Stony Brook researchers: Lunar dust unsafe for humans

Moon dust is nothing like soils on this planet and could prove toxic to astronauts who journey to Earth's closest celestial sibling  for long-term missions, an interdisciplinary team of scientists at Stony Brook University has found.

Emerging discoveries about the orb on Earth’s outskirts — 238,900 miles away — define it as airless, waterless, dark, dusty and potentially inhospitable to long-term human habitation. Moon dust is noxious to human cells and capable of damaging DNA, a series of laboratory analyses has revealed.

Stony Brook’s findings add to reams of NASA studies involving research about a world that may appear dead to the unaided eye but is a “bustle of unseen commotion,” centered largely on the activity of moon dust, NASA lunar scholar Michael Collier has found.

The dust levitates. It also leaps from one region of the moon to the next. And stunningly — Collier's ongoing research has shown — moon dust can whip itself into electrically charged clouds that move in a unified direction across the lunar landscape, swarming like bees.

When Stony Brook scientists exposed human lung cells to simulated moon dust in the lab, about 90 percent died. The same percentage of mouse brain cells succumbed following identical exposure.

Simulated moon dust was so toxic to human lung-cell DNA that scientists couldn’t even measure the extent of the damage because the genetic material was completely destroyed.

The simulated dust was derived from pulverized Earth rocks that were ground into a fine powder that carried the same charge as the electrostatic dusts found on the moon. The orb is constantly swept by streaming solar winds, blown off the sun at a million miles an hour, exposure that imbues dust particles with an electrical charge.

“We don’t have the experience yet of a long term presence on the moon. When the astronauts went there, the dust stuck to their spacesuits and was difficult to get off,” said Bruce Demple, a biochemist at Stony Brook University School of Medicine and a researcher on the lunar dust team.

The electrostatic state of lunar dust causes it to be clingy, which explains why the fine, gritty dust stuck to Apollo spacesuits.  

After inhaling moon dust decades ago, Apollo 17 astronaut Harrison Schmitt described coming down with “lunar hay fever” — sneezing, watery eyes and sore throat. Schmitt piloted the last U.S. moon mission in December 1972.

Apollo astronauts' time on the moon was brief, but proposed exploratory and military journeys are likely to be longer. Future planetary explorers and space cadets may be on the moon bouncing around in a gravity-free world for extended periods of time.

“If we have a presence on the moon, there will be exposures to the dust,” Demple said. “And our moon isn’t the only place where this kind of exposure can occur. We are also investigating Phobos and Deimos, the moons of Mars.”

Investigations into the moon’s mysterious dust had been underway long before the Trump administration’s proposal of a far-flung sixth branch of the U.S. military, a brigade called Space Force. And while skywatchers were dazzled by the longest “Blood Moon eclipse" of the century in late July, decades of NASA studies caution that the moon possesses deceptive beauty: Its dust is radically different from soils that pervade Earth.   

Demple, who describes himself as an Apollo nerd, collaborated with postdoctoral researcher Rachel Caston, a geneticist in the School of Medicine, and Joel Hurowitz, an assistant professor in the department of geosciences, to better understand lunar dust.

“The moon will probably be the first destination in sending astronauts back into space,” Hurowitz said, noting the moon is the closest extraterrestrial site to Earth.

But Hurowitz and the other Stony Brook researchers are raising intriguing new questions about long-term human safety.

Although NASA has been well aware for decades that the space environment and zero gravity can pose health risks, the subject of toxic dusts on distant spheres has been mostly overlooked, Caston said.

“NASA has done small studies in animals, but those studies really didn’t bridge the gap to examine the cellular effects,” said Caston, who was the lead author of a Stony Brook research paper on lunar dust published earlier this year in GeoHealth, a journal of the American Geophysical Union.

Caston and her colleagues found moon dust to be toxic, even in minute doses. She said cells used in the analysis were introduced to several types of dusts that resemble soils in the lunar highlands as well as those found in the moon’s volcanic plains. The cells were propagated under controlled conditions before being exposed to dust samples, she said.

Samples of lunar soil were too scarce and valuable to use in the research, Hurowitz explained, so the researchers depended on substitutes.

“Just a few precious samples were brought back from the moon during the Apollo era,” said Hurowitz, who is handling the geological aspects of the research. “The types of rocks you would find there are not found here on Long Island.”

The team turned to the next best thing, rocks harvested from Earth's water-starved regions such as the Mojave Desert, home to Death Valley, a mostly barren badland in southeastern California.

Harvested rocks were put into a special grinder and the process of pulverizing them imparted an electrical charge, generating a primary feature of moon dust.

Lessons on toxic dust inhalation already abound on Earth. Noxious dusts can have an adverse effect on the human respiratory tract, causing wheezing and lung-tissue scarring.

What’s different about moon dust is its potential to inflict cellular harm in tiny quantities. The findings, the team agreed, raise new concerns about sojourns not only to the moon but to the storied red planet, Mars.

“The surface of the moon is not protected by an atmosphere,” Demple said, and without that protective shroud, the moon’s soil is under constant bombardment by charged particles that stream through space from the sun.