News | Science Selection January 2014 | Volume 122 | Issue 1
Cooking Up Indoor Air Pollution: Emissions from Natural Gas Stoves
Wendee Nicole was awarded the inaugural Mongabay Prize for Environmental Reporting in 2013. She writes for Discover, Scientific American, National Wildlife, and other magazines.
Citation: Nicole W. 2014. Cooking up indoor air pollution: emissions from natural gas stoves. Environ Health Perspect 122:A27; http://dx.doi.org/10.1289/ehp.122-A27
Published: 1 January 2014
Related EHP Article
Natural gas cooking appliances, which are used by a third of U.S. households, can contribute to poor indoor air quality, especially when used without an exhaust hood.1 Gas stoves emit nitrogen dioxide (NO2), carbon monoxide (CO), and formaldehyde (HCHO), each of which can exacerbate various respiratory and other health ailments.2,3,4 In a study reported in this issue of EHP, researchers from Lawrence Berkeley National Laboratory and Stanford University developed a simulation model to estimate gas stoves emissions and the exposures experienced by different household members.5
The model used a sample cohort representing Southern California households, of which more than half use natural gas to cook. The investigators obtained data on the homes and the occupants, including how often they cooked breakfast, lunch, and dinner. The team estimated air exchange rate (i.e., the rate at which outdoor air replaces indoor air), the amount of time people spent at home, and outdoor profiles for NO2 and CO (indoor concentrations of these two pollutants are heavily influenced by outdoor levels, whereas HCHO concentrations typically depend on a variety of sources). They assumed one adult cooked in each home and that any children aged 0–5 years would be in close proximity to the adult while he or she was cooking.
Gas burners were estimated to add 25–33% to the week-averaged indoor NO2 concentrations during summer and 35–39% in winter. The variability between seasons likely reflected the fact that air ventilation is lower in winter. For CO, gas stoves were estimated to contribute 30% and 21% to the indoor air concentration in summer and winter, respectively. In this case, the appliances contributed relatively more CO during summer because outdoor concentrations tend to be lower then. The appliances added little to indoor HCHO concentrations relative to other indoor sources such as furniture and building materials.5
© Food Photography by Eising/Corbis
The model predicted that when homes did not use venting range hoods, household exposures frequently exceeded benchmarks the authors set based on federal and state health-based standards.6,7 It also indicated that cooks and young children, who were assumed to be in closest proximity to the stove, would have the highest exposures.
Based on these modeling results, the investigators estimated that, during a typical winter week, 1.7 million Californians could be exposed to CO levels that exceed standards for ambient air, and 12 million could be exposed to excessive NO2 levels, if they do not use venting range hoods during cooking. “Clearly we have unhealthy situations indoors since we exceed outdoor standards in homes,” says lead author Jennifer Logue of Lawrence Berkeley National Laboratory.
In colder climates, people may not want to use vents because they send warm indoor air outside. But the authors suggest that increasing the use of venting range hoods could reduce indoor air pollution as well as exposures to these chemicals. Even greater reductions could be achievable with improved hoods that capture pollutants more effectively, or quieter hoods that people are more likely to turn on.
“A vent is a solution but not the only solution,” says Greg Diette, a Johns Hopkins University professor of medicine, epidemiology, and environmental health sciences. “Another solution is to swap out the stove [for an electric model].” Diette has also tested a promising air cleaner that adsorbs gases.
Charles J. Wechsler, an adjunct professor with the Environmental and Occupational Health Sciences Institute, Rutgers University, points out that adsorbents have finite life spans, but it can be difficult to know when it’s time to change them. “An exhaust system that incorporates a heat exchanger might be more promising,” he says. “Such units are used in Scandinavia.” Heat exchangers reduce heat loss to the outdoors.
Logue points out that simply cooking food, even on electric burners, also emits pollutants, especially particulate matter and acrolein. “Just switching from gas to electric will not solve all your pollution issues with cooking,” she says.
1. Klug VL, et al. Cooking Appliance Use in California Homes—Data Collected from a Web-based Survey. LBNL-5028E. Berkeley, CA:Lawrence Berkeley National Laboratory (August 2011). Available: http://homes.lbl.gov/sites/all/files/lbnl-5028e-cooking-appliance.pdf [accessed 5 December 2013].
2. Jarvis D, et al. The association of respiratory symptoms and lung function with the use of gas for cooking. Eur Respir J 11(3):651–658 (1998); http://www.ncbi.nlm.nih.gov/pubmed/9596117.
3. Jarvis D, et al. Association of respiratory symptoms and lung function in young adults with use of domestic gas appliances. Lancet 347(8999):426–431 (1996); http://dx.doi.org/10.1016/S0140-6736(96)90009-4.
4. EPA. Formaldehyde: Hazard Summary [website]. Washington, DC:U.S. Environmental Protection Agency (updated 18 October 2013) Available: http://www.epa.gov/ttnatw01/hlthef/formalde.html [accessed 5 December 2013].
5. Logue JM, et al. Pollutant exposures from natural gas cooking burners: a simulation-based assessment for Southern California. Environ Health Perspect 122(1):43–50 (2013); http://dx.doi.org/10.1289/ehp.1306673.
6. EPA. National Ambient Air Quality Standards (NAAQS) [website]. Washington, DC:U.S. Environmental Protection Agency (updated 21 November 2013). Available: http://www.epa.gov/ttn/naaqs/ [accessed 5 December 2103].
7. ARB. California Ambient Air Quality Standards (CAAQS) [website]. Sacramento, CA:Air Resources Board, California Environmental Protection Agency (updated 24 November 2009). Available: http://www.arb.ca.gov/research/aaqs/caaqs/caaqs.htm [accessed 5 December 2013].
If you’re attending the American Public Health Association (APHA) 2016 Annual Meeting and Expo in Denver (October 30–November 2), stop by the NIEHS booth (#1214) in the Exhibition Hall. Children’s Health Editor Martha M. Dimes will be available to discuss EHP submissions, Children’s Health topics, and more.
EHP is pleased to launch its new Children’s Health page. This dynamic page will feature timely children’s health research and news as they are published in EHP as well as links to related material. The page includes its own “Search Children’s Health” function so visitors can search our full library of children’s health content by topic, author, or publication year and find exactly the information they need. Bookmark the page or access it via the “Featured Children’s Health” section on EHP’s home page. (more…)
EHP is proud to announce that “Polychlorinated Biphenyl and Organochlorine Pesticide Concentrations in Maternal Mid-Pregnancy Serum Samples: Association with Autism Spectrum Disorder and Intellectual Disability,” published in EHP on 23 August 2016, has been selected by the Children’s Environmental Health Network (CEHN) as its October 2016 Article of the Month. CEHN Article of the Month summaries discuss the potential policy implications of current children’s environmental health research. The CEHN summary can be viewed here.
Featured Children’s Health
Veronica A. Tinney, Jerad M. Denton, Lucy Sciallo-Tyler, and Jerome A. Paulson
Jerome A. Paulson and Claire L. Barnett
Kim G. Harley, Katherine Kogut, Daniel S. Madrigal, Maritza Cardenas, Irene A. Vera, Gonzalo Meza-Alfaro, Jianwen She, Qi Gavin, Rana Zahedi, Asa Bradman, Brenda Eskenazi, and Kimberly L. Parra
Rebecca Massa Nachman, Guangyun Mao, Xingyou Zhang, Xiumei Hong, Zhu Chen, Claire Sampankanpanich Soria, Huan He, Guoying Wang, Deanna Caruso, Colleen Pearson, Shyam Biswal, Barry Zuckerman, Marsha Wills-Karp, and Xiaobin Wang