Air of Salt Lake City in 35 Years
This is a web-based visual study of the air quality data of Salt Lake City published by the EPA from 1980 to 2014. The purpose is to visually examine the air quality of Salt Lake City, and perhaps more importantly, its developing trend in the last decades.
The visualization uses the Air Quality Index color (AQI) code, established by the EPA, to show the general change of patterns of air quality in the past thirty-five years. The composition of the pollution is also shown, using percentage values of the five major air pollutants.
The end result shows clearly that there has been a decline of the yearly AQI from 1980 to 1997, after which it remains roughly at a constant level. This is contrary to popular public opinion — the air quality in Salt Lake City has become steadily worse in the last decade.
The pollutants that contribute to the pollution have also changed. Today, the air pollution in Salt Lake City is dominated by ozone, PM2.5 and No2.