US Drinking Water May Contain Double the 'Forever Chemicals' Than Reported, Study Finds

Drinking water across the United States could contain twice the amount of per- and polyfluoroalkyl substances (PFAS), commonly known as forever chemicals, than previously reported, according to a new study from researchers at Texas Christian University.

The study analyzed over 1.8 million records from the Environmental Protection Agency (EPA) concerning PFAS levels in public water systems. Researchers found that by classifying measurements below the agency's minimum reporting threshold of four parts per trillion (ppt) as zero, current EPA reports only capture about 44 percent of the average PFAS concentration.

This method of reporting means that the actual presence of these persistent chemicals in public water systems may be significantly higher than officially documented. PFAS are known to remain in the environment for extended periods and have been linked to a range of health issues, including reproductive problems, liver damage, certain cancers, and developmental delays in children.

The EPA data indicates that at least 176 million Americans consume water from systems where at least one type of PFAS has been detected. However, more than half of the test results fall below the EPA's minimum reporting limit and are consequently treated as zero in official summaries.

Based on PFAS levels and population reliance on these water systems, the greatest estimated discrepancies between reported and actual concentrations were found in California, followed by Texas and Florida. "When the levels of these chemicals are below our reporting limit, it’s often treated as zero when we calculate how widespread they are," said Gehendra Kharel, the study's first author and an associate professor at Texas Christian University. "We set out to understand how treating those results as zero changes the picture of PFAS occurrence in drinking water."

The study, published in Cell Reports Sustainability, examined data for 25 types of PFAS with at least one national detection. The researchers used this data to estimate the difference between conventionally reported PFAS concentrations and those found in their revised analysis.

According to the study's model, the national average concentration of PFAS in drinking water is estimated to be closer to 5.2 nanograms per liter, compared to the conventional estimate of about 2.6 nanograms per liter.

The EPA recommends using filtered water to reduce exposure to PFAS. While Kharel cautioned that the findings do not automatically indicate a health risk for every below-limit measurement, he noted that the study provides a more comprehensive understanding of PFAS presence. "When a water quality report says 'not detected,' that means below the reporting limit, not zero," Kharel stated. "Our method gives water agencies and utilities a way to account for that difference, so they can see where more testing would help and be clearer about what they do and do not know."

Research continues to explore the full spectrum of health risks associated with PFAS and the specific exposure levels that can lead to long-term damage. The EPA acknowledges that even low levels of PFAS can accumulate in the body over time, potentially causing issues like high cholesterol, reproductive challenges, developmental problems, liver damage, and certain types of cancer.