I read an interesting study on effective air quality legislation. The article is “Health and Air Quality Benefits of Policies to Reduce Coal-Fired Power Plant Emissions: A Case Study in North Carolina,” by Li YR and JM Gibson from the September 2014 issue of Environmental Science & Technology. In the article, the authors analyzed particulate matter to determine the effectiveness of air quality controls the state passed to comply with the Clean Air Act. The authors studied emissions of sulfur dioxide (SO2) over a ten year period to measure trends across the state.
In 1990, the US government passed the Acid Rain Program (ARP) as an amendment to the Clean Air Act. Congress sought to reduce SO2 emissions. Throughout the 1990s, North Carolina struggled to meet the ARP guidelines. In response, the state passed the Clean Smokestack Act in 2002. The Clean Smokestack Act targeted North Carolina’s coal plants to “progressively reduce SO2 emissions by 72% by 2013, relative to 2002 emissions.”
Previous studies of particulate matter pollution were more general in scope. The studies assumed that the health benefits were the same regardless of the source of the particulate matter; despite growing evidence that particulate matter toxicity is source specific. This study differed from previous studies by directly measuring SO2 concentrations from coal plants and comparing that to health burdens in North Carolina. The author’s hypothesized that as SO2 emissions decreased, the health of North Carolinians would improve.
The authors gathered data from the EPA’s National Emissions Inventory (NEI) and Clean Air Market’s Program (AMPD) databases from 2002 - 2012. The authors divided the state into three different regions: the costal plain, the piedmont and the mountains. North Carolina, as a whole, was then compared to other states in the region using the EPA’s Air Quality System and Federal Land Management databases. The data collected was aggregated to create trends of SO2 pollution for the subregions in North Carolina and to compare North Carolina with other southeastern states. The authors compared their dataset to county level population and morbidity rates from the CDC.
The authors found that coal plants remained the major source of SO2 in their research time period. However, the emissions of SO2 , measured in tons, were reduced by almost 90%. Most of this reduction came in the piedmont. During this same time period, sulfur dioxide particulate matter deaths decreased by 63% or an estimated 1,700 people. The decreases in SO2 and morbidity were greater in North Carolina than the rest of the region. These findings support the effectiveness of regulations in fighting particulate air pollution.
The authors did a lot of leg work here. The article made a persuasive case that regulations can improve the environment and human health. I was a bit surprised that the EPA had not done it’s own analysis since it was mostly their data being used. The article made me curious about other examples of positive impacts that regulation can have. Impacts that occur in rather short timeframes.
Arguments are often made against environmental regulations because they cost too much and hurt the economy. Durning the time period of this study, 2002 - 2012, North Carolina’s population and economy grew at a similar rate to the rest of the region. Which would seem to undercut that argument. The reductions of particulate matter in our air did not come at the cost of our state’s growth. This feels like a win-win that nearby states should model.