The researchers from US studied the effects of road and traffic density on children's lung function and respiratory symptoms in one of the border towns and found that the asthamatic patients had increased respiratory problems , the Science Daily reported.
''Our results show that close proximity to vehicular traffic-related emissions, either at home or at school, can lead to chronic effects in the respiratory health of children with asthma,'' said Fernando Holguin, the lead author of the study from Emory University School of Medicine.
Traffic-related pollutants are known to be associated with asthma severity, but to what extent they affect airway inflammation and lung volume in both asthmatic and nonasthmatic children was unknown.
To investigate how specific traffic-related pollutants affected children's lung function and respiratory symptoms, the researchers recruited 200 age- and sex-matched asthmatic and non-asthmatic school children from ages six to 12. Over the course of a year, they measured road and traffic density and traffic-associated pollutants near the children's homes and schools, and evaluated each child's lung function and respiratory symptoms consecutively for four months.
Asthmatic children, but not children without asthma, were affected by living in homes in areas with high road density. They had higher levels of exhaled Nitric Oxide (NO), as well as reductions in both lung volume and airflow. Living within 50 meters of high density road areas increased the chances of respiratory symptoms in asthmatic children by more than 50 per cent.
The findings support and add to previous studies which have looked at the effects of traffic emissions on children, but it may have been underpowered to detect significant associations between respiratory outcomes and specific pollutants.