LAUSR

There are few ambient air measurements of extended lists of carcinogenic polycyclic aromatic hydrocarbons (cPAHs); which are pollutants useful in source identification and significant contributors to cumulative inhalation cancer potency. We present findings from a multi-year ambient air sampling study with comparisons of cancer risk estimates for monitoring sites influenced by a variety of sources based on Minnesota Department of Health guidance. Cancer risks were calculated from raw cPAH measurements and cPAH measurements adjusted by wind direction to reflect the full potential impact of the facility's air emissions. MDH cPAH Guidance was used to calculate additive cancer risks for all cPAHs analyzed in this study, as well as the following priority cPAH groups: the EPA16, the EU15 + 1, the EU7 (ambient air), a scaling to Benzo[a]pyrene, and the polycyclic aromatic hydrocarbons (PAHs) categorized by IARC as carcinogenic. The highest cPAH risks were from the urban mixed source site. Benzo[c]fluorene was the highest contributor to the cumulative inhalation risk. Adjusting cPAH concentrations by wind direction to reflect full source emissions had a large impact on data for the traffic site and the refineries, but less to no difference for the shingle manufacturing sites. If not all cPAHs are analyzed in a monitoring study, the risk estimates from the EU15 + 1 priority PAHs was the closest surrogate to a full suite of cPAHs followed by the use of a multiplier times a surrogate PAH.