NEW YORK, NY December 08, 2008 —More than half are in Brooklyn, with large numbers in Queens and Manhattan. Local sources of pollution include Brooklyn's Pfizer Plant and Navy Yard, Long Island City's Keyspan Power Station, and New Jersey refineries.

But EPA Regional Spokesman Elias Rodriguez says the newspaper's findings are limited, because it simply merged school locations with an EPA database of known industrial pollution.

RODRIGUEZ: So this is only a screening tool meant to aid researchers and stakeholders in where they can look further to examine potential problems.

REPORTER: The newspaper analysis also didn't include accidental spills, smaller emitters, and car exhaust, which together could account for as much as 80 percent of airborne toxins.

The city's public and private schools are among the worst third of nearly 128,000 schools that USA Today ranked by local industrial air pollution.