Oral Presentation Society of Environmental Toxicology and Chemistry Australasia 2021

Microplastic contamination of an unconfined groundwater aquifer in Victoria, Australia (#88)

Subharthe Samandra 1 2 , Julia M. Johnston 2 , Julia E. Jaeger 1 , Bob Symons 1 , Shay Xie 1 , Matthew Currell 3 , Amanda V. Ellis 4 , Bradley O. Clarke 2
  1. Eurofins Environment Testing Australia & New Zealand, Melbourne, Victoria, Australia
  2. School of Chemistry, Australian Laboratory for Emerging Contaminants , The university of Melbourne, Melbourne, Victoria, Australia
  3. School of Engineering, Royal Melbourne Institute of Technology , Melbourne, Victoria, Australia
  4. Department of Chemical Engineering, The University of Melbourne, Melbourne, Victoria, Australia

This is the first study to show microplastics contamination in groundwater from rural Victoria, Australia. Microplastics are often reported in biotic and abiotic environments, but little is known about their occurrence in groundwater systems. In this study, eight of the most commonly found microplastics in the environment (polyethylene, PE; polystyrene, PS; polypropylene, PP; polyvinyl chloride, PVC; polyethylene terephthalate, PET; polycarbonate, PC; polymethylmethacrylate, PMMA; and polyamide, PA) were analysed in triplicate groundwater samples (n = 21) from five sampling sites across seven sealed groundwater monitoring bores from Bacchus Marsh (Victoria, Australia) using Agilent’s novel Laser Direct Infra-Red (LDIR) imaging system. Microplastics were detected in all samples, with PE, PP, PS and PVC detected in all seven bores. The average size of the microplastics identified was 89 ± 0.55 µm from 18 to 491 µm. The average number of microplastics detected across all sites was 38 ± 8 microplastics/L, ranging from 16 to 97 particles/L. PE and PVC in total contributed to 59% of the total sum of microplastic detected. PE was consistently detected in all seven bores (average: 11 particles/L), while PVC was more pronounced in a bore adjacent to a meat processor (52 particles/L) compared to that of its overall average of 12 particles/L. A statistically significant positive correlation was observed between PVC and PS (R = 0.934, p = <0.001). As this study collected samples from sealed groundwater bores, the most probable avenue for microplastics was permeation through soil. Therefore, to further understand the fate and transport of microplastics within a groundwater system, it is necessary to analyse a greater range of groundwater bores not only from Australia but throughout the world.