Wired has a story which talks about a danger to possible future inhabitants of the Moon that is rarely brought up: the highly abrasive lunar dust. Unlike Earth, the Moon has no erosive capabilities to smooth the edges of rocks or dust. As a result the lunar dust has arms that stick out, like Velcro, and sticks to everything. As the astronauts who walked on the moon found out, the dust scratched lenses and corroded seals within hours. Some of the particles are only microns across which means once they get into your lungs, they stay there. This could cause a lung disease similar to silicosis.