Demystifying the Diwali ban

The Diwali air pollution issue has gained currency in the public discourse majorly from the standpoint of the public health and environmental threat that it poses on a pan-India scale. 

With the intention of resolving the issue, the Supreme Court imposed a ban on the sale of firecrackers last year on a pilot basis in Delhi. 

However, this year the strategy is seemingly more rational and holistic, mindful of environmental health concerns as well as the celebratory sentiments, which are otherwise difficult to curb, owing to the various implementation challenges intricately linked with socio-economic factors and cultural practices. 

In an attempt to understand the efficacy of the 2017 ban at reducing fine particulate matter, a local monitoring station was set up during the Diwali period in a typical urban pocket of South Delhi, characterized by the presence of an affluent urban neighbourhood, an urban slum, an urban village and a resettlement colony. 

The station enabled collection of granular data at one-minute resolution and reflected that local PM2.5 levels were as high as 2500 µg/m3 with the 24-h median PM2.5 concentrations having increased by 300% on the day of Diwali. 

The impact of Diwali emissions was seen on ambient PM2.5 levels up to two days after the festival. The neighbourhood levels captured by the local monitor is important to understand the magnitude of actual exposure contrary to the centrally located CPCB monitors, which reported relatively lower values. 

Although the prevalence of particulate matter in the ambient air is contingent upon a number of factors, mainly meteorological conditions, emissions of such escalating levels require a more graded approach rather than a blanket ban. 

The Supreme Court’s order this year for “green and improved” firecrackers concurs with a scientific rationale and is aligned with socio-political complexities involved in imposing such measures. 

While endorsing some of the criticism about the ban being discussed in the public domain, one can  agree with the fact that it does not limit the ban of cracker-burning to the festival of Diwali, but also a few other festivals and wedding celebrations, recognizing the practice as a problem rather than being an event-centric intervention. 

Additionally, it attempts to address the problem at a manufacturing level without upsetting the economic ecosystem of cracker producers. The ban on its sale through online channels is also laudable given that those availing frequent online platforms for shopping are usually the higher income strata, who naturally have more disposable income to purchase crackers. 

However, one needs to be mindful of the fact that the presence of particulate matter in the ambient conditions are heavily dependent on meteorological conditions and the two-hour time period recommended could well be characterised by inversion or very stable atmospheric conditions, which may become an antithesis to the intention of the pollution redressal measure.

Also, vigilance mechanisms need to be substantiated with behaviour-centric approaches to be deployed well ahead of this time at a mass scale and in a context-sensitive way aligned with regional sentiments and practices in order to tackle the issue in a holistic fashion. 

At the same time enforcement of existing policies such as ban of cracker burning around health facilities need to be aggressively imposed to reduce exposure related threats to vulnerable groups. 

Similarly, congested neighbourhoods, where the likelihood of emission entrapment is higher, are needed to be rigorously prevented from the use of crackers. 

The timeliness of the proposed air pollution control measures to tackle burning during festivities can, however, be criticized given that it needs to be mindful of sensitization and preparedness on the part of manufacturers to produce green or “reduced emission crackers”.  

The procurement of raw material and chemicals for mass scale production does not begin right before the festivity, but in accordance to the life-course of a production mechanism. 

From the perspective of the general public, even though there seems to be a resonance with the need for pollution curbing measures, it does seem to upset an age-long sentiment. Under such circumstances, phasing out can only happen when strategies to curtail emissions are popularized, implying the need for dissemination of knowledge on the various emission levels of cracker types and the subsequent health risks that they pose. 

Catastrophic air pollution issues need to be unpacked to provide a plethora of measures that communities can adopt and alternate with. Simultaneously, attention to peri-urban locations and smaller cities with poor air quality monitoring are also important owing to the acute nature of the exposures that take place while burning the crackers.  

The measures undertaken so far are understandably in an experimental phase and need to evolve in a more timely manner to allow all stakeholders - manufacturers, users and regulators - to prepare ahead. The recognition of the problem on this scale and intention to improvise strategies are, however, appreciable. 

— The writers are with the Centre for Environmental Health, PHFI