Nearly one out of three people in Beijing belongs to the mobile population, according to the capital's population and family planning commission.

The municipality's mobile population reached 5.4 million in October, accounting for nearly 30 percent of the total, the commission's deputy director Li Yunli said.

More than 80 percent of the capital's mobile population belongs to the China-unique category of rural migrant workers, Li told a conference on population in Beijing on Monday. The remainder is mostly made up of people visiting for less than a month.

She added that migrant workers would comprise the vast majority of both the capital's and the nation's mobile population for a long time to come. Currently, the national mobile population stands at 150 million.

The most recent influx of migrant workers boosted the capital's population to about 17.4 million by October, signaling Beijing's population would likely exceed its threshold of 18 million earlier than previous forecasts, Li said.

The total population would continue to grow in Beijing over the next five or 10 years, Li said, and "that would further strain scarce resources, including land, water and energy".

Previous research has suggested that accommodating more than 14 million residents would exceed Beijing's food- and water-supply capacities.

More than 130,000 people were born in Beijing in 2007 as of October, and more than one-third of them were born to migrant families, Li said. And according to her, there would be even more births next year.

This year, most of the capital's unplanned births were to migrant families, Li said.

"Family planning among migrant workers is crucial to China's overall family planning, and the construction of a new socialist countryside and a harmonious society," deputy director of the State Population and Family Planning Commission Wang Guoqing was quoted as saying by Xinhua news agency earlier.

In addition, most of the migrant workers in Beijing work labor-intensive jobs in fields such as manufacturing, home furnishing, catering, cleaning and domestic services.

Most migrant workers received little education, with 60 percent of them dropping out after junior middle school mainly because of financial problems, Li explained.

More than half of them earn less than 1,200 yuan ($160) per month and live in poorly equipped rental rooms, Li added.

Researcher with China Foundation for International and Strategic Studies Qin Xiaoying said that if migrant workers remain economically and socially marginalized, mental anguish could flourish among the demographic and threaten social stability.

The commission urged governments at all levels to improve public services for the migrant population, protect their legal rights and interests, and reduce discrimination against them.

(China Daily December 5, 2007)