Air Quality Guide for Nitrogen Dioxide
This guide provides you with information about ways to protect your health when nitrogen dioxide levels reach the unhealthy range, and ways you can help reduce nitrogen dioxide air pollution.
What You Should Know About Nitrogen Dioxide and Your Health
- Nitrogen dioxide comes from vehicles, power plants, industrial emissions and off-road sources such as construction, lawn and gardening equipment. All of these sources burn fossil fuels.
- People who live or work near busy roadways can experience high exposures.
- People with lung disease, children, older adults, and people who are active outdoors may be particularly sensitive to ozone.
- Find out more about air quality through TV, radio, newspapers, AirNow and EnviroFlash (www.enviroflash.info), so you can take steps to protect your health.
Revisions to the National Ambient Air Quality Standards for Nitrogen Dioxide
On January 22, 2010, EPA strengthened the healthbased National Ambient Air Quality Standard (NAAQS) for nitrogen dioxide (NO2). EPA set a 1-hour NO2 standard at the level of 100 parts per billion (ppb). EPA also retained the annual average NO2 standard of 53 ppb.
The 1-hour standard will protect public health by limiting people’s exposures to short-term peak concentrations of NO2 – which primarily occur near major roads. Community-wide NO2 concentrations will be limited to levels below those that have been linked to respiratory-related emergency room visits and hospital admissions.
Additionally, EPA established ambient air monitoring and reporting requirements for NO2. In urban areas, monitors are required near major roads and in other locations where maximum concentrations are expected. EPA has placed a number of monitors in locations to help protect communities that are susceptible to NO2-related health effects.
What is nitrogen dioxide and where does it
How does nitrogen dioxide affect health?
Scientific evidence links short-term NO2 exposures, ranging from 30 minutes to 24 hours, with adverse respiratory effects including airway inflammation in healthy people and increased respiratory symptoms in people with asthma.
Studies also show a connection between short-term exposure and increased emergency room visits and hospital admissions for respiratory illnesses.
Who is sensitive to nitrogen dioxide?
Individuals who spend time on or near major roads can experience NO2 exposures considerably higher than occur away from roads. These exposures are of particular concern for sensitive groups, such as people with lung disease including asthma, children and older adults.
Does my community have unhealthy NO2 levels?
Unlike ozone and particle pollution, which can be of concern over large regions, NO2 levels are appreciably higher in close proximity to pollution sources (e.g., vehicles on major freeways, factories). Health effects associated with NO2 are much less likely farther away from these pollution sources.
NO2 in heavy traffic or on freeways can be two times as high as levels measured in residential areas or on lesser traveled roads. Monitoring studies have shown that within approximately 50 meters of heavy traffic/ freeways, NO2 concentrations may be 30 to 100 percent higher.
|US EPA Office of Air and Radiation (6301A)