The Environmental Protection Agency tracks seven pollutants at air quality monitoring stations in Delaware, and we currently meet National Ambient Air Quality Standards for six of them.
Kent and Sussex counties meet the standards for all seven. New Castle County misses meeting the standard for ground level ozone by a marginal amount, less than 3 percent of the time, thus meeting the standard over 97 percent of the time.
The standards are established through a rigorous process to determine safe exposure levels, and then the standard is reduced another 20 percent as an extra margin of safety. New Castle County is well within that safety margin even on days when it is slightly high. Air quality in Delaware would get an “A” by almost any measure.
However, not according to the American Lung Association. In 2016, ALA gave Delaware an “F” in all three counties! How can that be?
ALA grades on quite the curve. Meeting the standard 100 percent of the time gets an “A”. Meeting the standard 99 percent of the time, incredibly, yields an “F.” On top of using a ridiculously tight curve, ALA ignores the EPA standard and uses their own preferred version.
Ozone is not emitted directly but forms from chemical reactions between nitrogen oxides and volatile organic compounds, which occur both as manmade and naturally occurring chemicals. Those reactions are accelerated by sunlight and heat so tend to peak on hot summer days when temperatures exceed 95° F. Summers with a lot of heat waves have more days with high ozone levels.
Great Smoky Mountains National Park in Tennessee gets its name from the summer haze formed from volatile compounds emitted by pine trees in the park. The park would have gotten an “F” from the ALA for ozone even before man occupied the continent! In 1980, Delaware was significantly over the standard almost half the year, but a lot of hard, expensive work has cleaned things up.
Today, many areas of the country are approaching natural background levels for…