A review of Calcasieu Parish, La., school records could tip off researchers as to whether pollution in the area has affected students’ ability to learn, a toxic substance specialist said.

Earlier this year, researchers ran blood tests for Mossville, La., residents and found higher-than-normal levels of dioxin, which scientists have associated with cancer, birth defects, and skin ailments.

Peter Orris, a doctor at Chicago’s Cook County Hospital and a consultant for the Agency for Toxic Substances and Disease Registry, said dioxin also has been linked to concentration and other learning problems.

Reviewing student performance, along with certain types of testing, should help researchers identify whatever learning disabilities exist because of area pollution, Orris said.

Mossville residents were told in April about relatively high dioxin levels.

Doctors had drawn blood from 28 longtime residents and sent it to the Centers for Disease Control and Prevention in Atlanta, which found above average amounts of dioxin in 12 people. Four of those had levels 2-3 times higher than normal.

Dioxin is a byproduct in the manufacture of chlorine and vinyl products.

Researchers have yet to pinpoint the source of dioxin in the area. Officials with local industry, which includes a Condea-Vista plant in Mossville and other factories in the Lake Charles area, say they are trying to determine where the substance is coming from as well.