Study: People in parts of U.S. and beyond breathe unhealthy ozone pollution more than 2 weeks a year

February 5, 2018

Despite significant gains in controlling ground-level ozone pollution, some residents of California, Arizona, Colorado, Texas, the Midwest and the Mid-Atlantic spent more than 15 days each year between 2010 and 2014 breathing unhealthy levels of pollution, according to information from a new global database developed with NOAA support.

Ground-level ozone in the form of smog, shown here in Denver, Colorado, is a growing problem in the western United States and elsewhere around the world.

People living in parts of southern Europe, South Korea and southern Japan and China also experienced more than 15 days a year of ozone levels averaging more than 70 parts per billion, the health standard established by U.S. Environmental Protection Agency.

These are some of the findings from the first major analysis of the most comprehensive database of surface ozone observations ever assembled — the Tropospheric Ozone Assessment Report offsite link— compiled from more than 4,800 ozone monitoring stations around the world. The new research was published February 5 in the journal Elementa: Science of the Anthropoceneoffsite link.

Ground-level ozone, the primary component of smog and one of six main pollutants regulated by the U.S. Clean Air Act, is created when natural and industrial pollutants emitted into the air react with sunlight.

“TOAR is not just a report,” said Owen Cooper, a CIRESoffsite link scientist working at NOAA who chairs the TOAR Steering Committee. “We created the largest database of surface ozone, and we’re making these data freely available to anyone who wants to investigate the impact of ozone on human health, vegetation and climate.”

Future TOAR studies will provide a global assessment of the ozone levels experienced by vegetation, observed ozone levels that affect climate as well as a historical analysis that explores how ozone levels have changed globally since the early 20th century.

> Learn more about the human health effects of ground-level ozone.


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