By Shambhavi Shukla:
Note: This article has been republished from Down To Earth.
Diwali is less than a week away and New Delhi’s air quality has already plunged to ‘very poor’ levels. Delhi’s air quality index showed a reading of 318 and 306 on October 23 and 24 respectively, both categorised as ‘very poor’. It is unusual for levels to rise this early in the season. The air quality has been fluctuating between the ‘poor’ and ‘very poor’ categories, made worse by a sudden dip in temperatures and low wind speed.
“Diwali traffic has been a factor for the increasing levels of pollution in the city” said Anumita Roy Chowdhury, executive director at Delhi-based non-profit Centre for Science and Environment (CSE). Crop burning in the neighbouring states has also affected air pollution levels, she added.
According to the satellite images from NASA, there is an increase in the number of crop fires in Haryana and Punjab. Locally too, waste burning has been rampant. The Environment Pollution Control Authority’s ‘Hawa Badlo’ app has started receiving many complaints within four days of its launch on September 21. Most of these are related to waste burning from different parts of the city and neighbouring Noida.
An analysis of the air quality done by CSE between October 7 and October 24 showed that air quality on almost 78 per cent of the days was ‘very poor’, on 16.6 per cent of the days, it was ‘poor’, and on 5.6 per cent of the days, it was ‘moderately polluted’. This was when the 24-hour average value was considered for the localities of Punjabi Bagh, R K Puram and Anand Vihar.
India Meteorological Department officials have said that the wind speed might come down just before or on Diwali. Ravinder Vishan, scientist at the Regional Meteorological Centre, said the northwesterly winds until October 28 were favourable for dispersion of pollutants. “But we see the wind pattern changing around October 29 when it may become calm. Visibility will reduce and winds may have a westerly influence. This will obviously lead to accumulation of aerosols, which will be accentuated by fire-crackers during Diwali,” he said.
When CSE analysed the air quality from August 15 to October 5, 2016, it found that the levels of pollution had started to rise within the first week of October. The PM2.5 levels were comparatively higher this year in comparison to 2015 levels, possibly due to low wind speed during the first week of October and crop fires in the neighbouring states.