Occurrence of triclosan in plasma of wild Atlantic bottlenose dolphins (Tursiops truncatus) and their environment

Triclosan (2,4,4-trichloro-2'-hydroxydiphenyl ether) a synthetic, broad-spectrum antibacterial agent that is widely used in personal care products and various textiles has been identified in numerous lakes and streams and in human plasma and breast milk around the world. This compound has been found to be acutely toxic to various marine organisms. A 2005 survey of wild bottlenose dolphins (Tursiops truncatus) in Charleston, SC (CHS) (n = 13) and Indian River Lagoon, FL (IRL) (n = 13) revealed the presence of triclosan in their blood plasma. Triclosan was detectable in 31% of the CHS dolphins, with concentrations ranging from 0.12 to 0.27 ng/g wet weight (mean 0.18 ng/g). The range of plasma concentrations for IRL dolphins was 0.025 to 0.11 ng/g wet weight (mean 0.072 ng/g) with 23% of the samples having triclosan at detectable concentrations. Triclosan was further detected through 24-hour composite sampling of primary influents (2800 ng/L and 3400 ng/L) and effluents (190 ng/L) of two waste-water treatment plants (WWTP) in the CHS area in 2008. The triclosan removal efficiencies between influent and effluent samples for the two WWTP were 93% and 94%. Surface waters receiving outflow from the WWTP had triclosan values ranging from 4.9 to 14 ng/L (mean 7.5 ng/L; n = 18). This was the first assessment to report bioaccumulation of triclosan in marine mammals and heightens the need for further monitoring and toxicological assessments in marine mammals.