Profiling the endocrine disrupting properties of triazines, triazoles and short-chain PFAS.

ABSTRACT

Persistent, mobile and toxic (PMT) compounds released to the environment are likely to pollute drinking water sources due to their slow environmental degradation (persistency) and high water solubility (mobility). The aim of the present study was to create in vitro hazard profiles for sixteen triazoles, nine triazines and eleven PFAS based on their agonistic and antagonistic effects in estrogen receptor (ER), androgen receptor (AR) and thyroid hormone receptor (TR) reporter gene assays, their ability to bind human transthyretin (TTR), and their effects on steroidogenesis. The triazole fungicides tetraconazole, bitertanol, fenbuconazole, tebuconazole, cyproconazole, difenoconazole, propiconazole, paclobutrazol and triadimenol had agonistic or antagonistic effects on the ER and AR. Difenoconazole, propiconazole and triadimenol were also found to be TR antagonists. The triazine herbicide ametryn was an ER, AR and TR antagonist. The same nine triazole fungicides and the triazines atrazine, deethyl-atrazine and ametryn affected the secretion of steroid hormones. Furthermore, PFAS compounds PFBS, PFHxS, PFHxA, PFOS, PFOA and GenX and the triazoles bitertanol, difenoconazole and 4-methyl benzotriazole were found to displace T4 from TTR. These results are in line with earlier in vitro and in vivo studies on the endocrine disrupting properties of triazines, triazoles and PFAS. The present study demonstrates that this battery of in vitro bioassays can be used to profile compounds from different classes based on their endocrine disrupting properties as a first step to prioritize them for further research, emission reduction, environmental remediation and regulatory purposes.