“It’s not elevated to the point where it’s necessarily like an immediate ‘evacuate the building’ health concern,” said Dr. Albert Presto, an associate research professor of mechanical engineering at Carnegie Mellon’s Wilton E. Scott Institute for Energy Innovation, who is working on the university’s chemical monitoring effort in East Palestine. “But, you know, we don’t know necessarily what the long-term risk is or how long that concentration that causes that risk will persist.”

Much of what scientists know about chemical exposure comes from people’s contact with chemicals at work, Preston said, which generally means exposure for about eight hours a day. People now living in East Palestine are in constant contact with the chemicals, he said, and the impact of that kind of exposure on the human body is not fully understood.