Bengaluru:
Get up early, get out there and exercise in the fresh morning air - wisdom that has been handed down through generations. But perhaps, it may be safer to snuggle down and stay in bed until a bit later, at least during winter mornings in Bengaluru.
An ongoing study by scientists at the Indian Institute of Science in Bengaluru has shown that air quality is actually at its worst early in the morning - between 5.30 and 7.30am.
Associate Professor Prosenjit Ghosh, who works at the institute's Department of Earth Sciences, told NDTV, "In morning there is a large growth of CO2 concentration because of a process called atmospheric inversion which is because of all the pollutants which go up into the atmosphere. Instead of cooling the atmosphere, it warms up and there is some kind of trapping mechanism which allows all these pollutants to stay near the ground."
"It settles down at night time and by the morning, what we really get is very high concentration which makes it very difficult... In the morning time you anticipate very clean air but what you really get is very dirty air which has high CO2 in it," Professor Ghosh added.
NDTV met morning walkers at the famous Lalbagh Garden in the city and told them of this research finding.
"I think morning is pollution free. Since childhood we are learning that morning is fresh air and exercise is very good... But morning we are walking and we are feeling fresh," said a morning walker.
"Early morning the visible pollution is less, so people don't have any idea. Practically there is no other option... Afternoon, evening and all is actually not possible," said another.
Some were completely shocked. "I am surprised and shocked with what you are telling me. Looks unlikely that we can change, this is the hour we get to change. We will give it a thought."
As the day progresses, the harmful gases have a chance to escape. Plants also get busy absorbing CO2 in the process of photosynthesis. Professor Ghosh says the best time to exercise outdoor would be "Afternoon. They have to take off from their offices."