Air quality in 12 of 20 counties in Missouri improved in 2014 compared to 2013, while air quality in 5 declined, and air quality in 3 counties was unchanged. The data come from the Air Quality System Data Mart maintained by the EPA , which contains data on the air quality of a number of Missouri counties going back to the early 1980s. For a fuller discussion of air quality and the data maintained by the EPA, or for a map of the counties, see my previous post.
The graphs at right show the percent of monitored days on which the Air Quality Index was in the Good Range. The top graph is for a group of counties along the Mississippi River, the middle one is for a group of counties in the Kansas City-St. Joseph region, and the bottom one is for a widely scattered group of counties in neither of the other two groups.
First, the percentage of good air days increased in 12 out of the 20 counties. Most of the improvements were small, but the percentage of good air days increased 14% in Jefferson County, 8% in Clinton County, and 7% in Iron County.
On the other hand, 5 counties experienced a lower percentage of good air days. In Cass County the percentage of good air days decreased by 18%, and in Stoddard County, it decreased by 15%.
The results are variable across counties and across regions. Thus, I suspect that the causes may relate to local factors in each county. For instance, the results in Jefferson County may relate to the closure of the Doe Run lead smelter.
I suspect that both electricity consumption and vehicle miles driven increased in Missouri during 2014, however data is not yet available, so I can’t test my hunch. Both contribute to poor air quality, so if they did increase, then the improvement in air quality in the majority of counties would be all the more impressive.
Second, in some Missouri counties the percentage of good air quality days was quite high in 2014. In the Mississippi River group, Lincoln and Perry Counties tied for the highest percentage of good air days, with 93%. In the Kansas City-St. Joseph group, it was Clinton County with 94%. In the Other group, Monroe, Iron, Boone, and Taney Counties all had good air day percentages at or above 95%.
Third, as in 2013, the City of St. Louis had the lowest percentage of good air days of any county in Missouri: 48%. That should be no surprise given its history in the annals of air pollution (see previous post). Fewer than half of the measured days in St. Louis City had good air quality, and the fact that the number did not improve is troubling. The only other county giving St. Louis a contest for lowest percentage of good air days was Jackson County, the location of Kansas City, with 52%.
Over a longer term, the chart for the Mississippi counties is somewhat encouraging. The lines start pretty low for some of those counties, but have a clear upward trend. The chart for the Other counties is also encouraging. The lines start pretty high, and most have an upward trend. The chart for the Kansas City-St. Joseph counties is more equivocal, however. Air quality in most of these counties has declined since 1983. Some appear to have begun to recover, but only Clinton County has air quality equal to or better than in 1983.
Environmental Protection Agency. Air Quality Index Report. This is a data portal operated by the EPA. Data for 2014, Missouri, and grouped by County downloaded on 11/6/2015 from http://www.epa.gov/airdata/ad_rep_aqi.html.