Trump's EPA head Scott Pruitt confirmed today (Feb. 17)

Smog in Beijing, by 螺钉 (Own work) [CC BY-SA 3.0 ], via Wikimedia Commons
As Oklahoma's attorney general, Scott Pruitt sued the EPA 14 times, trying to roll back its protections against mercury, vehicle exhaust, and other  air pollution.

Thanks largely to the EPA, the U.S. has until now maintained good air quality compared to many other countries:

Environment is a health issue. Air pollution is believed to contribute to the deaths of 1.6 million people each year in China

For more on Pruitt and his Senate confirmation, see