Mumbai construction-site monitors show zero pollution, Awaaz Foundation questions accuracy

Construction is under way at hundreds of places in Mumbai, with dust and pollution spreading in the air. Even so, the air-quality monitors installed at these sites are showing pollution levels of "zero" or only a single digit. The Awaaz Foundation has directly questioned the accuracy of these machines at construction sites in Bandra and Khar.

Sumaira Abdulali, the foundation's head, has written to Chief Minister Devendra Fadnavis and Municipal Commissioner Ashwini Bhide. She has strongly demanded that the data from such suspect machines not be included in the municipal corporation's official records until they undergo a full technical check and certification.

The foundation examined the machines at construction sites in Bandra and Khar between March and May and between September and October 2026. For this, the machines were photographed 230 times over 38 days. The readings of the machines over 26 days, between March 23 and May 5, were then compared with data from the official air-quality stations at Kherwadi and BKC on the Central Pollution Control Board's SAMEER app.

The comparison showed a very large gap between the readings at the official stations and those on the construction-site machines. For eight consecutive days, the PM10 reading at the Kherwadi or BKC stations was above 100 micrograms per cubic metre. At the same time, active construction sites nearby were showing as if there was no pollution at all.

There is an active construction site on Nargis Dutt Road in Pali Hill. There, the PM2.5 reading, a dangerous fine particulate, was shown as flat "zero" on April 13 and 24. On April 24, the PM10 reading was also zero. Notably, on April 13 the PM10 level on the same machine was 34, yet PM2.5 was recorded as zero. Such zero readings are almost impossible in the middle of active construction, so suspicion has deepened that these machines are faulty, have been tampered with or are misleading.

On 16 of the 26 days examined, at least one machine showed a PM2.5 reading below 10 micrograms per cubic metre. On March 29 and 31, five of six machines showed PM2.5 between zero and nine. On April 3, PM10 was 91 at Kherwadi and 133 at BKC, but the machines at the construction sites were creating the impression that the air was in good condition.