Children living near busy streets are more likely to get cancer, study shows

By Katy Human
Camera Staff Writer

Living on a busy street may increase a child's risk of cancer, according to a new study.

Children who lived near streets traveled by more than 20,000 cars a day were six times more likely to develop cancer than those who lived in quieter neighborhoods, where local traffic was less than 500 vehicles per day, the study found.

Car emissions contain a variety of cancer-causing substances, such as benzene and toluene.

The study, published in February's Journal of the Air & Waste Management Association, included about 600 children living in the Denver-metropolitan area, including Boulder and Longmont.

"These studies are simply implicative, they are not nailed down," cautioned Howard Wachtel, a professor in electrical and computer engineering at the University of Colorado and one of the authors of the new study.

"On the other hand, I think people should be aware that this is one of those things under scrutiny" as a cause of childhood cancer, he said.

Wachtel has long been interested in the debate about whether the electromagnetic fields near high-power lines increase childhood cancer risk.

In the past, he has suggested that families who live along high-power lines may be exposed to other risk factors, such as high volume traffic (since the lines tend to run along major thoroughfares) or socioeconomic factors.

But this new study, which was funded by the electric utility industry, does not let electromagnetic fields off the hook entirely.

Wachtel and his co-authors have discovered a possible synergy between electromagnetic fields and traffic. Kids living near both busy streets and high-power lines had a risk of cancer even greater than those living near high traffic alone.

Wachtel said he'll discuss that finding in a future publication. The current paper deals only with traffic-related risk.

Jeff Houk, an environmental engineer with the Environmental Protection Agency in Denver, said researchers have long understood that cars emit cancer-causing compounds along with less-dangerous pollutants and greenhouse gases.

"There are a number of constituents of exhaust that are known carcinogens or suspected carcinogens," he said. "Benzene is probably the best known one."

In a report published in 1993, EPA scientists estimated that about 275 incidents of cancer in the United States every year could be attributed to the toxic ingredients in exhaust.

Robert Pearson, an engineer with Radian International in Denver and one of Wachtel's co-authors on the new report, said he hopes parents don't overinterpret the new results. Childhood cancer is extremely rare to begin with — only one in about 20,000 children will get cancer.

Pearson and Wachtel said more research will help them nail down the relationships among car emissions, electromagnetic fields and childhood cancer.

"This implies an exposure to air pollution but that would have to be backed up by real measurements," Wachtel said."We have to get out there on Broadway to look at the real geometry of these (air pollution) curves."

Meanwhile, Pearson said, "this is just one more reason to move to a quiet neighborhood."