Embryo/larval toxicity and transcriptional effects in zebrafish (Danio rerio) exposed to endocrine active riverbed sediments

• Published in: Environmental science and pollution research international 2020-04, Vol.27 (10), p.10729-10747
• Main Authors: Viganò, Luigi, Casatta, Nadia, Farkas, Anna, Mascolo, Giuseppe, Roscioli, Claudio, Stefani, Fabrizio, Vitelli, Matteo, Olivo, Fabio, Clerici, Laura, Robles, Pasquale, Dellavedova, Pierluisa
• Format: Article
• Language: English
• Subjects: Antioxidants; Apoptosis; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Biotransformation; Contaminated sediments; Contamination; Correlation analysis; CYP1A protein; Cytochrome P450; Danio rerio; Disruption; Earth and Environmental Science; Ecotoxicology; Embryos; Endocrine disruptors; Environment; Environmental Chemistry; Environmental Health; Environmental science; Estrogen receptors; Estrogens; Exposure; Genes; Genotoxicity; Hatching; Insulin-like growth factor II; Larval development; Oxidative stress; Principal components analysis; Research Article; River beds; Rivers; Sediment chemistry; Sediment pollution; Sediment samplers; Sediments; Sensitivity analysis; Signal transduction; Thyroid; Thyroid gland; Thyroid transcription factor 1; Toxicity; Toxicity testing; Transcription; Triclosan; Waste Water Technology; Water Management; Water Pollution Control; Zebrafish
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-019-07417-8

Sediment toxicity plays a fundamental role in the health of inland fish communities; however, the assessment of the hazard potential of contaminated sediments is not a common objective in environmental diagnostics or remediation. This study examined the potential of transcriptional endpoints investigated in zebrafish ( Danio rerio ) exposed to riverbed sediments in ecotoxicity testing. Embryo-larval 10-day tests were conducted on sediment samples collected from five sites (one upstream and four downstream of the city of Milan) along a polluted tributary of the Po River, the Lambro River. Sediment chemistry showed a progressive downstream deterioration in river quality, so that the final sampling site showed up to eight times higher concentrations of, for example, triclosan, galaxolide, PAH, PCB, BPA, Ni, and Pb, compared with the uppermost site. The embryo/larval tests showed widespread toxicity although the middle river sections evidenced worse effects, as evidenced by delayed embryo development, hatching rate, larval survival, and growth. At the mRNA transcript level, the genes encoding biotransformation enzymes ( cyp1a , gst , ugt ) showed increasing upregulations after exposure to sediment from further downstream sites. The genes involved in antioxidant responses ( sod , gpx ) suggested that more critical conditions may be present at downstream sites, but even upstream of Milan there seemed to be some level of oxidative stress. Indirect evidences of potential apoptotic activity ( bcl2/bax