air quality study 

"Stronger emission controls in North Carolina may have saved lives by reducing deaths from respiratory illness, according to an academic study published Monday.

During the past few decades, the state has tightened its air quality standards through adherence to federal legislation such as the Clean Air Act and the state's 2002 Clean Smokestacks Act. The state's success in reducing air pollution may explain a substantial decline in deaths from the respiratory illnesses asthma and emphysema during corresponding periods, reported Duke University scientists in the International Journal of COPD on Monday.

The release of the study comes as state lawmakers are considering legislation this week that eliminates some of the state's air-quality stations, part of the framework for measuring pollution across the state."
Read more here: http://www.newsobserver.com/2014/06/23/3957644/duke-scientists-report-air-pollution.html#storylink=cpy