Volume 105, Number 41 - October 9, 2008
brought to you online by Pinedale Online
UW ozone forum draws big crowd
Over 120 members of the public attended an informational forum on ozone at the Pinedale Auditorium on Tuesday night, organized
by the University of Wyoming’s School of Environment and Natural Resources. The event was sponsored by the Sublette County Commissioners and included presentations by four national experts of air quality and its effects. The topics ranged from the chemistry of ozone and its health effects to the regulatory policy and implementation. A question and answer discussion followed the lectures.
First to present was Dr. Derek Montague, an associate professor in the Department of Atmospheric Science at the University of Wyoming. His speech centered on the science of ozone, including its history, structure, formation and atmospheric presence.
First discovered by Swiss scientist Christian Schonbein back in 1840, ozone is indeed a form of oxygen, and its presence can be found in all levels of the atmosphere.
Ozone does serve a positive role, but at lower altitudes, it can also be damaging. The ozone found in the stratospheric layer, or that above 40,000 feet, is where the highest concentration is found.
“Up there it provides a very useful function,” said Montague.
At this layer of the atmosphere, ozone helps protect the Earth from ultra-violet radiation from the sun by absorbing these harmful rays.
At lower altitudes, however, ozone can facilitate the greenhouse effect.
“The other unfortunate aspect of ozone in the lower atmosphere is that it’s an air pollutant,” said Montague. “And I’m sure we’re aware of that.”
At these lower altitudes, called the troposphere, sunlight reacts with nitrogen dioxide (NO2) releasing an oxygen atom (O) and leaving a nitrous oxide (NO) molecule. The released O combines with other oxygen molecules to produce ozone (O3).
Volatile organic compounds (VOCs) in the air then react with the nitrous oxide (NO) molecule left over from the sunlight split and produce NO2, which allows the process to repeat all over again. The more VOCs in the air, the faster the process occurs, and the faster the tropospheric ozone levels will rise. At the local level, weather patterns also play a significant role in ozone amounts.
“In general, ozone air pollution episodes are normally associated with summertime in the city,” said Montague.
The Northern Hemisphere, which is where most of the human population lives, has seen these levels rise at the highest rate, a sign that humans are contributing to these levels according to Montague.
“The question we should really ask is what activities generate ozone,” Montague said.
While humans are the primary source of nitrogen oxides, VOCs come not only from humans, but also from the natural processes of the Earth.
Needless to say, the science of ozone is complex, and any plans to alleviate its negative impact must take this range of factors into account.
This negative impact often involves the detrimental effect on human health, and next to speak was Dr. Fred Miller, a former statistician for the Environmental Protection Agency and a current independent consultant in radiation and inhalation toxicology. His presentation focused on these health effects, including their cause, affected populations, elevation’s effect and remedial action.
“This is an extremely dynamic situation,” said Miller. “It is not at all static.”
Most often, high levels of ozone affect the lungs, though according to Miller, evidence also suggests that the heart is also adversely affected.
But the respiratory system is clearly affected.
A cough can develop, a sore throat, pained breathing and fatigue, and often, these symptoms come on quickly.
For those with asthma, the symptoms are magnified in both onset and severity. And according to Miller, those who exercise during times of elevated ozone are far more susceptible to dangerous doses due to the increased breathing patterns and full lung usage.
“So it makes sense that when you exercise, you’re going to get faster and deeper penetration,” Miller said.
Studies have yet to be produced that measure the health effects of ozone at high elevations. Thus, Miller’s statements on the issue were limited to inferred conclusions.
Having seen the ozone data from the Pinedale area, Miller did have cautious advice for the audience.
“This is something we need to confront, but it’s not a matter of all of a sudden you’re all going to drop dead or you’re all going to have this or that,” he said. “It is something that is a concern, but not panic.”
However, he did suggest ways to limit the general health effects of ozone.
During times of elevated levels, people should stay indoors when possible. If working or exercising outdoors, people should avoid the hottest parts of the day.
