Exploratory Data Analysis of US Air Quality

• Activity Number: 297 - SPEED: Food, Environment, Biomedical Imaging and Physical System Visualization/Learning, Part 1
• Type: Contributed
• Date/Time: Tuesday, July 30, 2019 : 8:30 AM to 10:20 AM
• Sponsor: Section on Statistical Graphics
• Author(s): Xuemao Zhang*
• Companies: East Stroudsburg University
• Keywords: Air quality; cluster analysis; longitudinal data analysis; map visualization

Abstract

What are the patterns of U.S. air quality over years? The data set “Air Quality Measures on the National Environmental Health Tracking Network” available on \url{https://www.data.gov/} is analyzed in this paper. This data set about ozone and particulate matter (PM2.5) contains data from approximately 4,000 monitoring stations around the country from 1999 to 2013. The tools of map visualizations, cluster analysis and longitudinal data analysis are applied. It is found that Eastern United States and California have highest PM2.5 levels, while the Central United States and Hawaii have lowest PM2.5 levels. California has largest, over 20, DOZ (Number of days with maximum 8-hour average ozone concentration over the National Ambient Air Quality Standard), while all other areas in US have average DOZ 10 or less. Moreover, California has largest, over 3, PRPM (Percent of days with PM2.5 levels over the National Ambient Air Quality Standard), while other areas in US have average DOZ 2 or less. Furthermore, it can be seen that the overall air quality of US has been improved over the 15 years that the data were collected.