Botany Bay near Sydney Airport and the former Caltex refinery site at Kurnell are being investigated for elevated levels of toxins suspected of being linked to numerous cancer cases in Australia and overseas.
A Fairfax Media investigation revealed the St George and Sutherland Shire sites were among 10 in Sydney, 25 in NSW and 90 across the nation that authorities are investigating for elevated levels of per- and polyfluoroalkyl chemicals (PFAS).
At all but a handful of the sites, most residents have been continuing with everyday life, oblivious to the toxic threat that lurks nearby.
The Fairfax Media investigation revealed at least 21 children at a high school in the US have battled cancer through their school years while growing up in a city whose water supply was contaminated with PFASs.
Fairfax Media has previously revealed 50 cancer cases over a 15 year period near the Williamtown air base, an area that has also been contamined with PFAS chemicals from firefighting foam.
The Botany Bay area, near Sydney Airport, is a known hotspot and fishing restrictions were introduced at the end of last year.
The NSW Environment Protection Authority suggested people limit their consumption of eight species of fish caught from Port Botany and the Georges River.
But when approached by Fairfax Media last week, the huddle of fishermen casting their lines into the bay at the mouth of the Cooks River near Brighton-Le-Sands said they were unaware of any guidelines.
“I haven’t been told,” Joey Carino said around sunrise on Wednesday. Soon after he reeled in a silver trevally, one carrier of the chemical spreading through Sydney in food, water, soil and air.
Another Sydney site is the Caltex plant in Kurnell, where preliminary sampling took place last year.
The chemicals were found in surface water beyond the boundary of the site.
Seven military bases across NSW are being investigated, including the Holsworthy Army Barracks.
PFAS detected on and off the barracks, on Macarthur Drive at Holsworthy, but Defence claims exposure pathways are limited as ground and surface water use appears to be minimal in the area.
In 2009, a global agreement was reached to ban one of the chemicals, PFOS, by listing it on the United Nation’s Stockholm Convention.
In the years since, Australia is one of the only countries that has not ratified the decision, which would cost an estimated $39 million. At least 171 countries have agreed to the phase-out, including the UK, Germany and China.
Meanwhile, the federal government is defending multiple class actions from towns across Australia where contamination has occurred.
The Department of Health maintains there is no consistent evidence the toxins cause “important” health effects, in contrast to the US EPA, which has concluded they are a human health hazard that - at high enough levels - can cause immune dysfunction, hormonal interference and certain types of cancer in humans.
The assistant environment minister Melissa Price has responsibility for the issue and was not available for comment on Sunday.
Man-made PFAS chemicals were a lucrative discovery for industry due to their unusual properties: they have been described as “virtually indestructible” in the environment and repel grease, oil and water.
They were manufactured by Fortune 500 company 3M for half-a-century, with the two best known of the family called perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA).
PFOS was the key ingredient in 3M’s popular fabric protector Scotchguard, and was used widely in firefighting foams, food packaging and metal plating. The company also manufactured vast quantities of PFOA for sale to Dupont to produce Teflon cookware.
By the time 3M made the surprise announcement it would be voluntarily exiting the PFAS business in 2000, PFOS had contaminated the blood of more than 95 per cent of the human population along with wildlife in remote corners of the globe.
Due to their long biological half-life, the chemicals take years to exit the body, but average levels in the blood of Australians plummeted about 56 per cent in the decade following the phase-out announcement.
The chemicals still pose a threat in Australia today, mainly because of their use in Aqueous Film Forming Foam (AFFF), a fire retardant manufactured by 3M and used by the military, commercial airports, fire brigades and heavy industry for decades.
In many cases the run-off was flushed directly into the environment following training exercises, polluting the land, food chain and aquifers supplying drinking water.