Tracing industrial sulfur contributions to atmospheric sulfate deposition in the Athabasca oil sands region, Alberta, Canada

► Atmospheric sulfate deposition rates are elevated on industrial sites. ► δ18O values of sulfate (SO4) at high deposition rates are isotopically distinct. ► δ18O values are suitable for quantifying industrial sulfur (S) contributions to SO4 deposition. ► δ34S values of SO4 indicate reduced S emissions from tailing ponds.