The San Francisco Bay Area has been named as one of the most polluted regions in the nation when it comes to categories that scientists say contribute to climate change, according to a new report.
The "State of the Air 2018" report from the American Lung Association gave three out of the nine Bay Area counties a failing grade for ozone pollution.
Alameda, Contra Costa and Santa Clara were among the counties that received an "F" in annual average of unhealthy ozone or particle days recorded over the three-year period of 2014 to 2016.
The report found that ozone pollution was made worse between 2014 and 2016 compared to a previous report, according to the American Lung Association. On the other hand, improvements were seen for short-term and year-round particle pollution.
The collection of San Francisco, San Jose and Oakland ranked sixth in the nation for short-term particle pollution, according to the data. Year-round, the region ranked 10th.
Particle pollution comes from cars and dirty engines as well as from smoke from fireplaces and wildfires.
The Bay Area placed 13th in ozone pollution, which scientists say is a result of warmer temperatures.
Millions of residents face an elevated health risk from pollution due to age, pre-existing conditions or living in a lower-income community, the American Lung Association said.
Pollution may cause asthma attacks, lung cancer, reproductive harm, wheezing and coughing and even cardiovascular harm, according to the Lung Association.
Things residents and authorities can do to help protect clean air include protecting the Federal Clean Air Act and supporting regulation of vehicle emissions, the association said in its report.
The national rankings were put together utilizing air reports from 2014, 2015 and 2016, according to the American Lung Association.