A retired I-B-M employee says he has cancer caused by breathing toxic chemical vapors during the 22 years he worked at the IBM plant in Rochester. He's suing several chemical manufacturers in what his lawyer says has the potential to be the first of several similar suits in Minnesota. Minnesota Public Radio's Laurel Druley has this report. 65-year-old Ron Porter filed his lawsuit Friday in Dakota County District Court in Hastings. Porter alleges his exposure to more than 40 toxins at the I-B-M facility is directly related to his battle with non-Hodgkin's lymphoma. Porter is asking for reasonable compensation in excess of 50,000 dollars.