Read the full report (Division of Environmental Health)

Per- and poly-fluoroalkyl substances (PFAS) are a class of thousands of organic fluorinated chemicals that are resistant to heat, water, and oil. They have been used for decades in hundreds of industrial applications and consumer products. Several types of PFAS are associated with health effects in people including pregnancy-induced hypertension, liver damage, high cholesterol, thyroid disease, decreased vaccine response, decreased fertility, asthma, small decreases in birth weight, and testicular and kidney cancer.

In 2016, the U.S. Environmental Protection Agency (EPA) established a Lifetime Health Advisory (LHA) of 70 parts per trillion (ppt) for two PFAS, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), individually or in combination.2 The Michigan Department of Health and Human Services (MDHHS) published non-enforceable public health drinking water screening levels for PFAS in February 2019. Public health drinking water screening levels were developed for five PFAS analytes: PFOA (9 ppt), PFOS (8 ppt), PFNA (9 ppt), PFHxS (84 ppt), and PFBS (1,000 ppt). These screening levels represent the level at which scientists have determined there is minimal risk of health problems to the most vulnerable populations. Effective August 3, 2020, the Michigan Department of Environment, Great Lakes, and Energy (EGLE) (previously named Michigan Department of Environmental Quality, or DEQ) promulgated maximum contaminant levels (MCLs) for seven PFAS, which provide drinking water standards for public water systems in Michigan. These standards are 8 ppt for PFOA, 16 ppt for PFOS, 6 ppt for PFNA, 51 ppt for PFHxS, 420 ppt for PFBS, 400,000 ppt for PFHxA, and 370 ppt for HFPO-DA.

EGLE found PFAS in samples of private drinking water wells in areas near former waste disposal sites in northern Kent County, Michigan, in 2016. Throughout the resultant investigation, EGLE found concentrations of PFOS and PFOA ranging from below lab detection limits to concentrations exceeding 50,000 ppt; these values are orders of magnitude above the EPA LHA and MDHHS’s screening levels. As of September 2018, 1,783 private drinking water wells in the northern Kent County area were tested for PFAS. Of these, 982 had detections of any of the PFAS for which the water was tested, and 299 had detections of total measured PFAS over 70 ppt.

While exceedances of health-based screening levels do not confirm that harm to human health will occur, they warrant further investigation of the extent of human exposure to these chemicals. The U.S. Centers for Disease Control and Prevention (CDC), Agency for Toxic Substances and Disease Registry (ATSDR) developed an approach for investigating PFAS exposure called the PFAS Exposure Assessment Technical Tools (PEATT). The PEATT is designed to investigate PFAS exposures resulting from contaminated municipal water. In spring 2018, MDHHS and the Kent County Health Department (KCHD) committed to investigate PFAS exposure from private residential drinking water wells using a modified version of the PEATT protocol.

The objectives of this exposure assessment were to:

  1. Determine the mean concentration of 30 PFAS in participants’ serum.
  2. Determine the mean concentration of 30 PFAS in participants’ unfilitered private well water and filtered private well water (for those with drinking water filters).
  3. Describe the data on individual characteristics that could affect PFAS exposure of elimination.
  4. Compare concentrations of PFAS in participants’ serum to those among participants in the National Health and Nutrition Examination Survey (NHANES), a national survey representative of PFAS concentrations in the U.S. general population.

This preliminary report describes the demographics of people who participated in the exposure assessment and provides a preliminary description of the results of serum testing (the first objective above). It does not describe PFAS in water samples or how PFAS found in water samples relate to PFAS found in serum. This report also compares participants’ serum PFAS concentrations to those of other populations.

Future reports will characterize PFAS concentrations in private drinking water wells, examine the association between private drinking water well PFAS concentrations and serum PFAS concentrations, describe self-reported factors that could affect PFAS exposure or elimination, and make additional
comparisons between participants’ PFAS serum concentrations and NHANES (objectives 2, 3, and 4 above).