|Title||The effect of penetration factor, deposition, and environmental factors on the indoor concentration of pm2.5 sulfate, nitrate, and carbon|
|Publication Type||Conference Proceedings|
|Year of Publication||2002|
|Authors||Thatcher, Tracy L., Melissa M. Lunden, Richard G. Sextro, Susanne V. Hering, and Nancy J. Brown|
|Secondary Title||Proceedings of the Indoor Air 2002 Conference, Monterey, CA|
|Publisher||Indoor Air 2002, Santa Cruz, CA|
Indoor exposure to particles of outdoor origin constitutes an important exposure pathway. We conducted an intensive set of indoor particle measurements in an unoccupied house under differing operating conditions. Real-time measurements were conducted both indoors and outdoors, including PM2.5 nitrate, sulfate, and carbon. Because the time-scale of the fluctuations in outdoor particle concentrations and meteorological conditions are often similar to the time constant for building air exchange, a steady state concentration may never be reached. The time-series experimental data were used to determine the effect of changes in air exchange rate and indoor/outdoor temperature and relative humidity differences on indoor particle concentrations. A multivariate regression was performed to investigate the difference between measured indoor concentrations and results from a simple time-dependent physical model. Environmental conditions had a significant effect on indoor concentrations of all three PM2.5 species, but did not explain all of the model variation.