Locusts can detect the "forever chemicals" contaminating Michigan water supplies, and a Michigan State University engineering lab wants to turn that ability into cheap, portable sensors that could screen sites across the state.

Associate professor Debajit Saha and his team in MSU's College of Engineering published findings Monday, Aug. 17, in the Journal of Hazardous Materials Advances showing that neurons in a locust's brain produce distinct patterns when exposed to different PFAS compounds, including PFOS, one of the most common forever chemicals. The insects detected PFOS at concentrations similar to those found in contaminated environmental samples, according to MSU Today.

"There is a tremendous need for technologies that can identify them at very low concentrations," Saha told WLNS.

PFAS contamination sites in the Lansing area include the Lansing Airport Hangar and the Grand Ledge Army Aviation Support Facility. As of September 2025, no cleanup timeline had been set for a contaminated site in Lansing, according to Bridge Michigan. Statewide, Michigan has more than 200 known PFAS-contaminated sites.

Current detection relies on liquid chromatography-mass spectrometry, equipment that is expensive, requires specialized lab facilities and cannot be deployed in the field. Most existing methods target only specific compounds, making broad screening difficult.

Saha's team recorded neural activity from the odor-processing region of locust brains while exposing the insects to gases containing several PFAS compounds. Each chemical produced what the researchers call an "odor fingerprint." The finding surprised the team because PFAS are entirely human-made and have existed for only a few decades, leaving no obvious evolutionary reason for the locust's strong response.

Nobody expected it to work.

Lead author Summer McLane-Svoboda, a doctoral candidate in Saha's lab, said in the MSU press release that the team was unsure whether the locust brain would respond to PFAS at all. Once they saw distinct neural patterns for different compounds, she said, they realized biology could become a sensing platform for the chemicals.

The next step: testing environmental water samples collected across Michigan to see whether the method works outside the lab. The researchers aim to miniaturize the technology into portable biological sensors capable of rapidly screening multiple PFAS compounds in the field.