Benzotriazole is anti-estrogenic in vitro but not in vivo

Abstract

24 Benzotriazole (BT) is an anti-corrosive agent, which is well known for its 25 use in aircraft deicing and antifreeze fluids (ADAFs), but is also used in 26 dishwasher detergents. It is highly persistent in the environment, and BT is 27 therefore frequently found in runoff emanating from large airports, as well as in 28 the surrounding groundwater. In addition, BT has recently been found to be 29 ubiquitous in Swiss waste water treatment plant (WWTP) effluents and their 30 receiving waters. However, there is very little in the way of chronic toxicity data 31 available on which to base a sound ecological risk assessment of this chemical. 32 In vitro assays conducted using a recombinant yeast (anti-)estrogen assay 33 indicated that BT possessed clear anti-estrogenic properties. The potency of this 34 chemical was approximately one-hundred times less potent than Tamoxifen, 35 which was used as a positive control. However, a subsequent in vivo study, 36 involving the analysis of vitellogenin induction and somatic indices in adult 37 fathead minnows exposed to BT at concentrations of 10, 100 and 1000 μg/L for 38 two weeks, showed no evidence of anti-estrogenic activity of this compound. The 39 possibility exists that higher concentrations of BT may yet induce the type of 40 activity observed in vitro, although the concentrations used here already far 41 exceed those reported in surface water samples. Further, adverse effects may 42 be observed in fish or other organisms exposed to BT for a longer period than 43 that employed here, although such studies are costly and are unlikely to be 44 included in standard risk assessment procedures. A rigorous investigation of the 45 chronic toxicity of BT is imperative. 46