An air quality index (AQI) is a number used by government agencies to communicate to the public how polluted the air currently is or how polluted it is forecast to become. As the AQI increases, an increasingly large percentage of the population is likely to experience increasingly severe adverse health effects. The United States Environmental Protection Agency(EPA) has developed an Air Quality Index that is used to report air quality. The map shows the 50 metropolitan areas in the US with highest carbon monoxide levels. The drop down also allows the user to see other measures like AQI and max CO value in the year 2016. The original data has this CO measurement over the span of one year, with measurements taken each day. However for the purposes of the assignment this has been condensed to top 100 metros and average values are taken. The original dataset has also been attached below. Link to dataset : https://aqs.epa.gov/aqsweb/airdata/download_files.html
The Albers equal-area conic pr