor concentrations of ionic substances in fine particles track closely for the major ions, while the concentrations of ions in coarse particles are very low compared to outdoors due to the high efficiency of filtration systems for these particles and the low internal generation rate.