After publication the authors discovered a mistake in the air concentration calculations. PAH air concentrations reported in the original article are therefore incorrect. The calculation error resulted from using incorrect units of the ideal gas constant, and improper cell linkages in the spreadsheet used to adjust air concentrations for sampling temperature. Correcting this error changes air concentrations significantly relative to those reported in the published article. This correction also changes some of the conclusions reported in the original article.
Due to the impact of this correction on the reported findings, all authors retract the original article. The original article was published on March 26, 2015 and retracted on June 29, 2016.