Although State-owned mines and factories often provide medical checkups and treatment for their workers, migrant workers in small and private mines and factories that make up to 90 percent of pneumoconiosis patients do not have such luxuries, Wang adds.

Once migrant workers contract the chronic disease, paying for the costly and ongoing treatment becomes a big issue.

Current laws stipulate that employers must provide work injury insurance for employees and ensure the country's work injury insurance fund covers treatment fees and compensation to those with occupational diseases. But to qualify for claims, employers must pay for the insurance, which often is impossible in small and private mines and factories.

In most cases, the medical insurance for farmers covers little for pneumoconiosis treatment, and it is very hard to get compensation and treatment from the employers, because by the time the patients are diagnosed with the disease, the small and private mines and factories would most likely have gone bankrupt or disappeared, according to Yuan Yue, a government civil affairs official with Renhuai city, Guizhou province.

Renhuai provides migrant worker patients regular medical and living subsidies. But it is not easy for every place to do that. Even if local governments want to offer free medical treatment and living subsidies, the patients usually live in underdeveloped areas, and the tight financial budget there makes the help from government very difficult, Yuan says.

Zhao Defa, director with Renhuai's Disease Control and Prevention Center, says the best way to reduce the harm of pneumoconiosis is prevention.

"Pneumoconiosis is preventable as long as there are enough effective precautions, such as regular medical checkups, masks and dust control," Zhao says.

"Government departments should work closely so that the employers provide enough protection to workers."