New study shows gains in air quality have slowed significantly
The USA’s long battle against air pollution isn’t over yet.
Following five decades of progress in cleaning up our air, pollution gains have slowed significantly, a new study concludes.
The result means it might be more difficult than previously thought for the U.S. to achieve its goal of cleaner air, scientists said.
“Although our air is healthier than it used to be in the ’80s and ’90s, air quality in the U.S. is not progressing as quickly as we thought,” said National Center for Atmospheric Research scientist Helen Worden, a study co-author. “The gains are starting to slow down.”
The two pollutants studied were carbon monoxide and nitrogen oxide, both of which contribute to ground-level ozone.
Smog forms on warm, sunny days and is made worse from chemicals from car and truck tailpipes and from industrial smokestacks.
Exposure to elevated ozone can lead to coughing and difficulty breathing and make respiratory diseases such as asthma worse, according to University of Maryland air scientist Ross Salawitch.
The study said pollution levels from nitrogen oxide fell 7% from 2005 to 2009, but only 1.7% from 2011 to 2015. That translates to a 76% slowdown between the late 2000s and early 2010s.
This contrasts sharply with a more rosy outlook from the Environmental Protection Agency, which said the slowdown in reductions was only 16%.
“We were surprised by the discrepancy between the estimates of emissions and the actual measurements of pollutants in the atmosphere,” said Zhe Jiang, lead author of the study.