WILLOWBROOK, Ill. (AP) — A new federal study shows people living near a contract sterilization company in a western Chicago suburb face some the country’s highest cancer risks from toxic air pollution.

The Chicago Tribune reports that federal officials began investigating Sterigenics International last year after surrounding communities were identified on a national map of health hazards from breathing toxic chemicals.

The U.S. Environmental Protection Agency posted the study online without notice on Friday.

Nearly 20,000 people in southeast DuPage County live within a mile of the Willowbrook facility. Four schools and a day care center also located near the facility.

Since 2011, the company has been owned by a private equity firm co-founded by Illinois Gov. Bruce Rauner, who left the firm in 2012 to begin campaigning for public office.

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