Long-lasting risks of so-called 'forever chemicals'
WHAT ARE PFAS CHEMICALS?
* PFAS is the short name for a family of manufactured chemicals used in industry and consumer products since the 1940s
* There are thousands of types of per- and poly-fluoroalkyl substances (PFAS) and they are valued for their heat, water and stain-repelling properties
* They are in a vast range of products including food packaging, make-up, paint, carpet and fabric
* Australia began phasing out certain types of PFAS-containing firefighting foams in 2004 but their use has left a costly legacy of contamination at defence bases and airports
WHY ARE PFAS CHEMICALS PROBLEMATIC?
* PFAS are sometimes referred to as forever chemicals because they are long-lived and don't easily break down
* They are often toxic and can accumulate in plants, including agricultural crops, and in animals, including humans
* Experts say they are ubiquitous, meaning they are found everywhere on earth in air, soil and water
HOW DO PFAS CHEMICALS AFFECT HUMANS?
* Scientists suspect PFAS might pose broad health risks including cancer but research is inconclusive
* The US Environmental Protection Agency cites peer-reviewed scientific studies showing exposure to certain levels of PFAS may lead to increased risk prostate, kidney and testicular cancers
* The EU says PFAS can lead to liver damage, thyroid disease, obesity, fertility issues and cancer
* Australians generally have at least three types of PFAS in their bodies: PFOS, PFOA and PFHxS
* PFOS and PFOA were the active ingredients used in the firefighting foams that have since been phased out; PFHxS was commonly present in the foams as a manufacturing impurity
* The defence department began phasing out its use of foams containing PFOS and PFOA in 2004 with states, territories and other agencies following
* PFOS, PFOA and PFHxS are readily absorbed through the gut and once present in a person's body it takes two to nine years before levels go down by half
WHAT ARE THE ENVIRONMENTAL CONCERNS?
* PFAS have been shown to be toxic to some animals and can bioaccumulate and biomagnify in some wildlife, meaning animals higher up the food chain may accumulate high concentrations in their bodies
* The toxicity, mobility, persistence and bioaccumulation potential of PFAS means they have the potential to cause serious environmental and human harms depending on exposure levels
* PFOS and PFOA are highly persistent and can travel long distances in water and in the air.