BARBIES, POOL PARTIES AND…..the uninvited guest, OZONE
Summer brings us barbeques, pool parties, mountain biking, sundresses and wonderful balmy evenings, but it also ushers in ozone season. And unfortunately, this summer has seen one health advisory after another being released by the Utah Department of Air Quality. Today, Pioneer Day, ozone exceeded the threshold deemed safe by the EPA of 75 ppb (parts per billion), just as it did yesterday and the day before.
But what is ozone and should we worry about it?
Ozone is a gas that occurs both in the Earth’s upper atmosphere and at ground level. Ozone can be “good” or “bad” for your health and the environment, depending on its location in the atmosphere. Ground-level ozone is one of six criteria pollutants that is deemed harmful to public health (http://www.epa.gov/air/criteria.html) and is thus monitored nation-wide.
Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. “Bad” ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue. In essence, ozone exposure gives your lungs a “sunburn. OUCH!
Healthy people also experience difficulty breathing when exposed to ozone pollution. Because ozone forms in hot weather, anyone who spends time outdoors in the summer may be affected, particularly children, outdoor workers and people exercising. Millions of Americans — including Utahns — live in areas where the national ozone health standards are exceeded.
Ground-level or “bad” ozone also damages vegetation and ecosystems. It leads to reduced agricultural crop and commercial forest yields, reduced growth and survivability of tree seedlings, and increased susceptibility to diseases, pests and other stresses such as harsh weather. In the United States alone, ground-level ozone is responsible for an estimated $500 million in reduced crop production each year.
How Can Ozone Be Both Good and Bad?
Ozone occurs in two layers of the atmosphere. The layer closest to the Earth’s surface is the troposphere. Here, ground-level or “bad” ozone is an air pollutant that is harmful to breathe and it damages crops, trees and other vegetation. It is a main ingredient of urban smog. The troposphere generally extends to a level about 6 miles up, where it meets the second layer, the stratosphere. The stratosphere or “good” ozone layer extends upward from about 6 to 30 miles and protects life on Earth from the sun’s harmful ultraviolet (UV) rays.
What Causes “Bad” Ozone?
Ground-level or “bad” ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC. Tailpipe emissions are the number one culprit in the creation of ozone.
What Is Being Done About “Bad” Ozone?
Under the Clean Air Act, EPA has set protective health-based standards for ozone in the air we breathe. (These guidelines were recently revised, making the standard more stringent. However, Utah Moms for Clean Air petitioned the EPA arguing that the standard of 75 ppb was not adequate to protect public health. The medical literature suggests that negative health impacts are seen as low as 40 ppb.)
Throughout the country, including in Utah, additional programs are being put into place to cut NOx and VOC emissions from vehicles, industrial facilities, and electric utilities. Programs are also aimed at reducing pollution by reformulating fuels and consumer/commercial products, such as paints and chemical solvents, that contain VOC.
What can you do?
So what can you do to help reduce your contribution to ozone and protect you and your family? Start by signing-up for air alerts at the Utah Department of Air Quality (http://www.airquality.utah.gov/). DAQ will alert you at least one day in advance when our air is predicted to be unhealthy. Ozone typically peaks in mid-afternoon, so on red and yellow air alert days avoid physical exertion during the hottest part of the day, when ozone, which again is sunlight dependant, reaches its greatest levels. Exercise instead in the early morning or after dark. On bad air days like today, I also do my best to keep my kids inside during peak ozone hours (ozone breaks down quickly indoors).
As for your reducing your contribution to ozone please consider the following, especially on Red and Yellow alert days:
• Refrain from using a gas-powered lawn mower, blower, trimmer or weed cutter. Your neighbors will thank you just for the reduction in noise pollution!
• Fill your gas tank during cooler evening hours.
• Reduce driving by carpooling, taking public transit, walking, biking or telecommuting.
• Do not idle your car for more than 10 seconds. (An idling car emits 20 times more pollution than one driving at 30 miles per hour)
• Use low or no VOC paint. (Check-out the Green Building Center in Salt Lake City for sources).
• Set your thermostat a few degrees higher in the summer (saving energy saves you money and saves our air).
• Send letters to Governor Huntsman and other elected officials demanding action on our poor air quality (Salt Lake City gets an “F” grade from the American Lung Association!)
Together, we can make a difference. Together, we can create a future where we can all breathe freely — and where ozone stays off our pool party guest list!
*Much of the information above was gratefully borrowed from a June 2003 EPA brochure entitled: “Ozone.”
