Zee Media Bureau/Salome Phelamei

New Delhi: A survey conducted by the Breathe Blue and Heal Foundation shows that Delhi's children have the weakest lungs, as compared to kids from other metros.

The survey released on the eve of World Asthma Day shows that four out of every 10 kids in the Capital suffer from severe lung problem.

The survey reveals about 40% of Delhi's kids have compromised lung function

It showed 21% of kids in the national capital had poor lung function and another 14% had bad lung function.

For the survey, the Breathe Blue graded children`s lung function as excellent, good, satisfactory, bad and poor based on various international scales.

According to the survey, Mumbai`s children fared the best with 73% of the surveyed children having good lung function. Of the remaining, 13% children have poor and 14% have poor lung function.

In Bangalore, the affected children percentage stood at 36%, whereas in Kolkata, about 35% of children have been affected.

The survey covered 2,000 children in Mumbai, Delhi, Bangalore and Kolkata in the age group of 8-14, aimed at screening their lung health.

Overall, about 35% of the surveyed children across metros have poor lung function, indicating poor air quality.

The World Health Health Organisation (WHO) has long held air pollution as a major environmental risk to health.