ZHENGZHOU, June 9 (Xinhua) -- Liao Shide, a farmer in Southwest China's Guizhou Province, went to work in a gold mine in an adjacent province for years. After going back home early this year, Liao quickly died of silicosis, a lung disease caused by continued inhalation of siliceous mineral dust.

    Up till then, of all the 118 migrant workers from Liao's village who flocked to the gold mine, 12 had been killed by the same disease.

    With China's agricultural production system introducing more mechanization, many local farmers are left idle at home and become migrant workers, taking up temporary jobs in cities and towns across China.

    For the lack of protection measures, they often become the victims of occupational diseases.

    In 2002, a lung-disease hospital in east China city Wuxi of Jiangsu Province found that some 159 migrant workers who were laboring in sand factories in the city have caught silicosis. Doctors said most of them could not make another ten years of lives.

    Liu Xinxiang, a farmer from Sichuan Province, told Xinhua that his three sons were among the migrant workers hired by the sand factories. "All of my three sons died from the disease later, and none of them were over 40 years old," the heartstricken farmer said.

    Liu later went to Wuxi, and witnessed the factory that deprivedhim of his children. "When machines were crushing stones into sand,the mineral dust simply pervade the room and I could see nothing three meters away," the old man said. Without dustproof apparatuses and masks, Liu's sons had to work here for 15 hours per day.

    In 2003, over 100 migrant workers in a quartz factory in southeast China's Fujian Province were found to have silicosis and19 of them died later.

    In 2004, of 100 farmers who went from Guizhou's Ziyun County towork in south China's Guangxi Zhuang Autonomous Region, 40 had checked up with silicosis and a dozen died.

    China's incidence of pneumoconiosis, a general name for all lung diseases caused by continued inhalation of mineral or metallic dust, is one of the highest in the world.

    Up to the end of 2001, the accumulative total of pneumoconiosispatients had amounted to nearly 570,000 in China, with an annual increase of 10,000 and an annual death toll of 5,000, over 90 percent of them were migrant workers.