> What? What are you even talking about?

The massive alternate media and medicine market selling supplement and shibboleth around rejecting evidence-based medicine for miasmas.

> LITERALLY NO WAY TO CONTROL. Did you know air pollution contributes?

Yes, we famously have no idea how pollutants affect our health.

> You clearly do not know much about allergies

And you’ve clearly put as much thought into this evaluation as your other comments.

I grew up with severe allergies. They’re now basically treated, apart from spot treatment required when I bust through a patch of grass seed on a hike.

> Not talking about just allergies here

You’re specifically not talking about allergies. A “robust” immune system causes allergies. A childhood bereft of exposure to allergens causes allergies. There is no resilience to antigen under-exposure.

And yes, we can control for PM2.5 and many other pollutants that don’t disperse homogenously into the atmosphere. As can we for various food-borne pollutants. (We can also put other animals in entirely contrived atmospheres, and we do. Then we try the other hypotheses. The evidence speaks to in explanatory path into which pollutants play a role, but not the commanding one.)