Wildfire smoke contains PAHs that, after infiltrating
indoors,
accumulate on indoor materials through particle deposition and partitioning
from air. We report the magnitude and persistence of select surface
associated PAHs on three common indoor materials: glass, cotton, and
mechanical air filter media. Materials were loaded with PAHs through
both spiking with standards and exposure to a wildfire smoke proxy.
Loaded materials were aged indoors over ∼4 months to determine
PAH persistence. For materials spiked with standards, total PAH decay
rates were 0.010 ± 0.002, 0.025 ± 0.005, and 0.051 ±
0.009 day–1, for mechanical air filter media, glass,
and cotton, respectively. PAH decay on smoke-exposed samples is consistent
with that predicated by decay constants from spiked materials. Decay
curves of smoke loaded samples show that PAH surface concentrations
are elevated above background for ∼40 days after the smoke
clears. Cleaning processes efficiently remove PAHs, with reductions
of 71% and 62% after cleaning smoke-exposed glass with ethanol and
a commercial cleaner, respectively. Laundering smoke-exposed cotton
in a washing machine and heated drying removed 48% of PAHs. An exposure
assessment indicates that both inhalation and dermal PAH exposure
pathways may be relevant following wildfire smoke events.