Comparison of the Ames Salmonella assay and Mutatox genotoxicity assay forassessing the mutagenicity of polycyclic aromatic compounds in porewater from Athabasca oil sands mature fine tailings
Rea. Madill et al., Comparison of the Ames Salmonella assay and Mutatox genotoxicity assay forassessing the mutagenicity of polycyclic aromatic compounds in porewater from Athabasca oil sands mature fine tailings, ENV SCI TEC, 33(15), 1999, pp. 2510-2516
Citations number
49
Categorie Soggetti
Environment/Ecology,"Environmental Engineering & Energy
The oil sands in the Athabasca region of northeastern Alberta, Canada, repr
esent a significant hydrocarbon resource that is currently exploited by min
ing, followed by separation of bitumen from sand using hot water flotation.
This process generates large quantities of bitumen-contaminated tailings.
Current research involves an assessment of whether the tailings ponds can u
ltimately be converted to biologically productive lakes, with one unresolve
d issue being the toxicity of the polycyclic aromatic compounds (PACs) that
might be released from the tailings. In this paper, we have identified sev
eral polycyclic aromatic hydrocarbons in the porewater from oil sands matur
e fine tailings and have compared the responses of 17 PACs in the Ames and
Mutatox genotoxicity assays. The Mutatox assay was unsuitable as a surrogat
e for the Ames test in this application; poor(50%) concordance between the
hive assays occurred because the mechanism of light emission in the Mutatox
assay is un certain, leading to positive responses that could not be unamb
iguously associated with genotoxicity. Benzo[a]pyrene equivalency factors (
BEFs) in the Ames assay were determined for a large number of PACs, from th
is work and from literature data, to express the genotoxic potencies of env
ironmental mixtures in terms of benzo[a]pyrene equivalent concentrations (B
EQs). In the case of porewater samples obtained from the mature fine tailin
gs, even extracts concentrated 10,000-fold we re below the detection limit
of 1 mu g/L BEQ, consistent with the value of 0.14 mu g/L calculated using
BEFs of PACs identified in the porewater.