PFAS presence in the schools in Maine

Per-fluoroalkyl and poly-fluoroalkyl substances (PFAS) are also known as forever chemicals due to their resistance against degradation, but when they break down, they produce smaller PFAS. This group of molecules comprises thousands of substances that have been used since the 1940s due to their lipophobic and hydrophobic-like properties. The basic structure of these molecules consists of a fluorinated alkyl chain with a polar head group that affects the surface tension in liquids  (Dickman, 2022.)  Perfluoroalkyl substances have all their carbon in their tail fluorinated, as shown in A, whereas polyfluoroalkyl substances also have some carbons bonded to a hydrogen atom, as presented in image B below.

-> A study where the concentrations for different PFAS were measured from the blood of patients conducted by the Center for Disease Control (CDC) in their National Health and Nutrition Examination Survey (NHANES) concluded that most people in the US have traces of PFAS in their blood ( ATSDR .)

Some of the molecules commonly found in the blood are:

• Perfluorooctane sulfonic acid (PFOS): It can be found ubiquitous in the environment even though it has been phased out of the market in the US, but it may still be found in imported products. PFOS has been present in some firefighting foams used at airports, firefighter training facilities, and military airfields.

• Perfluorooctanoic Acid (PFOA): Used particularly for manufacturing polytetrafluoroethylene, commonly known as Teflon. Similar to PFOS, it can be found in the environment even though it has been removed from market use for a few decades. PFOA was also used in firefighter foam and non-stick cookware.

• Perfluorohexanesulfonic acid (PFHxS): This compound has been used in stain-resistant fabrics, fire-fighting foams, food packaging, and as a surfactant in industrial processes.

After two decades of surveying and collecting data, the CDC identified a decrease in the concentration of PFAS found in the blood of surveyed people since the discontinuation of the production of major PFAS in the early 2000s. But again, there are more than ten thousand PFAS, so while we are not getting exposed to these ones anymore, we are still getting exposed to many others that have yet to be regulated.

PFAS possess a unique molecular structure that grants them distinct properties. This structure consists of a hydrophobic tail, a chain of carbon atoms saturated with fluorine atoms, and a hydrophilic head. The fluorinated tail repels water (hydrophobic) and fats (lipophobic) due to the strong electronegativity of fluorine. This creates a barrier that prevents both water and fats from adhering to the molecule. However, the hydrophilic head, with its opposing characteristic, attracts water. Therefore, these amphiphilic molecules exhibit the seemingly contradictory property of being repelled by water while simultaneously having an affinity for it (Krafft and Riess, 2015).

One of the intriguing aspects of PFAS is their structural similarity to fatty acids. Just like fatty acids, PFAS consist of a chain of carbon atoms. However, in PFAS, the hydrogen atoms attached to the carbon are replaced with fluorine atoms, creating an extremely stable and resilient structure. This resemblance allows PFAS to interact with the same biological pathways as fatty acids, potentially disrupting normal bodily functions.

When PFAS enter our bodies, they can bind to receptors that are typically activated by fatty acids. This can lead to a reduction in the bioavailability of fatty acids, meaning that there are fewer free fatty acids available for our bodies to use. This can disrupt various metabolic processes, as fatty acids play crucial roles in energy production, cell signaling, and inflammation regulation( India-Aldana et al., 2023 ).

This video from  MinuteEarth  offers a quick visual representation of this process here:

Research suggests that high levels of PFAS exposure may be associated with various health problems, including:

• Cancer: Some studies have linked PFAS exposure to certain cancers, like kidney and testicular cancer.

• Reproductive and Developmental Issues: PFAS exposure may affect fertility and pregnancy outcomes, potentially leading to low birth weight and developmental delays in children.

• Liver and Immune System Effects: PFAS can harm the liver and weaken the immune system, making it harder for the body to fight off infections.

• High Cholesterol: PFAS exposure has been linked to increased levels of cholesterol, which can increase the risk of heart disease.

Additionally, the type and concentration of PFAS chemicals, as well as the duration of exposure, can all play a role in determining the health effects on different age groups and genders.

