Is the smoke released from the chimneys of Kunming's Anning salt mine harmful?

Harmful. The chimneys of the salt mines in Anning, Kunming, release harmful smoke. The main emissions are coal, coke, coking coal, etc. The combustion produces dust, carbon dioxide and other waste gases. Kunming, also known as Spring City, is a prefecture-level city in Yunnan Province, the provincial capital, and the central city of the central Yunnan urban agglomeration. It is one of the important central cities in western China approved by the State Council.