Asthma linked to pollution affects 4M children a year worldwide

April 12 (U Between 2010 and 2015, roughly 4 million children globally developed asthma annually from inhaling nitrogen dioxide produced largely by motor vehicle exhaust, a new study says.

Within the United States, the cities with the highest rate of childhood asthma are Los Angeles, New York, Chicago, Las Vegas and Milwaukee, according to research published in April in The Lancet Planetary Health.

"Our findings suggest that millions of new cases of pediatric asthma could be prevented in cities around the world by reducing air pollution," said Susan Aneberg, a researcher at George Washington University and study author, in a news release.

The study listed estimates of new pediatric asthma incidences in 194 countries and 125 cities throughout the world. Overall, 13 percent of those cases were associated with nitrogen dioxide pollution.

The researchers said this is the first study to count the global cases of pediatric asthma connected to nitrogen dioxide.

In the 125 cities, the rates of children who developed asthma from nitrogen dioxide intake range from 6 percent in Orlu, Nigeria, to 48 percent in Shanghai, China. Eight of the top 10 cities where nitrogen dioxide was attributable to childhood asthma are in China, ranging from 37 percent to 48 percent. Moscow and Seoul both had 40 percent.

More than 6 million children in the United States have asthma, according to the Centers for Disease Control and Prevention.

"Improving access to cleaner forms of transportation, like electrified public transport and active commuting by cycling and walking, would not only bring down nitrogen dioxide levels but would also reduce asthma, enhance physical fitness and cut greenhouse gas emissions," Aneberg said.

The researchers said that cities with high levels of nitrogen dioxide levels also had high greenhouse emissions. Following through with existing plans to clean up the environment, they said, could help curb new cases of asthma and other health problems related to air pollution.

"That finding suggests that the World Health Organization guideline for nitrogen oxide might need to be re-evaluated to make sure it is sufficiently protective of children's health," said Pattanun Achakulwisut, a researcher at George Washington University and study lead author, in news release.