Pulmonary Toxicity Studies of Lunar Dust in Rodents C.-W. Lam,1, 2,* J. T. James,1 N. Khan-Mayberry,1 D. Hammond,2,3 R. Hunter,4 R. McCluskey,5 L. Taylor,6 B. T. Chen,7 P. C. Erdely,7 and V. Castranova.7 1Johnson Space Center Toxicology Group and 2Wyle, NASA Johnson Space Center, Houston, TX; 3Bioanalytical Core Labo-ratory, NASA Johnson Space Center, Houston, TX; 4Dept. of Pathology and Laboratory Medicine, University of Texas Medical School, Houston TX; 5Center for Disease Control, Atlanta, GA; 6Dept. of Earth & Planetary Sci-ences, University of Tennessee, Knoxville, TN; and 7Health Effect Laboratory Division, National Institute for Oc-cupational Safety and Health, Morgantown, WV. *Chiu-wing.Lam-1@nasa.gov

Introduction: NASA plans to build an outpost on the lunar surface for long-duration human habitation and research. The surface of the Moon is covered by a layer of fine, reactive dust, and the living quarters in the lunar outpost are expected to become contaminated by lunar dust. Because the toxicity of lunar dust is not known, NASA is concerning about its toxicity. We studied the pulmonary toxicity of lunar dust similant (JSC-1), and are currently assessing the toxicity of lunar dust in lungs of exposed rodents. The results of our preliminary study examining the biomarkers of toxicity in bronchioalveolar fluid (BALF) from mice intratracheally instilled (ITI) with the lunar dust show that the dust is somewhat toxic (more toxic than TiO2, but less than quartz dust). More extensive studies have been initiated to further examine BALF and lung tis-sues for histopathological lesions in rodents exposed to lunar dust by ITI and by inhalation. The results of these studies will reveal the toxicological risk of inha-lation exposures to lunar dust and are essential for set-ting exposure limits on airborne lunar dust for astro-nauts living in the lunar habitat.

NLSI Lunar Science Conference (2008) 2136.pdf

Preliminary Results and Conclusions

In the pilot study in mice given equal doses of each lunar dust, titanium dioxide, and quartz (0.3 or 1 mg per mouse), we observed that lu-nar dust in the lung caused greater influx of blood neutrophils (white blood cells) from the blood (in response to inflammation signals from the lung) than that induced by TiO2, but less than that caused by quartz.

Lunar dust is somewhat toxic (saline <TiO2 < lunar dust < quartz)

Further Studies

Larger scale (core) studies have been initiated to further assess the biomarkers of toxicity in lung lavage fluid samples and histopathology of the lungs in rodents exposed to the lunar dusts (aged and activated) and reference dusts by intratracheal instillation.

Histopathology of lung tissues in rodents ex-posed to lunar dust by inhalation will be stud-ied.

Significance

The results of these studies will reveal the toxico-logical risk of inhalation exposures to lunar dust and are essential for setting exposure limits on airborne lunar dust for astronauts living in the lunar habitat. References Lam C.W. et al. (2002). Inhal. Toxicol. 14: 901-916. Lam C.W. et al. (2002). Inhal. Toxicol. 14: 917-928 Latch, J.N., and Lam C.W. et al. (2008) Inhal. Toxicol. 20

(2):157-165.

NLSI Lunar Science Conference (2008) 2136.pdf