Air pollution controls linked to lower death rates in North Carolina

National and state air pollution controls that went into effect in the early 1990s coincide with decreasing death rates from emphysema, asthma and pneumonia among people in North Carolina, according to a study. Using mortality trends from state public health data, along with monthly measurements from air-monitoring stations across North Carolina from 1993-2010, the researchers were able to draw a close association between improved air quality and declining death rates from respiratory illnesses.