E. N. Kelly et al., PNAS 2009, Oil sands development contributes polycyclic aromatic compounds to the Athabasca River and its tributaries

Proceedings of the National Academy of Sciences, published online before print December 7, 2009; doi: 10.1073/pnas.0912050106

Oil sands development contributes polycyclic aromatic compounds to the Athabasca River and its tributaries

1. Erin N. Kelly^a,
2. Jeffrey W. Short^b,
3. David W. Schindler^a,^*,
4. Peter V. Hodson^c,
5. Mingsheng Ma^a,
6. Alvin K. Kwan^a and
7. Barbra L. Fortin^a
   
   
   ^aDepartment of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9; 
   ^bOceana, 175 South Franklin Street, Suite 422, Juneau, Alaska 99801; and^cDepartment of Biology and School of Environmental Studies, Queen's University, Kingston, ON, Canada K7L 3N6
   

Abstract

For over a decade, the contribution of oil sands mining and processing to the pollution of the Athabasca River has been controversial. We show that the oil sands development is a greater source of contamination than previously realized. In 2008, within 50 km of oil sands upgrading facilities, the loading to the snowpack of airborne particulates was 11,400 T over 4 months and included 391 kg of polycyclic aromatic compounds (PAC), equivalent to 600 T of bitumen, while 168 kg of dissolved PAC was also deposited. Dissolved PAC concentrations in tributaries to the Athabasca increased from 0.009 μg/L upstream of oil sands development to 0.023 μg/L in winter and to 0.202 μg/L in summer downstream. In the Athabasca, dissolved PAC concentrations were mostly <0.025 μg/L in winter and 0.030 μg/L in summer, except near oil sands upgrading facilities and tailings ponds in winter (0.031–0.083 μg/L) and downstream of new development in summer (0.063–0.135 μg/L). In the Athabasca and its tributaries, development within the past 2 years was related to elevated dissolved PAC concentrations that were likely toxic to fish embryos. In melted snow, dissolved PAC concentrations were up to 4.8 μg/L, thus, spring snowmelt and washout during rain events are important unknowns. These results indicate that major changes are needed to the way that environmental impacts of oil sands development are monitored and managed.

*Correspondence e-mail: d.schindler@ualberta.ca

Link to abstract: http://www.pnas.org/content/early/2009/12/04/0912050106.abstract

Link to free, open-access full paper: http://www.pnas.org/content/early/2009/12/04/0912050106.full.pdf+html