Ohio ranks second worst among 19 stats in the first attempt by the Centers For Disease Control to compare lead poisoning rates among children. The Plain Dealer reports that Cuyahoga County has the highest percentage among all the counties surveyed in Ohio and that about 85 percet of the county's cases are those of Cleveland. The study of children poisoned by exposure to lead based paint was done in 1989 and was published in December. Lead poisoning was linked to a drop in I.Q. in a study published last November y Doctor Bruce Lanphear, a pediatric researchers with Children's Hospital Medical Center in Cincinnati. The Centers For Disease Control says one of its national health objectives for 2010 is eliminating of childhood lead poisoning.