MCKEES ROCKS, Pa. -- On Wednesday, the Allegheny County Health Department released results of air monitoring performed inside the Sto-Rox Elementary School.

The school requested the monitoring after a USA Today article said the air outside the school had one of the highest levels of pollution in the country.

Sto-Rox Elementary was listed as the 28th worst school for toxic air pollution in the nation out of 128,000 schools.

The county's sampling does not show any detectable concentration of dicyclopentadiene (DCPD) in the air inside or outside the school, as suggested in the newspaper article.

However, measurable concentrations of benzene and toluene were found at two locations inside the school.

Concentrations of benzene were several times higher than outdoor concentrations measured around the same time at the outdoor sampling locations.

Benzene and toluene are known to be emitted by industrial sources on Neville Island, but it can be emitted from diesel and gasoline engines and have been linked to cancer.

The school said it has added more fresh air ventilation to help address the problem.

"You can't have the little ones breathing any of that in. We breath enough bad chemicals in everyday when we are walking outside, let alone in the schools," said parent Joseph Horth.

The Health Department will continue to sample the air and will visit the area with portable instruments to measure toxic chemicals in real time.