This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: In 2023, professor Damian Helbling was getting a lot of calls and emails from local residents. The Environmental Protection Agency (EPA) had just announced regulations to limit per- and polyfluoroalkyl substances (PFAS)—some of which have been linked to cancers and other negative health effects—in drinking water.
Ithacans and others in the region wanted to know about levels in the ponds, lakes, streams and creeks in their proverbial backyards. "Anybody in the public could just search online for "PFAS' and "Cornell," and they would find me," said Helbling, professor of civil and environmental engineering in the Cornell Duffield College of Engineering. "But I had no idea how to answer their questions.
There were no data locally." A group of undergraduates in Helbling's research group has since filled the gap, taking more than 500 samples across 300 bodies of water, including all 11 Finger Lakes and many tributaries, ponds and even puddles that persistently pool after rain. They've screened the samples for 24 common PFAS and added the data to an interactive map. The map shows PFAS hot spots but also relieves some fears: Overall, the concentrations of PFAS in the Finger Lakes are relatively low.
"There was definitely relief knowing that generally we're not seeing elevated levels across the region," said Alex Van Den Hende '25, M.Eng. '25, who first created the map's infrastructure with Helbling's mentorship. "We saw that relief in the public's response but also concern that there is in fact contamination—that maybe you're not immediately affected, but there's potential for more significant impacts in the future." PFAS don't break down easily, accumulate in the environment and the body, and have been linked with lower fertility, hormone disruption and certain cancers; the Centers for Disease Control and Prevention has found PFAS in the blood of 97% of Americans surveyed. But regional data on PFAS contamination in water often consist of a small number of samples taken at long intervals.
Helbling said the students' Finger Lakes data set is unique in its breadth of sites and samples taken over time. The students found that the amount of surface water in the Finger Lakes region seems to effectively dilute PFAS, so that overall levels remain low. The hot spots—where levels did exceed guidance values for safety set by New York state—are largely in places the group expected: in standing bodies of water near airports and fire training stations.
At these sites, deicing fluids for planes and fire-extinguishing foams, known sources of PFAS, appear to spike the levels, which then decline over time. Those hot spots are not sources of drinking water and are often isolated from other waterways, limiting their impact. "But these elevated sites might tell us how we can better monitor and do source control," said Gregory Pepin '27, a civil engineering major in Cornell Duffield Engineering.
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