Gas Stoves and Indoor Air Quality – Fresh Air on a Hot Topic

by Sandhya Sethuraman and Maria A. di Landro

gas stove
Emissions from gas stoves cause poor indoor air quality and health problems

Urged by scientists’ findings on the links between gas stove use and their contribution to indoor pollution and increased risk of respiratory illnesses, the CPSC (Consumer Product Safety Commission) has recently begun to consider a ban on gas stoves. More than 40 million U.S. households rely on gas stoves to cook with, but many are not aware of their negative impacts on indoor air quality and climate: natural gas appliances release nitrogen oxides, particulate matter, formaldehyde, and carbon dioxide into the air, and they can leak methane, even when not in use. Higher indoor pollution levels, as a consequence of gas stove emissions, can have various respiratory impacts, including asthma, coughing, wheezing, and difficulty breathing. In this article, we provide more details on what academic research has found, including the estimated fraction of current childhood asthma associated with gas-stove use in each state. We also discuss how various states are already taking initiative and are working to move away from new gas stove installation. Using New York as a case study, this article describes their new bill that effectively bans the use of gas stoves in the construction of new buildings starting in 2024 and what the response from the public has been. In the meantime, there are various measures the public can take to protect themselves from gas stove emissions.

What’s the controversy?

A torrent of information, data, and dissent followed the initial CPSC announcement — scientists urged reform while political parties made the debate about consumers’ freedoms. To make some sense of the dialog: 

  • In December, Senator Cory Booker (D-NY) and Representative Don Beyer (D-VA) published a report strongly urging the CPSC to consider a ban on gas stoves. They argued that gas stoves emit high levels of pollutants like nitrogen dioxide (NO2), carbon monoxide (CO) and fine particulate matter (PM2.5). 
  • Amid debates surrounding gas stoves, consultants with ties to the American Gas Association have criticized research which linked gas stoves to childhood asthma.
  • Voices on the right have argued that removing gas stoves from homes is an infringement on their basic rights. Senators Cruz and Manchin introduced legislation in early February to bar the CPSC from using federal funding to ban gas stoves, arguing that it “constitutes government overreach.” 
  • The American Gas Association also pushed back against the ban, arguing that housing would become more expensive as “electric homes require expensive retrofits.”

The resulting debate became clear: ban gas stoves in future buildings and transition to electric stoves instead, or continue as we always have? 

What’s happening right now? (NYC Case Study)

Currently, over 70 percent of greenhouse gas emissions in New York City comes from indoor air pollution in homes, but changing the internal piping and structures of old New York City buildings (retrofitting) is nearly impossible. Because many buildings went up before 1930, ripping out the existing infrastructure and effectively transitioning to more efficient and sustainable energy has proven to be a daunting task. 

In December 2021, New York’s City Council voted to ban the use of fossil fuels — and by extension gas stoves — altogether in new buildings. This law was scheduled to go into effect this year for structures shorter than seven-stories tall and in 2027 for all buildings. As of late, the council has asserted that co-ops and condominiums — newer, more modern buildings — are poised to make a difference in the short term if they make the necessary electrical upgrades and incentivize resident collaboration. 

Why gas stoves?

Simply put, gas stoves have gained attention because of how ubiquitous they are. Over one third of U.S. households — more than 40 million homes — cook with gas stoves. Natural gas appliances generate carbon dioxide, particulate matter, formaldehyde, and nitrogen oxides when natural gas is burned as a fuel, and leak methane into the air, often even when they are not in use. 

According to researchers at Stanford, gas stoves themselves have the same climate impact as about 500,000 gasoline-powered cars. Current EPA estimates are incomplete themselves, failing to account for the reality of gas pipelines (which leak much more than reported), and usually not including leakage within buildings at all. 

Additionally, the health impacts of having stoves in such close proximity to residents is well-understood. Because they are often central to homes, the respiratory impacts of pollutants — like asthma, coughing, wheezing and difficulty breathing — are often difficult to control and treat. People interact directly with their stoves (more so than other gas appliances), and the constant exposure to formaldehyde, carbon dioxide, nitrogen oxides, and methane can have long term health effects. 

The impacts of gas stoves are not equal either. As emphasized by Booker and Beyer, gas stoves have a larger impact on Black, Latino and low income households, who experience the “cumulative burden” of gas stove emissions and broader air quality impacts every day. In the global south, poor ventilation and living conditions mean that women and children are also disproportionately affected by indoor household emissions. 

