Something is lurking in your water and food. That very thought raises my "fight-or-flight" response, and if it doesn't raise something similar for you, it probably should. Think about it this way: imagine that every glass of water you drink could cause you more harm than good. Or could the popcorn you just opened and are about to eat could be putting you at risk.
What am I talking about? Per- and polyfluoroalkyl substances, better known as PFAS. Here, I share some basic information about PFAS and why you should care about them.
What are PFAS?
PFAS are a group of complex human-made chemicals that repel both oil and water. This, among other properties, makes them useful in a variety of applications. Globally, there are more than 3,000 products that either once used or still use PFAS.1 Common examples include food packaging, stain-resistant fabrics and carpets, non-stick kitchenware, paints, adhesives, electronics, personal care products and firefighting foams.2 However, only a limited amount of information exists on the extent of PFAS usage.3 This includes the question of quantity: how much has accumulated in the environment?
These substances are mixtures of fluoropolymers containing carbon-fluorine monomers.1 "Perfluoro" (or "perfluorinated") is a general term for hydrocarbons where all hydrogen atoms are replaced by fluorine.1 Thus containing the perfluoroalkyl moiety CnF2n+1–.4 "Poly"-fluorinated refers to species where not all H atoms have been replaced with fluorines, but the carbon-fluorine backbone structure is still predominant. It is the stability of the C-F bonds, which prevents these compounds from naturally decomposing in the environment and makes them highly resistant to acids, bases, oxidants, and heat. "Perfluoroalkyl and polyfluoroalkyl substances," aka PFAS, and represent a compound class of potentially hundreds of chemicals of different chemical structures and behaviors.
These substances have been manufactured and used in products in the US since the 1940s, as shown in Figure 1.
Figure 1. Discovery and manufacturing history of select PFAS (Source: Muller, R. and Yingling, V. History and Use of Per- and Polyfluoroalkyl Substances (PFAS). Interstate Technology and Regulatory Council (ITRC). April 2020, p 2.)
Why should you care?
The problem with these chemicals is their inability to break down. Simply put, they don't decompose naturally in the environment and tend to accumulate over time.
"So what?" you might ask. Well, acute exposure to PFAS and their residues could have detrimental health effects. This includes liver damage, thyroid disease, decreased fertility, high cholesterol, obesity, hormone suppression, and cancer.2,5,6
Recognizing these potential risks, news about PFAS contamination is making mainstream headlines, and it is becoming a core topic for reports and scientific studies. For example, in Australia, aviation firefighters were found to have up to 20 times the average level of toxic chemicals in their blood.Yet, even with these studies, the health effects of PFAS are still widely debated.
So, how are people exposed?
Exposure to PFAS comes through food, consumer goods and water. Because these substances linger in the environment and are water-soluble, they can't be removed by most in-home filters or standard wastewater treatment methods. Water sources near industrial sites, oil refineries, airfields, military bases where firefighting foam is used and wastewater treatment plants are more likely to be contaminated. So, if your drinking water comes from one of these sources, you're at a higher risk of being exposed. And if you purchase food that is packaged in PFAS-laced material, you're exposed. Remember, PFAS are non-biodegradable and builds up over time, so if you consume a fish from PFAS-laced water, you will be exposed to PFAS. For a better understanding of PFAS in food, read this blog.
There you have it: an overview of what are PFAS and why you should care. If you'd like to learn about analytical techniques available to test for PFAS and its precursors effectively, read this blog.
- Schaider, L.A., Balan, S.A., Blum, A., Andrews, D.Q., Strynar, M.J., Dickinson, M.E., Lunderberg, D.M., Lang, J.R. and Peaslee, G.F. Fluorinated Compounds in U.S. Fast Food Packaging. Environ. Sci. Technol. Lett. 2017, 4, 3, 105−111. https://doi.org/10.1021/acs.estlett.6b00435.
- Richardson, S.D. and Ternes, T.A. Water Analysis: Emerging Contaminants and Current Issues. Anal. Chem. 2018, 90, 1, 398–428. https://doi.org/10.1021/acs.analchem.7b04577.
- Wang, Z., Dewitt, J.C., Higgins, C.P. and Cousins, I.T. A Never-Ending Story of Per- and Polyfluoroalkyl Substances (PFASs)? Environ. Sci. Technol. 2017, 51, 5, 2508–2518. https://doi.org/10.1021/acs.est.6b04806.
- Buck, R.C., Franklin, J., Berger, U., Conder, J.M., Cousins, I.T., de Voogt, P., Jensen, A.A., Kannan, K., Mabury, S.A. and van Leeuwen, S.P. (2011). Perfluoroalkyl and polyfluoroalkyl substances in the environment: Terminology, classification, and origins.Integr Environ Assess Manag, 7: 513–541. doi:10.1002/ieam.258.
- Lewis, R.C., Johns, L.E. and Meeker, J.D. Serum Biomarkers of Exposure to Perfluoroalkyl Substances in Relation to Serum Testosterone and Measures of Thyroid Function among Adults and Adolescents from NHANES 2011–2012. Int. J. Environ. Res. Public Health. 2015, 12, 6098–6114. https://doi.org/10.3390/ijerph120606098.
- Grandjean, P. and Clapp, R. (2015). Perfluorinated alkyl substances: emerging insights into health risks. New Solut. a J. Environ. Occup. Heal. policy, 25: 147–163. doi:10.1177/1048291115590506.
About the author
Tai Siew Hoon is a senior field application specialist for the South East Asian region at SCIEX. She has more than 15 years of experience working with LC-MS/MS, primarily focusing in food, environmental and forensic applications. Backed by her rich technical expertise in LC-MS/MS operations and strong understanding of the MS market, she has helped customers in the region with their LC-MS/MS applications. Siew Hoon graduated with a Bachelor of Science in Chemistry from the National University of Singapore.