|
Description:
|
The Caspian region and specifically the Apsheron peninsula of Azerbaijan is known to be polluted with a variety of environmental contaminants , making risk assessment difficult . The wetlands of Sumgayit contain particularly complex mixtures of contaminants . Flow cytometry and the micronucleus assay were used to assess chromosomal damage in aquatic turtles and frogs inhabiting contaminated wetlands in Azerbaijan . By evaluating biomarkers that are indicative of somatic effects , elevated chromosomal damage was documented at several sites in Azerbaijan relative to reference sites . Sediment samples were analyzed for polycyclic aromatic hydrocarbons (PAHs ) , organochlorines (OCs ) , and mercury to evaluate contaminant associations with genetic damage . Sediment samples revealed heterogeneous patterns of PAH and mercury concentrations throughout Sumgayit . Significant positive correlations were documented between both PAH and mercury sediment concentrations and chromosomal damage . Population genetic methods were employed to study the effects of long -term chronic contaminant exposure in marsh frogs from Sumgayit . The Sumgayit region has reduced levels of genetic diversity , likely due to environmental degradation . One of the most contaminated sites in Sumgayit , WTP , appears to be a source of new mutations as a result of an increased mutation rate . Finally , the Sumgayit region seems to act as an ecological sink , with levels of gene flow into the region exceeding gene flow out of the region . This study provides not only exposure and biomarker data , but also an integrated method for assessing the cumulative population impacts of contaminant exposure by studying both population genetic and evolutionary effects . The results presented here will be used in conjunction with those of ongoing research involving both wildlife and humans to develop comprehensive ecological and human risk assessments . |