Air Pollution Controls Lower Death Rates from Asthma and Emphysema in North Carolina

Air pollution doesn't just impact the environment; it can also impact your health. Now, scientists have found that air pollution controls may be doing some good for public health. It turns out that controls that went into effect in the early 1990s coincide with decreasing death rates from emphysema, asthma and pneumonia in North Carolina.

"While a few studies have analyzed the associations of both air quality and health over a long period, they were typically limited to analyses of a specific air pollutant or a couple of pollutions," said H. Kim Lyerly, one of the researchers, in a news release. "In contrast, we leveraged access to multiple disparate databases containing either environmental or health data, and we were able to study longitudinally a number of air contaminants, including both particulate matter and noxious gases over almost two decades."

In order to better understand how air pollution controls have affected the public, the researchers analyzed a 17-year period after air pollution measures were instituted. During this time period, national requirements lowered emissions from automotive engines, chemical plants and coal-fired power plants. Regulations also targeted emissions that contributed to acid rain and the depletion of the ozone layer in the atmosphere.

Using both the public health and environmental monitoring data, and controlling for factors such as lower smoking rates, the researchers calculated how each one-unit reduction in the air pollution components coincided with a drop in deaths from emphysema, asthma and pneumonia.

In the end, the researchers found that lower sulfur dioxide levels had a significant correlation with lower death rates for emphysema, asthma and pneumonia. In addition, they found that decreases in carbon monoxide resulted in lower death rates for emphysema and asthma while lower particulates corresponded with lower emphysema death rates.

"This is a new way of using and analyzing the information we are collecting in separate databases," said Lyerly. "It would be very difficult to conduct a randomized trial to gather the data for policy changes. By following levels of air pollution and respiratory health over time, we could measure changes prior to and after implementation of these policies. Our study leverages these collected data in a way that it can contribute to the dialogue on whether pollution controls are effective in improving public health."

The findings are published in the International Journal of COPD.