Toxic levels of air pollution are disrupting the lives of millions of people in South Asia forcing closure of schools, impacting sporting events and leaving governments urging people to stay in doors to avoid health problems.
The worsening air pollution is an annual problem for South Asian nations as winter approaches and cold, heavy air traps pollution in a thick layer of smog.
South Asia has become the global hotspot for air pollution, with studies finding four of the world's most polluted countries and nine of the 10 most polluted cities in the region.
