I live in the Midwest (near Chicago) and know our air quality is always pretty bad.

I googled "health risks midwest US" and got a few hits... who knows what our environmental exposures are:

Mercury
http://www.uwsp.edu/geo/courses/geog100/ENS-Mercury.htm

Radon?
http://energy.cr.usgs.gov/radon/rnus.html

Pesticides
http://findarticles.com/p/articles/m...3/ai_n13807334

Just brainstorming a little about what our 'midwest' risks might be~ not so much about how they might affect us.