BULLSBROOK residents and former firefighters will probably take little comfort from the Department of Defence’s latest reports on toxic chemicals once used at Pearce air base.
Perfluoroalkyl and polyfluoroalkyl substances (PFAS) use has largely stopped at the air base so the department is mainly dealing with historic contamination and rightly planning for a clean-up operation.
But nothing has been done to check the health of former firefighters, who were exposed to the toxic chemicals every day, or that of Bullsbrook residents near the air base some of whom may have been drinking bore water for many years.
According to Australian health authorities there is no consistent evidence that exposure to PFAS causes adverse human health effects but that is of no comfort to former firefighters and Bullsbrook residents, who may have been exposed to the chemicals.
Dr Peter Spaford from Coalition Against PFAS (CAP) said the lack of clear consistent and internationally aligned information being provided to the Australian community on the potential risks of PFAS was deeply concerning.
CAP said the most extensive and authoritative PFAS human health study to date was the C8 Science Panel which determined probable links to at least six serious human diseases.
The study involved three independent epidemiologists who took blood samples from 69,000 people in the Ohio River Valley.
Their study identified kidney cancer, testicular cancer, thyroid disease, ulcerative colitis, pregnancy-induced hypertension (pre-eclampsia) and high cholesterol as serious diseases which were probably linked to PFOA exposure.
As reported in Toxic chemicals not just a Pearce air base issue, (Echo News, August 25, 2016) information on the enHealth (the Environmental Health Standing Committee of the Australian Health Protection Principal Committee) website said PFOA and PFOS were readily absorbed through the gut, and once the chemicals were in a person’s body it took about two to nine years, depending on the study, before those levels went down by half, even if no more was taken in.
Some of the aqueous film forming foams once used at the air base to put out fires and for training purposes included PFOA, PFOS and PFHxS.
Many countries have phased out the use of PFAS due to their persistence, bioaccumulation and environmental toxicity.
The detailed site investigation report and human health risk assessment reports carried by GHD Pty Ltd established that some of the chemicals have stayed on the base but others have travelled through ground water and surface water supplies ending up in bores used by residents and in the Ki-it Monger and Ellen brooks.
PFAS investigation and management branch assistant secretary Luke McLeod said after an ecological risk assessment was finalised a PFAS management area plan would be put in place.
The reports presented to residents in Bullsbrook on July 24 found PFAS had been detected above the relevant guidelines in on-base soil and groundwater samples but that soil samples collected on residential properties within the investigation area did not detect PFAS above relevant guidelines.
“PFAS was found in groundwater on-base in contaminated areas up to about 14m below ground level,’’ the report said.
“All of the on-base source areas recorded PFAS in exceedance of the health-based guidelines but PFAS was not detected in on-base groundwater 30m below ground level.
“Groundwater samples collected from six residential bores detected PFAS above drinking water guidance values – the department is supplying alternative water to these properties.’’
An update sheet said initial key outcomes showed PFAS exposure risks were ‘low and acceptable’ for children (and adult workers) at the air base childcare centre and for people using Ellen Brook and Ki-it Monger Brook for recreational purposes, including catching and consuming yabbies.
The risks were also ‘low and acceptable’ for people using bore water for showering, swimming pools, irrigation and playing under sprinklers.
By Anita McInnes