The same scenario repeats every year before and after Diwali: pollution. Irrespective of the fact that the AQI will rise to hazardous levels, people remain carefree, enjoying crackers and fireworks. However, CSE’s pre-winter, pre-Diwali analysis attributes this to local pollution sources, with vehicle emissions leading the way.
A new pre-Diwali and pre-winter analysis of air pollution in Delhi by Centre for Science and Environment (CSE) has found that despite a slowdown in farm fires, the air quality in the capital has been going for bad to worse – and the reason is high contribution of local air pollution sources such as vehicles. When only the local sources of air pollution in Delhi are assessed, and contributions from external sources are excluded, the transport sector emerges as the biggest contributor, accounting for more than half of the pollution coming from only the local sources, says the CSE analysis.
“Usually, every year, the contribution of farm fires to Delhi’s air quality during this first phase of winter is considered the biggest problem, detracting attention form the local sources of air pollution. But this year, the air quality of Delhi has turned from poor to very poor even when for most part of this phase, the contribution of farm fires has remained less than 1 to 3 per cent, reaching up to 8-16 per cent only on two days. This exposes the problem of higher contribution of local air pollution sources,” says Anumita Roychowdhury, executive director, research and advocacy, CSE.
“What is stunning is the very high contribution of vehicles among the local sources of Delhi, to Delhi’s air quality – it is more than half. With the overall number of farm fire count declining, the city cannot hide behind its smokescreen anymore. This demands very stringent advanced action at scale and with speed to minimise the local pollution in Delhi and its surrounding region,” she adds.
The CSE analysis has come at the onset of winter and just before the anticipated peaking of episodic air pollution from stubble burning and bursting of firecrackers during Diwali. “It focuses on current trends in PM2.5 levels to understand the nature of the change in air quality and the changing pattern of the contribution of different sources of air pollution to overall particulate pollution in Delhi,” says Shambhavi Shukla, programme manager, clean air programme, CSE.
Shukla adds: “The PM2.5 levels during this phase of winter of 2024 appear to be similar and even higher compared to the same time frame during the previous winters — suggesting that air quality has not improved substantially and is at risk of worsening.”
“An added challenge has been the escalation in congestion index of major roads across Delhi, that has further aggravated the pollution exposure. Vehicles caught in congestion and idling emit several times more than their normal on-road emissions,” say Shubham Srivastava, programme officer, clean air programme, CSE; Srivastava has analysed the traffic congestion in Delhi.