By PAUL PETERSON
Leader staff writer
Unlike Sunday’s ozone-action advisory, which resulted from a level orange forecast, Independence Day ozone levels were rated free of health risks to people known for vulnerabilities to potential ozone exposure, according to air-quality index numbers available from Arkansas Department of Environmental Quality.
According to Metroplan transportation planner John Hoffpauer, the ozone season, from May through September, is reaching its peak, and now is the time to take precautionary measures to reduce environmental hazards and physical health risks.
The public is asked to take voluntary action to reduce ozone emissions. Seasonal measures include carpooling, walking or taking public transportation, lowering travel frequency during rush hour traffic, keeping vehicles well-tuned and utilizing alternative work arrangements.
Although today’s air quality should not pose health risks for most people, unusually sensitive individuals are encouraged to routinely check the Air Quality Index and Ozone Forecast in newspapers, on the radio, television and the Internet.
“Our Web site lays out who’s at risk,” Hoffpauer said, explaining why and how ozone occurs, as well as ways to reduce exposure and emissions of ozone forming chemicals.
“Pollutants in the atmosphere, such as tail-pipe exhaust, are what’s known as precursor emissions,” Hoffpauer said. “Also, conditions must be right. First, it must be hot, with direct sunlight, and no real wind or breeze. With those ingredients, gas fumes produce resin that is very easy to smell across the atmosphere. If you breathe in too much (ozone), it’s like a sunburn on the lungs, especially individuals with asthma, emphysema, a summer cold or any pulmonary disease.”
Those at greatest risk of ozone exposure are individuals working outside. “People who work outside breathe in more often,” Hoffpauer said. “Deeper breaths take in more pollutants. It takes time for chemical reactions to take place. It’s usually midday before ozone concentrations become a problem.”
Others at high risk to ozone exposure include children and elderly, and people with respiratory difficulties. High ozone concentrations may reduce visibility, aggravate pre-existing conditions such as asthma, bronchitis, common colds, emphysema, influenza and pneumonia. It also may cause symptoms in otherwise healthy people who engage in strenuous outdoor activity.
Hoffpauer said ozone levels build during the afternoon before reaching their peak and dissipate overnight, and a slight breeze or heavy winds can disperse ozone-causing agents and reduce chances for formation.
But wind direction can deliver harmful agents to certain locations where ozone levels are known to increase, Hoffpauer said.
If central Arkansans and the weather don’t cooperate to lower ozone levels this summer, federal regulations could prohibit or discourage new industry and new road construction for more than a decade in Lonoke, Pulaski, Saline and Faulkner counties, according to MetroPlan officials.
Because ozone is in large part caused by the burning of fossil fuels, exacerbated by sunlight and heat, officials try to discourage activities like driving, cutting grass and gassing up the car during daylight hours in the summer.