Understanding human exposure to benzotriazoles (BZTs) and benzotriazole UV-stabilizers (BUVs) in the Australian population using human biomonitoring

Benzotriazoles (BZTs) are a class of chemicals consisting of the parent benzotriazole compound and its methylated, chlorinated and hydroxylated derivatives. Benzotriazole UV-stabilizers (BUVs) are another class specific only to compounds with the same benzotriazole backbone attached to a phenolic moiety that is substituted with differing functional groups. BZTs are high-production chemicals primarily used as metal corrosion inhibitors while BUVs are used as UV-absorbers to protect products from UV exposure-related degradation. Both groups have been reported to exhibit toxicity in different in vitro and in vivo models while BUVs are also known for their bio-accumulative properties due to their high lipophilicity. BZTs are regarded as emerging pollutants (EPs) and some of them have drinking water regulations imposed in Australia. Several BUVs have been listed as substances of very high concern (SVHCs) and just recently, UV-328 was the first non-halogenated compound to be considered under Annex A of the Stockholm Convention on Persistent Organic Pollutants (POPs). Information regarding human exposure to BZTs and BUVs is very limited worldwide and in Australia, there is basically none. BZT exposure is commonly assessed by analysing urine samples using LC-MS while BUV exposure has been proposed to be evaluated using blood, bile and faeces samples with GC-MS. Overall, there’s no information regarding Australian population exposure to these chemicals, specifically, drivers of exposure, exposure trends and where does the Australian population sit in this space. This PhD project aims to understand the Australian population exposure to BZTs and BUVs by developing methods for analysis and conducting systematic studies on human exposure.