There's frequently talk about returning astronauts to the Moon and establishing a permanent lunar base, but scientists at Stony Brook University say that prolonged exposure to lunar dust could make staying there a risky business. In tests, exposure to dust particles of simulated lunar soil resulted in up to 90 percent of human lung cells and mouse neurons being killed, with the potential for increased cancer risk also evident.

When the first American astronauts set foot on the Moon in 1969, one of the first things they encountered was the peculiar properties of the lunar dust that covers the surface of our only large natural satellite. Unlike the soil on Earth, lunar soil is the product of millions of years of micrometeorite impacts, extreme temperature variations, and constant cosmic ray bombardments occurring in a waterless vacuum.

Without the effects of oxygen, water, and biological activity to moderate them, the dust particles on the Moon become tiny, abrasive, chemically reactive, and carry a high static charge. The result is a very unpleasant blackish gray powder that clung fiercely to the astronaut's suits, wore at the joints that sealed their helmets, gloves, and other fittings, and produced hay fever symptoms that persisted even after returning to the orbiting Command Module.

Led by Rachel Caston, a geneticist at Stony Brook University School of Medicine, the team's work on simulated lunar soil indicates that while the watery eyes and runny noses of the Apollo crews were only temporary, those working for months at a time at a manned lunar outpost could face more serious disorders, such as cancer.

According to Caston, the effects of lunar dust is similar to silicosis – a condition found in coal miners or those who breathe in toxic dust from dust storms or volcanic eruptions. The tiny silica particles settle in the alveoli of the lungs, where they can cause gross damage or even affect the DNA of cells, resulting in cancer.

Using recreated lunar soils designed to simulate those found in the lunar highlands, Caston's team exposed growing human lung cells and mouse brain cells to variants of the dust under controlled conditions. They found that when the dust was ground fine enough, it killed up to 90 percent of all cells. It also significantly damaged the DNA in the mouse neurons, but killed the human cells so effectively that it wasn't possible to measure DNA changes.

Exactly how the dust causes so much damage is still unclear, but the team believes that it may have to do with causing an inflammatory response inside the cells or by triggering the production of free radicals, which can strip electrons from certain molecules and negatively impact their functionality. But whatever the mechanism, the study indicates that lunar dust may be more than just a housecleaning problem.

The research was published in GeoHealth.

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