How do they know? By sending 'healthy' volunteers into such spaces.
During this time, researchers measured participants’ total respiratory impedance, resistance, and reactance with the use of an impulse oscillometry, a noninvasive way of measuring the physical properties of respiratory movement during quiet breathing. Results showed that short-term exposure to concentrated secondhand smoke significantly and immediately impacted participants’ airways, invoking such physiologic changes as increased airway impedance and resistance. Participants showed no clinical signs or feelings of discomfort during the test.What did their test add to current knowledge?
Well, the Environmental Protection Agency has already declared secondary smoke to be a danger to health. But it has also declared all particulates under a certain size (PM2.5) to be dangerous to the same degree:
So what is the difference between secondary smoke and PM2.5 from any other source, in the eyes of EPA? None, it would seem.
- There is no safe level of exposure to PM2.5;
- Inhaling PM2.5 can kill within hours of exposure; and that
- PM2.5 can also cause cancer…
Why yet another study telling us what we already know, that scientists have decreed that PM2.5 and secondary smoke are a danger to our health that we must never be subjected to, and against which regulations already exist. Especially since the research involves exposing subjects to these substances like the EPA does here.
Why don't they show us how effective air cleaning would be in such a situation? Now that would be worth doing. We might learn something that we don't already know.