SEATTLE - An expert's testimony that each "identified exposure" to asbestos substantially contributes to mesothelioma differs from the type of "each and every" exposure challenged by a defendant, a Washington federal judge held Dec. 13 in allowing trial testimony from three experts (Joanne K. Lipson, et al. v. ON Marine Services Co. LLC, Ferro Engineering Division, No. 13-1747, W.D. Wash.; 2013 U.S. Dist. LEXIS 175317).