Air quality in 9 out of 24 counties in Missouri improved in 2017 compared to 2016, while air quality in 14 declined. The data comes from the Air Quality Index Report 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.
Figure 1 at right show the percent of monitored days on which the Air Quality Index (AQI) 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. The charts represent every year from 2003-2017. In addition, they chart the data for 1983 and 1993 to give a long-term perspective.
(Click on figure for a larger view.)
Compared to 2016, the percentage of good air days increased in 9 out of the 24 counties. Most of the increases were small, but the percentage of good AQI days jumped by 32% in Stoddard County, by 23% in the Andrews County, by 19% in New Madrid County, and by 16% in the Jefferson County.
The percentage of good AQI days fell in 14 counties. In most cases the decline was small, In only Iron County was the decline as large as 10%.
Missouri’s 3 largest metropolitan areas, St. Louis, Kansas City, and Springfield had good air years in 2016, and counties associated with those cities all slipped in 2017.
In almost all Missouri counties the percentage of good air quality days was high in 2018. In no county was it below 60%, and it was 80% or above in 18 out of the 24 counties. As in previous years, the outstate group led in the percentage of good AQI days, which is expected because they don’t experience the concentration of pollution sources that large cities do.
In 2017, the City of St. Louis had the lowest percentage of good air days of any county in Missouri: 62%. St. Louis County had the second fewest, at 68%. In 1983, the percentage of good AQI days was 14% and 16% in those counties. St. Louis still has plenty of air quality challenges, but we’ve come a long way.
Clean air to breath should be everybody’s birthright. Looking at the chart, it is easy to see that over the long term, Missouri has greatly improved its air quality. It is just as easy to see, however, that we have more to do, especially in our large metropolitan areas.
Environmental Protection Agency. Air Quality Index Report. This is a data portal operated by the EPA. Data downloaded on 7/31/2017 from http://www.epa.gov/airdata/ad_rep_aqi.html.