News Release
For Immediate Release
Contact: Beth Gorman (520) 740-3343
Tucson, Arizona (April 23, 2007)- Pima County Department of Environmental Quality reports that during the winter air pollution season, from October through March, carbon monoxide and particulate matter pollution levels remained below the National Ambient Air Quality Standards. The summer ground-level ozone season has begun and with the new and more protective ground-level ozone health standard implemented by the U.S. Environmental Protection Agency in March, this region may exceed the health standard this summer. PDEQ will be working closely with local agencies to provide air pollution advisories when pollution levels are elevated to better protect those who are sensitive to air pollution. Local up-to-the-hour air pollution levels are available at 882-4AIR and www.airinfonow.org for use by the public to reduce their exposure when levels are elevated. Ozone “movies” are also available at this website.
PDEQ uses the federal Air Quality Index (AQI) as a measure of the pollutant levels detected in the air quality monitoring network. The AQI measures good air quality on a scale from 1-50; moderate air quality from 51-100; and unhealthy air quality 101 and above. For the seventh year in a row, carbon monoxide pollution levels were in the good range every day during the 183-day season. The region has not exceeded federal standards for carbon monoxide in over 17 years. Particulate matter (PM10) air pollution levels were in the moderate range 18 days out of the 183 days during the 2007-2008 season, compared with 22 for the same time frame in 2006-2007. The highest AQI value for PM10 during the 6 months from October through March 2007-2008 was 73 compared with 100 in 2006-2007. The last time the EPA health standard for PM10 was violated was in 1999.
“We are very concerned about exceeding the ground level ozone standard since there are a large number of individuals in our community considered ‘at-risk’ for health problems when ozone levels are elevated,” said Beth Gorman, Program Manager for PDEQ. Ground level ozone is monitored by PDEQ at nine different air quality monitoring sites in eastern Pima County.
“Of all the pollutants we monitor for, ozone is the most complex and challenging to fully comprehend and predict,” said Gorman. Ozone is not emitted by any one source. It is created when just the right amount of volatile organic compounds combine with oxides of nitrogen in the presence of sunlight. This photochemical reaction is sensitive to weather conditions and to other pollutants that are in the air. Ozone is more readily formed on warm, sunny days when the air is still. The ebb and flow of ozone levels can be observed throughout eastern Pima County on “ozone movies” available on the PDEQ Air Info Now website at http://www.airinfonow.org/html/ozoneMC.html.
PDEQ will continue to work with the American Lung Association to increase public awareness of the health problems associated with ozone pollution and issue advisories, when concentrations reach levels that could adversely affect sensitive populations. People most at risk include children, outdoor workers and exercisers, and individuals with respiratory disease. At elevated levels, ground-level ozone can cause acute respiratory problems, temporarily reduce lung capacity by 20 percent in some adults, aggravate asthma, inflame lung tissue, impair the bodies’ immune system, and increase school absenteeism along with hospital admissions and emergency room visits.
Since approximately 60 percent of our air pollution is caused by motor vehicle use, individuals can reduce the amount of pollution they create by doing the following:
• driving less;
• keeping cars properly maintained;
• refueling vehicle after 6:00 PM during the summer;
• stopping at the click when pumping gasoline to avoid fumes and spills;
• combining trips into one outing;
• avoiding idling at schools and drive-thru windows; and
• carpooling, taking the bus, riding a bike and/or walking on short trips.
Other sources of the ingredients that form ozone include emissions from power plants and consumer products. Therefore, conserving electricity, avoiding the use of charcoal lighter fluid, and using manual gardening equipment, as opposed to gasoline powered equipment, will help to reduce the potential for ozone to be created.
For more information on the health effects of air pollution, actions that can be taken to reduce air pollution, and up-to-the-hour air quality information, call the Pima County Department of Environmental Quality at 740-3343 or click on www.airinfonow.org.
Oxides of Nitrogen + Volatile Organic Compounds + Heat & Sunlight = Ground-level Ozone
Understanding the AQI*
The purpose of the AQI is to help you understand what local air quality means to your health. To make it easier to understand, the AQI is divided into six categories:
Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are:
"Good" The AQI value for your community is between 0 and 50. Air quality is considered satisfactory, and air pollution poses little or no risk.
"Moderate" The AQI for your community is between 51 and 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms.
"Unhealthy for Sensitive Groups" When AQI values are between 101 and 150, members of sensitive groups may experience health effects. This means they are likely to be affected at lower levels than the general public. For example, people with lung disease are at greater risk from exposure to ozone, while people with either lung disease or heart disease are at greater risk from exposure to particle pollution. The general public is not likely to be affected when the AQI is in this range.
"Unhealthy" Everyone may begin to experience health effects when AQI values are between 151 and 200. Members of sensitive groups may experience more serious health effects.
"Very Unhealthy" AQI values between 201 and 300 trigger a health alert, meaning everyone may experience more serious health effects.
"Hazardous" AQI values over 300 trigger health warnings of emergency conditions. The entire population is more likely to be affected.
*Excerpt taken from the EPA.gov website
OZONE HEALTH IMPACTS:
PYRAMID OF EFFECTS
PROPORTION OF POPULATION AFFECTED
From EPA Office of Air Quality Planning and Standards
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