School children hold plants during the Good Air Summit in New Delhi, on Nov. 13, 2019. Over 1,000 school children from Delhi and outskirts on Wednesday joined a national movement for clean air and pledged to conserve the environment. (Xinhua/Javed Dar)

School children perform a skit during the Good Air Summit in New Delhi, on Nov. 13, 2019. Over 1,000 school children from Delhi and outskirts on Wednesday joined a national movement for clean air and pledged to conserve the environment. (Xinhua/Javed Dar)

School girls wearing pollution masks attend the Good Air Summit in New Delhi, on Nov. 13, 2019. Over 1,000 school children from Delhi and outskirts on Wednesday joined a national movement for clean air and pledged to conserve the environment. (Xinhua/Javed Dar)

School children perform a skit during the Good Air Summit in New Delhi, on Nov. 13, 2019. Over 1,000 school children from Delhi and outskirts on Wednesday joined a national movement for clean air and pledged to conserve the environment. (Xinhua/Javed Dar)