India, Oct. 28 -- With winter fast approaching, symptoms such as a runny nose, an irritated throat and a lingering cough are going to be exceedingly common across households. And in many cases, they will be brushed off as seasonal allergies. However, pulmonologist Dr Amit Kumar Mandal believes that the simple explanation often presents an incomplete picture.

"Across much of North India, air quality deteriorates sharply between October and February, and a significant share of what passes for allergy is the respiratory system reacting to polluted air, a distinction that determines whether a symptom is a passing nuisance or an early warning," he told HT Lifestyle.

The pulmonologist explained that fine particulate matter (PM2.5) is small en...