A California appeals court ruled yesterday that pesticide companies can be sued over concerns that home bug sprays are making people sick. The court in Los Angeles rejected arguments by Dow Chemical and other chemical manufacturers that they were protected from suits covering chemicals approved by the U.S. EPA for residential use. It said the EPA-approved warning labels could not be challenged, but a jury could still decide that a chemical’s dangers to human health outweighed its benefits. The case involves a couple who believe that ant spray used by their landlord caused brain damage to an unborn daughter and sickened a baby daughter.