Scientists who hope to establish a human colony on the moon have long been working through ways to generate water, food, energy and breathable air in an environment that is very different to that of Earth. As David Grossman reports for Popular Mechanics, a new study suggests that long-term missions to the moon will have to contend with yet another problem: lunar dust.

Because the moon does not have much of an atmosphere, charged particles from the upper layers of the sun constantly pelt its surface. The particles cause lunar soil to become electrostatically charged. Now, a paper published in GeoHealth, a journal of the American Geophysical Union (AGU), suggests that breathing in this dust can lead to severe health effects in humans, including bronchitis and cancer.

Lunar dirt is hard to come by, so researchers conducted their study with dust samples from Earth that are similar to what is found on the moon’s highlands and volcanic plains. They then exposed human lung cells and mouse brain cells, which were grown under controlled conditions, to the dust.

The team found that every type of dust they tested inflicted some sort of damage on the cells’ DNA. Samples that had been ground to a powder fine enough to be inhaled were particularly noxious; they killed up to 90 percent of both cell types. The damage to the human lung cells was so extensive that researchers could not accurately measure it.

As Ryan F. Mandelbaum of Gizmodo points out, the new study is not ironclad. The researchers did not use real moon dust, for one, and they relied on cells that had been grown in a lab, rather than a living human or animal. Scientists also do not know precisely why the lunar-like dirt killed the cells. According to an AGU statement, researchers suspect that the dust “could be initiating an inflammatory response within the cell or generating free radicals, which strip electrons from molecules and prevent them from functioning properly.”

Though it leaves some questions unanswered, the new study supports previous hints that lunar dust might pose risks to human health. When astronauts visited the moon during the Apollo missions of the 1960s and 70s, they reported experiencing sneezing, watery eyes and sore throats. According to the AGU statement, Apollo 17 astronaut Harrison Schmitt described his reaction as “lunar hay fever.”

These astronauts were on the moon for a relatively short period of time. But the new study suggests that prolonged exposure to lunar dust might impair airway and lung function, leading to more severe illnesses like bronchitis. Should the dust cause inflammation in the lungs, human settlers of the moon might face an increased risk of cancer, Bruce Demple, a biochemist at Stony Brook University School of Medicine and senior author of the new study, says in the statement.

“If there are trips back to the Moon that involve stays of weeks, months or even longer,” Demple added, “it probably won’t be possible to eliminate that risk completely."