1 research outputs found
Prioritization of Contaminants of Emerging Concern in Wastewater Treatment Plant Discharges Using Chemical:Gene Interactions in Caged Fish
We
examined whether contaminants present in surface waters could
be prioritized for further assessment by linking the presence of specific
chemicals to gene expression changes in exposed fish. Fathead minnows
were deployed in cages for 2, 4, or 8 days at three locations near
two different wastewater treatment plant discharge sites in the Saint
Louis Bay, Duluth, MN and one upstream reference site. The biological
impact of 51 chemicals detected in the surface water of 133 targeted
chemicals was determined using biochemical endpoints, exposure activity
ratios for biological and estrogenic responses, known chemical:gene
interactions from biological pathways and knowledge bases, and analysis
of the covariance of ovary gene expression with surface water chemistry.
Thirty-two chemicals were significantly linked by covariance with
expressed genes. No estrogenic impact on biochemical endpoints was
observed in male or female minnows. However, bisphenol A (BPA) was
identified by chemical:gene covariation as the most impactful estrogenic
chemical across all exposure sites. This was consistent with identification
of estrogenic effects on gene expression, high BPA exposure activity
ratios across all test sites, and historical analysis of the study
area. Gene expression analysis also indicated the presence of nontargeted
chemicals including chemotherapeutics consistent with a local hospital
waste stream. Overall impacts on gene expression appeared to be related
to changes in treatment plant function during rain events. This approach
appears useful in examining the impacts of complex mixtures on fish
and offers a potential route in linking chemical exposure to adverse
outcomes that may reduce population sustainability