However, there has been much done to improve environmental conditions in the inner city of Milwaukee. Many factories in downtown Milwaukee relocated out of the state, lessening the suspended particulate matter in the air. Also, monies were spent on improving the air quality. However, there has not been a T.S.P. episode or sulfur dioxide exceedance since 1991. All sources of air pollution have been well monitored and controlled to make the environment more asthma- friendly.
Indoor environment is also a major contributor to high asthma rates in urban areas.
The higher crime rate in the inner city, larger population sizes, and dependence on indoor entertainment is correlated with hours spent indoors. Researchers led by Dr. David Rosenstreich of New York's Albert Einten College of Medicine examined 476 asthmatic kids from 8 impoverished neighborhoods and found that cockroach allergies were the leading cause of attacks. Although exterminators work daily to eliminate insects, they do not eliminate the leftover cockroach bodies that are trapped within the old walls of most houses. The cockroaches and dust mites are virtually inescapable. Anyone would develop asthma in these conditions because the immune systems of Americans have evolved to fight parasites, not cockroaches and dust mites.