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EPA's End-of-Season Ozone Data Show Increase in Smoggy Days in New England

Release Date: 10/01/2002
Contact Information: Andrew Spejewski, EPA Press Office, 617-918-1014

BOSTON – At the close of the 2002 summer ozone season, the U.S. Environmental Protection Agency today announced that New Englanders suffered an increase in the number of unhealthy air quality days this year.

The increase in the number of days with unhealthy air this year was directly related to the increase in the number of hot days this year. Sunlight and high temperatures speed the formation of ground-level ozone smog, and many areas of New England this year had the most days exceeding 90 degrees since 1983, one of the worst years on record for bad air quality.

Based on preliminary data, there were 43 days when ozone monitors in New England recorded concentrations above the level considered healthy. Last year, there were a total of 32 unhealthy days. Ground level ozone, the main ingredient of smog, is unhealthy when average concentrations exceed 0.08 parts per million over an eight-hour period.

The number of unhealthy days in each state this summer were as follows: 36 days in Connecticut (compared to 26 in 2001); 29 days in Massachusetts (27 in 2001); 16 days in Rhode Island (15 in 2001); 17 days in Maine (15 in 2001); 13 days in New Hampshire (10 in 2001); and five days in Vermont (two in 2001).

Although warm temperatures this summer led to the increase in unhealthy days this year, the long-term trend in the number of unhealthy days in New England is downward. Peak ozone concentrations have significantly decreased over the last 30 years.

"When we look back to the air quality conditions a generation ago, we can feel proud of the advances we've made in reducing pollution," said Robert W. Varney, EPA's New England administrator. "A summer like this one, however, reminds us that our efforts to use cleaner cars and fuels and our commitment to reducing power plant emissions and conserving energy in our own daily lives must continue."

Historical charts of unhealthy air days from 1983 through 2002 are available for each state on EPA New England's web site at: A preliminary list of the unhealthy readings recorded this summer by date and monitor location, and corresponding air quality maps for each day, can be found at:

Ground-level ozone (smog) is formed when volatile organic compounds and oxides of nitrogen interact in the presence of sunlight. Cars, trucks and buses give off the majority of the pollution that makes smog. Fossil fuel burning at electric power plants, which run at high capacities on hot days, gives off significant amounts of smog-making pollution. Gas stations, print shops, household products like paints and cleaners, as well as gasoline-powered lawn and garden equipment, also contribute to smog formation.

EPA is working on several fronts to reduce emissions from transportation sources. For example, EPA has issued tougher tailpipe emission standards for cars and light-duty vehicles, including sport utility vehicles that will begin in 2004. These new standards for the first time ensure that SUV's, mini-vans and light-duty trucks meet the same low levels of tailpipe emissions as other passenger cars. Also, heavy duty diesel trucks will be required to meet new very stringent standards in 2007.

In addition, EPA has asked companies to join our Commuter Choice Leadership Initiative, which is a voluntary, national standard of excellence for employer-provided commuter benefits. Twenty-one companies have joined in New England accounting for more than 26,000 employees. Companies that meet the national standard provide incentives for employees to commute to and from work using alternatives means of transportation, such as mass transit, biking, walking, and van pools.

The record demand for electricity this summer is also a factor contributing to air pollution. High electricity demand worsens air quality by forcing power plants in the region to run at or near peak capacity, thus increasing air emissions from those plants. For the second year in a row, New England set records for electricity demand. This year's all-time record electricity demand of 25,524 megawatts on Aug. 14 exceeded the previous all-time record of 25,158 megawatts set on Aug. 9, 2001. In addition, seven of New England's 10 highest electricity demand days were recorded this July and August - all on days when unhealthy levels of ozone were also recorded in New England. On the record demand day, Aug. 14, unhealthy levels of ozone - in excess of 150 percent of EPA's air quality standard - were recorded in Connecticut, Massachusetts and Maine.

EPA is working to address the air pollution challenges resulting from this increase in energy demand. EPA has taken aggressive steps to reduce pollution from power plants upwind of New England. These actions will result in an additional reduction of about 1 million tons of nitrogen oxides from power plants in the eastern United States by 2004. In addition, EPA has drafted proposed legislation, known as the Clear Skies Initiative, that establishes mandatory reduction targets for emissions of sulfur dioxide, nitrogen oxides and mercury from power plants nationwide. The Clear Skies Initiative would reduce emissions of these three key pollutants by 70 percent over the next 15 years. This initiative is being considered by Congress.

Exposure to elevated ozone levels can cause serious breathing problems, and aggravate asthma and other pre-existing lung diseases. It can also make people who are vulnerable more susceptible to respiratory infection. Studies have shown an association between ozone levels in the outdoor air and increased hospital admissions for respiratory causes, such as asthma. Ozone air pollution in the northeastern United States has been associated with as much as 10 to 20 percent of all summertime respiratory hospital visits and admissions.

To inform New Englanders about ozone levels, EPA maintains an ozone mapping system that shows "real-time" images and daily forecasts of ground-level ozone levels. The daily ozone forecast is available from May through September on the EPA's air pollution information web page at Citizens can also sign up at this web address to receive free smog alerts from EPA's New England office.