Republican presidential candidate Jeb Bush (left) and John Kasich talk at the Republican Presidential Debate on November 10, 2015, in Milwaukee, Wisconsin. (Photo: Scott Olson/Getty Images)

Ben Carson is just the latest political candidate to declare himself to be "a breath of fresh air." Research suggests borrowing that cliché would be particularly inappropriate for some of his opponents—including Jeb Bush, John Kasich, and Chris Christie.

A new study concludes that states with Republican governors have higher levels of air pollution than those run by Democrats.

Using Environmental Protection Agency data from 1975 to 2013, economists Louis-Philippe Beland of Louisiana State University and Vincent Boucher of Université Laval in Quebec report "Democratic governors significantly reduce concentrations" of at least three major pollutants.

"Our analysis suggests that party affiliation has a significant impact on air pollution," they write.

"The concentrations of nitrogen dioxide, ozone, and particulates are significantly lower under Democratic governors."

Their study, published in the journal Economics Letters, looked at each state's yearly average concentrations of five major air pollutants: carbon monoxide, ground-level ozone, nitrogen dioxide, particulate matter, and sulfur dioxide.

"The five pollutants are covered by the Clean Air Act, and are targeted by the EPA for their negative impacts on health, on the environment, as well as properties," the researchers write. "Of these pollutants, ozone and particulates have the strongest impact on health, and can lead to, or exacerbate, respiratory problems, especially for people with asthma."

These numbers were matched with the party affiliation of the state's governor in any given year, as well as such variables as the margin of his or her victory.

"We find that the concentrations of nitrogen dioxide, ozone, and particulates are significantly lower under Democratic governors," they write. Levels of the other two pollutants also trended down under those conditions, although the difference between Republican and Democratic administrations did not reach that level of significance.

Beland and Boucher list three possible reasons behind their findings: Democratic administrations may have put into place more stringent air quality standards, provided the resources for better monitoring, and/or implemented stronger enforcement programs.

Importantly, they found changes in pollution levels "mostly happen below EPA standards." In other words, states with Democratic governors are more likely to put into place pollution controls that exceed the federally mandated requirements.

"This suggests that national regulations, such as EPA standards, are effective in reducing pollution, and tempering the political power play between Republican and Democratic governors," they conclude.

So, when voting for governor, it'd be wise to think about how important clean air is on your priority list, and what tradeoffs you are or are not willing to make to bring pollution levels down. While you can safely ignore claims that a candidate is a "breath of fresh air," don't forget the truth of another shopworn slogan: Elections have consequences.

Findings is a daily column by Pacific Standard staff writer Tom Jacobs, who scours the psychological-research journals to discover new insights into human behavior, ranging from the origins of our political beliefs to the cultivation of creativity.