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Clean Air NJ


How is Smog Created?

Ground-level ozone, also known as smog, is an air pollutant known to cause a number of health effects and negatively impact air quality and the environment in the state of New Jersey.  Smog is formed when oxides of nitrogen (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight.  Smog can irritate any set of lungs, but those with lung-related deficiencies should take extra precautions on bad ozone days.

The What's Your Air Quality Today? page on this site tells you how to sign up to receive notifications and find out when your local air has reached unhealthy ozone levels.  Since each ozone episode is different, depending on a number of meteorological and air quality factors, you can find out the specifics on ozone exceedances in New Jersey’s non-attainment areas this year by clicking here.

Why Smog Matters: Understanding the Link Between Weather and Ozone Formation

Smog, otherwise known as ground-level ozone, can be a summertime air pollution problem in the region, and weather plays a key role in the levels of ozone that we experience. Meteorologists and other weather professionals and enthusiasts can help educate the public about smog’s health effects, and provide tips on minimizing exposure to ozone and simple actions to take that reduce ozone formation.

Click on a presentation below to hear New Jersey’s meteorology and air quality experts talk about how to educate the public about this weather-dependent pollutant.

  • Expanding weather forecasts to address ozone health issues – Dan Zarrow, NJ101.5 Meteorologist ( PDF - MP4 )
  • How ground level ozone is formed — Ann Marie Carlton, Rutgers Atmospheric Chemist ( PDF - MP4 )
  • Weather trends and hot summer days – Dave Robinson, NJ State Climatologist/Rutgers ( PDF - WMV )
  • Health effects of ozone — Kevin Stewart, American Lung Association of the Mid-Atlantic Environmental Director (a longer presentation from Mr. Stewart with more details on ozone’s health effects can be found here.) ( PDF - MP4 )
  • NJDEP’s Ozone Forecasting - Greg John, NJDEP ( PDF - WMV )

The opinions and information contained in these presentations are solely those of the original author and as such, do not necessarily reflect the official policy or position of NJDEP or the State of New Jersey.

What’s New on CleanAirNJ:  Check here to for help in choosing  the most efficient vehicle for your family.

Greater Mercer Transportation Management Association announces New Jersey Walking School Bus app now available to help parents identify groups of children to make walking to school a safe experience.

The Division of Air Quality at the New Jersey Department of Environmental Protection is responsible for monitoring and reducing  smog concentrations in New Jersey. This is accomplished with an integrated system of actions:

  • Monitor existing air quality via a set of air monitors that measure current and long-term air quality parameters and determine whether NJ meets federal air quality standards. Visit

  • Estimate air emissions in the State, identify actions to reduce air pollutants and quantify how these actions will help meet federal air quality standards. Visit

  • Develop and implement strategies to reduce emissions from diesel and gasoline fueled vehicles and equipment.  Visit

  • Regulate and issue permits to facilities which emit air pollutants to ensure that federal air quality standards are met. Visit

  • Conduct compliance and enforcement activities to ensure that facilities are complying with their air permits, and vehicles comply with idling and inspection requirements. Visit