Zhang Haichao, a common migrant worker, showed that he indeed had black lung disease.[File photo]

Pneumoconiosis, also known as black lung disease, is a regular killer among migrant workers in certain industries and has claimed 4,834 lives through 2000 to 2008 in central China's Hubei province, a local health official told the Chutian Metropolis Daily.

The disease, caused by inhaling metallic or mineral particles or gas, could lead to a limitation of air flow to and from the lungs, causing shortness of breath. The condition is normally irreversible and usually gets worse over time.

At least 21,760 patients were diagnosed of pneumoconiosis in Hubei province through 2000 to 2008 and the group is growing, according to Li Guangming, deputy bureau chief of the provincial health department, who leafleted lung disease-themed playing cards at a health campaign at Wuchang Railway Station, a hub of homecoming migrant workers.

Bai Yibing, another health official, urged workers to have regular health check-ups, a routine largely ignored by small- and medium-sized factories.