PFAS Levels Remain Elevated Even Three Years After Exposure in Michigan

A recent study from researchers at Michigan State University highlights the long-term impact of exposure to per- and polyfluoroalkyl substances (PFAS) in drinking water, particularly in communities affected by contamination from paper mill landfills.

The study, published in Environmental Science & Technology Letters, underscores the persistence of these harmful chemicals in both the environment and the human body, even after the contamination source is removed.

The study is the first biomonitoring investigation to explore the link between PFAS exposure and contamination from a local paper mill landfill.

The research focused on a community in southwest Michigan, where PFAS contamination in drinking water was first detected in 2018. The contamination originated from a nearby abandoned paper mill landfill, which had disposed of PFAS-laden waste, leading to elevated levels of the chemicals in surrounding groundwater. 

Participants were split into two groups: those who had drank municipal water and those who drank from water collected in their private wells.

The researchers measured PFAS concentrations in both groups' drinking water and their blood. They found that those who consumed the municipal water with higher PFAS concentrations had significantly elevated levels of these substances in their blood. Long-term exposure to PFAS-contaminated drinking water was identified as the primary predictor of elevated serum PFAS levels.

Importantly, even three years after the community switched to clean water, PFAS levels in blood remained high, demonstrating the chemicals' enduring presence in the human body.

PFAS are a group of man-made chemicals used for their water- and fire-resistant properties. They are found in a wide range of consumer products, including nonstick cookware, water-repellent clothing, food packaging, and even electronics. PFAS chemicals, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), are highly mobile, meaning they can easily migrate through soil and water, making them difficult to contain. Moreover, they break down very slowly, accumulating in both the environment and living organisms over time.

Due to their persistence, PFAS are often referred to as "forever chemicals," as they can remain in the environment and the human body for years. These chemicals are linked to a range of health risks, including liver damage, immune system disruption, and increased cancer risk.

The findings from this study highlight the importance of addressing PFAS contamination, particularly from less-recognized sources like paper mill landfills. While much of the research on PFAS exposure has focused on areas near fluorochemical manufacturers or military sites, this study expands our understanding by investigating industrial contamination from paper mills, an often-overlooked source.

The research revealed that the water source was the most significant factor in predicting PFAS levels in residents’ blood. Those who consumed water from more contaminated municipal sources had higher PFAS concentrations, with the levels increasing for each additional year of exposure.

Interestingly, the study also found gender differences, with women in the low-exposure group showing lower PFOS and perfluorohexane sulfonic acid (PFHxS) levels than men. This is likely due to biological factors, such as menstruation, childbirth and breastfeeding, which may reduce PFAS levels in women over time.

These findings underline the urgency of routine monitoring and intervention efforts to reduce PFAS exposure. 

“This research highlights how vulnerable our drinking water systems can be to contamination from old paper mills or landfills,” said study co-author Heather Stapleton, the Ronie-Richele Garcia-Johnson Distinguished Professor in the Nicholas School of the Environment at Duke University. “Likely, this city is not alone. Other cities or regions could be just as vulnerable. This work underscores the importance of routine monitoring for contaminants in our drinking water.”

The researchers broadly stress the need for further research to assess the toxicological effects of long-term PFAS exposure. Monitoring efforts should continue to track the health outcomes of individuals exposed to PFAS and evaluate the effectiveness of intervention strategies.

Looking ahead, the study provides a critical baseline for future investigations into the long-term effects of PFAS exposure on human health. The researchers call for more comprehensive studies that assess the health risks of PFAS and develop strategies to mitigate exposure in communities affected by contamination.

Michigan’s proactive stance on PFAS contamination — being among the few states to set state-level maximum contaminant levels for PFAS — has positioned it as a leader in addressing this issue.

While the U.S. Environmental Protection Agency (EPA) has taken steps to establish national PFAS standards and protect public health, ensuring that drinking water is free from PFAS remains a complex process. As lead study author Courtney Carignan, assistant professor in the MSU Department of Food Science and Human Nutrition, points out, PFAS testing is not equal across the board.

"We hope this work raises awareness about potential sources and pathways of PFAS in drinking water, which can be an important source of exposure,” said Carignan. “I think we can feel good as Michiganders that our state has tested all public drinking water supplies, but most states have done less testing, and people with private wells have to do their own.”

This research highlights the need for more widespread testing of drinking water, especially in areas near industrial waste sites, to prevent further PFAS exposure. 

Reference: Bauer RA, Bhattacharya A, Guo Y, et al. Elevated per- and polyfluoroalkyl substances (PFASs) in tap water and serum in a community near an abandoned paper mill. Environ Adv. 2025;20:100623. doi: 10.1016/j.envadv.2025.100623