News Release
For Immediate Release
Contact: Beth Gorman (520) 243-7446
Tucson, Arizona (October 13, 2009) – This summer, Tucson area residents had more days when the air quality was rated in the good range for ground-level ozone pollution when compared to the six previous summers, Pima County Department of Environmental Quality (PDEQ) reports. A variety of factors were researched by PDEQ staff to explain the decrease in number of days with moderate ozone pollution, including temperatures, rainfall, solar radiation, cloud cover, gasoline & diesel sales, relative humidity, and wind speed. However, none of these normally influential variables seemed to have a direct causal relationship to the lower ozone levels this summer.
“It is interesting that other cities across the country also experienced lower ozone levels during the summer of 2009,” said Beth Gorman, Sr. Program Manager with Pima County Department of Environmental Quality. “Ozone is a very complex air pollutant that is formed only when a certain ratio of ingredients is introduced into the air at right time of day and under just the right atmospheric conditions,” she continued. “And if one part of that formula is off, than the air pollutant will not form.” “It is possible that the economy had an influence on ozone levels -- if business is slow, then it is likely that related emissions are also down which could reduce the formation of ground-level ozone,” Gorman said. PDEQ does not have the resources to perform an emissions inventory at this time which would help quantify the amounts of various pollutants emitted into the air and provide a more definitive explanation for the lower ozone levels this summer.
Ozone was low, but one day during the summer of 2009, particulate matter pollution was very high. “That was the morning in July when the mountains completely disappeared,” said Gorman. On July 22, a dust storm originating near Casa Grande brought a huge cloud of dust into the Tucson area. That day, PDEQ air quality monitors recorded the highest readings in the history of monitoring that size of particulate air pollution. There was no mystery as to what caused that air quality issue, stated Gorman.
For up-to-the-hour air pollution information in Pima County click www.AirInfoNow.org or call (520) 882-4AIR.
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