Protruding from the flat roof of Paulsboro High School and overlooking several refineries are chimneylike devices that measure toxins in the air.

"I was expecting something bigger," said Schools Superintendent Frank Scambia, referring to equipment installed this year by the U.S. Environmental Protection Agency. "I envisioned it would be a towery thing, a tripod with gadgets all over it."

The unobtrusive machines are gathering data for a report on the possible short- and long-term effects of toxins on area residents. Interim findings in Paulsboro have offered little reason for concern in the short term, according to the EPA.

The measurements on two toxins - acetaldehyde and nickel - were well below the measurements that could lead to health problems in the short term, according to data released this week by the EPA.

Acetaldehyde, found in exhaust, can cause cancer of the respiratory tract; nickel, found in oil and coal combustion, is linked to bronchitis and lung cancer.

In October, the EPA reported that air outside the Paulsboro school contained low levels of heavy metals.

Still being monitored is benzene, a volatile organic compound (VOC) used to make plastics, lubricants, resins, and other things. Long-term exposure has been linked to leukemia and bone-marrow ailments.

The EPA announced that it would begin monitoring air quality at 62 schools nationwide in April, after identifying schools near heavy industry or in polluted urban areas.

In sharp contrast to Paulsboro, elevated levels of potentially carcinogenic toxins have been found at some schools in West Virginia and Ohio, according to the EPA interim results.

The school in Gloucester County, a few hundred feet from the Valero refinery, is the only one in the Philadelphia region being monitored. Six in Pennsylvania and one other in New Jersey are on the study list.

The EPA expected to release its final report this month, but that has been delayed by malfunctioning equipment used to test and analyze VOCs at some schools, including Paulsboro. Testing at those places is continuing.

Long-term effects of all the toxins are still being analyzed, and a final report is pending.

Elias Rodriguez, EPA Region 2 spokesman, said the final reports were expected within a few months. The agency, he said, is looking for contaminants associated with industries and cars, trucks, and airplanes after monitoring the air outside the schools during 60-day periods.

Besides Valero, the 475-student Paulsboro High School is also close to NuStar Energy, Exxon Mobil Research Laboratory, Air Products & Chemicals Inc., and the soon-to-be-shuttered Sunoco refinery.

Scambia said parents have not been alarmed by the testing because many of the families "have lived here long periods of time and are used to being neighbors to industry." He said he welcomes the testing because he believes no significant health risks will be identified.

"The unknown is always frightening, but if you do research," Scambia said, "it gives you a better picture of what you're dealing with."

Contact staff writer Jan Hefler at 856-779-3224 or jhefler@phillynews.com.