Two weeks, was all it took for the giant HEPA-filter lungs installed at Bandra (West) earlier this month, as part of an air pollution awareness campaign to change its colour- from chalk white to black. While health experts claim this to be a warning bell, air pollution campaigners, on the other hand, have urged the State Government to initiate steps in the right direction to ensure clean air for Mumbaikars.

A similar lung installed in Delhi (November 2018) just took 6 days to go black, another one put up in Bengaluru (January 2018) took 25 days to turn black.