While many are panicking over the risk of radioactivity from Japan's crippled Fukushima nuclear power station spreading to China, mainland experts have warned that at least 2,000 missing civilian radioactive sources pose a more direct threat to public health.
The civilian radioactive sources - for a wide range of industrial and medical uses - required careful tracking, but some went missing because of lax management.
'No Chinese people have died in nuclear military or nuclear power plant accidents from 1954 to 2007, but in sectors applying civilian nuclear and radiation technologies, 10 were killed, 49 fell ill and 16 were burned in the same period,' Pan Ziqiang, from China National Nuclear Corp, told the Southern Weekly.
Between 1988 to 1998, more than 1,000 people were irradiated in 300-odd radioactive accidents, with at least 30 cases every year, the weekly cited Fan Shengan , a radiological expert from the Health Ministry, as saying. It said the accident rate in China was 40 times that in the United States in the 1990s.
Radioactive sources are used throughout the world for a variety of peaceful and productive purposes in industry, medicine, research and education, and in the military.
For example, cobalt-60, one of the sources, is used medically for radiation therapy as implants and as an external source of radiation exposure. It is used industrially in levelling gauges and to X-ray welding seams and other structural elements to detect flaws. It is also used for food irradiation, a sterilisation process.
In 2004, the State Environmental Protection Administration teamed up with the Healthy Ministry and the Ministry of Public Security to carry out a nationwide survey that found more than 140,000 radioactive sources had been in the possession of at least 10,000 civilian enterprises across the country, with 70,000 in use but more than 2,000 missing.
A 'regulation on prevention and protection against radiation from radio isotopes and radioactive devices' enacted in 2005 said all radioactive source owners should pay storage costs for all expired sources.
'[But] China failed to set up a comprehensive legal system to monitor the whole process of application of both nuclear technology and radioactive sources,' said Professor Wang Canfa, an environmental expert at the China University of Political Science and Law in Beijing. 'Our regulations were just based on environmental protection. They're not as serious as [those under Japanese and US law].'