New England Ozone Levels Are Improving

Published December 1, 2007

The number of days on which ozone levels in New England states exceeded federal standards continued a long-term decline this year, according to information released by the U.S. Environmental Protection Agency (EPA) on October 1.

EPA documented 26 days this year when ozone monitors exceeded federal standards somewhere in New England. The 26 days exceeded the record low of 16 days reported in 2006, but “over the longer term, however, the air quality in New England continues to improve,” EPA reported.

Preceded by Record Decline

The increase in above-standard ozone days from the 2006 record low was due to warmer-than-usual weather during the summer ozone months, EPA reported.

“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,” EPA reported. “Sunlight and high temperatures speed the formation of ground-level ozone smog; many areas of New England had more days exceeding 90 degrees this summer than during last summer. August and September were especially hot, dry and sunny for much of New England.”

Recording stations in Connecticut and Massachusetts exceeded federal ozone standards most often, but neither state reported more than 20 incidents of exceeding federal ozone standards. Maine, New Hampshire, Rhode Island, and Vermont reported fewer than 10 days in which stations exceeded federal ozone standards.

Improvement Continues

“Although warm temperatures this summer led to an increase in unhealthy days, over the long-term New England has experienced a decreasing number of unhealthy ozone days,” EPA observed. “Also, peak ozone concentrations have decreased significantly over the last 30 years. In 1983, New England had 90 unhealthy days, compared with 26 this summer. Overall, peak ozone concentrations in New England have decreased by more than 20 percent since 1980.”

EPA also noted that on the 26 days when one or more stations exceeded federal ozone standards, fewer stations exceeded federal ozone standards than in the past.

“Another measure of air quality in New England is the geographic extent of the unhealthy air quality. This is determined by counting the number of air quality monitors that recorded exceedances of EPA’s health-protective 8-hour ozone standard,” EPA explained.

“A higher number of monitor exceedances means a more extensive area of unhealthy air quality,” the report continued. “When comparing the 2007 ozone season to the 2001 ozone season, a New England summer with temperature data similar to this summer, the total number of monitored exceedances dropped from 349 in 2001 to 175 this past summer. This is an approximately 50 percent decrease in the number of areas exceeding the standard over this six year period.”

Improvement Should Continue

Clean air experts note the federal standards reflect an exceedingly cautious EPA mindset, where there is little evidence of significant health risks even on days when ozone exceeds the federal standards. There is, at this time, no clinical evidence that ozone levels of 0.08 parts per million, or more, cause disease or death.

“Assertions that reducing ozone will lead to fewer cases of asthma and other alleged health problems are contradicted by the scientific evidence,” said Joel Schwartz, a visiting fellow at the American Enterprise Institute.

In an October 1 news release, EPA promised to keep the public abreast of small particle (dust) pollution, which is independent of temperature, and to aggressively regulate the emission of diesel, particulate, and ozone precursors. Requirements being phased in between 2004 and 2009 will result in reduced vehicle emission of particulates and ozone precursors.

The result will be vehicles that are 77 to 95 percent cleaner than older models. The program also imposes a 90 percent reduction in sulfur in gasoline and a 90 percent reduction of nitrogen oxide and particulate emissions.

John Dale Dunn, M.D., J.D. ([email protected]) is a policy advisor for The Heartland Institute and a member of the Board of Science and Policy Advisors of the American Council on Science and Health.

For more information …

“New England Experienced More Smog Days During Recent Summer, But Long-Term Trend Is Still Toward Cleaner Air,” U.S. Environmental Protection Agency, October 1, 2007:!OpenDocument