President Trump has claimed that air quality is improving under his watch, saying earlier this month, "We have the cleanest air in the world, in the United States, and it's gotten better since I'm president." Yet, the facts tell a different story.

World Health Organization data says otherwise. When looking at fine particulate matter, a key to air pollution, the U.S. ranks tenth in the world, well below several European countries, Australia, Canada and New Zealand, as the New York Times reported.

"We do not have the cleanest air and we have not crossed the finish line when it comes to pollution," said former Obama U.S. Environmental Protection Agency (EPA) Chief Gina McCarthy, now director of the Center for Climate, Health and the Global Environment at the Harvard School of Public Health, as the AP reported.

Fine particulate matter is especially relevant after the EPA rolled back the Obama-era Clean Power Plan Wednesday, as EcoWatch reported. Fine particulate matter is a byproduct of the burning that frequently comes from power plants, engine exhaust and wildfires. It is also hazardous to human health, leading to asthma and respiratory inflammation, and increasing the risk for lung cancer, heart attack and stroke, according to the New York Times.

Furthermore, EPA data found there were significantly more polluted days each year of Mr. Trump's than in any year of President Obama's second term, according to the AP. And the worst of the bad days jumped even more than the 15 percent rise in unhealthy air. On average, there were nearly 140 times, in 2017 and 2018, when a city's air pollution reached "very unhealthy" and "hazardous" levels with the air quality index greater than 200. That's more than two-and-a-half times the average of nearly 55 from 2013 to 2016, the AP reported.

"Today it feels like the future of our kids and our country is at stake," said McCarthy.

Federal regulations since the Clean Air Act of 1970 that limit the emissions of certain chemicals and soot from factories, cars, and trucks helped dramatically improve air quality. In fact, a recent study, found that air pollution related deaths fell by about 30 percent in the two decades between 1990 and 2010.

Yet, air pollution is still a scourge. EPA data says that more than 110,000 million Americans live in counties with unhealthy levels of air pollution, according to the New York Times. And one recent study found that air pollution in the U.S. led to 107,000 premature deaths and cost the country $866 billion in 2011. Of the early deaths, 57 percent were caused by energy consumption — 28 percent were transportation related, 14 percent were from coal-fired and gas power plants, while 15 percent were caused by agricultural activities like manure storage, as CNN reported.

"Cars and trucks are much cleaner than they were, power plants are cleaner, industrial operations are cleaner," said Paul Billings, a representative of the American Lung Association, to the New York Times. "But cleaner air is not clean air."