After four decades of improving air quality, the United States has started to take a step backwards. The last two years the number of polluted days has increased. Federal data shows there were 15% more days with unhealthy air over the U.S. in 2017 and 2018 then there were on average from 2013-2016. In that four-year span, Americans had the fewest number of polluted days since 1980. Scientists say it’s too early to see the effects of change in environmental policies of the Trump Administration, however they believe that Trump’s moves to weaken environmental regulations and ease enforcement is a dangerous slide. About 100,000 Americans each year die prematurely because of polluted air.