The results of a new study by George Washington University show that about 4 million children worldwide develop asthma annually because of nitrogen dioxide inhalation through air pollution. Based on data from 2010 to 2015, the study estimates that 65% of these new cases of asthma occur in urban areas.

Published in Lancet Planetary Health, the study is the first to qualify the worldwide burden of new pediatric asthma cases linked to traffic-related nitrogen dioxide by using a method that considers high exposures to this pollutant that occur near busy roads.

Investigators linked global data sets of nitrogen dioxide concentrations, pediatric population distributions, and asthma incidence rates with epidemiological evidence relating traffic-derived nitrogen dioxide pollution with asthma development in children. They were then able to estimate the number of new pediatric asthma cases attributable to nitrogen dioxide pollution in 194 countries and 125 major cities worldwide.

The researchers noted that an estimated 13% of the annual pediatric asthma incidence worldwide was linked to nitrogen dioxide. China accounted for about 760,000 cases of asthma per year, followed by India at 350,000 and the United States at 240,000.

New study finds millions of children worldwide develop asthma each year due to traffic-related air pollution [news release]. Washington, DC: George Washington University Public Health; April 20, 2019. Accessed July 22, 2019.