(JACKSON, Miss.) — The Mississippi Department of Environmental Quality (MDEQ) announced today that the 2017 Ozone Season ended on October 31 without any counties in Mississippi exceeding the current ozone standard set by the Environmental Protection Agency (EPA). Ozone levels have continued a downward trend in the last 10 years dropping well below EPA’s current standard of 70 parts per billion (ppb).

“This year’s results continue to tell the story that Mississippi has great air quality, and that trend is only continuing. We had some of the lowest numbers since the Mississippi air monitoring program began. 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 prevent ozone action days, and it’s important that we continue these efforts. It is gratifying to see the results and to avoid the punitive measures that can be implemented when EPA’s standards are exceeded,” said Gary Rikard, MDEQ Executive Director.

*For 2017 the ozone sampling results are:
Bolivar County: 62 ppb
DeSoto County: 62 ppb
Hancock County: 60 ppb
Harrison County: 64 ppb
Hinds County: 61 ppb
Jackson County: 63 ppb
Lauderdale County: 56 ppb
Lee County: 58 ppb

MDEQ issues ozone and particle pollution (PM2.5) forecasts for the Mississippi Gulf Coast, the Jackson Metropolitan area, and DeSoto County daily April 1 through October 31. This information is available to the public as well as being provided to weather media for inclusion in daily weather reports. For more information and to sign up for the daily forecasts, use the following link: http://bit.ly/2g0qDCN.

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.

The following two graphs chart ozone sampling results since 2008 and since 1977 and are linked in the text below.

*preliminary results for 2017.
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Click on the text below for the two graphs:

Graph showing ozone design values across the state over the past ten years continuing to trend downward well below the standard.

Graph showing ozone design values for each site across Mississippi averaged together annually since 1977 depicting continued improving values across the state well below the standard.

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