Mock moon dust kills cells and alters DNA — What about real dust?

In a study published in the journal GeoHealth, scientists from Stony Brook University School of Medicine in Stony Brook, New York found that simulated lunar soil is toxic to human lung and mouse brain cells.

No humans or live mice were sent to the moon or exposed to the mock lunar dust in the laboratory, and that is definitely a good thing. Up to 90 percent of human lung cells and mouse neurons died when exposed to dust particles that mimic soils found on the moon’s surface.

Lunar dust causes reactions similar to the sneezing and sniffles brought back with Apollo Astronauts who visited the lunar surface. “I didn’t know I had lunar dust hay fever,” commented Apollo 17 geologist-astronaut Jack Schmitt at the time.

Buzz Aldrin was the Lunar Module pilot on Apollo 11. On July 20, 1969, he was the second human being to set foot on the Moon, following mission commander Neil Armstrong.

NASA

The Apollo Astronaut’s experience coupled with the new study’s results suggest prolonged exposure to lunar dust could impair airway and lung function, according to Bruce Demple, a biochemist at Stony Brook University School of Medicine and senior author of the new study. If the dust induces inflammation in the lungs, it could increase the risk of more serious diseases like cancer, he said.

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

NASA Lunar Sample Return Container with Lunar soil on display at Space Center Houston Lunar Samples Vault, at NASA’s Johnson Space Center. Photo taken on July 12, 2017.

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The properties of lunar dust
Lunar dust is quite different from the dust we see in our homes here on Earth. House dust is composed of organic materials, like skin cells, pet dander, and pollen grains. And, it is soft. You can wipe it off with a soft cloth and it won’t scratch the furniture, and for the most part, it isn’t very thick.

Let’s talk about lunar soil for a moment. Lunar soil or lunar regolith is actually not soil as we know it. Regolith is inorganic, having been formed from the mechanical disintegration of basaltic and anorthositic rock resulting from continuous meteoric impacts and bombardment by interstellar charged atomic particles over millions of years.

The Mare Mare Serenitatis or Sea of Serenity on the Moon as it really is below layers of dust accumulated over billions of years.

Bruce Campbell (Smithsonian Institution, National Air and Space Museum); Arecibo/NAIC; NRAO/AUI/NSF

The constant mechanical weathering grinds the particles into finer and finer pieces composed of grains 1 centimeter in diameter or less. Lunar dust generally refers to even finer materials than lunar soil. There is no official definition of what size fraction constitutes “dust.”

However, some scientists place the cutoff at less than 50 micrometers in diameter, while others at less than 10 micrometers. A micrometer is one-millionth of a meter.

Another difference in Earth soil and lunar regolith – First, the moon is extremely dry, so there are no minerals with water as part of their structure, such as clay or mica, which are found on Earth. Secondly, lunar regolith and lunar dust are chemically reduced, rather than being significantly oxidized like the Earth’s crust.

This is due to the constant bombardment of lunar soil and dust by protons (i.e. hydrogen (H) nuclei) from the solar wind. Additionally, with the untold number of meteorite and micrometeorite impacts, the lunar surface is covered in a thick layer of lunar dust. The dust is electrically charged and sticks to any surface it comes in contact with.

Buzz Aldrin deploying the Solar Wind Collector (SWC) on the moon

NASA/APOLLO 11

And because of its makeup, being rock and glass particles, it is abrasive. This means it cannot be wiped off a spacesuit or any machinery because it can damage the surface. It is so fine it can get into electronic instruments and cover the face masks of helmets. It is insidious and everywhere.

The results of the study using simulated lunar dust
Because lunar dust on Earth is sparse, the researchers used different mixtures of dust samples from Earth that resemble soil found in lunar highlands and the moon’s volcanic plains.

According to the study, “all the simulant types killed or damaged the cells’ DNA to some degree. Simulants ground to a powder fine enough to be inhaled killed up to 90 percent of both human and mouse cell types.

The simulants killed the human lung cells so effectively the researchers couldn’t measure the DNA damage. The simulants also caused significant DNA damage in mouse neurons.”

Astronaut Edgar D. Mitchell, Apollo 14 Lunar Module pilot, moves across the lunar surface as he looks over a traverse map during extravehicular activity (EVA). Lunar dust can be seen clinging to the boots and legs of the space suit.

NASA

The study concludes: “We found significant cell toxicity in neuronal and lung cell lines in culture, as well as DNA damage associated with the exposure. Unexpectedly, these effects did not reflect the ability of the simulants to generate free radicals.”

Now that the researchers have demonstrated danger with the simulated dust, “they hope they’ve made enough of a case to acquire some real lunar dust from NASA that was recovered from the Apollo missions,” Demple said.

The study, “Assessing Toxicity and Nuclear and Mitochondrial DNA Damage Caused by Exposure of Mammalian Cells to Lunar Regolith Simulants,” was published in the journal GeoHealth.