Chicago, the windy city--this wind might bring some special problems to people with asthma. Chicago and Asthma on this Moment of Science.
There are more cases of asthma in the Chicago area per capita per year than in any other place in the country.
It's unclear whether or not pollution has anything to do with the large number of asthma cases. Most cities that big are going to generate a lot of pollution. Scientists now think that Chicago's notoriety for being a bad place to live if you have asthma has much to do with the lake breeze effect. On a daily basis, an air mass from over Lake Michigan sweeps in toward the city and then back out over the Lake.
The catch is that when this breeze sweeps in toward the city early in the day, it picks up pollution rising in the air from approximately five to seven million commuters during early morning rush hour. When this air mass takes those pollutants with it toward the lake, the heat of the sun causes the various pollutants to react with one another, creating more toxic compounds. So when this breeze blows back toward the city at night, people in the city may be exposed to especially high levels of pollution that is more reactive and hazardous to health.
More research needs to be conducted. Besides continuing their research in Chicago, the scientists plan to study cities with similar air patterns, such as Detroit and Toronto.