Unfortunately, this storyline is getting all too familiar: There’s a chemical of concern that poses a public health risk. Industries have widely used this chemical for decades, but its health impacts are not well studied, and the potential harmful properties of this chemical have been suppressed by the manufacturer. The class of chemicals this time: PFAS or per- and polyfluoroalkyl substances. According to the Michigan Department of Environment, Great Lakes, and Energy (EGLE) more than 1.5 million residents have been drinking water contaminated with PFAS and there could be as many as 11,300 potential sites where PFAS may have been used.
How did PFAS get here?
PFAS are a family of more than 3,000 manufactured chemicals that were put into production in the 1950s. The unique chemical properties of PFAS allowed manufacturers to create waterproof, stain resistant, and non-stick products. PFAS have been used in practically everything, including carpeting, waterproof clothing, food paper wrappings, upholstery, takeout containers, furniture, some cosmetics and more. They were also used in a firefighting foam called AFFF, which branches of the armed forces and fire departments used all across the country. Some forms of PFAS have been phased out of use, but many others are still used widely in commercial products and manufacturing processes today.
How do PFAS impact our health?
There are a number of ways a person can come in contact with PFAS, but the most common way is through drinking water. So far, researchers have only studied a handful of these chemicals for their health implications. However, preliminary research suggests that PFAS is highly toxic to humans and that some forms of it bioaccumulates in our bodies. It may increase thyroid disease, decrease fertility in women, cause developmental issues in infants and older children, and increase blood pressure and cholesterol levels. They have also been linked to increased risks of kidney and testicular cancer.
Currently, the EPA’s recommended lifetime health advisory limit is set at 70 parts per trillion (ppt) for PFOA and PFOS (the two best-studied PFAS compounds). However, a health advisory limit is non-enforceable, meaning that drinking water system operators are not required to adhere to this recommendation. What's more, research has demonstrated that 70 ppt is far too high to be protective of human health and the environment.
What are PFAS drinking water standards?
A drinking water standard is an enforceable limit on the amounts of certain chemicals that can be present in public water systems. The chemical standards or limits are intended to protect the public from negative health impacts of exposure to toxic chemicals via drinking water.
In the absence of federal progress, Governor Whitmer and her administration have moved rapidly to ensure that Michigan residents are better protected from exposure to harmful levels of PFAS by directing EGLE to set drinking water standards for PFAS chemicals.
The state is considering limits for the following PFAS chemicals:
- PFNA (6-parts per trillion)
- PFOA (8-parts per trillion)
- PFOS (16-parts per trillion)
- PFHxS (51-parts per trillion)
- GenX (370-parts per trillion)
- PFBS (420-parts per trillion)
- PFHxA (400,000-parts per trillion)
How can the standard be strengthened?
Setting science-based drinking water standards is a critical and necessary step in the right direction. There are also changes to the rules that EGLE should make in order to further strengthen them.
Michigan Environmental Council recommends these policy solutions to ensure the standards fully protect human health and the environment against PFAS:
Set a cumulative standard. In addition to setting numeric standards for individual compounds of PFAS, the state should set a cumulative limit. A cumulative limit would better protect the public against additive or synergistic effects from exposure to multiple PFAS chemicals. It would also create a level of protection for residents exposed to PFAS chemicals that are not included in the seven slated for a drinking water standard.
Require a health review in two years. The state is moving forward with setting drinking water standards for seven PFAS compounds. While a step in the right direction, that approach leaves thousands of PFAS compounds unregulated. The science on the risk and toxicity of PFAS chemicals is rapidly developing; standards set today could be quickly out of date as new research on toxicity comes in. To ensure Michigan remains ahead of the curve and maintains science-based standards that are protective of public health, the state should conduct a health review two years after the PFAS drinking water standards go into effect. This requirement should be written into the PFAS drinking water rules.
Conduct at least three years of quarterly sampling. We do not know enough about how PFAS moves in the environment or if there are seasonal changes to discharges of PFAS to be able to set reduced sampling frequencies. The current rule requires some quarterly sampling, but also allows water plants to potentially reduce to sampling every six months or only once a year. At a minimum, given the unknowns, all water systems should test quarterly for three years. That will give the state a solid baseline of knowledge to know when PFAS may or may not spike and which supplies are most at risk of exposure. From there the state can better establish a reduced sampling frequency process.