Minnesota Pollution Control Agency

Contact: Mark Sulzbach, 651-296-7768 Toll-free: 1-800-657-3864 Saint Paul, Minn. - Each spring the Minnesota Pollution Control Agency (MPCA) reminds citizens that April marks the start of the ozone pollution season. In recent years, very few pollution health alerts in Minnesota were called due to ozone levels - most have been caused by fine particle pollution. But this year may be different. On March 13, 2008, the U.S. Environmental Protection Agency significantly lowered the ozone standards to be more protective of human health. New, more protective fine particle pollution (PM2.5) standards will also be adopted. Both new stricter standards go into effect May 1, which coincides with EPA's Air Quality Awareness Week, running from April 28 through May 2. Sensitivity to ozone varies, but elevated levels can cause irritation to eyes, nose and throat, and make breathing difficult even in healthy people. High ozone levels can trigger respiratory problems such as asthma and chronic bronchitis attacks in those who already suffer these diseases. Fine particle pollution causes similar problems and irritations as ozone, but also can trigger cardiovascular and heart problems for individuals with these existing health issues. "Our air in Minnesota is cleaner than it was 20 years ago," said Rick Strassman, the MPCA's air monitoring supervisor. "But the stricter standards, improved monitoring equipment and subsequent air alerts may make people think otherwise." The MPCA uses the EPA's color-coded Air Quality Index (AQI) with a 0-500 scale, to convey air quality readings to the public. Air alerts are triggered at 101 (orange) which reaches the "unhealthy for sensitive groups" category. Sensitive groups include senior citizens, young children, anyone with respiratory or heart problems and anyone who exercises strenuously. These groups should take it easy and reduce the intensity and duration of physical activities during an alert - walk, don't run, for example. Because ozone is scrubbed out by air conditioning, exercising in an air conditioned environment is preferable to exercising outside during ozone alerts. However, fine particle pollution will not be reduced by air conditioning and indoor levels can be the same or higher than outdoors. "Every year more medical and scientific studies reveal greater health dangers at lower levels of pollution," Strassman said. "This year there will be more alerts in Minnesota because the standards have been changed to be more protective. The new AQI measurement of 101 for ozone would have been equal to an AQI of 77 with the old guidelines. The new fine particle threshold to trigger an air health alert would have equaled about 88 with the old guidelines." Ozone, a colorless and odorless gas, is created when volatile organic compounds (VOCs) mix with nitrogen oxides in hot sunny weather. In Minnesota, that means the ozone season runs April through September. VOCs and nitrogen oxides (and fine particle pollution) are emitted when fossil fuels are burned. Fumes from chemicals and petroleum products can emit VOCs, too. Wood smoke also contains particle pollution. To reduce ozone and fine particle pollution, citizens can help by reducing electricity use, driving and idling less, refueling vehicles after 8 p.m., limiting the use of paints and solvents, and cutting back on recreational fires. Surprisingly, small gas engines such as gas-powered lawn mowers emit more VOCs per hour than a modern car, because they lack pollution control technology. Consider mowing less often, replacing grass with annuals, or using reel or electric mowers. Visit the MPCA AQI Web page at http://aqi.pca.state.mn.us/ to check the hourly AQI values, find information on air pollution health effects and to sign up to receive free email air pollution health alerts. See the Minnesota Department of Health Web site at www.health.state.mn.us/divs/eh/air/index.htm for additional information on air quality health issues.