GULANG, Gansu: Ma Jiangshan wheezes like a broken accordion. His lungs are a diseased mess after 18 years down a gold mine and, despite accruing massive debt to pay for urgent surgery, doctors say his condition will kill him.

Like many farmers in the impoverished and remote Gulang county, Gansu province, where low rainfall often causes poor harvests, 37-year-old Ma turned to the mines to earn extra money. The work was dirty and hard, but the salary was decent.

In almost two decades, Ma paid no attention to the damage it was doing to his health. He worked long hours and rarely wore a facemask. He never thought for one second his job could cost him his life.