No one enjoys scrubbing a dirty pot. Non-stick cookware can feel like a blessing, but the chemicals that are used to make them “non-stick” are “forever chemicals,” because they do not break down once released into the environment.

These chemicals are per- and polyfluoroalkyl substances, or PFAS. Since their introduction into consumer and industrial products, PFAS chemicals have been found in water around the world, in plants, in dust, and in the air. Because they are present almost everywhere, we get exposed to them through our food, drinking water, and air, and they can then build up in our bodies.

Several studies have linked PFAS exposure to health issues like reduced effectiveness of the measles vaccine, poorer bone development in children, and inflammation. Following studies like these, some PFAS compounds have been phased out and banned, or are set to be banned, from things like food packaging. These bans and phasing out steps only apply to certain chemicals in the PFAS family, such as PFOS and PFOA, and companies have since shifted to replacement PFAS. The main difference between new and old PFASs is that the newer PFAS are smaller, "short chain" molecules, which were originally thought to build up in living tissues less than legacy PFAS.

These newer PFAS chemicals have now been found to be increasing in breast milk, according to a recent study published in ACS Environmental Science & Technology. Since breast milk is the primary source of nutrition for many infants, these infants are exposed to any contaminants in breast milk. In this study, the researchers measured the levels of legacy and current use PFAS in breast milk, calculated how much the infants were ingesting daily, and also compared how the PFAS levels in breast milk have changed over time.

Among the 50 breast milk samples the researchers measured, the newer short chain PFAS compunds made up 15 percent of the PFAS in the samples. Out of the four short chain PFAS detected in the breast milk in this study, perfluoroheptanoic acid was found in 98 percent of samples, showing that exposure to short chain PFAS is becoming widespread. Comparing these results to previous data showed that the amount of short chain PFASs in breast milk has been increasing since 2000, coinciding with the shift from legacy to replacement PFAS.

Despite the trends towards increasing PFAS in breast milk, do we really need to be concerned about them? After all, just because something is there does not mean it is necessarily bad.

While the study does show increasing amounts of short chain PFAS in breast milk, the amounts of PFAS the infants in the study ingested each day were below the guidelines published by the US Environmental Protection Agency (EPA). But these guidelines focus more on legacy PFAS like PFOA and PFOS, as there is still relatively little data available for short chain PFAS like perfluoroheptanoic acid. Also, different states in the US have different guidelines for these compounds, with some of them very different from the EPA guidelines. For example, the maximum amount of PFOA allowed in drinking water in Michigan is about ten times lower than the EPA's guidelines.

New studies on short chain PFAS chemicals indicate these compounds could cause organ damage and affect fat deposition and fetal sex hormones. These emerging data, combined with the large variations in published guidelines, raise concerns about the increasing exposure we have to these relatively unknown chemicals, and shows that we need stricter and more thorough guidelines before introducing new chemicals into the market. This is especially true because legacy PFAS have also been linked to organ damage, effects on fat deposition, and sex hormone levels in children. When different chemicals have similar health effects, they can sometimes act together to amplify these effects in a process called synergism, which has been shown to occur in human liver cells exposed to PFAS mixtures.

There are data that show that the amount of legacy PFAS like PFOA and PFOS decreases in blood serum and breast milk after exposure decreases because our bodies slowly remove PFOA and PFOS through urine and feces. These decreases mean that bans on PFAS compounds are likely to be effective. Companies shifted to short chain PFAS on the assumption that they would not accumulate in our bodies as much as, or that they would be removed from our bodies faster than, legacy PFAS compounds. However, scientists have found that some short chain PFAS actually stay in our bodies for longer than legacy PFAS.

Although current levels of short chain PFAS in our bodies might not be dangerous, if exposure begins as early as in the fetal stage and continues over our lifetimes, it is quite possible that eventually we will have enough PFAS in our bodies to feel the negative health effects.

New data can help consumers make informed decisions about the products they purchase and consume, and this can help reduce exposure to contaminants such as PFAS chemicals. However, companies should also be held accountable for conducting risk assessments on any potential toxins used in their products. While it may not be possible to eliminate PFAS entirely because of their use in things like firefighting, we can push for safer alternatives in applications like food packaging.