The Colorado Department of Public Health & Environment has discovered elevated levels of benzene near Bella Romero 4-8 Academy in Greeley, as confirmed in separate tests two weeks apart.

The school is approximately 1,200 feet from a well pad and associated oil and gas extraction facilities. The state is investigating the O&G operations, and whether they may have played a role in the measurement.

“While we can’t say conclusively why this instance of elevated benzene occurred, the state is taking further action now to ensure the kids in this school and people in this community have peace of mind and clean air to breathe,” John Putnam, director of environmental programs with the CDPHE, said in a statement.

Benzene is colorless and odorless, and is part of crude oil and gasoline. Glue, paint, and detergent also have benzene, and the Centers for Disease Control and Prevention reports that indoor benzene levels are often higher than those outdoors.

Long term, benzene can decrease red blood cell count, causing anemia and affect the immune system.

The state began targeted air monitorings in the wake of its report on the health risks of oil and gas. The study concluded that there may be adverse health impacts from O&G operations, but only in rare, worst-case situations.