1. 3M Company, Medical Department, St. Paul, Minnesota, American Red Cross, North Central Region, St. Paul, Minnesota, University of Minnesota, Division of Environmental Health Sciences, Minneapolis, Minnesota, 3M Company, Environmental Laboratory, St. Paul, Minnesota, American Red Cross, Carolinas Region, Charlotte, North Carolina, American Red Cross, Southern California Region, Los Angeles, California, American Red Cross, Pacific Northwest Region, Portland, Oregon, American Red Cross, Greater Alleghenies...