(JACKSON, Miss.) — The Mississippi Department of Environmental Quality (MDEQ) announced today that the 2021 Ozone Monitoring Season ended on October 31 with all counties in Mississippi well below the current ozone standard of 70 parts per billion (ppb) set by the Environmental Protection Agency (EPA). Ozone levels in the state have continued a downward trend in the last 10 years.


“This year’s results chronicle the continuing trend of Mississippi’s excellent air quality. There has been a concerted effort for several years among local officials, industry, citizens, and MDEQ to inform the public about ozone and to take steps to reduce ozone-producing pollution on days when ozone is forecast to be high. It is gratifying to see the results of those efforts and to avoid the punitive measures that can be implemented when EPA’s standards are exceeded,” said Chris Wells, MDEQ Executive Director.


For 2021, the ozone sampling results for MDEQ’s monitoring sites are:


·        Bolivar County:  61 ppb

·        DeSoto County:  64 ppb

·        Hancock County:  58 ppb

·        Harrison County:  58 ppb

·        Hinds County:  57 ppb

·        Jackson County:  60 ppb

·        Lauderdale County:  54 ppb

·        Lee County:  57 ppb

In Mississippi, the Ozone Monitoring Season extends from March 1 to October 31 annually.  MDEQ issues both ozone and particle pollution (PM2.5) forecasts daily for the Mississippi Gulf Coast, the Jackson Metropolitan Area, and DeSoto County from April 1 through October 31. This information is provided to weather media for inclusion in weather reports and is available to the public. For more information and to sign up for the daily forecasts, use the following link:  Air Quality Forecast.


Ground level ozone is not emitted directly into the air, but it is created by chemical reactions between oxides of nitrogen (NOX) and volatile organic compounds (VOCs).  This happens when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources chemically react in the presence of sunlight.  Ozone at ground level is the main ingredient in “smog.”  Under the Clean Air Act, EPA establishes primary air quality standards to protect public health and secondary standards to protect public welfare that includes protecting ecosystems, plants, and animals.


More information about MDEQ’s Air Quality Monitoring Program can be found here.


The attached two graphs chart ozone sampling results in Mississippi since 2012 and 1977, respectively.