A Lasting Sadness: The Hidden Dangers of PFAs
“The sadness will last forever.”
~Vincent van Gogh
Vincent may have changed his conclusion if he knew about PFAs, perhaps the only thing capable of outlasting his sadness, except Keith Richards. PFAs are a modern industrial creation and comprise a group of chemicals known as perfluoroalkyl and polyfluoroalkyl substances. They are commonly referred to as “forever chemicals.”
All members of this group, which contain a carbon-fluorine bond in their structure, share four common characteristics: they are resistant to water, fats, and degradation and are thermally stable. They are a key component of many fire retardants, and individuals who have high occupational exposure to PFAs, like firefighters, have a significantly higher risk of certain types of cancer, such as colon cancer.
PFAs are also commonly used in the manufacture of many household items such as cleaning products. Because they resist decay and accumulate in the environment, they are frequently detected in such commonly encountered substances as drinking water and indoor dust. They enter into the food-health discussion because they have been approved by the United States Food And Drug Administration (FDA) for use in food contact applications.
Two PFAs, perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are particularly concerning. Food sources of PFOS and PFOA include fish, seafood, meat, meat products, eggs, egg products, milk, dairy products, and drinking water – which means you can find it in just about every available food product. That includes agricultural products like corn exposed to PFA-contaminated soil, water, or biosolids. These compounds are rapidly absorbed from the human gastrointestinal tract, are not metabolized, and are excreted through the urine and feces. They have a human half-life of five years for PFOS and two to four years for PFOA.
As noted in a European report, “Contamination of food with PFOS and PFOA is thought to occur mainly through two different processes (i) from bioaccumulation in aquatic and terrestrial food chains and (ii) as a result of [the] transfer of PFOS, PFOA and their precursors from contact materials used in food processing and packaging. Contamination can also arise when food-producing animals are exposed to sources of pollution, such as wild boars feeding at dumpsites.” The report went on to note that these compounds “were detected in blood samples of almost all individuals [humans] assessed, demonstrating ubiquitous exposure.” Both PFOS and PFOA were also found in human breast milk, in newborns, and in residents living in remote sub-Arctic indigenous communities.
Earlier this month, the International Agency for Research on Cancer (IARC) classified PFOA as carcinogenic to humans and PFOS as possibly carcinogenic to humans.
Colorectal cancer (CRC) is the third most common cancer and the second most prevalent cause of cancer death worldwide. Approximately 80 percent of CRC cases are thought to be related to environmental exposure of some kind. The current study observed that CRC cells immersed in a PFA solution demonstrated increased cell motility and metabolic changes consistent with cancer metastasis. The magnitude of the effect appears “dependent not only on concentration [of PFAs] but also on the exposure time and genetic profile [of the cancer cells].”
- An in vitro study examining the effects of two common PFAs (perfluoroalkyl and polyfluoroalkyl substances), perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), in the role of colorectal cancer.
The Take-Away:
- The study used exposure levels similar to those detected in firefighters and others in frequent contact with PFAs.
- These compounds, known as “forever chemicals,” are ubiquitous in the environment and thus the food supply; virtually every person tested demonstrates exposure and accumulation.
- Foodborne sources include not only drinking water and food but also:
- Non-stick cookware,
- Gaskets, O-rings, and other parts and processing aids used in food processing equipment,
- Food packaging (e.g., grease-proofing agents in fast-food wrappers, microwave popcorn bags, take-out paperboard containers, moisture-resistant food packaging, etc.)
- These compounds are not metabolized in humans (excreted through urine and feces unchanged) and exhibit a long half-life, meaning they stick around for quite a while.
- The presence of these compounds (recently designated in the case of PFOA as carcinogenic) in the setting of highly malignant colorectal cancer cells resulted in an increase in attributes associated with metastasis.
The Caveats:
- The study utilized metabolomics to ascertain data, but all in vitro studies require a pause in applying the findings to real humans in the real world.
Potential pathways for PFAs entry into the US food supply
This study highlights a need to understand food-health interactions in the context of the exposome—that is, all environmental influences (biological, chemical, environmental, social, etc.) upon a person from conception until death. The additional caveat regarding food is that when we eat, we internalize all those environmental exposures – and all the sadness.
Additional Resources:
EFSA Panel on Contaminants in the Food Chain (CONTAM). (2018, March 22). Risk to human health related to the presence of perfluorooctane sulfonic acid and perfluorooctanoic acid in food . Retrieved from https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.2018.5194 doi:10.2903/j.efsa.2018.5194
FDA. (2023, May 5). Authorized Uses of PFAS in Food Contact Applications. Retrieved from FDA.gov: https://www.fda.gov/food/process-contaminants-food/authorized-uses-pfas-food-contact-applications#:~:text=Non%2Dstick%20cookware%3A%20PFAS%20may,require%20chemical%20and%20physical%20durability.
FDA. (2023, August 28). Testing Food for PFAS and Assessing Dietary Exposure. Retrieved from FDA.gov: https://www.fda.gov/food/process-contaminants-food/testing-food-pfas-and-assessing-dietary-exposure
IARC. (2023, December 1). IARC Monographs evaluate the carcinogenicity of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). Retrieved from IARC.WHO.int: https://www.iarc.who.int/news-events/iarc-monographs-evaluate-the-carcinogenicity-of-perfluorooctanoic-acid-pfoa-and-perfluorooctanesulfonic-acid-pfos/
Vost, K., Saab, N., Silva, P., Cutzwiler, G., & Steketee, A. (2021). Risk assessment of per- and polyfluoroalkyl substances (PFAS) in food: Symposium proceedings. Trends in Food Science & Technology, 116: 1203-1211 https://doi.org/10.1016/j.tifs.2021.05.038.
