India, Oct. 20 -- Layers of smog and the acrid sting of pollution cloaked the Capital on Diwali eve, prompting the Commission for Air Quality Management (CAQM) to invoke stage 2 measures under the Graded Response Action Plan (Grap), as residents braced for yet another festive day marred by toxic air before the celebrations kicked off.

The 24-hour average Air Quality Index dipped to 296 (poor) at 4pm, from Saturday's 268 at the same time, according to data from the Central Pollution Control Board. However, the number at 4pm progressively began to surge upwards after dusk, breaching the "very poor" threshold to touch 300 by 6pm. It settled at 310at 11pm. Weather experts warned that the situation is unlikely to abate till the end of the wee...