President Moon hopes collaboration with China will improve air quality in the country.

Blame for pollution is focused on failure of coal plant to filter emissions.

As lichen has disappeared, the herd has changed its diet. This adaptation could have global implications for reindeer facing a warming climate.

A major source of pollution comes from wood-burning stoves. Other sources are vehicle exhaust systems, power plant emissions and heating oil. The air pollution can permanently harm respiratory function and cause other health problems.