Levels of XXXX and dibenzothiophenes in wetland sediments and aquatic insects in the oil sands area of northeastern Alberta, Canada.

@entity2556 @entity2555
An immense volume of tailings and tailings water is accumulating in tailings ponds located on mine leases in the oil sands area of Alberta, Canada. Oil sands mining companies have proposed to use tailings- and tailings water-amended lakes and wetlands as part of their mine remediation plans. @entity2555 ( @entity2556 ) are substances of concern in oil sands tailings and tailings water. In this study, we determined concentrations of @entity2556 in sediments, insect larvae and adult insects collected in or adjacent to three groups of wetlands: experimental wetlands to which tailings or tailings water had been purposely added, oil sands wetlands that were located on the mine leases but which had not been experimentally manipulated and reference wetlands located near the mine leases. Alkylated @entity2556 dominated the @entity2556 profile in all types of samples in the three categories of wetlands. Median and maximum @entity2556 concentrations, especially alkylated @entity2556 concentrations, tended to be higher in sediments and insect larvae in experimental wetlands than in the other types of wetlands. Such was not the case for adult insects, which contained higher than expected levels of @entity2556 in the three types of ponds. Overlap in @entity2556 concentrations in larvae among pond types suggests that any increase in @entity2556 levels resulting from the addition of tailings and tailings water to wetlands would be modest. Biota-sediment accumulation factors were higher for alkylated @entity2556 than for their parent counterparts and were lower in experimental wetlands than in oil sands and reference wetlands. Research is needed to examine factors that affect the bioavailability of @entity2556 in oil sands tailings- or tailings water-amended wetlands.
