EMSL conducted high level morphological and chemical characterization of various asbestiform minerals for the USEPA. Samples were supplied by USEPA scientists, University and contractor participants and were analyzed by EMSL utilizing TEM with SAED and EDXA. This analysis will be used to support risk assessment through numerous toxicological studies conducted by USEPA researchers. Asbestos bioassays of fish and rat tissues were analyzed by EMSL to determine asbestos-induced mutagenicity.