What does the academic research say?

The push to “go electric” is backed by science, as the harmful byproducts of combustion are often emitted directly into the air indoors without proper ventilation systems in place. Indoor gas stove cooking is clearly connected to respiratory illness, and more than 12% of childhood asthma cases in the U.S. can be linked to gas stoves. 

A few key results: 

  • State-by-state differences in pollution levels from gas stoves, and therefore impacts, are correlated with their prevalence in the household, which means that a one-size-fits-all solution via blanket legislation is likely to fail. For example, Illinois experiences the highest childhood asthma burden from gas stoves (21.1%), followed by California (20.1%), New York (18.8%), Massachusetts (15.4%), and Pennsylvania (13.5%). Florida, where the demand for gas stoves is low, has the lowest burden (3%) (U.S. Energy Information Administration, via CNN).
  • There are existing benchmarks for “unsafe” pollution and residential exposure limits. For instance, Canada has a maximum residential exposure limit of 90 parts per billion (ppb) over an hour of exposure, and 11 ppb in the long term (> 24 hours) for NO2.
  • Gas stoves contribute different amounts of methane to the atmosphere based on when and how they are being used. A recent study published in Environmental Science & Technology found that 76% of the total methane emissions from stoves come from the steady-state off state (indicating significant leakage). 
Population attributable fraction of current childhood asthma associated with gas stove use in the U.S. From Gruenwald et al., Int. J. Environ. Res. Public Health 202320(1), 75;

What can you do?

  • Ventilate: exhaust streams are necessary in any kitchen; turning on a fan or opening a window is a good way to mitigate some of the negative effects of cooking on a gas stove. Many range exhausts don’t vent to the outside, but rather recirculate stove emissions back into the kitchen. Ventilation to the outside can greatly improve indoor air quality.  
  • Educate: launch education campaigns to better understand the risks associated with gas stoves, and how these can be minimized, especially for disadvantaged groups. 
  • Advocate: push for gas stoves to be sold with range hoods that meet mandatory performance standards, and for ventilation to the outdoors instead of recirculation. Additionally, gas stoves should be equipped with leak proof valves, which can be shut on and off to prevent methane exposure. 

Proyecto Estudiantil: Prueba de la Eficiencia de Filtración de Algunos Tipos de Máscaras Comunes

por John Garcia Almazán, Maria Di Landro, y Sandhya Sethuraman

Unas mascarillas N95, KF94, y quirúrgica
Unas mascarillas N95, KF94, y quirúrgica. Foto por V.F. McNeill

Los Estados Unidos ha entrado en su tercer año desde el primer caso del coronavirus (COVID-19) confirmado en el país. Debido a las vacunas y otros medidas de salud pública, los casos de COVID-19 están bajo control hoy, pero la enfermedad sigue siendo altamente transmisible y, a veces, peligrosa. En este artículo, consideramos opciones de equipo de protección personal (EPP) en forma de máscaras faciales. Mascarillas que filtran bien la materia particular del aire que inhalamos son valiosas para prevenir infecciones. Teniendo en cuenta la escasez de máscaras y la presencia de mascarillas falsificadas en el mercado, es importante saber qué máscaras disponibles al público son realmente eficientes y efectivas para prevenir la propagación de COVID-19.

Realizamos varios experimentos en una cámara climática. Una muestra del material de diferentes marcas de máscaras estuvo expuesto a partículas pequeñas (10-800 nm). Seguimos las líneas directrices de NIOSH y probamos la filtración de partículas de NaCl a tres velocidades faciales diferentes, midiendo la eficiencia de filtración (la eficacia de las máscaras para proteger al usuario de estas partículas) en función del tamaño de las partículas.

Eficiencia de filtración del material de una mascarilla quirúrgica negra, medida para varios tamaños de partículas y tres velocidades faciales
Tipo de máscara5.3 cm/s10 cm/s15 cm/s
3M Aura (N95)979797
máscara quirúrgica negra889178
Dr. Puri KF94989595
Eficiencia de filtración general (%) para tres tipos de máscara facial, y tres velocidades faciales.

