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Motorists drive on a major road as smog covers the capital's skyline in New Delhi on November 2, 2016. New Delhi's air quality has steadily worsened over the years, a consequence of rapid urbanisation that brings pollution from diesel engines, coal-fired power plants and industrial emissions. / AFP / PRAKASH SINGH (Photo credit should read PRAKASH SINGH/AFP/Getty Images)

Motorists drive on a major road as smog covers the capital's skyline in New Delhi on November 2, 2016. 
New Delhi's air quality has steadily worsened over the years, a consequence of rapid urbanisation that brings pollution from diesel engines, coal-fired power plants and industrial emissions. / AFP / PRAKASH SINGH        (Photo credit should read PRAKASH SINGH/AFP/Getty Images)