RESEARCH ARTICLE Occurrence and potential risk of triclosan in freshwaters of São Paulo, Brazil—the need for regulatory actions Cassiana C. Montagner & Wilson F. Jardim & Peter C. Von der Ohe & Gisela A. Umbuzeiro Received: 3 May 2013 /Accepted: 7 August 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract Triclosan (TCS) is a broad-spectrum bactericide, highly toxic to algae, which is released into the environment via wastewater effluents. Predicted no-effect concentrations (PNECs) for aquatic biota have been proposed in the litera- ture, varying from 1.4 to 1,550 ng/L, reflecting contradicting protection goals. In this work, six rivers in the state of São Paulo were monitored for TCS and caffeine, a tracer for untreated sewage disposal, over a period of more than 1 year. From 71 samples analyzed, 32 contained TCS at concentra- tions above the limit of quantification, ranging from 2.2 to 66 ng/L, corresponding to a frequency of exceedance of the lowest PNEC of 86 % (six out of seven sites). No correlation between TCS and caffeine was observed, and one of the reasons for that could be the different use patterns in the local populations. Given the high values found in the investigated rivers, TCS seems to be a strong candidate in the priority list of compounds that should be regulated in Brazil to preserve the aquatic environment. Keywords Triclosan . Caffeine . Emerging compounds . Protection of aquatic life . Surface waters . SPE-LC-MS/MS Introduction Triclosan (TCS, 5-chloro-2-(2,4-dichlorophenoxy)phenol) is a broad-spectrum bactericide used in pharmaceuticals and personal care products of daily use, such as toothpaste, hand soaps, skin creams, mouthwashes, deodorants, household cleaners as well as in functional clothing, such as sports shoes and underwear (Bester 2005). Once in the sewer system, the compound is partially removed in wastewater treatment plants (WWTPs) and finally disposed in the receiving aquatic eco- system (Wick et al. 2011). Previous studies investigated the fate of TCS in different sewage treatment processes and found that the removal efficien- cy depends on the technologies that were applied in the different stages of the treatment (Kookana et al. 2011; Bester 2005; Singer et al. 2002; Sabaliunas et al. 2003; Kuster et al. 2008; Loraine and Pettigrove 2006; Halden and Paull 2005; Venkatesan et al. 2012). This is especially true for countries where the effluent of WWTPs is the main anthropogenic source of contamination into rivers. In China, on the contrary, environ- mental concentrations of the two biocides TCS and triclocarban in river water and sediment were related to the total urban domestic sewage discharge (including untreated wastewater) at the river basin scale (Zhao et al. 2013). In countries like Brazil, where the sanitation system is often deficient and large amounts of raw sewage are released directly into the surface water bodies, the contamination scenario is even more worrying. TCS is a nonvolatile compound, relatively soluble in water, with a log K ow of 4.8 (Fig. 1), which makes it a persistent and bioaccumulative compound (Zhao et al. 2010). In water, it can be transformed into dioxin-like compounds through photolysis in a first-order reaction, with half-lives of a few hours up to several years, depending on the amount of sunlight, pH, and the presence of cosolutes, metal ions, and organic matter (Aranami and Readman 2007). TCS was developed as a bactericide that is effective against a wide range of gram-positive and gram-negative bacteria as Responsible editor: Leif Kronberg C. C. Montagner (*) : G. A. Umbuzeiro Faculty of Technology, University of Campinas, Limeira, SP, Brazil e-mail: montagner@ft.unicamp.br W. F. Jardim Institute of Chemistry, Environmental Chemistry Laboratory, University of Campinas, Campinas, SP, Brazil P. C. Von der Ohe Department of Effect-Directed Analysis, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany Environ Sci Pollut Res DOI 10.1007/s11356-013-2063-5