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Fine Particulate Matter (PM2.5) in Outdoor Air

Summary Indicator Report Data View Options

Fine Particulate Matter (PM2.5) in Outdoor Air: Annual Average PM2.5 Concentration, by County, New Jersey, 2022

Why Is This Important?

Particulate matter (PM) is a mixture of solid particles such as dust, ash, smoke and droplets in the air. PM can be emitted directly from a source (e.g., smoke stacks, tail pipes or construction sites) or can form in the atmosphere from chemicals emitted by power plants, industries and cars. Fine particles -- 2.5 microns in diameter or less (PM2.5) -- are of greatest health concern since they can be breathed deep into the respiratory tract. Exposure to these particles can lead to asthma attacks, coughing, shortness of breath, bronchitis, lung cancer, and premature death.


Number of days in which the average concentration of fine particulate matter exceeds the regulatory standard at a monitoring point. Fine particulate matter is defined as particles that are 2.5 microns in diameter or less (PM2.5).

Data Sources

  • Bureau of Air Monitoring, New Jersey Department of Environmental Protection
  • U.S. Environmental Protection Agency (EPA)

How the Measure is Calculated

Numerator:Number of days in a year in which the PM2.5 concentration at a monitor exceeded the National Ambient Air Quality Standard of 35 micrograms per cubic meter, averaged over 24 hours.

How Are We Doing?

For 2021, NJDEP had eighteen PM2.5 monitoring sites around the state. There are ten filter-based monitors and 14 continuous monitors. Six sites have both. Additionally, there are three PM10 monitoring sites, and five sites where black carbon is monitored. A complete report on New Jersey's air quality can be found at []. Air quality in New Jersey has been improving. New Jersey's air monitoring program evaluates hourly air quality readings using the Air Quality Index (AQI). The AQI uses five of the six pollutants for which there are national health-based standards (ground-level ozone, particulates, carbon monoxide, nitrogen dioxide, sulfur dioxide) and compares the composite pollutant levels to the federal standards in order to assign an air quality rating such as "good" or "unhealthy". In 2021, none of the filter-based FRM PM2.5 monitoring sites were in violation of annual NAAQS of 12.0 ug/m3. There were two exceedances of the 24-hour NAAQS (35 ug/m3) at two sites, Elizabeth Lab on July 20, and Camden Spruce Street on July 21. Over those days, a wildfire in the western U.S. and Canada caused an exceedance event across the Northeast states. The annual mean concentrations of PM2.5 measured at the ten filter-based samplers ranged from 6.28 ug/m3 at the Chester monitoring site, to 10.31 ug/m3 at the Camden Spruce Street monitoring station. The highest 24-hour concentrations ranged from 21.0 ug/m3 at Chester to 50.9 ug/m3 at Elizabeth Lab.

What Is Being Done?

New Jersey has put added emphasis on controlling emissions from diesel engines due to the severe adverse health effects associated with exposure to the components of diesel particles. Success story: Recommendations for Reducing Smog Throughout NJ and Beyond [] Success story: Air Quality and Asthma in NJ Children [] Success story: Collaborating to Diminish Smog and Improve Health in NJ []

Available Services

The NJDEP's Bureau of Air Monitoring measures air pollution levels in New Jersey around the clock and compare them to national health standards. Updates and forecasts are sent to the wire services and other media, and health advisories are also issued when air pollution reaches unhealthful levels. The NJDEP's Bureau of Air Monitoring web site contains information on current air quality as well as historic trends. The web site is: [] The USEPA compiles air quality data from around the country and presents it to the public on the following web site: [] To sign up to receive air quality alerts, sign up at EPA's Enviroflash website: [] Throughout the year, as part of the nightly news, local TV networks frequently broadcast a map showing the next day's air quality forecast for the different regions of the state. Check your TV listings for channel information.

More Resources

NJDEP "What's in My Community?" mapping application: [] On the map you will find every facility with an air permit registered with the Division of Air Quality at the New Jersey Department of Environmental Protection.

Indicator Data Last Updated On 05/22/2023, Published on 02/07/2024
Environmental Public Health Tracking Project, New Jersey Department of Health, PO Box 369, Trenton, NJ 08625-0369, e-mail: (