%0 Conference Proceedings
%A Tracy L Thatcher
%A Melissa M Lunden
%A Richard G Sextro
%A Susanne V Hering
%A Nancy J Brown
%B Proceedings of the Indoor Air 2002 Conference, Monterey, CA
%D 2002
%G eng
%I Indoor Air 2002, Santa Cruz, CA
%P 846-851
%T The effect of penetration factor, deposition, and environmental factors on the indoor concentration of pm2.5 sulfate, nitrate, and carbon
%V 1
%X <p>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.</p>