SAN DIEGO, USA. While there is still no conclusive data indicating that indoor concentrations of nitrogen dioxide from gas appliances are the cause of lung disease, the circumstantial evidence of the harmful effects of gas stoves on lung function is quite compelling, stated the participants in a debate in favor of their ban.[1]
In what the moderator called “one of the most enjoyable discussions to date,” experts presented their views on the risks that cooking with natural gas poses to lung health and discussed ways to mitigate those harms. The debate took place at the American Thoracic Society (ATS) International Congress 2024.
Arguments in favor: gas stoves cause lung diseases
Arguing in favor, Dr. John R. Balmes, of the University of California San Francisco, in the United States, and a physician member of the California Air Resources Board, admitted: “I would never have said that gas stoves cause lung diseases , but that’s what they assigned me.”
The specialist pointed out that natural gas ─methane─ is a powerful greenhouse gas and that cooking with it generates nitrogen dioxide with high concentration peaks in the home, especially in the kitchen, but also in other rooms.
“We know that nitrogen dioxide is an irritating gas that can cause bronchoconstriction, airway hyperresponsiveness and inflammation and increases the risk of exacerbations of asthma and chronic obstructive pulmonary disease,” he said.
The U.S. Environmental Protection Agency’s standard for nitrogen dioxide in outdoor ambient air is 100 parts per billion or less, which are levels needed to prevent asthma exacerbations. Separate meta-analyses showed an increase of 1.05 in the incidence of asthma per two parts per billion of nitrogen dioxide and a 1.07 increase in the incidence of chronic obstructive pulmonary disease per five parts per billion of nitrogen dioxide. nitrogen, Dr. Balmes noted.
The respiratory effects of gas stoves were highlighted in a 2013 meta-analysis of ten studies from North America and Europe, which showed a odds ratio Pooled (OR) for current asthma 1.34. Based on this data, the authors of a 2022 paper estimated that 13% of childhood asthma could be prevented by eliminating gas stoves.[2]
Although the causal link is missing, there is an abundance of data indicating that natural gas is not good for anyone, he acknowledged.
Arguments against: more evidence needed
Arguing against the issue, Dr. Meredith McCormack, MPH, professor of medicine in the Division of Pulmonary and Critical Care Medicine at Johns Hopkins University in Baltimore, United States, said, “There is a need for more definitive data to define whether gas stoves cause lung diseases.
However, Dr McCormack did not hold the natural gas industry accountable, noting that a systematic review and meta-analysis of gas cooking in high-, middle- and low-income countries showed that domestic use of gaseous fuels versus electric shocks were associated with a higher risk of asthma (1.11 overall), chronic obstructive pulmonary disease (1.15) and pneumonia (1.26).[2]
However, the relationship between gas and asthma risk was only significant for adults, and data on the risks of chronic obstructive pulmonary disease and pneumonia or other respiratory infections came almost exclusively from low-income countries, he noted.
Despite the lack of evidence of a causal relationship, Dr. McCormack noted that indoor nitrogen dioxide is an air pollutant that acts as a respiratory irritant and that its levels indoors in homes with stoves have been shown to be higher. gas are more than double that of homes with electric stoves.
Other data demonstrate that indoor nitrogen dioxide is associated with increased symptoms and use of rescue medication in children with asthma, dyspnea, nocturnal symptoms, reduced lung function, and exacerbations of chronic obstructive pulmonary disease.
Other studies have shown that changing from a gas stove to an electric one can reduce nitrogen dioxide concentrations in the home by up to 50%, but clinical trials are still needed to demonstrate the health benefits of this change, he said.
Even if a gas stove is replaced with an electric or induction stove, family members with asthma are exposed to other hazards, such as secondhand smoke, kitchen exhaust, burning candles or incense, outdoor particles that sneak inside, mold and allergens from mice or cockroaches.
In common
Environmental interventions that can benefit all members of a household—not just those with chronic obstructive pulmonary disease—include smoking cessation, air cleaners equipped with charcoal filters, stove hoods that vent outside, integrated control pest control, hypoallergenic pillow and mattress covers, high-efficiency particulate air vacuum, and mold and radon reduction.
Dr. Balmes and Dr. McCormack ultimately agreed that gas stoves contribute to respiratory morbidity and that both state and national policy changes are necessary to support the transition to cleaner indoor air, with financial incentives available to residents. households with lower incomes.
“It is a climate change mitigation imperative for all of us to abandon gas appliances if we want to face the climate emergency,” said Dr. Balmes.
End of indoor combustion
George D. Thurston, Sc. D., professor of Medicine and Population Health at the NYU Grossman School of Medicine, New York City, United States, who attended the debate, commented that the participants talked about nitrogen dioxide but they did not address the issue of particle pollution generated by gas stoves.
According to Thurston, the combustion of natural gas produces particles of very similar composition to those produced by the combustion of coal, oil or diesel and pointed out that interventions such as extractor hoods only work if they really ventilate to the outside and are not simple fans that recirculate the air. inside the house. And even when ventilation works as it should to remove air from the house, it only returns it to the atmosphere, where it contributes to climate change.
“We need homes without combustion. That is the unifying principle. We have to keep our eyes on that prize,” he concluded.
Dr. Balmes, Dr. McCormack and Thurston, Sc. D., have disclosed no relevant financial relationships.
This content was originally published in the English edition of Medscape.
