Researchers from the United States have discovered that breathing on the lunar surface could be hazardous to your health.

They have found that the fine-grained dust that covers the moon is sharp-edged, chemically active and ubiquitous.

"The dust is electrostatic - it just sticks to everything," explained University of California San Diego Associate Professor Chantal Darquenne, who is working under a NASA grant to study how moon dust lodges in the lungs.

The first wave of lunar explorers didn't have much to worry about since their forays were relatively short. The longest stay on the moon was a 75-hour visit by Apollo 17 in 1972.

However, lunar astronauts reported irritation and discomfort from exposure to dust, with symptoms ranging from sneezing, watery eyes and a peculiar smell resembling gunpowder, says NASA flight surgeon Jeff Jones.