From USA Today:

The federal government’s first attempt to assess the dangers from air pollution around schools is nearing completion, and the findings underscore the need for more extensive air monitoring, especially in pollution hot spots, the head of the Environmental Protection Agency says.

“There is work to be done still on air quality,” EPA Administrator Lisa Jackson says. “The best result would be to find that all of our concerns were overblown, but we’re not finding this in every case.”

Most of the air monitoring completed so far has not found dangerous levels of pollution, the EPA says, but outside a handful of schools, the tests showed concentrations of toxic chemicals higher than what the government typically considers to be safe for long-term exposure. The EPA’s study came in response to a 2008 USA TODAY investigation that identified hundreds of schools where the air appeared to be rife with industrial pollution