HARRISBURG, Pa. - Both parties in a Pennsylvania Supreme Court case challenging the causation standard in an asbestos action now agree that the plaintiffs lack evidence of regular and frequent exposure given the court's rejection of the "each and every" exposure theory, the court held Sept. 26 (Margaret Howard, et al. v. A.W. Chesterton Co., et al., Nos. 48 EAP 2012, 49 EAP 2012, 50 EAP 2012, Pa. Sup.).