More than 7% of the 3,497 children surveyed across 19 schools are unaware of their underlying asthmatic symptoms, reveals an study by civic–run King Edward Memorial (KEM) Hospital at Parel.

The survey, conducted by the department of chest medicine at the hospital, suggests that the increasing congestion and pollution in the city may lead to children being vulnerable to asthma that lay undiagnosed.

In the survey, the doctors studied 3,497 children from 19 government–aided and civic schools in areas including Ghatkopar, Kurla, Mulund, Dadar, Byculla, and Vasai for asthma and related ailments.

Even as close to 3% of the children surveyed were aware that they are asthmatic and were on medication, more than 7% of the surveyed children were unaware of their condition and have been put in the "grey" zone after they showed asthmatic symptoms.

The study also revealed that the vulnerability of children developing asthma varies from place to place. Close to 15% children in Kurla were put in the "grey" zone, which is more than double the number of children vulnerable to asthma in Ghatkopar and Mulund. In Byculla and Dadar, the number of vulnerable children dipped to as low as 3%.

During the study, children were asked to vigorously blow air through a portable lung function device which measures "peak flow rate," a measurement of air blowing capacity of an individual based on his/her height and weight.

"Values of peak flow rate for children vary between 150 to 400 depending on their height and weight. A large number of children who have abnormal lung health and are predisposed to developing asthma have been tracked in the study. These children should be immediately referred for further diagnosis, leading to early intervention," said Dr Amita Athavale of the KEM Hospital.

Close to 54% of the affected children reported asthma due to exposure to multiple factors such as dust and smoke.

"Children are at a higher risk of asthma as their lungs are in process of growth," said Dr Naveen Arora, senior scientist, Institute of Genomics and Integrative Biology, New Delhi. "In addition, they indulge in large–scale outdoor activity in dusty playgrounds and gardens. Multiple factors including sudden cold climate, dust, smoke, strong incense stick smell, pollen and pollutants contribute to asthma in children."

Arora added that areas with heavy congestion, industries and traffic are more prone to affect children and lead to an eventual asthmatic condition.