MIDLAND, Pa. In this borough of 2,900 in the westernmost part of the state, the steel industry used to be the primary employer. Today, Midland's schools offer the most jobs — and now are beginning to unravel a mystery that could affect the health of their students.
The highest readings appeared near seven of the schools, including Midland. At those locations, USA TODAY's monitoring showed pollution at levels that could make people sick or significantly increase their risk of cancer if they were exposed to the chemicals for long periods.
SEE THE RESULTS: Schools listed with chemical concerns