Skip to content

EPA Strengthens Nitrogen Dioxide Rules for First Time in 35 Years

The Environmental Protection Agency (EPA) today announced a new "one-hour standard" aimed at limiting Americans' short-term exposure to nitrogen dioxide (NO2), a pollutant created by cars, power plants, and other industrial sources.

The Environmental Protection Agency (EPA) today announced a new “one-hour standard” aimed at limiting Americans’ short-term exposure to nitrogen dioxide (NO2), a pollutant created by cars, power plants, and other industrial sources.

US_regulate_national_auto_emissions.jpg(Photo: TreeHugger)

NO2, a main ingredient in smog, is linked to adverse respiratory health effects such as chronic asthma. In creating a new one-hour NO2 exposure limit of 100 parts per billion (ppb), the EPA noted that the risk of short-term NOX exposure is particularly acute near major highways.

As EPA chief Lisa Jackson said in a statement:

This new one-hour standard is designed to
protect the air we breathe and reduce health threats for millions of
Americans. For the first time ever, we are working to prevent
short-term exposures in high risk NO2 zones like urban communities and
areas near roadways. Improving air quality is a top priority for this EPA. We’re moving
into the clean, sustainable economy of the 21st century, defined by
expanded innovation, stronger pollution standards and healthier
communities.

The rule will be enforced by setting up monitors near roads in areas with more than 500,000 residents, according to the agency, with a deadline of 2013 for the beginning of pollutant tracking. The EPA said it plans to work directly on 40 new monitors for cities and towns with the most significant NO2 exposure.

It’s worth noting, however, that major cities have remained out of compliance with EPA air-quality standards for years without losing significant amounts of federal highway money, as the federal government often threatens. Moreover, the EPA has not changed the current annual NO2 standard of 53 ppb.

Streetsblog has migrated to a new comment system. New commenters can register directly in the comments section of any article. Returning commenters: your previous comments and display name have been preserved, but you'll need to reclaim your account by clicking "Forgot your password?" on the sign-in form, entering your email, and following the verification link to set a new password — this is required because passwords could not be carried over during the migration. For questions, contact tips@streetsblog.org.

More from Streetsblog USA

Waymo Means Way Mo’ Cars, According To Uber Docs

April 17, 2026

Friday Video(s): Kidical Mass, Night-Biking in Tokyo, and More

April 17, 2026

Look What You Made Friday’s Headlines Do

April 17, 2026

Talking Headways Podcast: Second-Hand E-Bikes Can Be The Way Forward

April 16, 2026

Florida Town Gives New Residents Free Golf Carts to Replace Their Cars

April 16, 2026
See all posts