Tyre additive chemicals, tyre road wear particles and high production polymers in surface water at 5 urban centres in Queensland, Australia.

Plastics pollution is a global issue impacting every part of our environment. Tyre road wear particle (TRWP) plastics pollution is thought to be one of the largest pollution sources in urban environments. These plastics are also of concern due to the presence of additive chemicals, incorporated during manufacture, that can be released into the surrounding environment. This study aimed to provide information on concentrations of a range of anthropogenic plastics related pollutants in the Australian environment through a scoping study of surface water in 5 key urban centres around Queensland, Australia. Samples were analysed for a suite of 15 common tyre additive chemicals, TRWPs and 6 common high production polymers, and included the new transformation product of concern 6PPD-quinone which has recent reports of causing mass mortality events in certain aquatic species. The additives were ubiquitously detected (2.9-1440 ng/L) with 6PPD-quinone concentrations lower than in previous studies (<0.05-24 ng/L) and TRWPs detected at 18 of the 21 sites (<MDL to between 690 and 1990 μg/L). Of the high production polymers, polyethylene and polypropylene were detected at the highest concentrations (16-1750 and <0.7-37 μg/L respectively) with profiles highly variable between sites. A traffic related additive profile was determined at 7 sites, which all had nearby traffic related sources. Concentrations of additive chemicals were significantly correlated with average daily traffic volumes (p = 0.006), although concentrations of TRWPs were not correlated. Generally, concentrations were in line with or lower than concentrations in other geographical regions, although it is noted samples were collected during the dry season and further sampling during the tropical wet season would be of interest.