Tuesday, May 29, 2001 at 2:31 PM
With Memorial Day weekend behind us, summer can't be too far away. But along with backyard barbeques and trips to the beach, summer can also bring high ozone days, days when you're not supposed to gas up your car until after sunset. High ozone can cause breathing difficulties for seniors and people with respiratory problems. It can also trigger asthma attacks in children and adults. But did you know that even low levels of ozone can affect the quality of life for sensitive populations? 90.3's Karen Schaefer brings us this primer on ozone.
Karen Schaefer- Ozone forms at two places in our atmosphere. High above the Earth, the naturally-occurring ozone layer helps shield us from solar radiation. But ozone can also form closer to the ground from the imperfect burning of fossil fuels. And that, says Kevin Snape, executive director of the Clean Air Conservancy in Cleveland, is where ozone can cause us problems.
Kevin Snape- Ozone is a quality of life issue. The easiest way to think of it is ozone is a sunburn of your lungs. It’s unlikely to kill you, but it can make you miserable for a while.
KS- What happens is this: ozone is an unstable gas composed of three oxygen molecules—O3—loosely bonded together. As it breaks down, individual molecules of oxygen spin off and bond with other molecular structures, including the tissue in our lungs. Dr. Dorr Dearborn, a pediatric pulmonologist with University Hospitals, says that causes a swelling of lung tissue, making it harder to breathe. And he says for people with respiratory problems like asthma, that can mean real discomfort.
Dorr Dearborn- An analogy that I make to my patients is that, like I said, asthma is like having a rash in your airways. Ozone is like taking sandpaper to that rash.
KS- Dearborn says high ozone can actually trigger asthma attacks. And it further diminishes lung capacity in people with emphysema and chronic bronchitis. People who work outdoors are also affected, as are older people and children, who breathe at a faster rate than adults. In 1974, the U.S. EPA set national standards for ozone risk at 120 parts per billion. But in the 1990’s Dr. Dearborn says studies on the health effects of ozone produced some startling new results.
DD- The levels of ozone, we used to think that they had to be fairly high in order to produce much disease. But more recently we’ve recognized that comparatively low levels of ozone can be of significant concern.
KS- The U.S. EPA has responded by setting new ozone risk standards of 85 parts per billion over an 8-hour period. Heidi Griesmar of the Ohio EPA says her agency monitors ozone levels daily from April through October, when warm weather creates the ideal environment for the formation of ozone pollution.
Heidi Griesmar- Towards afternoon, like 3 to 5 o’clock, right around the 5 o’clock hour when we tend to have the highest levels. It’s right after the day gets very, very hot and cars have been driving around all day. And then after 6 or 7 in the evening, they go back down. They normally go down over the weekends.
KS- On days when ozone levels are below 60 parts per billion, no one is really at risk. But when ozone rises above 85 parts per billion, sensitive populations begin to be affected. As the ozone in the atmosphere goes up, that population expands until—above 120—everyone is at risk. Dr. Dearborn says the best way to protect yourself is to stay indoors during peak ozone hours.
DD- There is some protection afforded by staying inside and not going out. That’s not perfect, because we ventilate our homes with outside air. But there isn’t much else that we can do practically to avoid it. About all we have to offer is to increase their medications.
KS- But ozone levels may not be the same everywhere. The Ohio EPA has three monitors in Cuyahoga County that measure ozone pollution from fixed sources such as industry, as well as sources that are mobile, like automobiles and lawn mowers. But Kevin Snape of the Clean Air Conservancy believes that topography, wind directions and even tall buildings can cause ozone to accumulate in pockets, creating local variations in ozone levels. Last summer his group began monitoring ozone in various Cleveland neighborhoods. He says they found considerable differences between one neighborhood and another.
KSn- And so what we’re doing this year is we’re putting 15 monitors out in the region. And we’re trying to get a much more accurate picture of what’s on the ground, what’s going on in the neighborhoods, and seeing if one neighborhood is chronically higher than another neighborhood. Why we’re doing this is we’re trying to put more information into peoples’ hands that is unique to their neighborhood, to their life, so that they can make better decisions.
KS- Heidi Griesmar at the Ohio EPA says the agency hasn’t reviewed the Conservancy’s data and can’t comment on its accuracy. But she does admit that the additional information may be of help to residents trying to assess their risk of ozone exposure. New studies of the health effects of ozone seem to indicate that long-term exposure in children could permanently affect their development of full lung capacity. Those studies still are inconclusive. But until more evidence is available, the consensus from the medical community is to monitor summer ozone readings - and behave accordingly. In Cleveland, Karen Schaefer, 90.3, 90.3 WCPN.
To get today’s updated ozone information, click here.
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