What are PFAS?

PFAS or "forever chemicals"

Polyfluoroalkyl substances, or PFAS, are widely-used chemicals that take a very long time to break down. First synthesized in the 1930s and 40s, these chemicals may be used in the manufacturing of nonstick cooking utensils, waterproof clothing, plastics, and even steel. They can also be found in products we use outdoors such as lawn fertilizer, pesticides, and motor oil. Due to how widespread their use is, PFAS are found in water, air, soil, and the bodies of plants and animals.

Both PFAS and heavy metals pose serious health risks to us and our environment. When we drink water or eat food with PFAS -- such as plants grown in areas with contaminated soil or fish from contaminated waters -- those chemicals enter our bodies and stay there. Higher levels of PFAS exposure correspond to increased risks of cancer, heart and liver disease, along with birth defects in both humans and animals.

High levels of PFAS have been found in waterways all around the world, including in our Great Lakes -- they're typically swept into storm drains by rain that empty into the lake -- and they don't break down. Lake Michigan has the second highest concentration of PFAS out of all the Great Lakes. Given the risks to human and environmental health they pose, we need a way to reduce them.

Why are they so destructive?

Chemicals classified as PFAS include perfluorooctanoic acid (chemical formula C8HF15O2 and modeled above), perfluorooctane sulfonate (C8HF17O3S), perfluorononanoic acid (C9HF17O2), and perfluorohexanesulfonic acid (C6HF13O3S), among others. Their chemical structures (see above) mean that they take a significant amount of time to break down into their elemental components.

Their molecules include a carbon-fluorine chain, which is one of the strongest covalent bonds found in chemistry. This is due to the electronegativity of the atoms. The high electronegativity of fluorine means that any bond it forms is going to be extremely polar, due to how many electrons fluorine attracts in comparison to other elements (including carbon). The electrons draw the carbon atom very close to the fluorine, making them very difficult to break apart. They were engineered this way because it is very beneficial in product design to have something that doesn't get damaged or break down easily -- unfortunately, that's a very harmful thing to have in the environment.

Destroying any chemical compound that includes the carbon-fluorine bond takes a large amount of energy – an amount that doesn’t often occur in the natural world. Thus, PFAS can remain in the environment for thousands of years without intervention.

Pesticides commonly contain PFAS, which then spread easily throughout plants and soil.

Another source of PFAS is fast food packaging -- that's what makes it grease-resistant.

Fertilizer Runoff

One significant source of PFAS in the Great Lakes are the chemicals found in many industrial and commercial fertilizers and pesticides. When it rains, the rainwater washes the chemicals on your lawn down the storm drains and out to the lake. Many common fertilizer PFAS contain phosphorus, which can be very dangerous to the environment in large amounts. Phosphorus stimulates algae growth in water, leading to blooms (image above) that block sunlight, increase the risks of bacteria, and unbalance aquatic ecosystems as a whole. This has become a very serious issue in certain parts of the lake -- for example, Green Bay experiences severe algae blooms which kill many fish and make the local beaches unusable.

Heavy Metal Waste

Another common form of chemical pollution in the Great Lakes -- though not a PFAS -- is heavy metal contamination. It's typically a result of industrial processes, either ongoing or in the past (as metals can remain in the soil for years after the initial contamination). Metals such as lead and cadmium have similar properties and health effects to PFAS -- they are or were widely used, they take a long time to break down, and they can stay in the body for years, causing cancers and other health issues. Additionally, heavy metals accumulate in the lake's wildlife, such as the fish -- the same fish we end up eating. Most of the lead and cadmium pollution in the Great Lakes is a result of steel mills and other industrial manufacturers that border them. Though heavy metal levels are low in Lake Michigan, the same cannot be said for the general lake system.

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