Observamos eficiencias de filtración consistentes con las especificaciones del fabricante para N95, KN95, KF94 y mascarillas quirúrgicas. Las máscaras N95 (3M Aura) demostraron la mayor eficiencia de filtración en todas las categorías, pero incluso el material de la máscara quirúrgicas negras o azules que generalmente se encuentran en oficinas y edificios públicos filtró la mayoría de las partículas.

En esta obra solo examinamos la filtración de muestras del material de mascarillas. En realidad, el ajuste de la máscara y el uso también son muy importantes para saber la eficacia de las máscaras para proteger al usuario.

ICYMI: India’s Air Pollution Crisis, By the Numbers

In this article, published in October 2017 on HuffPost India, Prof. McNeill and Dr. Julia Nunes break down the data for particulate air pollution in cities across India. Air pollution is at an unhealthy level for a large part of the year, in most Indian cities.

The pie charts show the number of days in the past year that the average PM2.5 level fell into the following three categories: Green days (PM2.5 < 35.4 μg m-3) are healthy or moderate, yellow days (35.5 μg m-3 to 55.4 μg m-3) are unhealthy for sensitive groups such as children, the elderly or those with lung disease, and red days (PM2.5 > 55.5 μg m-3) are unhealthy for all. For more information on the data sources:


Live reporting from Beijing: Air Quality in Crisis

V. Faye McNeill, Beijing, China, December 21, 2016

Haze over central Beijing, 12/20/2016. Photo credit: V. F. McNeill

Much of China, including the capital city, Beijing, is experiencing sustained heavy smog this week, with air pollution at hazardous levels for the past three days. Concentrations of fine particulate matter in Beijing’s air today exceeded 400 ug/m3, more than ten times China’s National Ambient Air Quality Standard (35 ug/m3). The episode has caused an increase in hospitalizations and disruptions in air traffic due to poor visibility. The government has declared a “red alert” and taken emergency measures including industrial shutdowns, odd-even traffic restrictions, and school cancellations to protect public health.

“I love Beijing.  I grew up here and spent my whole life here.  If it weren’t for the air pollution, I would love living here.  But now I think about leaving. Many people are leaving.”

Reduced visibility at Beijing’s airport. 12/20/2016 Photo credit: V.F. McNeill

Air quality is an ongoing issue in Beijing, and a major subject of concern for its residents. As one Beijing native told me: “I love Beijing.  I grew up here and spent my whole life here.  If it weren’t for the air pollution, I would love living here.  But now I think about leaving. Many people are leaving.” According to the U.S. Embassy, between 2008-2015, the daily average air quality index in Beijing fell in the “Unhealthy,” “Very Unhealthy,” or “Hazardous” categories 67% of the time. A severe air quality episode in January 2013 was somewhat of a turning point, leading to increased pressure on the government to tighten regulations. One outcome was the amendment of the national ambient air quality standards. Meeting the new standards for PM2.5 would be a major step towards protecting public health. But, as episodes like this one show, improvement is slow to come. Plans for local implementation and enforcement of the new air quality standards are still in the development stages. In some cases major changes in infrastructure are needed in order to reduce emissions, and this can take time. Local efforts alone won’t be enough: The city of Beijing has made bold moves towards eliminating coal burning within the city, but much of Beijing’s pollution comes from upwind sources, outside the city limits.

With the will of government and the people aligned, China is poised to turn around its air pollution problem. Unlike the U.S., which greatly improved its air quality in the last century and now must tackle climate, China is in a position to develop smart new policies and technology to improve air quality and reduce carbon emissions simultaneously.

NYC Air Quality – Improving? AIRE reports!

AII Air Quality NYC - US letter _Page_03ccording to the New York City Department of Health and Mental Hygiene, air quality in NYC is getting better.  Here at AIRE, we hypothesized the opposite last summer.  Based on a very unscientific survey of our own asthma responses and perceptions of visibility in the city, we suspected that summertime air quality had been on the decline in recent years (2014-2015).  To test this hypothesis, summer undergraduate researcher Silvia Vina Lopez gathered Air Quality Index (AQI) data for NYC from 2000-2015, and data on criteria pollutant (SO2, CO, NO2, O3, PM) concentrations from 9 NYSDEC monitoring sites around the five boroughs. Here are some highlights of her findings:

  • Overall, air quality has been improving since 2000.  Importantly, there has clearly been a steady decrease in the number of “bad air days”. Since 2000, the number of days categorized as “Unhealthy for sensitive groups,” “Unhealthy,” or “Very unhealthy” has been on the decline.
  • Since 2008, the number of “Good” air quality days has had an overall upward trend, but there indeed has been a sharp decrease in “Good” days since 2013.  Since “Moderate” air quality is also pretty good in the big scheme of things, this trend may be subtle to perceive as you’re walking the streets of NYC unless you have asthma (like us) or think about PM 2.5 a lot (also like us).

