Selective Uptake and Bioaccumulation of Antidepressants in Fish from Effluent-Impacted Niagara River

The continuous release of pharmaceuticals and personal care products (PPCPs) into freshwater systems impacts the health of aquatic organisms. This study evaluates the concentrations and bioaccumulation of PPCPs and the selective uptake of antidepressants in fish from the Niagara River, which connects two of the North American Great lakes (Erie and Ontario). The Niagara River receives PPCPs from different wastewater treatment plants (WWTPs) situated along the river and Lake Erie. Of the 22 targeted PPCPs, 11 were found at part-per-billion levels in WWTP effluents and at part-per-trillion levels in river water samples. The major pollutants observed were the antidepressants (citalopram, paroxetine, sertraline, venlafaxine, and bupropion, and their metabolites norfluoxetine and norsertraline) and the antihistamine diphenhydramine. These PPCPs accumulate in various fish organs, with norsertraline exhibiting the highest bioaccumulation factor (up to about 3000) in the liver of rudd (Scardinius erythrophthalmus), which is an invasive species to the Great Lakes. The antidepressants were selectively taken up by various fish species at different trophic levels, and were further metabolized once inside the organism. The highest bioaccumulation was found in the brain, followed by liver, muscle, and gonads, and can be attributed to direct exposure to WWTP effluent.