Annual U.S. Air Quality Trends and City Comparisons

U.S. Environmental Protection Agency's interactive report tracks national air emissions trends from 1970 and unhealthy air days in 35 major cities since 2000. The dataset enables comparisons of pollutants against GDP, vehicle miles, population, and energy consumption. It provides visualizations for exploring air quality changes over time and geography.

Use Cases

• Analyze trends in unhealthy air days across 35 major U.S. cities since 2000 to assess policy impact.
• Model relationships between key air emissions and national metrics like GDP, vehicle miles traveled, and energy consumption.
• Compare spatial and temporal changes for common air pollutants across different U.S. regions.
• Correlate air pollution levels with population data and health exposure indicators.

Strengths

• Longitudinal coverage of air emissions data starting from 1970.
• Includes comparisons against five key national indicators: GDP, vehicle miles, population, and energy consumption.
• Provides city-level analysis for 35 major U.S. metropolitan areas.
• Data is curated and published by the authoritative U.S. Environmental Protection Agency.

Limitations

• Data is presented via an interactive web application; underlying raw datasets may not be directly downloadable.
• Last known update was in November 2020, potentially missing recent trends.
• Specific row counts, column structures, and file formats are not detailed in the available metadata.

Provenance

Source

U.S. Environmental Protection Agency, Office of Air and Radiation, Office of Air Quality Planning and Standards.

Collection Method

Compiled from national monitoring networks and regulatory reporting.

Time Range

Trends from 1970; city-level data from 2000 onward.

Freshness

Annual report; last updated 2020-11-30.

Geography

United States, including 35 major cities and Puerto Rico.