Toxicity of Lunar Dust in Lungs Assessed by Examining Biomarkers in Exposed MiceNASA plans to build an outpost on the Moon for prolonged human habitation and research. The lunar surface is covered by a layer of soil, of which the finest portion is highly reactive dust. NASA has invited NIOSH to collaboratively investigate the toxicity of lunar dust. Dust samples of respirable sizes were aerodynamically isolated from two lunar soil samples of different maturities (cosmic exposure ages) collected during the Apollo 16 mission. The lunar dust samples, titanium dioxide, or quartz, suspended in normal saline or in Survanta (a bovine lung surfactant), were given to groups of 5 mice (C-57 male) by intrapharyngeal aspiration at 1, 0.3, or 0.1 mg/mouse. The mice were euthanized 7 or 30 days later, and their lungs were lavaged to assess the toxicity biomarkers in bronchioalveolar lavage fluids. The acellular fractions were assayed for total proteins, lactate dehydrogenase activities, and cytokines; the cellular portions were assessed for total cell counts and cell differentials. Results from the high-dose groups showed that lunar dust, suspended in saline, was more toxic than TiO 2, but less toxic than quartz. Lunar dust particles aggregate and settle out rapidly in water or saline, but not in Survanta. Lunar dust suspended in Survanta manifested greater toxicity than lunar dust in saline. The increase in toxicity presumably was due to that Survanta gave a better particle dispersion in the lungs. The two lunar dust samples showed similar toxicity. The overall results showed that lunar dust is more toxic than TiO 2 but less toxic than quartz.
Document ID
20090036343
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Lam, C.-W. (NASA Johnson Space Center Houston, TX, United States)
James, J. T. (NASA Johnson Space Center Houston, TX, United States)
Zeidler-Erdely, P. C. (National Inst. for Occupational Safety and Health Morgantown, WV, United States)
Castranova, V. (National Inst. for Occupational Safety and Health Morgantown, WV, United States)
Young, S. H. (National Inst. for Occupational Safety and Health Morgantown, WV, United States)
Quan, C. L. (NASA Johnson Space Center Houston, TX, United States)
Khan-Mayberry, N. (NASA Johnson Space Center Houston, TX, United States)
Taylor, L. A. (Tennessee Univ. Knoxville, TN, United States)