Highway to Asthma? New Results from a Study in Lima, Peru

Many people are aware of the traffic-related dangers of major roadways in developing countries. Road traffic injuries are the 11th leading cause of death globally, and 90 percent of these deaths occur in low- and middle-income countries. However, less is known about the critical link between living near highways and other health outcomes, including respiratory disease. Yesterday, a study published in the Journal of Allergy & Clinical Immunology found that teenagers living close to a heavily transited roadway in Lima, Peru, are more likely to have asthma and allergies than teenagers living farther away. This study is one of the first to explore the relationship between traffic exposure and asthma in developing countries.

The study included 725 adolescents between the ages of 13 and 15 years who lived near a highly trafficked avenue in Pampas de San Juan de Miraflores (Las Pampas), a shantytown located in the outskirts of Lima. The researchers found that adolescents living within 100 meters of the avenue were twice as likely to have asthma symptoms as adolescents living over 384 meters away. In addition, adolescents living closer to the avenue were more likely to test positive for various allergies. However, the study did not find an association between proximity to the road and exhaled nitric oxide (eNO), a common measure used to test people for asthma and respiratory tract infections. Furthermore, researchers did not find an association between indoor household particulate matter and proximity to the avenue.

Today, more than half of the world’s population lives in urban areas, and by 2050 the World Health Organization (WHO) predicts that 70 percent of people will live in urban areas. The majority of this rapid urbanization is occurring in developing countries, with many people moving into shantytowns and slums much like Las Pampas. This rapid growth often outpaces planning and infrastructure, resulting in inadequate or unsafe housing, dense traffic and air pollution, and poor water and sanitation services. The health consequences of this unchecked urban growth are broad, ranging from increases in interpersonal violence to infectious disease, and now, as this study suggests, a greater risk of asthma and allergies. Governments must start to address these new challenges with improved urban planning and policy changes in order to reduce risk factors for disease, including policies to regulate traffic and automobile emissions in settings similar to those of Las Pampas, Peru.

Other sources:

World Health Organization. Injuries: traffic. Available from: http://www.who.int/topics/injuries_traffic/en/.