Not lots of people are ready to accept the truth or understand it. We dismiss important information when it is not visible “out of sight, out of mind” and we get influenced when something is shiny and pretty.
Productivity
Poor air quality won’t kill you (at least not immediately and depending on the pollutants), but do you want to be an average employee, athlete, parent, student, or the best? Do you want your employees to work in mediocre conditions and perform poorly, or do you want them to be vibrant and productive?
Excellent indoor air quality will boost the performance of all. The main environmental parameters you must consider addressing are four, Particulate Matter (PM2.5), Carbon Dioxide (CO2), Temperatures, and Humidity. I haven’t included VOCs because poor ventilation and high CO2 levels will result in high VOC levels, so I made things easier.
Health
Air pollution is not easily understood by most people mainly because it is invisible. No one is going to drink a glass of water if the water is dirty but how many times have you had to breathe second-hand smoke, vehicle fumes, or wood-burning smoke! I will say with certainty there were many times and you don’t even worry or remember about it.
The respiratory system isn’t designed to deal with fine particulates and other pollutants. The gastrointestinal system, where solids and liquids get digested, can deal with contaminants because it can get rid of them through the two avenues designed by nature. Sure drinking or eating extremely spoiled food and drinks can lead to deadly diarrhea. However, the respiratory system cannot do something similar and pollutants get accumulated inside the lungs. The smallest pollutants like PM1.0 and gases are distributed through blood even to the brain.
Sure, you can cough, but once particles are inside us they are stuck around the walls because of the fluids. Here is an example of an adult male who was a non-smoker and his lungs are black because of the indoor and ambient pollution. He donated his body to science, and now people can see “him” at the museum of Granada in Spain.

I don’t want to repeat myself and tell you that you spend 86.9%NHAPS of your time indoors, but it’s a fact!
Air is the most important element because without it you only have 3 minutes to live. You literally remove years from your life when pollution is inhaled.
Finally, I believe it is time for researcher to look into the size distribution of the particles rather than generic PM2.5 values that can represent many potential size distributions.