Public Release: 

Ozone 'Chat Room' Provides Real-Time Air-Quality Research

Washington University in St. Louis

Environmental scientists at Washington University in St. Louis have developed a revolutionary Internet air pollution "chat room" that is helping to shape policy and provide a better understanding of how ozone, a nasty, unhealthy air pollutant, moves across the country.

Since spring 1996, Rudolf B. Husar, Ph.D., professor of mechanical engineering and director of Washington University's Center for Air Pollution Impact, Trends and Analysis (CAPITA), and Bret A. Schichtel, Ph.D., CAPITA research associate, have been key players in the air quality workgroup of the U.S. Environmental Protection Agency's (EPA) Ozone Transport Assessment Group (OTAG).

Instead of meeting in St. Louis or Washington, D.C., however, the air quality workgroup has a perpetual "virtual gathering" across the Internet. Through this real-time, interactive site, air-quality colleagues, comprising national air pollution experts, state air quality directors, industry representatives, environmental groups and EPA personnel, among others, have been able to make inferences about the regional nature of ozone and its long-range transport.

These findings better clarify the understanding of ozone and will affect regulations on industry and ultimately citizens. People in communities with unacceptable levels of ozone not only may suffer health effects from ozone pollution, but also may face government-imposed lifestyle changes, such as mandated car-pooling and other travel restrictions, limited or no outdoors barbecuing, and restricted hours to mow lawns and do other outdoor activities.

Summer Sizzle

The good old summer time is "Ozone Season." Ground-level ozone is a harmful pollutant that can cause health problems, especially for children, the elderly and people with respiratory conditions. A major contributor to smog, ozone is an irritating gas formed when hydrocarbons mix with nitrogen oxide in sunlight. Industrial and consumer activities, most involving combustion, are behind the formation of ground-level ozone, and sunlight and high temperatures play key roles in driving atmospheric levels to the damaging point.

Current EPA ozone attainment standards state that an area cannot exceed .12 parts per million of ozone averaged over an hour more than three times during the past three years. Ozone is measured hourly in 37 states that are considered to have an ozone problem. Anything above these measurements is considered non-attainment. Environmental amendments to the Clean Air Act of 1990 established five different categories of ozone non-attainment: (1) marginal; (2) moderate; (3) serious; (4) severe; and (5) extreme. Los Angeles is a category 5; St. Louis, which had been designated a 2, is expected to be upgraded to a 3. Many other communities face upgrades similar to St. Louis as EPA ponders tougher standards for both ozone and particulate matter later this summer.

"There is a two-fold revolution at work in the OTAG operation," says Husar, a veteran EPA consultant on acid rain and haze research. "For one, it has changed EPA's emphasis from command-control to consensus-building. Throughout its existence, EPA came up with regulations and enforced them with little input from others, least of which those who face the biggest sanctions. By building consensus beforehand, the stakeholders generally will agree to the basic principles of management decisions before they are implemented.

"Second, the interactive Internet approach has altered the way environmental research itself is done. Much wasted time and energy are eliminated by cutting down on travel and meetings, and fresh research is posted frequently. This way, people are able to observe and comment on the work as it is being presented, and everyone benefits."

The interaction of the air quality workgroup is made possible by CAPITA, the world's largest private library of air pollution literature and computerized data, begun at Washington University more than 20 years ago. Many hundreds of gigabytes are stored at and transferred through CAPITA, which has data that span more than 100 years of American pollution and energy consumption. The air quality workgroup focuses on data spanning 10 years, from 1986-1995. Group members can access hourly ozone measurements from air-quality sites in every county of the 37 states most heavily affected by ozone pollution. They also can access daily meteorological data, primarily consisting of wind speed and direction.

In addition to technical reports, color animations developed at CAPITA showing ozone movement across a map of the United States also can be accessed at this website. Scores of people visit the website daily, and there is nearly daily discussion on the information and ideas presented. Moreover, the data can be downloaded from CAPITA and used for other research, and specialized databases can be generated.

The website address is: http://capita.wustl.edu/otag/.

Finding The Culprit

"We provide the technical support for analysis of vast amounts of data pertaining to ozone so that we can enlighten the decision-makers," says Husar. "Historically, ozone has been considered a local problem maintained by cleaning up local emissions. But more recently, it's been recognized that attainment in some eastern U.S. areas cannot be achieved by simple cutbacks at the local level because a reasonably large fraction of the ozone occurring in such areas is actually transported in from the outside. So, whatever ozone is added on top is the ozone that is bumping the region into non-attainment."

One such area where this is occurring, Husar says, is the D.C.-New York corridor.

"The argument is that they cannot achieve attainment simply because most of the ozone is not theirs," he explains.

But where is it coming from? Answering that question is a major quest of the OTAG air quality workgroup, and through this new approach to environmental research, Husar and Schichtel have been able to reach some tentative conclusions that implicate their own region, the Midwest. Also, they are seeing new trends in the South.

"There is something special about the Midwest," says Husar. "There is always a pool of ozone in the greater Ohio River Valley -- roughly from Illinois to western Pennsylvania -- and when the wind blows from the Midwest toward the east, neighboring areas receive higher doses. The data are very clear on that."

Another observation: Compared with weekdays, ozone levels are reduced over weekends.

"Only humans operate on a weekly cycle, so this graphically ties human activity during the work week to ozone production," says Schichtel, who has concentrated greatly on meteorological data to develop ozone transport animations. The animations, available through the OTAG Washington University website, show pulses of ozone moving eastward with air flow across the Midwest.

In the South, high ozone is associated with slow wind speeds, an indication of higher local contributions of ozone. However, Schichtel says recent analyses once again cast suspicion on the Heartland.

"We're seeing some transport from the Midwest, which implicates the Midwest but doesn't prove that it is the source of higher levels," says Schichtel, who bases the observation on measuring wind and ozone data using a trajectory analysis.

There are two other OTAG subgroups, one dealing with policy, the other with computer modeling. Both use information and data gathered by the air quality workgroup.

"The beauty of the OTAG operation is that we can establish a virtual community of interacting people without having to be at a specific place," Husar says. "This is a dream come true for an environmental engineer -- to express your viewpoints and research and participate in something that has substantial meaning for the American public, all the while using our skills and resources from more than 20 years of work at CAPITA."

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