Far fewer kids might develop asthma if there were less traffic pollution, suggests a new study that researched the issue worldwide.
"Our study found that nitrogen dioxide puts children at risk of developing asthma and the problem is especially acute in urban areas," said study author Susan Anenberg, a professor of environmental and occupational health at George Washington University in Washington, D.C.
"The findings suggest that clean air must be a critical part of strategies aimed at keeping children healthy," she said in a university news release.
Two million new worldwide cases of childhood asthma a year may be caused by nitrogen dioxide, or NO2, according to the study.
The researchers studied ground concentrations of NO2, a pollutant emitted by motor vehicles, power plants and industrial sites, in 13,000 cities.
They also tracked new cases of childhood asthma between 2000 and 2019. Asthma is a chronic illness that causes inflammation of the lung's airways.
The team attributed 1.85 million new pediatric cases of asthma worldwide to NO2 in 2019. About two-thirds were in urban areas.
Tougher clean air regulations in higher-income countries like the United States may be helping, the research suggested. The percentage of pediatric asthma cases linked to urban NO2 fell from 20% in 2000 to 16% in 2019.
While NO2 levels have improved in the United States and Europe, this pollution has increased in South Asia, sub-Saharan African and the Middle East. Pediatric asthma cases linked to NO2 pollution represent a large public health burden for South Asia and sub-Saharan Africa, according to the study.
The researchers said more needs to be done to limit harmful emissions from vehicles and other sources of NO2.
"Reducing fossil fuel-powered transportation can help children and adults breathe easier and may pay big health dividends, such as fewer cases of pediatric asthma and excess deaths," Anenberg said. "At the same time, it would also reduce greenhouse gas emissions, leading to a healthier climate."
The findings were published Jan. 5 in The Lancet Planetary Health.
The U.S. Environmental Protection Agency has more on nitrogen dioxide (NO2).
SOURCE: The Lancet Planetary Health, news release, Jan. 5, 2022