Isotopic characterization of nitrate, ammonium and sulfate in stack PM2.5 emissions in the Athabasca Oil Sands Region, Alberta, Canada

► Stack-emitted PM2.5 in the Athabasca oil sands region is isotopically distinct. ► Nitrate in PM2.5 has unique δ18O and Δ17O values suitable for tracing emissions. ► Emitted nitrate in PM2.5 is not mass-independently enriched in 17O. ► Nitrate and ammonium in PM2.5 are often enriched in 15N. ► δ15N of NO3 and NH4 in PM2.5 are suitable tracers for industrial stack emissions.