(CNN) The US Food and Drug Administration confirmed that PFAS chemicals have made their way into the US food supply. On Monday, the FDA publicly acknowledged the initial findings of the agency's investigation into how the "forever chemicals" have been detected in the foods we eat.
PFAS is a family of nearly 5,000 synthetic chemicals that are extremely persistent in the environment and in our bodies. PFAS is short for perfluoroalky and polyfluoroalkyl substances and includes chemicals known as PFOS, PFOA and GenX, sometimes called forever chemicals. These chemicals all share signature elemental bonds of fluorine and carbon, which are extremely strong and difficult to break down in the environment or in our bodies.
These chemicals can easily migrate into the air, dust, food, soil and water and can accumulate in the body. They've been linked to adverse health impacts including liver damage, thyroid disease, decreased fertility, high cholesterol, obesity, hormone suppression and cancer.
In the body, PFAS chemicals primarily settle into the blood, kidney and liver. A study from 2007 by the US Centers for Disease Control and Prevention estimated that PFAS chemicals could be detected in the blood of 98% of the US population.
PFAS chemicals have been used by various industries because of their ability to repel oil and water. They've been manufactured since the 1940s and can be found in non-stick products, stains, paints, cleaning products, food packaging and firefighting foams.
The results of the FDA investigation were initially presented by the agency at the 29th annual European meeting of the Society of Environmental Toxicology and Chemistry in Helsinki last month. Images of the FDA's presentation at the meeting were first obtained by the advocacy group Environmental Defense Fund and published by the Environmental Working Group. The agency confirmed that the images were produced by the FDA.
The findings are now being presented on a newly updated FDA website about PFAS that is to be released this week. The FDA provided CNN with an advance copy of the website text.
"...due to potential health concerns related to these chemicals, the FDA is working to better understand the potential dietary exposure to PFAS" the website will say.
The FDA tested a dairy farm near a US Air Force Base where firefighting foams containing PFAS have been used. According to the FDA, area water samples tested 35 times greater than the current US Environmental Protection Agency health advisory of 70 parts per trillion.
The researchers analyzed 13 samples from the dairy farm, including water, animal feed and five actual milk samples. All 13 samples had detectable levels of PFAS that were of similar chemical structure as what was used in firefighting foams. The FDA said the samples were "determined to be a human health concern and all milk from the farm was discarded."
The FDA noted that even after the cows are no longer exposed to the PFAS contaminated water or feed, the accumulated chemicals can remain in the cow. Just 30 days of eating and drinking contaminated food and water would require 1.5 years for a cow to rid their system of the chemicals.
The FDA also analyzed produce samples from farms close to a PFAS manufacturing plant. The produce was sold at local farmer's markets. According to the FDA, area water wells are known to be contaminated with the PFAS known as GenX. Of the 20 produce samples tested, 16 were leafy greens such as lettuce, cabbage, kale and collard greens. Among those, 15 showed detectable levels of PFAS. According to the FDA, "samples were determined not likely to be a human health concern."
The agency also tested 91 samples of foods collected as part of the FDA's 2017 Total Diet Study. The study is an ongoing FDA program that monitors about 800 contaminants and nutrients that are in the average US diet. As part of this program, the FDA's Center for Food Safety and Applied Nutrition buys, prepares and analyzes about 280 different foods and beverages from across the country four times a year.
According to the website provided to CNN, 10 of 91 foods tested had detectable levels of PFAS, but at levels not considered to be of human health concern.
PFOS and PFOA are the two most-studied PFAS chemicals and have been identified as contaminants of emerging concern by the EPA.
PFOS was voluntarily phased out of production in the United States by 3M, its main manufacturer, starting in 2000. In 2006, PFOA began to be phased out as well. PFOA and PFOS are no longer manufactured or imported in the United States, but similar replacement chemicals like GenX remain.
In April of this year, the EPA announced a new PFAS plan, which included setting a maximum containment level for PFOS and PFOA.
The FDA said it's committed to better understanding the role of PFAS in food. The website notes it established an internal working group this year to evaluate this issue and are working with state partners to establish more local testing laboratories.