II Air Quality NYC - US letter _Page_04To dig deeper into these trends, Silvia investigated the frequency with which each criteria pollutant exceeded the 24 h NAAQS standards. She found that SO2 violations decreased between 2004-2009 and have stayed low. The City attributes this trend to changes in heating oil regulations. On the other hand, the frequency of PM2.5 violations increased over the same time period and has remained elevated since 2009. This value decreased somewhat between 2007-2015, consistent with the data presented in the City’s survey, which covered 2008-2014. However, the average number of PM2.5 violations 2009-2015 was still significantly higher than 2000-2005.

The verdict: air quality in NYC is not bad and getting better in general.  However, work needs to be done to reduce PM2.5 violations, and hold on to the gains made between 2008-2014.  One possible source of elevated PM2.5 not mentioned in the City’s report is secondary organic aerosol formation: the formation of PM2.5 in situ, due to gas-phase reactions of oxidants and volatile organic compounds (which can be natural or man-made).

Recommended Resource: “What’s Up in the Atmosphere? Exploring Colors in the Sky,” an aerosols storybook from The GLOBE Program

Scientists and educators from NASA and UCAR have written a storybook entitled “What’s Up in the Atmosphere? Exploring Colors in the Sky” aimed at elementary school-aged (K-4) children, in which atmospheric aerosols play a starring role.  The story follows a group of curious students who, under the guidance of their teacher, investigate the connection between the appearance of the sky and asthma symptoms in their fellow students on a given day.  The students in the story (and the readers) learn about atmospheric aerosols in the process.  The storybook includes a teachers’ guide with glossary.

Air Quality in Manila, Philippines

The AIRE team spends a few weeks every year visiting family in Manila, Philippines.  Like many vibrant megacities, Manila suffers from heavy traffic and poor air quality.  Starting in Summer 2015, the Philippine government has made real-time air quality monitoring data available from stations around Metro Manila.  Interested citizens can look up current PM2.5 levels and compare them to the 24 hour guideline value.  We note that the EMB 24 hr guideline value is 75 micrograms/m3, whereas the United States EPA 24-hour average PM2.5 standard is 35 micrograms/m3 (the yearly average standard is 15 micrograms/m3).

Quick Facts About Indoor Air

This long winter has had the AIRE team thinking about the amount of time we spend indoors, and the air quality there.

– These days, most people spend the vast majority of their time indoors (especially in the winter!). There is therefore high potential for exposure to pollutants indoors, i.e., at home or in the workplace.

– While what we think of as commonplace outdoor pollutants (e.g. car exhaust) may be less prevalent indoors than outdoors, other chemicals such as volatile organic compounds (VOCs) can be present at much higher concentrations indoors. Indoor VOCs may come from many sources including cleaning products, air fresheners, and new furniture. They can harmful to health on their own, or serve as precursors for the formation of aerosol particles.

– You have probably heard about secondhand smoke, which is the exposure of non-smokers by being around smokers. Thirdhand smoke can also be a problem. This occurs when nicotine, tar, and other harmful chemicals in tobacco smoke deposit on indoor surfaces like walls and carpets. People can be directly exposed to these chemicals through contact the surface, or reactions with gases like ozone may cause them to re-enter the gas phase.

We are looking forward to the warmer weather and more time in the fresh air outdoors!

Recommended Resource: Aerosol Science & Engineering

In honor of the 2014 Annual meeting of the American Association for Aerosol Research, happening this week in Orlando, FL,  we are very excited to share with you this series of educational modules on the science and engineering of aerosols (airborne particles).

These materials were developed by Profs. Pratim Biswas, of Washington University St. Louis, and C. Y. Wu, of University of Florida, through a collaborative grant from the National Science Foundation. The modules are aimed at an introductory college level, and are excellent for supplementing course materials or learning on your own.

The modules:

The complete lecture series for an introductory course on Aerosol Science and Technology from WUStL is available FREE through ITunesU!:

Additional information on this effort, and more resources: