Funny thing is that those air filters are reducing the exposure to PM2.5s. And it is PM2.5 particles that are associated with an increased risk for dementia.

Air pollution linked to dementia cases https://www.nih.gov/news-events/nih-research-matters/air-pollution-linked-dementia-cases

A systematic review with a Burden of Proof meta-analysis of health effects of long-term ambient fine particulate matter (PM2.5) exposure on dementia https://www.nature.com/articles/s43587-025-00844-y

How PM2.5 drives dementia: emerging mechanisms and unanswered questions https://doi.org/10.1093/lifemedi/lnag007

When i started my job just after covid, I found out that my coworkers hated the ~5 air purifiers that were bought for the few staff that were in every day, because they were incredibly noisy. They celebrated the day they were allowed to stop turning them on.

I asked if they ever changed the filters, to which they replied 'you can do that??'

...The filters didn't need changing, because all 5 of them still had plastic on them, and now we use them to circulate air if a room gets stuffy but another room is too cold (our HVAC is poorly adjusted for the building). They do that quite well, and very quietly too.

Hah, I'm glad to see the final reply. That's one I like to use from time to time, so I'm glad to see it's around enough to still be understood. heh

I didn't realize how much Reddit-isms annoy me until i left.