Lunar dust 'may harm astronauts'

Scientists are investigating the possible threat posed to astronauts by inhaling lunar dust. A study suggests the smallest particles in lunar dust might be toxic, if comparisons with dust inhalation cases on Earth apply. Teams hope to carry out experiments on mice to determine whether this is the case or not. Nasa has set up a working group to look into the matter ahead of its planned return to the Moon by 2020. A team at the University of Tennessee (UT) in Knoxville is also looking at ways of using magnets to filter dust from the living environments of lunar bases and spacecraft. The health effects of inhaling lunar dust have been recognised since Nasa's Apollo missions. Astronaut Harrison H (Jack) Schmitt, the last man to step on to the Moon in Apollo 17, complained of "lunar dust hay fever" when his dirty space suit contaminated the habitation module after an energetic foray on the lunar surface. The US space agency (Nasa) is now keen to assess the effects of more prolonged exposure and to address the problem before humans are sent back to the Moon in just over a decade.

Details of the work were presented to the Lunar and Planetary Science Conference in Houston, Texas. Nasa's Lunar Airborne Dust Toxicity Advisory Group (LADTAG), which includes medical doctors as well as scientists from UT, have been working to characterise the dust's properties. "I've been working on lunar samples for 35 years and I have looked at fractions down to a few microns (millionths of a metre), but never anything less," said Professor Larry Taylor, director of the Planetary Geosciences Institute at Tennessee.