It's one of the most beloved foods of all time. When you enjoy its enticing flavor, this toxin is probably as far from your mind as Earth is from the moon. Then along comes this troubling study showing it the worst food by a long shot - carcinogenic and linked to other illnesses.
Food testing by the U.S. Food and Drug Administration found PFAS chemicals in 10 of the 91 foods tested for 16 types of PFASs, some at levels far exceeding the advisory limit for PFOA and PFAS in drinking water; chocolate cake had the highest amounts — 250 times above the advisory limit
Per- and polyfluoroalykyl substances (PFAS) are widely used chemicals that make products water-, oil-, grease- and stain-resistant. The chemicals are also used in firefighting foam
PFAS chemicals take thousands of years to degrade, and are found in groundwater across the U.S.; PFAS chemicals used in food packaging can also migrate into the food
Health effects associated with older, long-chain PFASs such as PFOA, include liver toxicity and malfunction, neurobehavioral effects, reduced birth weight, disruption of immune- and endocrine systems, neonatal toxicity, kidney and testicular cancer, hypothyroidism and more
Research by the U.S. Centers for Disease Control and Prevention published in 2007 found PFAS chemicals in the blood of more than 98% of Americans tested
This article was previously published June 18, 2019, and has been updated with new information.
Per- and polyfluoroalykyl substances1,2 (PFAS) are widely used chemicals that make products water-, oil-, grease- and stain-resistant. The chemicals are also used in firefighting foam. One type, perfluorooctanoic acid or PFOA, is commonly found in older nonstick cookware.
PFOA and its cousin perfluorooctanesulfonic acid (PFOS) are associated with a wide array of health problems, including cancer, immune and thyroid dysfunction, low birth weight and more.3 Disturbingly, because PFAS chemicals take thousands of years to degrade, and are found in groundwater across the country,4,5 they've become a significant environmental threat.
Research6 by the U.S. Centers for Disease Control and Prevention published in 2007 found PFAS chemicals in the blood of more than 98% of Americans tested. And, while concentrations of some PFAS (including PFOA and PFOS) declined by 10% to 32% between 1999 and 2004, another PFAS called PFNA doubled, resulting in a net increase.
The decline of PFOA and PFOS can be explained by the fact that both have been phased out, PFOS starting in 2000 and PFOA in 20067,8 Still, due to their persistence in the environment, they're still showing up in the strangest places.
Sharon Lerner, a reporting fellow at The Investigative Fund and an investigative journalist for The Intercept and other major media outlets, has written extensively about PFAS and the industry's attempts to cover up the damage.9
Testing Reveals PFAS in US Food Supply
Research10,11 published in 2017 revealed 33% of fast food wrappers and containers contain fluorine, which suggests perfluorinated chemicals (PFCs) were used to give the paper that slick surface, and earlier studies12,13,14 have confirmed fluorinated chemicals can migrate from the packaging into the food.
Now, food testing by the U.S. Food and Drug Administration (performed in 2017 as part of its Total Diet Study15 and presented16 at the 2019 meeting of the Society of Environmental Toxicology and Chemistry) reveals PFAS chemicals are in the U.S. food supply,17,18,19,20,21 and at levels far exceeding the advisory limit for PFOA and PFAS in drinking water (there's currently no limits in food).
Of the 91 foods tested for 16 types of PFAS, 10 were found to contain the chemicals.22 As reported by PBS:23
"The levels in nearly half of the meat and fish tested were double or more the only currently existing federal advisory level for any kind of … PFAS. The level in the chocolate cake was higher: more than 250 times the only federal guidelines, which are for some PFAS in drinking water …
PFOS, an older form of PFAS no longer made in the U.S., turned up at levels ranging from 134 parts per trillion to 865 parts per trillion in tilapia, chicken, turkey, beef, cod, salmon, shrimp, lamb, catfish and hot dogs. Prepared chocolate cake tested at 17,640 parts per trillion of a kind of PFAS called PFPeA.
The FDA presentation also included what appeared to be previously unreported findings of PFAS levels — one spiking over 1,000 parts per trillion — in leafy green vegetables grown within 10 miles (16 kilometers) of an unspecified eastern U.S. PFAS plant and sold at a farmer's market."
Dairy Farm Near Air Force Base Forced to Ditch Toxic Milk
The FDA also reported that samples of drinking water and milk from cows raised on a farm near a U.S. Air Force base that uses PFAS-containing firefighting foam were found to contain disturbing amounts of the chemicals.
Drinking water contained 35 times more PFAS than the current health advisory level set by the U.S. Environmental Protection Agency (EPA), which is 70 parts per trillion (ppt).24 The milk contained high enough amounts it was deemed a human health concern, resulting in all milk from the farm being discarded.
In humans, the serum elimination half-life of PFOA ranges between 2.325,26 and 3.8 years,27 and for PFOS between 4.8 to 5.4 years.28 Similarly, it takes a long time for exposed cows to start producing clean milk. As reported by CNN Health:29
"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."
April 25, 2019, the EPA released draft interim guidance for groundwater contaminated with PFOA/PFOS above 70 ppt, which is a "key component of the agency's PFAS Action Plan," according to the press release.30 While that's great news, it seems clear we also need regulations for PFAS contamination in food and not just drinking water.
Sewage Sludge — A Major Source of PFAS on Farms
As recently reported by The Intercept,31 sewage sludge appears to be another major source of these toxic, persistent chemicals. Documents32 obtained by The Intercept reveal 44 samples of sewage sludge tested by the Maine Department of Environmental Protection all contained at least one PFAS chemical, and "In all but two of the samples, the chemicals exceeded safety thresholds for sludge that Maine set early last year."
Maine's tolerance levels for PFAS are set at 2.5 parts per billion (ppb) for PFOA, 5.2 ppb for PFOS, and 1,900 ppb for PFBS. Mike Belliveau, executive director of the Environmental Health Strategy Center in Portland, told The Intercept these levels are "probably about 10 times weaker than they should be," adding, "Even low parts-per-billion levels of PFAS in sludge can threaten the health of the food supply."
How Do PFAS Get Into the Food Supply?
At present, authorities do not know exactly how the chemicals are entering the food supply, but there are several possibilities, and it's likely to be a combination of factors. One is that the chemicals are leaching from food packaging.
Another theory is that when biodegradable packaging in which PFAS are used are composted, the chemicals enter the food chain via the compost.33,34 As noted in study35 published online May 29, 2019:
"The loads and leachability of 17 perfluoroalkyl acids (PFAAs) were analyzed in nine OFMSW [organic fraction of municipal solid waste] commercial composts and one backyard compost.
PFAA loads ranged from 28.7 to 75.9 micrograms/kilo for OFMSW compost that included food packaging and from 2.38 to 7.6 micrograms/kilo for composts that did not include food packaging.
Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) were detected in all composts; however, OFMSW composts were dominated by short-chain PFAAs (>64%) and perfluoroalkyl carboxylates (PFCAs, >68%), particularly the C6 PFCA."
A third hypothesis is that they're entering the food chain via contaminated groundwater.