Climate Progress, June 38, 2014
A group of Environmental Protection Agency science advisors are urging the agency to enact stricter limits on ozone, a pollutant that’s the main ingredient in smog and that can exacerbate asthma and other respiratory problems.
The scientists of the EPA’s Clean Air Scientific Advisory Committee sent a letter to the agency Thursday that made a scientific case for increasing the federal standards on ozone, which right now are set at 75 parts per billion (ppb). The committee said that setting the standard below 70 ppb and preferably as low as 60 ppb would better avoid some of the worst health effects of ozone, including, as the letter states, “decrease in lung function, increase in respiratory symptoms, and increase in airway inflammation.”
The worst of those health impacts are felt by vulnerable populations such as children, the elderly and people with asthma. But the letter states at the current standard healthy adults who stay outside for more than six and a half hours can experience respiratory issues. A limit of 70 ppb would still inadequately protect public health, the scientists say, so the more stringent lower bound of 60 ppm is important.
In 2010, the EPA estimated that a 60 ppb standard would avoid 4,000 to 12,000 premature deaths, 21,000 hospital and emergency room visits and cut down on the number of school and work days missed by 2.5 million.
“The recommended lower bound of 60 ppb would certainly offer more public health protection than levels of 70 ppb or 65 ppb and would provide an adequate margin of safety,” the letter states. “Thus, our policy advice is to set the level of the standard lower than 70 ppb within a range down to 60 ppb, taking into account your judgment regarding the desired margin of safety to protect public health, and taking into account that lower levels will provide incrementally greater margins of safety.”
EPA spokesman George Hull told the LA Times that the EPA “will respond appropriately” to the recommendations.
Though ozone is still in need of revised standards, another air pollutant that has been appropriately regulated by the EPA — nitrogen dioxide — has shown significant reductions in the U.S. in the last 10 years, according to new NASA data.
Nitrogen dioxide can also lead to respiratory problems and contributes to the creation of ozone and particulates. It’s emitted mainly from cars and coal-fired power plants.
The reductions are a result of EPA regulations, technological advancements and economic changes, NASA scientists said, and have occurred even as the number of cars on the road have increased over the last 10 years. Still, one scientist said, more work needs to be done — including advancements in ozone regulation.
“While our air quality has certainly improved over the last few decades, there is still work to do – ozone and particulate matter are still problems,” Bryan Duncan, atmospheric scientist at NASA’s Goddard Space Flight Center, said in a statement.
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