[Biological effects of lunar regolith dust]

It is important to understand the biological effects of lunar dust (regolith) if human activities, prolonged stays, and eventual habitation are to take place on the Moon.

This study explains the biological effects of regolith and is based on an assessment of findings from studies that used regolith and regolith simulants and knowledge derived from the physicochemical properties of terrestrial dust.

In vitro cell culture studies using regolith simulants showed that the cytotoxicity and biological activity of lunar dust were generally lower than those observed for crystalline silica. Similarly, animal exposure studies that investigated the effects of regolith and regolith simulants showed limited inflammation and fibrosis, suggesting that their pulmonary toxicity is intermediate between that of titanium dioxide and crystalline silica. Although no allergy-enhancing effects, such as those seen in bronchial asthma, were observed, allergy effects have been reported for Asian dust, which has similar constituent components. This suggests that regolith could potentially enhance allergic responses. Furthermore, the results obtained using terrestrial regolith simulants may underestimate the biological effects of regolith because the simulants do not include certain materials, such as agglutinates, that are only generated in the lunar environment.

Although the available experimental evidence does not suggest potentially severe cytotoxic, inflammatory, or fibrotic effects, careful evaluation of the chronic inhalation effects of lunar dust on future long-term lunar residents is required and this assessment should take into account its unique microstructure and surface chemical reactivity.