title: Effects of exposure to oil sands process-affected water from experimental reclamation ponds on Chironomus dilutus.
abstract: Effective detoxification of oil sands process-affected water (OSPW) is one issue associated with bitumen extraction in the Alberta oil sands. It has been suggested that reclamation ponds can be used to passively treat OSPW, potentially allowing for its safe return to the environment. In this study, OSPW was sampled in two batches (A and B) from the Syncrude Canada Ltd. West In-Pit (WIP) settling pond and from three experimental reclamation ponds - Big Pit, FE5, and TPW. Acute (10 d) and chronic (until adult emergence) exposures of Chironomus dilutus larvae to OSPW were conducted and survival, growth, development, and behavior were assessed. Masses of larvae exposed to WIP-OSPW were 64-77% less than the freshwater control (p < 0.001). Similarly, chronic exposure to WIP-OSPW resulted in significantly (p < 0.05) less pupation than in the freshwater control, with 31% (A) and 71% (B) less pupation of larvae exposed to WIP-OSPW. Rates of emergence were significantly less for larvae exposed to WIP-OSPW, with only 13% (A) and 8% (B) of larvae emerging as adults when exposed to WIP-OSPW, compared to 81% in the freshwater control (p < 0.0001). Pupation and emergence rates were significantly less in TPW than freshwater control (p < 0.05), but there were no differences observed in Big Pit or FE5. Lesser toxicity was observed in reclaimed OSPW compared to fresh OSPW and this coincided with lesser concentrations of NAs. The results presented are consistent with the hypothesis that an organic fraction is the cause of the toxicity of OSPW toward C. dilutus and that OSPW aged in reclamation ponds retains toxicity and therefore, more aggressive, targeted treatment of OSPW is required to accelerate decreases.
authors.affiliation: Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada.
authors.forename: Julie
authors.initials: J
authors.lastname: Anderson
authors.forename: Steve B
authors.initials: SB
authors.lastname: Wiseman
authors.forename: Ahmed
authors.initials: A
authors.lastname: Moustafa
authors.forename: Mohamed Gamal
authors.initials: MG
authors.lastname: El-Din
authors.forename: Karsten
authors.initials: K
authors.lastname: Liber
authors.forename: John P
authors.initials: JP
authors.lastname: Giesy
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D018533:Biomass; D002683:Chironomidae / Q000187:drug effects* / Q000254:growth & development; D004781:Environmental Exposure / Q000032:analysis*; D007814:Larva / Q000187:drug effects; D009821:Oils / Q000737:chemistry*; D061005:Ponds / Q000737:chemistry*; D011679:Pupa / Q000187:drug effects / Q000254:growth & development; D012822:Silicon Dioxide / Q000737:chemistry*; D016019:Survival Analysis; D023382:Toxicity Tests, Acute; D036401:Toxicity Tests, Chronic; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D009821:Oils; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide