3,166 construction sites in Mumbai have air sensors on display. I wanted to know if they could be trusted, so I started checking. Here's what bothers me most: the builders install these monitors, the builders maintain them, and the builders decide what residents see at their gate every morning. Nobody certifies the numbers before people rely on them. Unless this data is verified, it will mislead the very people it's meant to protect: the parent deciding if a child can play outside, the elderly neighbour stepping out for a walk. A pollution monitor nobody checks is just another hoarding. @CMOMaharashtra @Dev_Fadnavis @mybmc @mpcb_official @HTMumbai @Hepzia

The board said the air was clean. The air said otherwise. For 38 days, we watched the AQI displays outside construction sites in Bandra and Khar. 230 readings later, a pattern emerged: zeros, dashes, question marks. We checked them against official station readings and the US Consulate's monitors. The construction-site boards consistently came in lower. On April 24, a board near Pali Hill told passers-by there was no PM2.5 and no PM10 at all. Next to a construction site. These screens exist for one reason: to warn the people breathing that air. When they're wrong, mothers send kids out to play and the elderly go for their walk, trusting a number that means nothing. And nobody answers for it. @CMOMaharashtra @Dev_Fadnavis @mybmc @mpcb_official @mid_day @AditiAlurkar