Source‐Receptor Modeling of PAHs Using Deposition Levels in Winter‐Long Urban Snowpack

Abstract

Undisturbed urban snowpack effectively collects various airborne pollutants (including PAHs), which are deposited within the snowpack through the process of wet and dry deposition. The deposition‐capture and long‐term‐retention properties of snowpacks are utilized in developing a source‐receptor model for PAH source‐apportionment for various PAH species for the city of Sault Ste. Marie, Ontario, Canada. The source‐receptor modeling approach uses the source‐contribution results of a vector of PAHs as a means of characterizing the industrial and urban deposition contributions. The method described in this paper relates air concentration to deposition level without violating source‐receptor modeling's basic premise of linearity in the system response to system emission, thus providing opportunities for source apportionment in air concentrations and deposition levels. The results of source contributions match well the observed deposition levels in a qualitative sense for individual species. Statistical interpretation techniques are used to quantify the source contributions.