A chemical byproduct found in some treated drinking water in the U.S. that remained a mystery for more than 40 years may have finally been identified by scientists. The authors of the study, published Thursday in the journal Science,

Scientists at the University of Arkansas have identified a previously hard to isolate compound of a drinking water treatment chemical.

Scientists have identified the byproduct of a chemical used to disinfect tap water and prevent waterborne illnesses. Researchers urge testing for toxicity.