Anecdotally, I was diagnosed with asthma as a child and walked around with an inhaler for a few years. I liked it, it tasted funny and seemed like a cool gadget at the time. But I did not have asthma. And I'm convinced there's no way my parents would've been diagnosed with it 30 years ago with the minor symptoms I had.

So perhaps the asthma numbers are influenced by an increased willingness to diagnose it. Just a thought.

Auto immune diseases as a whole have increased over just the past 30 years; I'd speculate asthma is a part of this.

It will be interesting to see the driving environmental causalities behind these autoimmune disease increases if pollution is not a key variable.

Outdoor air quality isn't the only factor in developing asthma