Lung Bioassay of Ground Dwelling Mammals from the Grand Canyon Uranium Breccia Pipe Region Using Scanning Electron Microscopy

Small mammal lung tissue sections were examined to help assess the effects of weathering on bioavailability and toxicity from sites in different phases of the mine cycle within the Grand Canyon area. Hematoxylin and eosin slides of lung tissue from brush mouse, deer mice, and pocket gophers were examined by a veterinary pathologist who marked areas of the tissue that showed normal, inflammation, bronchiolar hyperplasia, mineralization, intracellular refractile debris, macrophages, and parasitic pathology. These selected areas were examined with scanning electron microscopy and energy dispersive spectroscopy to determine the size and composition of particulate matter, if present, in these areas.