Making news across the state this day is a study out of UNC Chapel Hill that newspaper headlines are claiming shows that North Carolina’s 2002 Clean Smokestacks Bill (CSB) is saving lives. These “results” are allegedly due to reductions in particulate matter in the air which results from the burning of coal (and other things like wood and gasoline). I say “newspaper headlines are claiming” because the authors of the study are much more cautious. In fact according the an article by the Charlotte Observer’s Bruce Henderson here is what they are saying about their results.

In June, Duke University scientists reported a substantial decline in deaths from asthma and emphysema as North Carolina tightened air standards under Clean Smokestacks and federal laws.

Despite that link, the Duke researchers cautioned that other factors such as medical histories or allergies could also help explain the trend.

Gibson acknowledged that it’s hard to tease out the role air pollutants play in premature deaths.

“There’s really no controversy that particulate matter is bad for your health,” she said. “It’s just the magnitude of the risk that’s in dispute.”

In other words beware, correlation is not causation and the improvements in health outcomes may or may not be related to the CSB.

But setting aside this important caveat, which is at odds with the headlines, let’s take a look at our neighboring states of South Carolina and Virginia, both of which chose not to implement similar legislation. While, according to the EPA, North Carolina has 3 counties that are in non-compliance with federal standards on PM2.5, 100 percent of South Carolina’s counties are in compliance with the EPA standards and the only 2 counties in Virginia that have compliance issues are Arlington and Loudon. Both are special cases as their air quality problems are dominated by Washington, DC area road congestion problems.