Teenagers living close to a busy road are more likely to have allergies and asthma than those living farther from traffic, a study of one shantytown in Peru suggests. The findings, published in the Journal of Allergy & Clinical Immunology, extend evidence linking traffic pollution to children's asthma risk. Until now, most studies have been done in urban areas of wealthier nations, where specific pollution sources can be hard to pin down. But in the shantytown in the current study -- located in the outskirts of Lima -- there is only one high-traffic roadway. And there are no nearby sources of industrial air pollution, said senior researcher Dr. William Checkley, of Johns Hopkins University in Baltimore, Maryland. That setting, he told Reuters Health, makes it easier to zero in on the potential effects of road traffic on asthma risk. Checkley and his colleagues studied 725 kids between the ages of 13 and 15 and found that roughly one in 10 had asthma symptoms in the previous year. And those who lived within 100 meters (328 feet) of the main roadway were twice as likely to have symptoms as those who lived at least 384 meters (1,260 feet) away. The researchers also found that the teenagers' risk of atopy -- a tendency to have allergic reactions -- inched up the closer they lived to the main road.