Fast breathing rates, combined with high ozone levels, produce elevated dosages when exposure occurs for an extended period of time.
As these health effects have become better understood, legislation that controls the contributing emissions has tightened. And the former chairperson of the EPA’s Clean Air Scientific Advisory Committee (CASAC), Dr. Rogene Henderson, spoke next on this regulatory policy.
She detailed the National Ambient Air Quality Standards (NAAQS), including their formation and the people in charge of forming them.
Through the Clean Air Act, the EPA Administrator, Stephen L. Johnson, is charged with setting these standards, and two types are required.
The primary NAAQS involves those directly related to human health. The secondary NAAQS relates to factors of general public welfare, including vegetation, soil, water, wildlife, visibility, weather and climate. In order to facilitate this process, Johnson appoints a panel of scientists (the CASAC) to review all relevant data.
“It should reflect the latest scientific knowledge,” said Henderson.
Every five years, the CASAC makes policy recommendations based on that data, though the administrator still has ultimate authority.
The six leading pollutants that are analyzed consist of carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter, and sulfur dioxide.
“For the primary standard to protect public health, it has to be set with a margin of safety,” said Henderson, “to address uncertainties associated with inconclusive scientific and technical information.”
In 2008, the CASAC recommended that the primary standard for ozone levels be set at an 8-hour interval of 60-70 parts per billion (ppb). As its secondary standard, the CASAC recommended a cumulative, seasonal standard of 7-15 parts per million (ppm) per hour.
In this instance, Johnson set the standard 75 ppb over an eight hour time period as both the primary and secondary standard, much to the Henderson’s dismay in light of the latest scientific evidence.
She hopes that the future of policy formation includes a multi-pollutant approach that will not isolate specific pollutants and establish individual standards, but rather a more comprehensive method that factors in all six.
“It’s a very difficult thing to do, but I think it’s something that a NRC (National Research Council) committee could address,” she concluded.
Once these standards are established, governmental agencies must enforce them not only at the federal level, but also at the state and local levels. Peter Hess, a retired deputy air pollution officer in San Francisco, was last to address the audience, and his speech focused on air quality legislation in action. He explained the definitions of this legislation, including the penalties for exceedances as well as the state and local agencies that are involved in the process.
“Exceedance is a reading at a state or local federally approved monitor of greater than or equal to the 75 ppb,” Hess began.
If an area or state surpasses the 75 ppb ozone standard over a three-year time span, it will meet the non-attainment criteria.
By March of 2009, state governors must make their non-attainment recommendations to the EPA Administrator, who will then have a year to categorize the area based on those recommendations.
“I think only this county, this region, has a wintertime ozone problem,” said Hess.
“And that’s going to bear a lot in the determination and making the difficult decision of non-attainment.”
Depending on the severity of non-attainment, a timeline will be established for that state to take mitigating actions and return to attainment standards.
When all is said and done, each state is responsible for its own air quality, and each must have a State Implementation Plan (SIP) to reach or uphold its attainment goals.
“The Clean Air Act is very, very clear on that,” Hess said. “The roadmap to attainment will be developed by the state, and that is the Wyoming DEQ (Department of Environmental Quality).”
The WDEQ is in charge of enforcing the regulations of the SIP.
And at the local level of government, input should be gathered from the public to address the SIP and its attainment plan.
For Hess, four crucial components are necessary for a good attainment plan. These include sound science, intelligent decisions, many voices during the planning process and learning from the attainment plans of others.
“Attainment is not only possible, it will happen with the applications,” Hess concluded. “We’re not dealing with rocket science here. We’re dealing with sound science. And there’s ways to attain air quality standards.”
Hess’ speech was the last presentation of the evening and was followed by an openmic session with the four participants, as well as Wyoming DEQ Director, John Corra.
Most of the questions involved the public’s concern for the health effects of ozone, including the effects on children and energy workers. A public notification plan of ozone alerts was also discussed.
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