Lunar Dust Toxicology
John Jr. investigates the effects of lunar dust on human lung cells
The National Aeronautics and Space Agency (NASA) is preparing to take the U.S. back to the Moon and beyond, venturing further into the solar system with an ultimate goal of sending a person to Mars. A key step in this plan includes building a permanent manned space station on the Moon. Space dusts of uncertain and varying composition will be significant health hazards on these missions, particularly for personnel stationed on the Moon. Spacesuits, the first line of defense, will not adequately address the hazard, and dust will become a common and increasing hazard to personnel stationed there and to those who come into contact with the spacesuits. The hazards arise from the dusts sticking to the spacesuits when the astronauts are on the moon’s surface and falls off inside their living space and into the air they breathe.
NASA has determined that lunar dust consists of heavy metals such as iron, aluminum and manganese and, therefore, anticipates that it will be toxic as well. The mechanisms of how metal particles cause toxic effects are poorly understood and thus, the risks of particle exposure is a major health concern for NASA as astronauts traveling in outer space, especially on planned lunar and Mars missions, will encounter dusts of a variety of sizes and compositions. Some of these dusts may contain elements currently unknown to mankind. NASA astronauts and personnel will be exposed to space dust from the Moon, eventually Mars and possibly beyond. It is essential that NASA’s lunar station design address dust exposure limits and the engineering controls needed to protect the health of NASA personnel and others.
Two published studies on the toxicology of space dust indicate that lunar and Martian dusts clearly exhibit toxic effects. These studies showed that in mice these dusts were more hazardous to the lungs than nuisance dusts (1-2). In addition to space dust, NASA personnel are also extensively exposed to engineered nanoparticles, which are used in a wide range of applications as NASA sees nanotechnology as providing an entirely new range of space architectures. NASA personnel working with these materials face uncertain health effects from nanoparticles. Thus, NASA needs to understand the aspects that make particles toxic to different organ systems in order to develop strategies to minimize and prevent toxic outcomes.
Our research objective is to develop a system for characterizing the potential cytotoxic, genotoxic and carcinogenic hazard of space dusts so that permissible exposure limits and engineering controls can be better determined to protect against them. We will create this system by using lunar dust as a model space dust and characterize its toxicology in different human cell types. We will then compare the effects and potency of lunar dust to particulates with known cytotoxic, genotoxic and carcinogenic effects. From this comparison, lunar dust exposure limits can be derived based on those established for the known particulates. Future efforts will allow us to apply this approach to other space dusts as well as nanoparticles used in NASA materials.
Inhalation and dermal exposure are major routes of exposure for lunar dust, and so we will focus on effects in human lung and skin cells including both fibroblasts and epithelial cells. We will also consider brain and immune cells as potential targets. We will compare the effects of two lunar dust simulants and lunar dust itself to the effects of titanium dioxide, aluminum oxide, quartz, particulate chromate and silver nanoparticles to provide a context for the potency of effect and to eventually determine permissible exposure levels. These experiments are currently underway.
Microgravity University: In addition to conducting experiments at our USM facilities, a team of undergraduate students from USM and UMO will be participating in NASA’s Reduced Gravity Student Flight Opportunities Program this summer. The program involves designing an experiment, raising funds, and traveling to Johnson Space Center in Houston, Texas to conduct experiments on NASA’s “Weightless Wonder,” a KC-135 aircraft which has a flight pattern to simulate microgravity (near-zero gravity) and hyper gravity (1.8-2x gravity we feel on earth). The team, led by John Wise, Jr., will test the effects of lead chromate and sodium chromate (two known carcinogens), as well as silver nano-particles (an emerging public health concern) on DNA damage and repair in human lung epithelial cells as well as the uptake of each chemical.
1. Lam C-W, James JT, Latch JN, Hamilton RF, Holian A Jr. Pulmonary toxicity of simulated lunar and Martian dusts in mice: II. Biomarkers of acute responses after intratracheal instillation. Inhalation Toxicology 14: 917-928, 2002.
2. Lam C-W, James JT, McCluskey R, Cowper S. Balis J, Muro-Cacho C. Pulmonary toxicity of simulated lunar and Martian dusts in mice: I. Histopathology 7 and 90 days after intratracheal instillation. Inhalation Toxicology 14: 901-916, 2002.
The Wise Laboratory is assisted in this work by a number of important collaborators and cooperators. In particular, the following prominent scientists and their teams provide significant support and input:
Dr. Douglas Currie is an Assistant Professor of Biology at the University of Southern Maine. He provides expert advice and guidance on the culture or brain cells and neurotoxicology.
Dr. Dianne Hammond is a senior scientist at the Johnson Space Center. She provides expert advice and guidance on the culture of cells in microgravity and in flight.
Dr. Antony Jeevarajan is Deputy Division Chief of the Habitability and Environmental Factors Division at the Johnson Space Center. He provides expert advice and guidance on the lunar dust, the Moon base mission and NASA priorities.
Dr. Michael Mason is an Assistant Professor in the Department of Chemical and Biological Engineering at the University of Maine and a member of the Institute for Molecular Biophysics. He provides expertise in particle chemistry and physics.
Dr. Ah-Kau Ng is Professor of Immunology in the Department of Applied Medical Sciences at the University of Southern Maine. He provides expert advice and guidance on the culture of immune cells and immunotoxicology.
Dr. Terry Shehata is Executive Director of the Maine Space Grant Consortium and ie the State NASA EPSCoR Director. He provides expert advice and direction on Maine and NASA’s Space research priorities. This project is being done in partnership with the Maine Space Grant Consortium.
Dr. Douglas Thompson is a Professor of Epidemiology and Associate Director of the Maine Center for Toxicology and Environmental Health at the University of Southern Maine. He provides expert advice and guidance on statistical analysis and study design.
Dr. William Wallace is a Research Scientist at the Johnson Space Center. He provides expert advice and guidance on lunar dust.
This work is generously supported by a grant from the National Aeronautics and Space Administration (NASA), the Maine Space Grant Consortium and the Maine Center for Toxicology and Environmental Health.