News Release
For Immediate Release
Contact: Beth Gorman (520) 243-7446
Tucson, Arizona (July 29, 2009) – Remember last week when the mountains disappeared behind a wall of dust? The Pima County Department of Environmental Quality (PDEQ) reports that on July 22, the department’s air quality monitors recorded the highest levels of particulate matter (PM10) ever monitored in Pima County. An air quality advisory was issued that morning by the department and the filters were collected from the monitoring sites the next day to begin the time consuming process required by the U.S. Environmental Protection Agency to determine the accurate weight of the particulate matter captured on the filters. The PM10 (particulate matter that is 10 microns or less in diameter) reading at the Orange Grove monitoring site for Wednesday, July 22 was 270 micrograms/cubic meter of air. The EPA Health Standard for PM10 is 150 micrograms/cubic meter.
PM10 filters from different monitoring sites during last week for comparison purposes.
Guess which ones were from Wednesday, 7/22/09.
The previous high PM10 reading was 235 micrograms/cubic meter in 1999 and it also was measured at the Orange Grove monitoring site. Other PDEQ monitoring sites in Pima County also recorded exceedances of the EPA Health Standard on July 22, but at lower levels. Since the high readings from last Wednesday can be attributed to a natural event (a dust storm near Casa Grande) they probably will not count towards a violation of the EPA Health Standard. “In 2008, ninety-six percent of the time, our levels of PM10 are in the healthy range,” said Beth Gorman of PDEQ. “The days when there are high winds or forest fires tend to be the times that we have unhealthy levels of particulates in our air and those at risk need to be cautious,” she continued. Numerous scientific studies have linked particle pollution exposure to a variety of problems, including: increased respiratory symptoms, such as irritation of the airways, coughing, or difficulty breathing; decreased lung function; aggravated asthma; irregular heartbeat; nonfatal heart attacks; and premature death in people with heart or lung disease.
PDEQ currently monitors for five different types of air pollution and up-to-the-hour information on particulate matter (PM10 and PM2.5), ground level ozone, and other air pollutants can be obtained from special instantaneous monitors at the PDEQ AirInfoNow.org website or by calling (520) 882-4AIR
###
