A University of Southern California study has indicated that children who go to school near busy roads increase their risk of asthma 45 percent.

The Keck School of Medicine study published in the journal Environmental Health Perspectives, said that attending school in high-traffic areas is almost the same as living near similar pollution sources, even though children spend only about a third of their waking hours at school.

Study lead author and preventive medicine Professor Rob McConnell said in a statement, "Exposure to pollution at locations other than home, especially where children spend a large portion of their day and may engage in physical activity, appears to influence asthma risk."

The health of 2,497 kindergarten and first-grade children in Southern California who did not have asthma when they were first screened, were tracked by the researches. They then observed the children for three years and studied traffic conditions around their schools and homes.

The researchers said that of the 2,497 students in the study, 120 developed asthma.

McConnell said, "It's important to understand how these micro-environments where children spent a lot of their time outside of the home are impacting their health. Policies that reduce exposure to high-traffic environments may help to prevent this disease."

He further noted that Asthma is the most common chronic childhood illness in developed countries and has been linked to environmental factors such as traffic-related air pollution. (With Inputs from Agencies)