There's some debate about this: asthma rates in cities tend to be worse in poorer neighborhoods where there's greater exposure to pollution and toxins. Some stu

There's some debate about this: asthma rates in cities tend to be worse in poorer neighborhoods where there's greater exposure to pollution and toxins. Some studies have also suggested there are particular allergens in inner-city neighborhoods that trigger it, from vermin, etc. Also: it's not clear that there's more asthma, or we're just diagnosing it more often, especially in poorer neighborhoods where folks might not have had much health care a hundred years ago.