Our study is specific to the elderly, but there is epidemiological evidence that air pollution also affects the health of the younger population.

This study provides strong evidence that daily hospital admission rates for cardiovascular diseases and respiratory diseases are higher when the fine particulate matter levels are increased from one day to the next.

This means that a reduction in fine particulate matter levels should provide health benefits in terms of lower hospital admissions for the elderly.

Air pollution can be a major health threat, especially for at-risk populations and those with respiratory illness. This study will help us target improvements to clean the air, improve the environment and enhance public health.

In Cook County, for example, about once every five days you'll have an increase in fine particulate matter of 10 units or more, so this happens quite often.

When we analyzed the data for heart failure, we observed a 1.28 percent increase in admissions for each 10 microgram per cubic meter increase in fine particle pollution. Most of these admissions increases occurred the same day as the rise in fine particle concentration, which suggests a short lag time between the change in pollution and the subjects' response.