Community scientists have tested nearly 700 kitchens in the District of Columbia and Maryland for nitrogen dioxide and found that nearly two-thirds exceeded the Environmental Protection Agency’s health standard for safe outdoor exposure to nitrogen dioxide.
When stoves, ovens, furnaces, and water heaters burn gas in our homes, they emit nitrogen dioxide. Though odorless and not visible at lower levels, nitrogen dioxide can have significant long-term impacts on human health, exacerbating respiratory issues and diseases.
When stoves, ovens, furnaces, and water heaters burn gas in our homes, they emit nitrogen dioxide, a chemical compound also known as NO2. Though odorless and not visible at lower levels, NO2 can have significant long- term impacts on human health, exacerbating respiratory issues and diseases.
Key Takeaways
Community scientists have tested nearly 700 DC and Maryland kitchens for NO2. Nearly two-thirds of the kitchens tested in District of Columbia and Montgomery County, Maryland had unsafe levels of nitrogen dioxide (NO2).
Of the 663 kitchens tested, 416 (or 63%) recorded NO2 readings at or above 100 parts per billion (ppb), the U.S. Environmental Protection Agency’s health-protective standard for one hour of exposure.
Of 269 kitchens tested in DC, 206 (or 77%) recorded readings over 100 ppb.
Of 394 kitchens tested in Montgomery County, 210 (or 53%) recorded readings over 100 ppb.
The average high NO2 concentration was 168 ppb for all 663 tests, 181 ppb in DC, and 159 ppb in Maryland.
The EPA’s 100 ppb NO2 health standard is for outdoor exposure. As we learned during the COVID-19 pandemic, breathing health- harming pollution concentrated indoor – where we spend most of our time – is far more dangerous. The EPA lacks the legal authority to regulate indoor NO2.
NO2 is linked to a range of negative health consequences, including respiratory diseases like asthma and chronic obstructive pulmonary disease (COPD) as well as cardiovascular issues such as hypertension and heart attacks. Emerging evidence has shown NO2 could be tied to increased risk of developing Type 2 diabetes as well as cognitive development and behavioral issues in children.
With majorities of homes tested in DC and Montgomery County having unsafe levels of NO2, policymakers and regulators in both jurisdictions must prioritize helping families upgrade to electric appliances.
The testing protocol involved turning on the stove for 30 minutes (either oven at 350° F and two burners on high, or turning on four burners and not the oven). Nitrogen dioxide levels were recorded after 15 minutes, at 30 minutes, and 15 minutes after the stove was turned off.
Stoves are centrally located in families’ living spaces and are typically not vented outside, trapping emissions inside the home. People usually stand directly above the stove as it emits pollutants, often with young or elderly family members nearby, leading them to directly breathe in this pollution. Because of these concerns, the Beyond Gas citizen scientists decided to test NO2 emissions in DC and Maryland kitchens.
We found indoor NO2 pollution levels from moderate gas stove use far above the health standard set by the EPA for outdoor exposure, demonstrating that DC and Maryland residents would be well served by an accelerated transition away from burning gas in our homes and buildings.