Figure 7-15 Indexes of Key Air Pollutant Emissions from U.S. Transportation: 1990-2014
Wednesday, February 22, 2017
SOURCE: U.S. Environmental Protection Agency, National Emissions Inventory Air Pollutant Emissions Trends Data, 1970-2014, Average Annual Emissions All Criteria Pollutants, Available at https://www.epa.gov/air-emissions-inventories/air-pollutant-emissions-trends-data as of April 2016.