I have an air filter Negative Ioniser that rates at 10M/cm2 & I use it within 0.5 metre for up to 8 hours when sleeping at night. I've been using it for good facial skin (pimples reduction) & improving lung characteristics. It elevates mood dramatically (even though I do not have depression), increases energy levels, lung breathing capacity, creates/circulates lung mucus so strongly I wake up in the middle of night due to mucus overflow
Good Day,
Wintersky