Rea. Madill et al., Preliminary risk assessment of the wet landscape option for reclamation ofoil sands mine tailings: Bioassays with mature fine tailings pore water, ENVIRON TOX, 16(3), 2001, pp. 197-208
Chemical and biological assays have been carried out on the "pore water" th
at results from the settling of the tailings that accompany bitumen recover
y from the Athabasca oil sands. Examination of the nonacidic extracts of po
re water by gas chromatography-mass spectroscopy allowed the identification
of numerous two- to three-ring polycyclic aromatic compounds (PACs), to a
total concentration of 2.6 mug/L of pore water. The PACs were biodegraded b
y microflora naturally present in the pore water. Acute toxicity was associ
ated principally with the acidic fraction (naphthenic acids) of pore water
extracts according to the Microtox assay; other work has shown that acute t
oxicity dissipates fairly rapidly. Both individual PACs and concentrated po
re water extracts showed minimal levels of binding to the rat Ah receptor a
nd induced minimal ethoxyresorufin-O-deethylase activity in primary rat hep
atocytes, showing an insignificant risk of inducing monooxygenase activity.
Taken together with previous work showing negligible mutagenic activity of
these extracts, we conclude that it should be possible to develop tailing
slurries into biologically productive artificial lakes. (C) 2001 by John Wi
ley & Sons, Inc.