Myself and the other poster are asking you politely to stow your ego and self-interested focus, and to think about why sweeping, nationwide changes in policy might have come about. I don't deny that you've experienced those issues firsthand; I'm saying it doesn't matter.

Put yourself in the time period: babes born after MLK was assasinated aren't even in elementary school yet, and we're at the height of white flight and the Marlboro Man and asbestos-infused flooring. You can't seriously hold that the shift to SFH-only zoning was predicated on smoking and mold concerns, can you?

If you honestly believe that such concerns, wholly divorced from racial and class politics, were the impetus for this shift, you're being irrational, and selfish. I apologize, because I know saying so can be considered rude, but it is the crux of our disagreement: it's not about you. Your personal concerns do not, by themselves, define the scope of a national problem.