Transport sector causing 39% of Bengaluru’s pollution

Bengaluru: Trucks and commercial vehicles have been found to be the biggest air polluters in Bengaluru, accounting for 39 per cent of the lethal particulate matter (PM 2.5) emissions in Bengaluru Urban district and 48 per cent in the BBMP area.

These are followed by industries, which continue to burn wood and coal despite availability of less polluting alternative fuels, a new study has revealed.

Led by Prof Gufran Beig, School of Natural Sciences and Engineering, National Institute of Advanced Studies, researchers worked for several months to develop accurate emission inventories if 200 square metre grids of PM 2.5 and the larger particulate matter (PM 10) in Bengaluru Urban district.

"In a first, we have identified 80 pollution hotspots of ultra fine resolution (200 sqm grids). What we see here is a snapshot of the major sources of pollution. We find that transport sector is the biggest polluter," Beig said.

Researchers adopted a hybrid model where field data, CCTV camera footage as well as photo and video clips from drones were analysed with artificial intelligence and machine learning tools. The results painted a stark picture of Bengaluru's air quality.

"We see that commercial vehicles, which make up just 4 per cent of a road fleet, account for half of all the PM 2.5 emissions from the transport sector. This may be due to poor maintenance of vehicles or their age. Cars and SUVs form 22 per cent of the fleet and account for 22 per cent. A whopping 70 per cent of the vehicles on the road were two-wheelers. Though their direct contribution to PM 2.5 is low, these vehicles stall traffic by breaking the flow and cause higher emission by other vehicles," Beig explained.

Fossil fuels a problem

The study said industrial pollution was driven by the choice of fuel in the boilers. Industries emitted 24 per cent of overall PM 2.5 mainly due to the burning of wood and coal by 19 per cent of the industries in the district. This also led to the high emission of PM 10.

A majority of the industries (27 per cent) used diesel, followed by electricity (25 per cent) and wood (19 per cent). "This reliance on fuels like diesel and wood highlights the potential for emissions reduction by adopting cleaner energy sources," the study said.

Of the 113.6 giga tonne per year of PM 10, dust accounted for 40 per cent followed by transport (24 per cent), industries (17 per cent) with the remaining shared by generators and other sources.

Need enforcement

Beig said enforcing norms for commercial vehicles and streamlining traffic by segregating vehicles, last-mile connectivity with seamless ticketing option, reducing metro fares and total ban on burning of wood in industries were some of the mitigation measures.

Director general of Environment Management Policy Research Institute (EMPRI) B P Ravi said many of the measures suggested by the study were low-hanging fruits.

"The study has some crucial pointers for policy making. Some of these solutions are easy to adopt. However, any change can happen only when all line departments are involved. At the same time, the findings need to be disseminated among the public to make them stakeholders," he said.