Study Reveals Lunar Dust is Less Harmful to Human Lungs than Polluted Urban Air

Inhalation of polluted air on a busy city street is more harmful to human lungs than breathing in lunar dust, as determined by Australian researchers.

Concerns about the toxicity of lunar dust emerged during the Apollo missions. The dust is electrically charged, allowing it to cling to astronauts’ suits. Upon returning to the lunar module, crew members inadvertently inhaled dust from the air, leading to respiratory issues that lasted around 24 hours.

Apollo 17 astronaut Harrison Schmitt described the experience as «lunar fever,» characterized by burning eyes, sneezing, and throat discomfort. After the mission, a physician involved in the lunar program reported similar symptoms after unpacking the used spacesuits, leading researchers to hypothesize that repeated exposure to lunar dust exacerbates its toxicity.

In their recent scientific study, the researchers conducted experiments using two lunar simulants — replicas of actual lunar dust, utilized due to the limited availability of original samples. These simulants closely resemble the lunar dust found on the Moon’s dark volcanic plains and its more ancient highlands. The particles of these simulants were smaller than 2.5 microns, which is sufficient for inhalation and retention in the lower respiratory tract.

The scientists introduced the simulant into two different types of lung cells: bronchial and alveolar cells, representing the upper and lower parts of the lungs, respectively. They then carried out a similar experiment using particle samples collected from a busy street in Sydney. Upon comparing the effects, the research team found that while lunar dust affects the lungs less intensely, it still causes some irritation.

The researchers noted that lunar dust does not appear to pose a risk for chronic conditions like silicosis, which results from inhaling silica dust and typically affects construction workers.

The findings from the Australian scientists are particularly relevant in light of preparations for the Artemis III mission, which will see humans return to the Moon for the first time since 1972. NASA has scheduled the launch of this mission for mid-2027.