Chasing Moon Dust
Katie Luc, an undergraduate research assistant, prepares a machine to slice mouse lungs.
Text and photos by Briana Lionetti
The dangers that a crew of NASA astronauts might face on a mission to the moon are well known from the days of Apollo: Launch and re-entry, radiation, space debris. But there’s one more that never got much attention.
Ever since astronauts walked on the moon, scientists have worried about the potential health hazards of microscopic lunar dust. Now a diverse team of researchers at Stony Brook University is trying to understand how it affects the human body, including how toxic it may be.
Lunar dust is not your everyday grime. It is constantly exposed to ultraviolet rays, which eliminates electrons and causes static cling, making the dust stick to anything it touches. At the same time, the moon is constantly hit by meteorites that break its surface into tiny slivers, making the lunar dust as sharp as glass.
“The very adhesive properties of the lunar dust caused astronauts respiratory problems on Earth,” said Bruce Demple, professor of pharmacological sciences at Stony Brook Medical School.
When Apollo 17 landed on the moon in 1972, astronauts Harrison Schmitt and Eugene Cernan set up experiments and collected samples from the surface. Schmitt and Cernan didn’t wipe the dust off their suits and complained of congestion and coughing on their way back to Earth, said Rachel Caston, a Ph.D. student in Demple’s lab. The astronauts experienced symptoms similar to hay fever, including runny noses, watery eyes, congestion and coughing.
The dust was discovered to contain silicon, a common element on Earth that can be dangerous to inhale. It can cause silicosis, which can scar the lungs and make it hard to breathe. Silicosis is seen in occupations such as mining, foundry work and glass manufacturing, according to the American Lung Association.
Demple and Caston are part of a larger extraterrestrial project, the NASA-funded RIS4E research team. Led by Timothy Glotch, associate professor of geosciences at Stony Brook, the project has a five-year grant from NASA to learn more about the geology of the moon and Mars to help prepare astronauts for future travels.
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In the white windowless lab of the Basic Science Tower at Stony Brook, Katie Luc, an undergraduate research assistant, prepares a machine to slice mouse lungs. The slices are 400 microns long, a tiny two-hundredths of an inch. Mice have five lungs, which Luc removes and douses with a lunar simulant — dust that resembles lunar dust but actually comes from a volcano in Hawaii. Then she lets the slices sit for 30 minutes. She repeats the experiment two or three times a month. Luc’s goal is to see what happens to lung tissue after short-term exposure to lunar simulant dust.
After a complicated series of DNA extractions, Luc can see that the DNA in the lung tissue has been altered. The proteins inside the cell change shape, which changes the way the DNA replicates. Something abnormal is going on, Demple says, but it’s too early in the research to link it to a specific disease or medical condition.
Slideshow: Katie Luc examines mouse lung samples
Although the lunar simulant they use is the closest thing these scientists have to real lunar dust, there are differences: Unlike the simulant, real lunar dust is exposed to constant UV radiation or solar winds, and comes from a world with no oxygen. “None of this is represented in our experiments,” Demple said. “Of course, we would like to get samples of the real thing one day.”
Glotch said that using the simulant is a first step. “Lunar soil and dust is very precious, and NASA doesn’t just give it out to anyone, especially for experiments that destroy the samples, which these experiments do,” he said. Once their testing procedures are perfected, they expect to get real moon dust, he said.
Across the hall from Demple’s lab, Jill Nissen, a postdoctoral researcher in neurobiology, is using lunar simulants and mice to study moon dust from a different angle: the immune system.
Nissen extracts bone marrow from the mice’s femurs, or thigh bones. The marrow contains immune system cells called macrophages that are responsible for cleaning up cells that don’t belong in the body. They also play a role in inflammation, Nissen said. He and Stefania Gourzi, a volunteer working in the lab, do the same slicing and use the same simulant as Luc but they’re looking for areas of inflammation – the places with the most macrophages.
Nissen and Gourzi have run into some challenges in these experiments. One batch of immune cells was infected with a disease, and they had to wait weeks for a new batch. They saw inflammation in the tissue, but Nissen explained that chopping up fresh immune tissue stresses out the individual cells, and sometimes that itself can cause inflammation. So they now must differentiate between inflammation from lunar dust and from cellular stress.
In another line of research, Donald Hendrix, a Ph.D. student in geology, is studying how water affects the toxicity of the lunar dust simulant. When we breathe in, anything in the air will react with the water inside our lungs. When Hendrix mixes the simulant with water, it produces a compound called a hydroxyl radical. This radical has been shown to cause lung cancer in human beings.
For all its success and fame, the Apollo missions sent just a small number of astronauts to the moon, and only for short periods. But future missions may be larger and last longer.
“As space travel technology advances, there will be an increased demand for tourism and manufacturing in outer space,” Hendrix said. “This means that the number of people that go into space will increase.”
Even without space travel, research into the toxicity of moon dust is worthwhile, Demple said.
“What we learn about the molecular effects of exposure to toxic agents in lungs will have broad utility for not only exposure to lunar dust but all types of Earth materials as well,” he said. “And understanding the underlying mechanisms is useful.”