Environmental risk assessment of freshwater sediments contaminated with triclosan

Abstract

The purpose of this study was to assess the environmental risk of sediments contaminated with triclosan to thropical aquatic invertebrates. Acute toxicity assays with Chironomus xanthus and chronic toxicity assays with Ceriodaphnia dubia were performed using spiked sediments with environmentally relevant concentrations of triclosan. We obtained a lethal concentration (LC50 96-h) in acute toxicity assays with C. xanthus of 45.26 µg g -1 and a no observed effect concentration (NOEC) and lowest observed effect concentration (LOEC) for C. dubia of 5.78 and 6.94 µg g -1 , respectively. According to equilibrium partitioning theory, these spiked sediment values are equivalent to interstitial water LC50 values of 47.28 μg L -1 for C. xanthus and an LOEC of 7.24 μg L -1 for C. dubia. Our results suggest that sediments contaminated with triclosan represent high risk to freshwater organisms, since this compound has been reported on the order of magnitude of µg g -1 in sediment near discharge of untreated domestic and industrial wastewater.

Potenciais riscos associados à qualidade de sedimentos em zonas de prospecção mineral: Rio da Várzea, Rio Grande do Sul - Brasil

“…Sedimentos contaminados por espécies químicas tendem a ser a maior ameaça para os organismos que residem no interior dos sistemas hídricos já que processos de resuspensão podem liberar novamente os contaminantes associados (BURTON;JOHNSTON, 2010;PUSCEDDU et al, 2017;SANTOLIN et al, 2015;SEDNET, 2004). O aporte de espécies químicas aos sistemas hídricos pode ocorrer naturalmente por meio de processos geoquímicos de intemperismo do material de origem ou como resultado das ações antrópicas (GERBERSDORF et al, 2015;SUNDARARAJAN et al, 2017).…”