Apollo astronauts all got 'lunar hay fever' - and ESA is still trying to figure out why

Every one of the 12 Apollo astronauts who walked on the Moon developed respiratory irritation from lunar dust clinging to their suits, with symptoms ranging from sneezing and nasal congestion to watering eyes lasting days. Inside the lander, the dust reportedly smelled like burnt gunpowder. Decades later, the toxicological risk of that dust remains an open question - and a blocker for sustained human presence on the Moon.

The dust is physically hostile in ways terrestrial particulates aren’t. It contains silicates (the same class of material that scars miners’ lungs on Earth), but unlike weathered earthly particles it’s sharp and spiky, never smoothed by wind or water. Low gravity keeps fine grains airborne longer, and constant solar radiation electrostatically charges the soil enough that it levitates and clings to equipment. Particles 50 times smaller than a human hair can lodge in lungs for months, and lab studies on lunar soil simulants show destruction of lung and brain cells under prolonged exposure.

ESA has assembled a research programme - including pulmonary physiologist Kim Prisk and toxicologist Erin Tranfield - to quantify the risk using simulant mined from a German volcanic region. The work is preparation, not curiosity: any sustained lunar surface operation has to solve dust mitigation before crew health becomes the limiting factor. The soil isn’t purely adversarial, though. It can be sintered into shelter bricks and processed to extract oxygen, both of which matter for long-duration missions.