BEIJING, April 29 (Xinhua) -- Pneumoconiosis, a work-related lung disease common in the mining and cement industries, is the top occupational killer in China, according to the latest government statistics.

    Since the 1950s, China has reported a cumulative total of 677,000 occupational disease cases, more than 90 percent of which were pneumoconiosis cases, said Su Zhi, an official with the Ministry of Health, here on Sunday.

    Excluding Shaanxi and Tibet, the year 2006 saw 11,000 new occupational disease cases, with pneumoconiosis accounting for 76 percent, Su said.

    "The proportion of pneumoconiosis cases was 1.44 percentage points higher than in 2005 and the latency period of the disease was shorter," he said.

    Miners and cement industry workers develop pneumoconiosis by breathing in coal and cement dust. The disease, which has a relatively long latency, may take several decades to manifest itself, but it is deadly, said Li Tao, an official with the Chinese Center for Disease Control and Prevention.

    According to Su, 23 percent of pneumoconiosis cases had latent periods of less than 10 years.

    He said the coal mining, non-ferrous metal exploitation and construction industries were the three most dangerous industries, causing 41 percent, 13 percent and 6.5 percent of total work-related illnesses last year.

    He also noted that 621 pneumoconiosis cases reported last year were found to involve laborers under the age of 18.

    The ministry vowed to strengthen supervision of coal mining, pharmacy and pesticide production this year, hoping to bring millions of migrant workers exposed to the risk of occupational disease into the health care network.

    Apart from lung disease, coal mine accidents kill 17 workers everyday on average in China, a fatality rate much higher than in neighboring India, for example.

    Other occupational diseases included acute poisoning caused by carbon monoxide and sulfur hydrogen -- particularly in coal mining and light industries, as well as chronic intoxication by lead and benzene, which often occurs in the metallurgy, electronic and mechanical industries, Su said.

    But experts say the figures hugely underestimate the real situation of work-related diseases in China.

    "Only 10 percent of the country's enterprises are monitored," said Li Tao.

    Small and middle-sized enterprises, which account for more than90 percent of the total, employ thousands of rural laborers but are not included in the monitoring and control system.

    A lack of awareness of occupational diseases and substandard operations in these firms pose a grave threat to employees' health, he said.

    Keeping tabs on the country's nearly 200 million migrant rural workers -- who are often engaged in risky jobs and move from one place to another -- is currently mission impossible, he added.