Children are often more vulnerable to the health effects of PFAS exposure than adults. Their developing bodies may be more susceptible to the harmful effects of these chemicals. Exposure during pregnancy or early childhood can impact development, potentially leading to issues like developmental delays and low birth weight, among others.

Older individuals may also be at increased risk because their bodies may have a reduced capacity to eliminate PFAS. This can lead to a buildup of these chemicals in their bodies over time, potentially increasing the risk of certain health problems, such as liver damage.

Research published in 2018 identified the presence of forever chemicals in human breast milk. There is the possibility that the chemicals are being transferred to the infant through breastfeeding, and the  CDC recommends the following :

With numerous protective health benefits, breast milk continues to be the ideal nutrition for infants, and in nearly every circumstance, the Centers for Disease Control and Prevention and the American Academy of Pediatrics recommend that nursing mothers continue to breastfeed their babies despite the potential presence of environmental contaminants.

Some of the most common pathways for PFAs to enter our body are:

USGS discovered in their most recent  study  that 45% of all the taps they tested contained at least one known PFAS in the water chemistry.

In 2023,  The Environmental Protection Agency (EPA)  proposed a Maximum Contaminant Level (MCL) for six PFAS: PFOA and PFOS as individual contaminants, and PFHxS, PFNA, PFBS, and HFPO-DA (commonly referred to as GenX Chemicals) as a PFAS mixture. The proposed MCL for PFOA and PFOS is 4 parts per trillion, and a Maximum Contaminant Level Goal (MCLG) of 0, suggesting that we should have no PFAS in our drinking water as it can be detrimental to our health. Below, we can see a risk exposure map displaying locations where the water was found to be above the 4 parts per trillion limit across the continental USA.

• Manufacturing Facilities: Many PFAS chemicals were historically produced and used in industrial processes, such as the manufacturing of non-stick cookware, textiles, and electronics. PFAS were used in these processes because of their unique properties, including water, oil, and heat resistance. This made them valuable for creating products with these characteristics.

• Wastewater Treatment Plants: PFAS can be discharged into the environment when products containing PFAS are washed or disposed of and end up in wastewater. PFAS can be resistant to breakdown during wastewater treatment processes, allowing them to be released into rivers and oceans. Additionally, industrial discharges into wastewater can introduce PFAS into the treatment system.

• Landfills: Products containing PFAS, such as fast-food wrappers and waterproof clothing, can end up in landfills, where they may release PFAS over time. PFAS are used in these products to provide water and grease resistance. When these products break down in landfills, PFAS can leach into groundwater and nearby surface water.

• Firefighting Foams: A significant source of PFAS in the environment is the use of firefighting foams (known as Aqueous Film-Forming Foams or AFFF) at military bases, airports, and industrial sites. AFFF is designed to rapidly extinguish fuel fires, making it essential for firefighting operations involving flammable liquids. PFAS are added to these foams to improve their ability to smother and suppress fires effectively.

It's important to note that the persistence and mobility of PFAS in the environment are key reasons why they can be found in various environmental compartments, including soil, water, air, and even wildlife. The widespread use and diverse sources of PFAS have contributed to their presence in many parts of the environment, making it a significant environmental and health concern.

A recent study has revealed that the floor waxing products used at schools throughout the country are a source of PFAS contamination in the environment  (Zhou et al., 2022.)  The deposition of PFAS in the environment from floor waxing products occurs after the products have reached the school's drainage system and pollute the effluent with PFAS contaminating surface water. Once the contaminated effluent reaches the surface water, it can percolate into the groundwater below and later contaminate nearby private wells, polluting the residents drinking water.

The six regulated PFAS in Maine are PFOS, PFOA, PFHxS, PFNA, PFHpA, and PFDA. We call these ME-6. The recommended limit is 20ppt, which is the result of the sum of the concentrations of the compounds included in ME-6.

Below, we can see a map showcasing the levels of PFAS found in schools across Maine. This information

• 30% of rural schools on private wells* have detectable PFAS in drinking water, and 20% are above the Maine standard of 20 ppt.

MDI neighbors attended a follow-up high school meeting in August and learned about additional sample results at the high school. All of these data (PFAS results of soils, surface water, groundwater, and high school effluent) have been added to the interactive map below: