The only scientist to walk on the moon found he was allergic to moon rocks in ironic twist

NASA launched 14 Apollo missions between 1961 and 1972. While most people know about Neil Armstrong’s historic Moon landing on July 20, 1969, with Apollo 11, fewer talk about the final Apollo mission that brought more scientists to the lunar surface. Oddly enough, Apollo 17 astronaut Harrison H. Schmitt discovered he had an allergic reaction after his walk on the Moon.

According to IFLScience, Schmitt made this startling discovery after returning to the lunar module in December 1972. Apollo 17 marked the final crewed mission to the Moon before the Apollo program ended. As a geologist, Schmitt was responsible for collecting rock samples from the Taurus-Littrow valley, the landing site near the Sea of Serenity.

He came in contact with lunar dust when he finally removed his safety suit inside the module. “The first time I smelled the dust I had an allergic reaction, the inside of my nose became swollen, you could hear it in my voice," Schmitt said at the Starmus space festival in 2019, per The Telegraph. "But that gradually went away for me and by the fourth time I inhaled lunar dust I didn’t notice that." However, Schmitt wasn't the only astronaut who suffered from an allergic reaction to the dust they encountered on the Moon's surface.

A flight surgeon who was on board with them had to pause his work while taking the safety suits out of the command module because he experienced a strong allergic reaction to the dust. This problem had significantly affected some of the future missions, per the words of Schmitt. “For some individuals, we need to find out whether they are going to have a reaction if they are going to be exposed chronically to Moondust," he said. “Now my suggestion is don’t ever let them be exposed to lunar dust and there are many engineering solutions since I was flying to keep dust out of the cabin, to keep it off the suit. It’s going to be primarily an engineering problem.”

The allergic reaction has been dubbed "lunar hay fever" by the European Space Agency and ever since Apollo 17's mission and Schmitt's experience, many other astronauts have suffered from the allergic reaction to some extent. Some individuals faced symptoms like mild sneezing or nasal congestion that recovered quickly but others had to suffer through it for a few more days. European Space Agency explained that the reason this phenomenon happens is likely because of the presence of static. "On the Earth, particles get smoothed out by erosion from wind and water," ESA explained.

But on the Moon, there is nothing to erode these dust particles, so it remains coarse and sharp. Since the Moon has a different atmosphere which protects it from radiation, the soil on the lunar surface becomes statically charged which sends these irritating dust particles into the air and makes it easier to get into the space equipment, safety suits and eventually into the lungs of the astronauts. “Particles 50 times smaller than a human hair can hang around for months inside your lungs," Kim Prisk, a pulmonary physiologist involved in human spaceflight, said in the ESA statement. "The longer the particle stays, the greater the chance for toxic effects."

Editor's note: This article was originally published on December 28, 2023. It has since been updated.