The Queensland Ambient PFAS Program – spatial and temporal variations of PFAS

In 2019 the Queensland Government commenced a large scale PFAS monitoring program in order to obtain a better understanding of ambient concentrations of PFAS throughout the state (Baddiley et al., 2020). Surface water samples were collected at 55 sites throughout Queensland every two months for one year, supplemented by sediment and biota samples at selected sites. The selected sites encompassed various land use types—conservation, agricultural, forestry and grazing and intensive uses (urban/industrial). Although PFAS are chemical compounds considered to be very widely distributed throughout the environment, the results from this ambient monitoring program indicates that this is not a completely valid statement in Queensland. Of the 55 ambient sites monitored, no PFAS were reported in any water sample collected from eight sites, and only perfluorooctane sulfonate (PFOS) was found at around the limit of reporting (0.0001 μg/L) at a further 21 sites. The highest concentrations and variety of PFAS were found at sites surrounded by urban and industrial land. Seasonal patterns in total PFAS and proportions of PFAS were seen in urban and industrial areas. At some urban sites, the concentration and number of PFAS increased throughout the drier season. In contrast, other sites had the opposite pattern, with the highest total PFAS being recorded in the wet season and decreasing in the dry season. At those locations where the highest concentrations of PFAS were reported, biota sampling was targeted to assess the risk to wildlife. Monitoring data for water and biota at these sites indicate that biota may be accumulating PFOS to levels that would constitute a risk to birds and mammals that consume aquatic organisms (on the basis of Canadian Federal Environment Quality Guidelines (ECCC 2018; HEPA 2020)).

Dr Susi Vardy is a Principal Scientist in Water Quality and Investigations at the Queensland Department of Environment and Science. She has expertise and an interest in environmental chemistry, emerging contaminants and assessment of environmental harm relating to chemical contamination. She is a current member of the National Chemical Working group and Secretary of the Society of Environmental Toxicology and Chemistry, Australasia.