China's health authorities are to launch this year the third nationwide survey on causes of death, a health official announced Monday.

Patterns of illness and death had changed over recent decades due to improved living and health conditions, so updated information was needed to optimize disease control plans and allocation of health resources, said Ministry of Health spokesman Mao Qun'an.

The survey, focusing on cancer and jointly launched by the Ministry of Health and Ministry of Science and Technology, would cover more than 100 million people, nearly 10 percent of the population.

It is expected to identify cancer death rates in various regions since 2000, as well as the geographical spread of major cancers, said Mao.

The findings would be used as a reference in the formation of the country's cancer control guidelines, and as a basis for establishing a cancer registration system and a study of key illnesses and related risk factors.

Two previous surveys on causes of death, in the 1970s and 1990s, showed rapid increases in cancer deaths in the urban and rural regions. Cancer has become the top killer of the Chinese people.

In the 1970s, cancer killed 700,000 Chinese every year, about 0.074 percent of the total population. In the 1990s, 1.17 million died of cancer annually, accounting for 0.094 percent of the population. At the beginning of this century, 1.5 million Chinese died of cancer every year, 0.115 percent of the population.

Health officials have warned that the toll might double in the next 20 years if no effective measures were taken.

(Xinhua News Agency June 13, 2006)