Assessing exposure of the Australian population to microplastics through bottled water consumption

The presence of microplastics in the environment is substantially documented; however, the pathways of dietary exposure to microplastics are not yet well understood. This is the first study to document the presence of microplastics in bottled water sold in Australia from commercial outlets. In total, 16 brands of bottled water (Australian Sourced: n = 11, Imported: n = 5) sold in the two largest supermarkets in Australia were analysed in triplicate (n = 48) for the presence of polyethylene, PE; polystyrene, PS; polypropylene, PP; polyvinyl chloride, PVC; polyethylene terephthalate, PET; polycarbonate, PC; polymethylmethacrylate, PMMA; and polyamide, PA. Microplastics were detected in 94% (n = 15) of the samples, with PP (n = 14, 88%), PET (n = 10, 63%), PA (n = 7, 44%), and PE (n = 6, 38%) the most frequently detected. On average, a litre of bottled water contained 13 ± 19 (St Dev) microplastics, ranging from 0 to 80 microplastics/L. The average size of the microplastics identified in this study was 77 ± 22 μm. It was found that bottled water sourced and packaged overseas contained four times as many microplastics compared to bottled water sourced in Australia. It was estimated that in 2017, 28.3% of the Australian population consumed on average 30.8 L of bottled water; therefore, using the result from this study it is estimated that Australians are exposed to 400 microplastics annually through the consumption of bottled water. To understand the total amount of microplastics that Australians could be exposed to through dietary routes, further work is required to observe the presence of microplastics in other beverages and food.