INDOOR AIR QUALITY = VENTILATION & AIR FILTERING
Did someone say filter?...Great Idea! There are classifications to rate the degree of filtration acheived known as MERV rating* (ie - MERV 13 is nice) . HEPA is a well understood technology which does a spendid job of removing reliably very small particles ... much better than the routinely used paper filters in most homes and small buildings.
What else can we do to make our breathing air cleaner? There is a long list - but if you can dilute and filter like above- you have done well!
We have many years ago discovered how to manage contaminated air to reduce the concentration of chemicals and infective agents and render it harmless.
This was determined in detail by mechanical engineers to create containment laboratories so that scientists could examine and learn about very ineffective and dangerous bacteria and viruses.
Containment laboratories and laminar flow operating rooms however cost millions and are gross overkill for general use.
It could however be possible to look at these engineering marvels and learn how we may be able to improve the health of our population.