THE state government has released more information after Echo News raised concerns state and federal departments are ignoring how toxic chemicals once used in firefighting foams ended up in dolphins and other animals in the Swan River.
A statement released by Environment Minister Stephen Dawson on Tuesday, December 19 said the state government was committed to identifying and managing the presence of environmental contamination from per- and poly-fluoroalkyl substances (PFAS) in WA.
Where did toxic chemicals come from? (Echo News, December 16) said state and federal knew PFAS had been found in dolphins living in the Swan River following the release of an SA EPA report earlier this year, which said its preliminary findings showed Swan River dolphins had some of the highest concentrations of perfluorooctane sulfonate (PFOS) – a PFAS substance – found in marine mammals worldwide.
Mr Dawson’s statement, which said PFAS can accumulate in the bodies of fish, animals and people and have been shown to be toxic to some fish and animal species, did not mention dolphins but did talk about testing black bream, blue swimmer crabs and also western school prawns.
His statement said PFAS were emerging contaminants, which meant knowledge of their ecological and human health effects was still evolving.
The government’s full position statement said the Department of Biodiversity, Conservation and Attractions (DBCA) undertook a screening assessment of PDAS in surface waters at 20 routine monitoring sites throughout the swan Canning Estuary and at 26 sites within its sub-catchments in December 2016.
The statement said PFAS were detected at all locations though water quality at all 20 routine monitoring sites in the estuary, and all but two of the sub-catchment sites, met the health based guidance values for recreational water.
“Results for PFOS and PFHxS combined at these 44 sites ranged between 0.0003 and 0.11 micrograms a litre,’’ the statement said.
“The two sub-catchment sites which exceeded the health based guidance value for PFOS and PFHxS combined in recreational water (of 0.7 micrograms per litre) were the Perth Airport north and south main drains, recording concentrations of 5.1 and 1.0 micrograms a litre, respectively.
“Sampling was repeated in June 2017 and PFAS were again detected at all sites, with similar results for PFOS and PFHxS in the two Perth Airport sub-catchments.’’
The areas of the Perth Airport north main drain in state jurisdiction are classified as contaminated – restricted use under the Contaminated Sites Act 2003 while the south main drain is classified as possibly contaminated – investigation required.
“A portion of the drain has now been replaced by a sealed pipe, and most of the remainder is fenced and not accessible to the public.
“The small unfenced section of the south main drain is not considered to be a recreational water body.
“Consequently, the Department of Water and Environment Regulation and WA Department of Health are satisfied that concentrations of PFAS in the south main drain do not pose an unacceptable risk to members of the public, and specific restrictions on use under the Act are therefore not required at present.
“In line with the government’s precautionary approach to the management of PFAS issues, and although Australian health authorities have advised that there is currently no consistent evidence that exposure to PFAS causes adverse human health effects, DBCA undertook preliminary sampling of black bream and blue swimmer crabs in the Swan Canning Estuary in June.
“Analysis of these samples indicates that PFAS concentrations in black bream fillets and blue swimmer crab meat were very low.
“Based on these preliminary data, WA DoH’s standing advice that it is safe to eat fish and crabs from the Swan and Canning rivers remains unchanged.’’
The results of further sampling of black bream, blue swimmer crabs and also western school prawns started in November and throughout the summer are expected to be available early next year.
The press release said it was the state government’s update on PFAS, outlining work already underway to identify and address the persistent pollutants but when Echo News first started reporting on PFAS contamination at Pearce air base in January 2016 all state departments contacted said they were not involved.
Bullsbrook Residents and Ratepayers Association president Anne Sibbel said the association was relieved the WA government had at last provided an official position on the PFAs contamination issue in the state.
“We look forward to ongoing proactive involvement by our state government on this concerning and widespread issue, she said.”
By Anita McInnes