%0 Journal Article
%K indoor exposure
%K black carbon
%K I/O Ratio
%K Infiltration Factor
%K Woodsmoke Particles
%A Tracy L Thatcher
%A Thomas W Kirchstetter
%A Christopher J Malejan
%A Courtney E Ward
%B Open Journal of Air Pollution
%D 2014
%N 04
%P 111 - 120
%R 10.4236/ojap.2014.34011
%T Infiltration of Black Carbon Particles from Residential Woodsmoke into Nearby Homes
%V 03
%2 LBNL-1003905
%8 11/2014
%! OJAP
%X <p>In many communities, residential wood burning is the source of a significant fraction of wintertime PM2.5 and produces exposures to nearby residents inside their homes. To evaluate the magnitude of this effect, black carbon particles were measured as a proxy for woodsmoke indoors and outdoors in a community where residential woodsmoke is the only significant particle source. Thirteen indoor/outdoor measurement pairs were obtained at 4 different residences and showed an average indoor/outdoor concentration ratio of 0.78 ± 0.21 for residences without indoor generation. In addition, a time dependent mass balance model was used in conjunction with aethalometer measurements taken over 16 nights at a single residence to estimate an average air exchange rate of 0.26 ± 0.08 h<sup>−1</sup>, an average deposition loss rate of 0.08 ± 0.03 h<sup>−1</sup>, and an average penetration factor of 0.97 ± 0.02. Using a mechanistic approach which utilizes these average values in a steady state model, the predicted average infiltration factor was 0.74 for the residence studied. The high values for both measured I/O ratio and modeled infiltration factor show that residential environments provide inhabitants with relatively little protection from recently generated<br />wood smoke particles.</p>