When School is an Asthma Danger Zone

in Asthma
Published: May 9, 2013

613-00708232With strong evidence that schools close to highways are setting off asthma attacks in kids, this 2011 Allergic Living magazine article asks: Isn’t it time urban planners added the issue to their homework?

Does the air around your child’s school trigger asthma attacks? George Thurston, an environmental health science professor at New York University, wanted to know, so a few years ago he enlisted a bunch of 5th grade students in the South Bronx to help. The kids lived in a neighborhood where 13 percent of children suffer from asthma and where the hospitalization rate for asthma was dramatically higher than in other areas of the city.

In some of the schools, the children and their teachers could see diesel trucks and buses rumble by all day long, spewing out dark, sooty vapors on their way to massive garbage dumps. Was there a connection between all that pollution and the kids’ frequent breathing troubles?

To answer the question, Thurston found 40 children with asthma in four schools in the South Bronx. He gave each child a rolling backpack with air-monitoring equipment. Thurston’s team carefully tracked their symptoms, and later, a local TV crew spoke to participants.

“It feels like somebody’s not letting me breathe,” ponytailed Aldores Lopez said shyly on camera. “My mum gets nervous. I don’t like it when my mum gets nervous.”

The results were striking. All the children’s asthma symptoms – wheezing, coughing and shortness of breath – increased on high traffic days. What’s more, the kids’ breathing troubles were exacerbated by a key pollution ingredient – soot, the carbon particles that look like black smoke spewing out of diesel trucks and buses. They become part of the tiny particulates that get trapped deep in the lungs.

Thurston’s study bolsters a body of research which makes a powerful case that highway-related pollution is a key trigger of asthma attacks in kids. A 2007 review of the research put it this way: “The health studies show elevated risk for development of asthma and reduced lung function in children who live near major highways.” That’s a serious warning when you consider that, according to the same research review, 11 percent of U.S. households are located within 325 feet of a four-lane freeway.

A 2011 study in the shantytowns near Lima, Peru, drives home the point: Teenagers who lived within 800 feet of a congested roadway were twice as likely to wheeze or to use medications for asthma as those who lived four blocks away. Pulmonologist William Checkley, the senior researcher from Johns Hopkins University, sums it up: “The closer to the road, the more disease.”

Many of the studies of the effects of vehicle exhaust have focused on where children live. But a new wave of research, like the South Bronx study, is targeting the air near and at school, where kids spend one-third of their waking hours.

At the University of Southern California, researchers looked at the highway effect both at school and at home by following nearly 2,500 kindergarten and Grade 1 students, none of whom had asthma at the outset. After three years, 120 of the children had developed the lung disease. “Children exposed to higher levels of traffic-related air pollution at school and at home are at increased risk of developing asthma,” the researchers concluded.

Yet it’s still not clear whether exposure to high volumes of traffic-related pollution causes asthma, says Jim Gauderman, an associate professor of preventive medicine at USC and the study’s lead author. It may instead trigger the symptoms of a disease that’s already there. Or, if it does cause the disease, it may be doing so at an earlier age, says Michael Brauer, a professor at the University of British Columbia’s school of environmental health. His research for Canada’s AllerGen research network suggests that children born to mothers who lived beside busy highways during pregnancy are more likely to develop asthma by age 4.

What’s not in dispute among the researchers is this: kids who live or learn near a highway are more likely to cough and wheeze. When you consider that asthma is the most common chronic disease in childhood, this is a major public health issue. Over seven million children in the United States live with asthma. Across North America, it’s the No. 1 cause of missed school days. Now consider this: one-third of U.S. schools sit within 1,300 feet of a major highway, in what the media has dubbed the “air pollution danger zone.”