Interesting Observations

While playing around the data visualizations of AQI Levels across several US Counties from 1980 to present, we noticed that the AQI Levels are generally going lower in recent years in most US Counties. Those counties have had higher Max AQIs and Median AQI Levels from 1980s to late 90s, but it is noticable that the levels are going down from 2000s onwards.

Going on to the data visualization of Main pollutants over time, it is noticable how Carbon Monoxide as a main pollutant peaked during the 1980s and dropped during the late 1990s, with PM10 rising as the Main pollutant in recent years. This could be the result of having more vehicles nowadays compared to 30 years ago in the 1980s.

Among the counties that we have selected for data visualization, it was surprising to see the high levels of SO2 in Hawaii, where other counties have PM10 as the main pollutant in the late 2010s. This signals a log of vog (volcanic smog), which we find interesting because it might mean that there are a lot more volcanic activities recently.

We also noticed that the counties are within the top 100 counties with highest badness for each pollutant seem to be the same across multiple pollutants