Oral Presentation Society of Environmental Toxicology and Chemistry Australasia 2021

Per-and poly-fluoroalkyl substances (PFAS) in the environment: an approach to define baseline ambient concentrations in relation to land uses (#62)

Paula Sardina 1 , Paul Leahy 1 , Simon Sharp 1 , Minna Saaristo 1 , Andrea Hinwood 1
  1. Environment Protection Authority Victoria, Macleod, VICTORIA, Australia

One challenge for environmental regulators and risk assessors is the identification of PFAS ambient concentrations (concentrations measured with no direct impact from point sources) against which to compare measured levels at impacted sites. In this study, we used multivariate techniques to define categories of PFAS baseline ambient concentrations for rivers influenced by different land uses. PFAS data were obtained from freshwater samples collected at 98 sites across Victoria, Australia. The land use proportion for each site was calculated using the Victoria Land Use Information System (VLUIS). The Australia Land Use and Management (ALUM) Classification was also used to allow the application of the defined categories Australia-wide. Three categories of PFAS baseline ambient concentrations were defined: low, medium and high-PFAS. The low-PFAS category represents sites with ≥85% conservation reserves (corresponds to ALUM primary classes 1 and 2). This category had the lowest ∑PFAS (min – max = <LOR – 0.0002 ug/L), with only PFOS (<LOR – 0.0002 ug/L) detected in samples. The high-PFAS represents sites with ≥50% highly developed land use (mainly urban, ALUM primary class 5). This category had the highest ∑PFAS (0.02 – 0.76 ug/L) and PFOS between 0.0007 – 0.081 ug/L (median = 0.011 ug/L). The medium-PFAS includes sites with >60% agriculture and sites with a mix of land uses (ALUM primary classes 3 and 4). ∑PFAS in this category ranged from 0.006 to 0.13 ug/L, with PFOS between <LOR – 0.048 ug/L (median = 0.001 ug/L). Other PFAS baseline concentrations for each category will be presented at the conference. This study provides the first comprehensive data of PFAS in freshwater environments in Victoria. It also provides streamlined and practical categories of PFAS baseline ambient levels that can be used state- and national-wide for comparison against levels measured from similar environments or when assessing risks at impacted sites.