Deriving a water quality guideline for protection of aquatic communities exposed to triclosan in the Canadian environment

Triclosan is an antibacterial and antifungal chemical used in a variety of consumer products including soaps, detergents, moisturisers, and cosmetics. Aquatic ecosystems may be exposed to triclosan following the release of remaining residues in wastewater effluents and biosolids. In December of 2017, Environment and Climate Change Canada (ECCC) released a Federal Environmental Quality Guideline (FEQG) report that contained a Federal Water Quality Guideline (FWQG) for triclosan. This guideline will be used as an adjunct to the risk assessment and risk management of priority chemicals identified under the Government of Canada’s Chemicals Management Plan (CMP). The FWQG value for triclosan (0.47?µg/L) was derived by ECCC using a hazardous concentration for 5 percent of species (HC5) from a species sensitivity distribution (SSD). The authors recalculated the FWQG after performing an independent analysis and evaluation of the available aquatic toxicity data for triclosan and compared our results with the ECCC FWQG value. The independent analysis of the available aquatic toxicity data entailed conducting a literature search of all available and relevant studies, evaluating the quality and reliability of all studies considered using thorough and consistent study evaluation criteria, and thereby generating a dataset of high quality toxicity values. The selected dataset includes 22 species spanning five taxonomic groups. An SSD was developed using this dataset following the ECCC approaches. The HC5 from the SSD derived based on our validated dataset is 0.76?µg/L. This HC5 value is slightly greater (i.e., less sensitive) than the value presented in ECCC’s final FWQG.

Authors: Hill KL, Breton RL, Manning GE, Teed RS, Capdevielle M, Slezak B. ; Full Source: Integrated Environmental Assessment and Management. 2018 Mar 12. doi: 10.1002/ieam.4042. [Epub ahead of print]

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