The Indian Institute of Technology Bombay (IIT Bombay) on Friday said its researchers have found that too much mucus can weaken the lungs’ defences, which can make people more prone to allergy attacks. The airways to the lungs have a naturally engineered defence mechanism that gets activated when any foreign material enters the airways by secreting a fluid called mucus to trap it.

However, for millions of people living in cities like Delhi, Mumbai, Bengaluru and other metros, the rising levels of air pollution have been posing a persistent health hazard, with heavy smog-filled air causing severe respiratory issues. In a recent study, IIT Bombay researchers have found that as mucus volume increases in response to pollution (or a foreign material) in the airways, its defence does not improve.