The average red states’ air is 10 percent cleaner than the average blue state, according to Environmental Protection Agency (EPA) data analyzed by The Daily Caller News Foundation.

The EPA data tracks average exposure to small particulates, which kill roughly 5.5 million people globally every year and cause most asthma. Particulate emissions have fallen by 35 percent since the year 2000, mostly in states that voted for Republicans.

The state with the cleanest air in America was Wyoming, which had a population-weighted average exposure to particulates of five. California’s air was the nation’s dirtiest, with an average weighted exposure of 12.5. The average red state had a weighted exposure of 8.31 while the average blue state had an exposure of 9.05. Adjusted for scale, this means that red states have air that is 9.87 percent cleaner than blue states.

The four states with the best air quality in the country, Wyoming, North Dakota, Montana and Alaska, are all red states. Only one of the five states with the worst air quality in the country is a red state. The worst air quality in the country is found in Illinois, Pennsylvania and California, which have all consistently voted for Democrats.

California has the worst air quality by a wide margin. The four worst cities in the country, Bakersfield, Fresno, Visalia, and Modesto, are are all in California. The state also has six cities on American Lung Association’s list of the ten cities with the worst air quality.

[dcquiz] TheDCNF concluded that a state was blue or red based on how it voted in each of the last four presidential elections. This methodology only factored in America’s 22 red states and 18 blue states. This means that if everything else was statistically even, red states should be over-represented in any list as there are more of them.

Democrats control both branches of the state legislature in Illinois, and California. Democrats have controlled these organizations for extended periods as well. This correlation between air pollution and Democratic control of state legislature is especially striking as Democrats are currently in full control of just 11 state legislatures while the GOP is in full control of 30 state legislatures.

Red states likely had such low levels of air pollution because they were quicker to switch to natural gas fired electricity, which emits far fewer particulates than conventional coal power. Democrat-voting states are slow to cut carbon dioxide (CO2) emissions compared to states that vote Republican, according to analysis by The DCNF.

Studies show that fracking for natural gas is responsible for almost 20 percent of the decline in emissions, while solar power is responsible for a mere one percent of the decline.

Large states such as California and Texas tended to have higher background levels of small particles, and pollution can pass over state boundaries from other states or other countries — so policy differences alone do not entirely explain differences between states.

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