It's the toxic secret that could be contaminating the meat you buy from butchers, supermarkets and fast food restaurants.
A year-long 9News investigation suggests authorities have been giving farmers the wrong advice about managing beef cattle contaminated with cancer causing chemicals found in soil around the Richmond Air Base in NSW.
While few of us think about just what might be in the meat we eat, farmer Alastair McLaren does have an idea - because 9News has been testing his cattle for a year.
It started when his cows were grazing on land 100 metres from the air base in north west Sydney.
It's contaminated with toxic chemicals - knowns as PFAS, PFOS and PFOA - previously used in fire fighting foam.
The results were alarming - with high levels detected across the herd.
The Department of Primary Industries advice is if cattle stay on the land and are given clean town water instead of contaminated ground water, PFAS levels would half within 165 days.
Half of the McLarens' herd remained on the Richmond farm and were switched to expensive town water.
Retesting showed their levels didn't decline at all - but rose.
The other half was sent away to another farm, feeding on clean grass.
Their toxic chemicals levels did decline.
The McLarens didn't want to sell their cattle, but with mounting bills, were forced to.
And they know cattle from contaminated land near bases around the country is entering the food chain.
"Butchers don't buy a rump steak. They buy a whole body of beef," Mr McLaren said.
"It goes into their whole shop.
"They are unsuspecting victims in all of this as everybody else is.
"Consumers need to be more aware so they need to ask questions of where their beef comes from".
9News has obtained a letter sent by the Australian Registered Cattle Breeders Association to the Prime Minister and Defence Minister.
It warns: "Producers in these contaminated areas are told they can sell their animals for human consumption.
"Producers have been told not to consume this meat.
"There is a serious potential threat to the Australian Beef Industry if it becomes public that animals with high levels of PFOS and PFOA are being allowed to enter domestic and export beef markets."
Robert Bilott is a US environmental lawyer, whose 20-year, billion-dollar legal win against chemical firm DuPont is the basis for the new film, Dark Waters.
While our Federal Health Department says there's no link between exposure and serious health effects, Mr Bilott says that goes against scientific evidence.
"That extensive study - done by independent scientists, including studying some 69,000 people drinking the chemical in their water out in West Virginia and Ohio - has confirmed links with serious disease, including two forms of cancer," he said.
No federal minister or department would comment.
Source: 9News https://www.9news.com.au/national/toxic-pfas-meat-farmers-could-have-wrong-advice-managing-cancer-cattle/ab54022b-7f9b-41b6-8450-dd966d2bb4ae