Children spend a lot of time outdoors playing tag, shooting hoops or climbing trees. If they live in cities, they might run around near busy roads. Parents always teach their kids to watch out for oncoming cars and never run into the street — but no one tells them not to breathe.
Just being outside near traffic can prove dangerous, contributing to their developing chronic asthma. An attack can leave a child literally gasping for air. And they don’t outgrow it. “Since there is still no cure, once a child develops asthma it will be a lifelong affliction,” said Pattanun Achakulwisut, a researcher at the George Washington University Milken Institute School of Public Health.
Asthma is the most common chronic illness among children globally, according to the World Health Organization (WHO), and occurs when inflammation causes the airways to narrow, prompting breathlessness and wheezing. It afflicts an estimated 235 million people, including adults, worldwide, WHO says. Children — whose airways are much smaller than those of adults — are especially vulnerable.
Asthma has many causes, including genetics and allergies. But chief among them is air pollution, especially from traffic. In fact, car exhaust — specifically particles of nitrogen dioxide or NO2 — is responsible for an estimated 4 million new cases of childhood asthma worldwide each year, according to new research published in The Lancet Planetary Health. Looked at another way, car exhaust is responsible for one in eight new childhood asthma cases diagnosed annually, the scientists said. Moreover, cars are a significant source of heat-trapping carbon dioxide, the chief culprit behind climate change.
The Lancet study adds to a growing body of scientific evidence that has emerged in recent years documenting the many risks of air pollution. The American Lung Association has just released its 20th annual “State of the Air” report, which found that 4 in 10 Americans live in areas with unhealthy air quality. And a recent report from the Health Effects Institute said that air pollution kills more people than smoking and projected that a child born today will die an estimated 20 months sooner than she would in absence of air pollution. In the United States, these health findings are especially troubling, as the Trump Administration has dismissed the documented dangers of climate change and is seeking to relax environmental protections.
In the United States, five cities — Los Angeles, New York, Chicago, Las Vegas and Milwaukee — accounted for the most childhood asthma cases related to air pollution exposure, according to the study. Globally, eight cities in China, including Shanghai, had the worst levels of NO2 emissions, followed by Moscow and Seoul. Orlu, a city in Nigeria, had the lowest.
“The breadth of the public health consequences that we found strongly suggests that actions need to be taken by national and local governments,” said Susan Anenberg, associate professor of environmental and occupational health at the Milken school and the paper’s senior author. “The good news is that there are many actions that can be taken to reduce nitrogen dioxide and traffic pollution, and these actions also have other important societal benefits. Since most of the impacts we found occurred in cities, and most of the nitrogen dioxide in cities is from traffic pollution, reducing emissions from vehicles would be a key step forward.”
The scientists, who also included Michael Brauer, a researcher at the University of British Columbia, used data from 2010 to 2015 to examine traffic-related nitrogen dioxide across 194 countries and 125 cities. They then connected them to the incidence of childhood asthma in those areas. The majority of the new cases — 64 percent — occurred in urban areas, according to the study.
“Using NO2 as a surrogate for [traffic-related air pollution], our study seeks to provide the first global estimate of the number of new asthma cases among children that are attributable to traffic pollution,” said Achakulwisut, lead author of the study. Nitrogen dioxide is monitored in many areas around the world and measured globally by satellites. Advances in measuring techniques have allowed scientists to see “the worldwide impacts of NO2 pollution in a way that more accurately reflects where children live and how close they are to traffic pollution hotspots,” she said.
Identifying these hotspots is one thing. Doing something about them is another. Anenberg said that policymakers should promote electric vehicles, improve public transit, and expand bike lines and running trails. Doing so would reduce air pollution, enhance physical fitness for everyone and, most importantly, improve children’s health.
“Every year of delay in transitioning away from our fossil fuel reliance means that we are jeopardizing the well-being of millions of children… in the short-run due to air pollution and in the long-run due to climate change,” Achakulwisut said.
Marlene Cimons writes for Nexus Media, a syndicated newswire covering climate, energy, policy, art and culture.