Researchers from George Washington University studied ground concentrations of nitrogen dioxide, or NO2 - a pollutant that comes from tailpipe vehicle emissions, power plants, and industrial sites. They tracked new cases of asthma that developed in children from 2000 until 2019 in more than 13,000 cities.
"Our study found that nitrogen dioxide puts children at risk of developing asthmaand the problem is especially acute in urban areas," said Susan Anenberg, a co-lead author of the article and a professor of environmental and occupational health at the varsity.
"The findings suggest that clean air must be a critical part of strategies aimed at keeping children healthy," she added.
The findings, published in the journal Lancet Planetary Health, showed out of the estimated 1.85 million new paediatric asthma cases attributed to NO2 globally in 2019, two-thirds occurred in urban areas.
Despite the improvements in air quality in Europe and the US, dirty air, and particularly NO2 pollution, has been rising in South Asia, Sub-Saharan African and the Middle East.