Being chemically inert isn’t enough for your lungs, the mechanical properties are also critical.

Microplastics aren’t necessarily chemically inert either, but it’s worth remembering just how delicate your lungs are.

Silica dust, PM25, and asbestos are all largely inert, and cause significant health issues.

Radon is one of the noble gasses, and is chemically inert, but harmful.

<https://en.wikipedia.org/wiki/Silicosis>

<https://en.wikipedia.org/wiki/Particulate_matter#Health_effe...>

<https://en.wikipedia.org/wiki/Asbestosis>

<https://en.wikipedia.org/wiki/Radon#Health_risks>