Article

Triclosan: environmental exposure, toxicity and mechanisms of action. J Appl Toxicol

Department of Biological Sciences, Alberta Water and Environmental Science Bldg, 4401 University Dr. W., University of Lethbridge, Lethbridge, Alberta, Canada.
Journal of Applied Toxicology (Impact Factor: 3.17). 05/2011; 31(4):285-311. DOI: 10.1002/jat.1660
Source: PubMed

ABSTRACT Triclosan [5-chloro-2-(2,4-dichlorophenoxy)phenol; TCS] is a broad spectrum antibacterial agent used in personal care, veterinary, industrial and household products. TCS is commonly detected in aquatic ecosystems, as it is only partially removed during the wastewater treatment process. Sorption, biodegradation and photolytic degradation mitigate the availability of TCS to aquatic biota; however the by-products such as methyltriclosan and other chlorinated phenols may be more resistant to degradation and have higher toxicity than the parent compound. The continuous exposure of aquatic organisms to TCS, coupled with its bioaccumulation potential, have led to detectable levels of the antimicrobial in a number of aquatic species. TCS has been also detected in breast milk, urine and plasma, with levels of TCS in the blood correlating with consumer use patterns of the antimicrobial. Mammalian systemic toxicity studies indicate that TCS is neither acutely toxic, mutagenic, carcinogenic, nor a developmental toxicant. Recently, however, concern has been raised over TCS's potential for endocrine disruption, as the antimicrobial has been shown to disrupt thyroid hormone homeostasis and possibly the reproductive axis. Moreover, there is strong evidence that aquatic species such as algae, invertebrates and certain types of fish are much more sensitive to TCS than mammals. TCS is highly toxic to algae and exerts reproductive and developmental effects in some fish. The potential for endocrine disruption and antibiotic cross-resistance highlights the importance of the judicious use of TCS, whereby the use of TCS should be limited to applications where it has been shown to be effective.

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    • "Moreover, their effects on zebrafish embryos were already studied within our group (Domingues et al., 2013, 2010; Oliveira et al., 2009). TCS is a common bactericide used in oral care products, acrylic products, plastic materials and cosmetics (Dann and Hontela, 2011) and has been frequently found in the environment. Singer et al. (2002) observed concentrations ranging from 42 to 213 ng L À 1 downstream of several sewage treatment plants in Switzerland. "
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    • "Despite regulatory action in the 1970s, trace residues of these chemicals are still present at appreciable concentrations in aquatic systems (Conka et al., 2014; Lohmann et al., 2012; Nomiyama et al., 2010). More recently, studies have demonstrated the potential environmental risks posed by emerging organic contaminants (EOCs), including halogenated flame retardants (HFRs), synthetic musks, and methyl triclosan, a degradation product of the common bactericide, triclosan (Brausch and Rand, 2011; Buerge et al., 2003a; Dann and Hontela, 2011; de Wit, 2002; Lam et al., 2009; Nakata et al., 2007; Stapleton et al., 2011). "
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    • "Ricart et al. (2010) used a measure of photosynthetic efficiency to determine a NOEC for the algal community of 0.42 ␮g l −1 . Generally, algae are considered the most sensitive organisms to TCS (Dann and Hontela, 2011). Cyanobacteria, such as Anabaena flos-aquae, are also sensitive with a NOEC of 0.67 ␮g l −1 . "
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