Off the radar: Is Bengaluru’s air quality getting seriously bad?

Rising construction dust, unaddressed road dust and waste-burning have all combined to trigger a never-before fall in the city’s once cherished air quality. With no letup in vehicle registrations and pollution regulations poorly monitored and executed, has Bengaluru reached a point of no return? Is the city heading the Delhi way? This might seem alarmist, but the signs are too loud and clear and the complacency too evident to be ignored.

No congestion killer plan will work when a city’s vehicle numbers are almost equal to its population. This is exactly where Bengaluru is trapped with its estimated 1.2 crore vehicles. But beyond the inevitable traffic jams, they have triggered an unprecedented spike in air pollution. A climate-tech start-up’s latest study shows that the city’s PM10 pollutant levels breached the national air quality standard for four years in a row, and it is getting even worse.

Rising construction dust, unaddressed road dust and waste-burning have all combined to trigger a never-before fall in the city’s once cherished air quality. With no letup in vehicle registrations and pollution regulations poorly monitored and executed, has Bengaluru reached a point of no return? Is the city heading the Delhi way? This might seem alarmist, but the signs are too loud and clear and the complacency too evident to be ignored.

The study by the start-up, Respirer Living Sciences, noted consistently high PM10 levels recorded at the city’s monitoring stations at Silk Board Junction, RVCE-Mailasandra, City Railway Station and Kasturi Nagar. Residential pockets such as BTM Layout and Hombegowda Nagar also crossed the safe annual average in the 2021-24 period. The message is clear: The pollution is spreading all across the city, and the fast-declining tree cover offers no respite.

Road dust and vehicular movement complement each other in amplifying the PM10 particles. “Bengaluru’s roads are bad, but even the good roads are not swept daily. In 2017, as part of a Task Force, we had recommended mechanical sweepers to keep at least roads in the CBD areas free of dust. Now, they sweep only the roads around Vidhana Soudha and Raj Bhavan,” notes a veteran technical expert who was attached to the Karnataka State Pollution Control Board (KSPCB) for three decades. He adds that white-topped roads generate more dust particles since the friction is higher compared to asphalted streets.

If roads are not swept daily, the dust particles are stirred up by the fast-moving vehicles. “These particles can move up to 1km vertically. Besides, motorcyclists are also exposed since the breathing height is about 1.5 metres,” the expert points out. After the seven-year Operations and Maintenance (O&M) contract ended on February 28, the Bruhat Bengaluru Mahanagara Palike (BBMP) had faced widespread public complaints related to unclean roads, accumulated silt and blocked shoulder drains.

Once the machines went idle, the Palike had tried manual clearing of roadside silt with pourakarmikas, outsourced workers and trucks. Following negotiations, the contractor who operated the machines has reportedly agreed to continue the services for another six months. However, not all machines are fit to run and the funds-starved BBMP is struggling to maintain them. Of the 25 sweeping machines, eight are truck-mounted and 17 self-propelled.

Widespread dumping of construction debris on the roadsides amplifies the road dust problem. If not cleared in time, wind takes the dust all around the area. Making this even worse are lack of adequate measures to nip the pollutants at the construction site itself. While the Bengaluru Metro Rail Corporation Limited (BMRCL) has barricaded its sites and uses water sprays to limit the dust, no such measures are seen in thousands of building construction areas across the city.