Suspended solids-associated toxicity of hydraulic fracturing flowback and produced water on early life stages of zebrafish (Danio rerio)

Hydraulic fracturing flowback and produced water (HF-FPW), which contains polyaromatic hydrocarbons (PAHs) numerous other potential contaminants, is a complex wastewater during the recovery of tight hydrocarbon resources. Previous studies on HF-FPW have demonstrated various toxicological responses aquatic organisms as consequences combined exposure to high salinity, dissolved organic compounds particle/suspended solids-bound pollutants. Noteworthy lack illustrating potentially toxic effects FPW suspended solids (FPW-SS). In this study, we investigated acute sublethal toxicity filtered from six authentic sample collected two wells, using sediment contact assay based early-life stages zebrafish (Danio rerio). PAHs profiles tests provided initial information potency samples. Upon mixture at selected doses (1.6 3.1 mg/mL), results showed adverse in larval zebrafish, revealed by increased Ethoxyresorufin-O-deethylase (EROD) activity. Transcriptional alterations were also observed xenobiotic biotransformation (ahr, pxr, cyp1a, cyp1b1, cyp1c1, cyp1c2, cyp3a65, udpgt1a1, udpgt5g1), antioxidant response (sod1, sod2, gpx1a, gpx1b) hormone receptor signaling (esr1, esr2a, cyp19a1a, vtg1) genes. The that even separated aqueous mixture, FPW-SS can induce organisms' early life stages. Since could bottom natural wetland acting continuous source current findings imply likelihood long-term environmental risks polluted sediments ecosystems due spills.