The US has enjoyed cleaner air for decades, but that quality is stagnating. In 2017 and 2018, the country suffered more polluted air, according to federal data, and even though health experts are unclear as to if this is the beginning of a trend, they agree that it’s a concern.

In 2017 and 2018, there was an increase of 15% in unhealthy air days when compared to the average of unhealthy air days from 2013 to 2016. During these four years, the US enjoyed the fewest unhealthy air days in history, so that 15% increase is actually substantial.

If you follow the news, you’ve probably heard President Trump say that the United States has the cleanest air in the world and it keeps getting better. But evidence shows otherwise.

In the first two years of President Trump’s term, there were more polluted air days than in any of the four years prior, according to data from the Environmental Protection Agency.

If we look at the things that affect air quality, it’s quite a complex combination of man-made and natural factors. Federal regulations that focus on limiting chemical emissions and soot from cars, trucks, and factories have provided an incredible improvement in air quality over time. However, air quality can be affected by natural factors as well, and that may be what’s behind this sudden stagnation of air quality in the US.

According to Bob Perciasepe, the President of the Center for Climate and Energy solutions, this stagnation is due more to a “flattening of progress” than a move into the wrong direction.

However, a move in the wrong direction is being made by the Trump administration, which aims at loosening regulations on cars and coal-fired power plants. Additionally, they are less willing to enforce rules that are currently in place, which was one of the main reasons the US has enjoyed a stretch of cleaner air for as long as it has.

According to scientists, we won’t see the full effects of these decisions yet, but they say that these changes will definitely reverse the improvement in air quality the country has made in the past few decades.

Improvement in air quality has occurred slowly over many years, and these changes promoted by the Trump administration threaten to reverse all this hard work.

In the latest air quality report from the EPA, we can see an increase of polluted air days. Five hundred and thirty-two American metropolitan areas reported 4,134 days in 2018 alone where the air quality index was higher than 100, which is unhealthy for young people, senior citizens, and people with lung or heart disease.

The quality of the air we breathe in every day matters. Studies show that around 100,000 Americans die prematurely each year as a result of polluted air. That’s an outstanding and alarming number.

Relaxing regulations on cars, coal plants, and other detrimental emissions contributors will only increase this number, causing a deterioration of air quality faster than ever before.