SAN FRANCISCO -- A new Cincinnati Children's Hospital Medical Center study shows that exposure to environmental tobacco smoke, even at extremely low levels, is associated with behavior problems in children and pre-teens. While the study examined 5 to 11 year olds with asthma, the findings most likely could be extrapolated to include children without asthma who "act out" or experience depression and anxiety, according to Kimberly Yolton, Ph.D., a researcher at the Children's Environmental Health Center at Cincinnati Children's and the study's main author The study will be presented at 8:30 a.m. Pacific time Sunday, April 30, at the annual...