New Delhi: A truck mounted with anti-smog gun is used to spray water droplets to curb air pollution, as a thick layer of smog engulfs the national capital following Diwali celebrations, in New Delhi, Saturday, Nov. 6, 2021. (PTI Photo/Atul Yadav) Gurugram: A metro train runs on a railway track amid low visibility due to a thick layer of smog, following Diwali celebrations in Gurugram, Saturday, Nov. 6, 2021. (PTI Photo) New Delhi: Security personnel stand guard amid smog at Vijay Chowk in New Delhi, Saturday, Nov. 6, 2021. A thick layer of toxic smog engulfed the national capital for the second consecutive day after Diwali celebrations. (PTI Photo/Vijay Verma) Ghaziabad: Commuters make their way amid low visibility due to a thick layer of smog following Diwali celebrations, in Ghaziabad, Friday, Nov. 5, 2021. (PTI Photo)