What a very interesting idea. Thank you for bringing it forward. I've wondered for a long time about the interplay of reasons for this sad epidemic.
That said, I would not say it's necessarily "leftist" to ascribe higher rates of asthma among black children to poverty. Inner-city conditions do expose children to irritants like cigarette smoke and allergens like cockroaches, mold and dust. A well-intentioned but ignorant mother may not have the focus or the funds to do things to put her asthmatic child in a hypoallergenic environment (pillow and mattress covers, a HEPA vacuum cleaner, air filters, etc.)
It's also possible that the kids who might once have been removed from the gene pool through death are now helped by new drugs and treatments to stay alive so that they can have kids of their own, and those kids inherit the genetic predisposition to asthma.
But a mother who doesn't get enough Vitamins D and E during pregnancy can also give birth to a kid predisposed to asthma, and it's made worse when the child doesn't get outside to play during the day and needs extra outdoor time because he has dark skin. You have to assume they're getting enough Vitamin D-supplemented milk.
It's leftist to jump to the conclusion that economic factors are the primary cause of the difference in asthma rates between black and white children.
A well-intentioned but ignorant mother may not have the focus or the funds to do things to put her asthmatic child in a hypoallergenic environment (pillow and mattress covers, a HEPA vacuum cleaner, air filters, etc.)
True, but that has nothing to do with the fact that the child is asthmatic in the first place, just an issue of how effectively it's managed. It's the higher asthma rate in inner city kids that is notable. It's a given that all medical conditions will be less well-managed in that sort of environment.