Health Risks
PFAS and Public Health: Why You Should Care About Contamination
The importance of addressing the use of PFAS in industry and their presence in our environment comes down to the potential risks that they pose to public health. Of the thousands of existing PFAS, only a handful have been studied extensively enough to determine their effects on human health. However, the research available indicates that these chemicals are linked to varying levels of toxicity.
Observed impacts of exposure to various PFAS on human health, including levels of certainty and developmental/birth effects. (European Environment Agency, eea.europa.edu)
How Certain are We? Obstacles to PFAS Research
The sheer number of existing PFAS makes categorizing and studying them in our environment a daunting task alone. When it comes to researching their impacts on the human body, even more complications and variables arise. Since PFAS have infiltrated so many corners of our environment, there are that many more avenues through which the chemicals can make their way into our bodies. Consumer products generally pose less of a threat - for example, you shouldn't be worried that wearing your waterproof raincoat will give you cancer. We become most at risk of accumulating harmful amounts of PFAS in our blood when they enter directly into our bodies - through the air we breathe, food we eat, and water we drink. However, the circumstances of such exposure can be highly variable; the amount of time someone is exposed, the concentration of PFAS in the source, and the route through which it entered their body can all ultimately affect the types of health issues which may result. These affects may also differ based on a person's age, sex, health status, genetic predispositions, etc.
What We Do Know
Of the chemicals which have been most widely studied, PFOA (perlfuorooctanoic acid) and PFOS (perfluorooctane sulfonate), including other long-chain PFAS (see The Science page) top the list. Referred to by some researchers as "legacy PFAS," these long-chain PFAS were federally phased out of U.S. manufacturing industries between 2002-2016. However, their longevity in the environment resulting from decades of contamination means that they continue to pose a very real threat of human exposure. Additionally, the concerning toxicological data which has resulted from existing research should add extra incentive to expand the effort to study other groups of PFAS.
Developmental and Birth Effects
Some of the more definitive (but alarming) results which have come out of PFAS research are those that pertain to their effects on developmental health in infants. Increasing evidence is indicating that they can be passed down from mother to child, with PFAS being found in breastmilk and the blood of placentas and umbilical cords. Different concentrations of PFOS in the prenatal blood screenings of mothers have been linked to various declines in the antibody counts and immune system functionings of their children. Both prenatal and infant/childhood exposure to some PFAS have been linked to decreased immune responses to some infections, as well as to certain vaccines. Exposure in the mother before or during pregnancy may also increase the risk of abnormal growth in utero, leading to lower birth weights or increased risk for the mother.
Diseases and Cancers
Studies conducted on populations (including workers who's industries use PFAS in their manufacturing) subjected to varying degrees of PFAS exposure have brought about results linking the chemicals to increased instances of some diseases and cancers. The evidence at hand suggests PFAS can suppress/effect thyroid function, particularly in women. Some studies have linked PFAS exposure to the development of thyroid disease, to which women also appear to be more susceptible. The effects of PFAS on thyroid function raises numerous concerns for metabolic and developmental/hormonal stability.
The liver is a particularly vulnerable target for PFAS because of its function - to detoxify our blood and regulate chemicals throughout the human body. As such, the liver becomes the primary storage area for long-chain PFAS such as PFOA and PFOS in the body. There is a substantial amount of evidence linking short and long-term PFAS exposure to altered liver enzyme function. Some research has also linked certain long-chain PFAS to increased instances of liver disease and cancer, particularly in cohorts of highly exposed industrial workers.
There is a solid base of evidence to suggest that PFAS exposure can be linked to a variety of negative effects on human kidney function. Such links have been made specifically to chronic kidney disease in both adults and children. Similar findings have indicated a possible relationship between long-chain PFAS and uric acid buildup, which can lead to bone and joint damage. Associations have also been made between PFAS exposure and higher instances of kidney cancer and kidney cancer mortality. The same is true for testicular cancer, which.