Asian air pollution caused 53% of instances in which EPA ozone limit was exceeded in Southern California-AGU peer reviewed study, 3/2/2012

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3/2/2012, “Asian emissions contribute to air pollution in western United States: study,” phys.org, American Geophysical Union

“To learn more about the mechanisms that transport air pollution across the ocean and determine the effects of Asian air pollution on air quality in the western United States, Lin et al. analyzed in situ and satellite measurements from May 2010 to June 2010 using a global high- resolution climate chemistry model….

They quantified the contribution of Asian pollution to surface ozone levels in both densely populated regions such as the Los Angeles area and rural areas such as national parks. They find that Asian pollution contributes as much as 20 percent of total ozone during springtime pollution episodes in western U.S. surface air.

Current guidelines from the Environmental Protection Agency dictate that, averaging over 8 hours, surface level air should have no more than 75 parts per billion per hour by volume of ozone. Although local pollution plays a large role on days when that standard is not met in Southern California, the authors estimate that 53 percent of the instances where that limit was exceeded would not have occurred without the contribution from Asian air pollution.”…
 
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Added: Link to study cited above:

2/27/2012, “Transport of Asian ozone pollution into surface air over the western United States in spring,” Journal of Geophysical Research, American Geophysical Union


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