Diwali is around the corner. We all love Diwali for the festive cheer it brings with it. This year, it is going to be a little silent because of the ongoing pandemic but we are sure you will create new ways to celebrate it and have fun. Light lots of diyas and candles, try your hands at rangoli or lantern making, meet your close family and friends (of course practicing social distancing) and have yummy food and sweets. Well, that’s the charm of Diwali.
One caution though! Be mindful of bursting crackers. The air is already unbreathable, especially in Delhi and surrounding areas. Every year in October, Delhi’s air quality starts to dip and this year is no different. The statistics say it all. The AQI (which is the benchmark for pollutants in the air), shot up to beyond 500 last year after Diwali when the safe limit for breathable air is just 50. The AQI is currently ranging from 200 to 400 in different parts of Delhi.
There are a variety of factors responsible for this poor to extremely poor quality of air in Delhi.
Change in Weather
The first and foremost reason is the input of pollutants followed by a change in weather and local conditions around this time. During monsoons, the prevalent direction of the wind is easterly. These winds, which travel from over the Bay of Bengal, carry moisture and bring rains to this part of the country. Monsoon withdrawal in October in northwest India changes wind direction from easterly to north-westerly, which constitutes 72% of Delhi’s winter winds. Storms carrying dust arrive from Rajasthan and sometimes Pakistan and Afghanistan. Also, the dip in temperature in winter lowers the inversion height (which is the layer beyond which pollutants cannot disperse) which leads to an increase in pollutants in the air. High-speed winds are very effective at dispersing pollutants, but winters bring a dip in wind speed overall as compared to summers. The combination of these meteorological factors makes the region prone to pollution.
When factors such as farm fires or paddy burning, dust storms, vehicular pollution, cracker burning are added to the already high pollution levels in the city, air quality dips further.
Farm fires also play a role in Delhi’s pollution. Last year, during peak stubble burning incidents, their contribution was 40% in Delhi’s pollution while it is currently at 2%-4% and is expected to increase in November.
Farm fires have been an easy way to get rid of paddy stubble quickly and at low cost for several years. The practice has thrived despite efforts made by the Centre and state governments to end it, primarily because other alternatives are found either unavailable or expensive or time-consuming by smaller farmers.
Other big sources
Apart from the above, the local conditions such as dust and vehicular pollution are the two biggest causes of dipping air quality in Delhi in winter. Dry cold weather means dust is prevalent in the entire region, which does not see many rainy days between October and June. Vehicular pollution is also a very big cause. It has been seen that the air quality becomes particularly bad post Diwali due to the burning of crackers. Despite the government banning the sale and burning of firecrackers, their use continues which leads to non-breathable air post-Diwali.
The Government has been making efforts to handle vehicular pollution through the introduction of cleaner fuel such as BS-VI fuel, push for CNG and electric vehicles, an odd-even scheme for vehicles. Construction ban, shutting down of schools have also been used as emergency measures to control the situation.
But we all can do our bit to help. How? To start with, say ‘NO’ to crackers. Opt for carpooling wherever possible to have fewer vehicles on road. Stop using polluting fuels such as diesel generators or vehicles and switch to cleaner fuels. Say ‘bye-bye’ to plastic bags. Do not burn waste or garbage. Recycle and reuse. Turn off lights when not in use. Educate others around you. If we all make these little efforts, we can do our bit in tackling the pollution mess.
Wishing you a safe and happy Diwali!