Jan 19, 2007

Mumbai's Winter Pollution Blues



Mumbai has been washed over by a blue haze these days — a concoction of gaseous compounds, dust and water vapour. The haze, or smog, is taking hold of the city and leading to pollution-related illnesses. The primary cause of the smog is vehicular pollution. Nitrogen dioxide (NO2), sulphur oxide (SO2), carbon monoxide and peracetyl nitrate are all found in vehicular exhaust. These combine with water and ozone to form smog. During winter, the cold air in the atmosphere does not rise. Pollutants are, hence, trapped to the ground.

Winters bring cloud cover closer to earth. As a result pollutants don't get dispersed easily because of reduced temperatures. The dispersion of gases and other pollutants is not easy. The ground level concentration of pollutants increases. There are many more suspended particles in the air during winters than any other season. This makes the air dense.

Since we inhale more polluted air than we would normally inhale in other seasons, it triggers off health problems. People suffering from asthma may get frequent attacks in winter because of their allergy to dust. Mumbai has numerous pollutants, vehicular being the most prominent. In winter the smog (a combination of smoke and all kinds of pollutants that form droplets of water) levels go up. This is because the smog doesn't disperse causing health problems.

Mumbai is blessed because it has sea on both sides. The pollution flushes out because of the wind. But people staying in heavily polluted and populated areas like Andheri, King's Circle, Chembur, etc have to be careful. Wearing sunglasses, covering your nose with a scarf can help but won't go a long way. That's because the body's natural defence mechanism cannot stop dust particles less than 10 micrometers in diameter. Almost 95% of the emissions from a vehicle are less than 10 micrometers. These go directly into your lungs. Unless the vehicles are reduced nothing can be done.


Traffic congestion, stalled traffic, truck traffic are the biggest contributors to the pollution. Hopefully, the Metro planned for the years 2009-2010 will provide a viable alternative public transport.