A multi-isotope approach for estimating industrial contributions to atmospheric nitrogen deposition in the Athabasca oil sands region in Alberta, Canada

Industrial nitrogen (N) emissions in the Athabasca oil sands region (AOSR), Alberta, Canada, affect nitrate (NO3) and ammonium (NH4) deposition rates in close vicinity of industrial emitters. NO3-N and NH4-N open field and throughfall deposition rates were determined at various sites between 3 km and 113 km distance to the main oil sand operations between May 2008 and May 2009. NO3 and NH4 were analyzed for delta N-15-NO3, delta O-18-NO3, Delta O-17-NO3 and delta N-15-NH4. Marked differences in the delta O-18 and Delta O-17 values between industrial emissions and background deposition allowed for the estimation of minimum industrial contributions to atmospheric NO3 deposition. delta N-15-NH4 values also allowed for estimates of industrial contributions to atmospheric NH4 deposition. Results revealed that particularly sites within similar to 30 km radius from the main oil sands developments are significantly affected by industrial contributions to atmospheric NO3 and NH4 deposition. (C) 2013 Elsevier Ltd. All rights reserved.