The irony is hard to miss. Indore, which has worn the crown of India’s ‘cleanest city’ in government’s Swachh rankings for seven straight years, has been struggling to clean up its air. The largest city in Madhya Pradesh has seen a 21% rise in levels of the pollutant PM10 between 2017-18 and 2023-24, according to recently released govt data.
Indore figured among 31 ‘non-attainment’ cities – where air quality had deteriorated since the 2017-18 base year – in a list of 130 that are monitored under the National Clean Air Programme (NCAP), which aims to reduce PM10 levels in these urban centres by up to 40% by 2025-26.
While the list of ‘non-attainment’ cities includes places such as Navi Mumbai and Vizag, which also ranked high in the 2023 Swachh ratings, Indore’s name stands out. It sees itself as a model city and has acquired an international reputation of sorts for cleaning up its act on sanitation and waste management, which form the basis of Swachh rankings. The city has been topping the Swachh Bharat surveys since 2016, but that’s also roughly the period that NCAP has examined to find a deterioration in the city’s air.
It’s not hard to see why the city’s air quality has been slipping. As the major commercial and industrial hub of the region, Indore has urbanised rapidly. A 2019 paper – Air Pollution Knowledge Assessments for 20 Indian Cities – published in Urban Climate found that the built-up area in Indore and its neighbourhood had grown about nine-fold between 1975 and 2014, the highest among the 20 cities the study looked at and more than double the average increase (4.2-fold) seen across these cities.
Indore has more than 3,000 micro, small and medium enterprise (MSME) units. Over 500 real estate projects are under construction in the district, according to Credai. Revenue from property registrations in the city jumped to Rs 1,339 crore, up 7.2%, between April and Oct 2024 compared with the corresponding period last year, according to official data.
The city is also a major transport hub. Three national highways pass through Indore – NH 52 (part of the old Agra-Mumbai road), NH 47 (Nagpur-Bamanbore in Gujarat) and NH 347BG (within MP). Besides, two major state highways, SH 27 and SH 31, run close to the city. Indore itself has more than 20 lakh vehicles. Per the Regional Transport Office, around 8,000 two-wheelers and 2,500-3,000 cars are registered every month in the city.
“Traffic management has failed to keep pace with the rate of new vehicles hitting the roads. There are substantial emissions from congested traffic, including from vehicle tyres, which are particularly harmful,” says city-based environmentalist O P Joshi.
Not surprisingly, the major contributor to Indore’s pollution is the road dust kicked up by traffic movement. Vehicular emissions come second. Per a source-apportionment study by Clean Air Catalyst, a flagship programme launched by the US Agency for International Development and a global partnership of organisations led by World Resources Institute, road dust contributes nearly three-fourths of the city’s coarse particulate matter (PM10), with transportation, industries, construction and household cooking making up most of the rest.
Road dust also leads in the share of fine particulate pollution (PM2.5) at 55%, followed by transportation, industries and household cooking.
This isn’t very bad news for city authorities. Dust management is the low-hanging fruit among pollution-mitigation measures and doesn’t involve harsh actions impacting people and livelihoods. “Road dust gets resuspended in the air due to vehicular movement and wind. Continued optimal cleaning of roads would help minimise its impact,” says Prakash Doraiswamy, senior scientist at Clean Air Catalyst and director of air quality at WRI.
Overall, too, Indore’s location lends it certain natural advantages.
“Unlike the bowl-shaped Indo-Gangetic Plains (IGP) where calm winds and low temperatures lead to an accumulation of pollutants, Indore is a much windier place with an average wind speed of around 11kmph, which blows away a lot of pollution. Also, unlike the alluvial soil in IGP, the black soil in central India kicks up less dust,” says Dipankar Saha, former head of Central Pollution Control Board’s air laboratory division.
“Pristine air quality remains one of our focus areas. We are advocating large-scale plantation and utilising machinery to sweep roads to minimise dust. To curtail vehicular emissions, we are augmenting our public transport fleet with electric and CNG vehicles,” says Indore divisional commissioner Deepak Singh.
If implemented well, these measures should make a dent in the city’s PM levels. However, to bring pollution down to India’s safe standards – 60 μg/m3 annually for PM10 and 40 μg/m3 for PM2.5 – Indore will have to do much more. A good place to begin would be data. The city recently increased the number of its air pollution monitors to seven. However, an analysis by Urban Emissions shows that the agglomeration of Indore, Dewas, Ujjain, Mhow and Pitampura needs a minimum of 26 monitors for particulate matter alone.
Only through granular data can Indore zero in on zones of high pollution to reach the level of sanitation in the air that the city seems to have achieved on the ground.