China, dubbed as the `World`s Factory`, discharged 25.49 million tonnes of sulphur dioxide in 2005, ranking number one in the world, the country`s national environmental watchdog said here on Thursday.

The amount of sulphur dioxide released last year was 27 per cent over that in 2000, the State Environmental Protection Administration (SEPA), said.

Out of the 25.49 million tonnes, 21.684 million tonnes was industrial discharge and 3.89 million tonnes was living discharge.

SEPA quoted a researcher as saying that each tonne of the discharge may cause 20,000 Yuan (about 2,500 U.S. dollars) of economic losses.

Calculating on that basis, china may have suffered a total of 509.8 billion Yuan (63.625 billion U.S. Dollars) the whole year of 2005.

The watchdog said China`s coal consumption increased more than 800 million tonnes in the 2001-2005 period, among which 500 million were used by the power industry which is under pressure to boost output to cater to the growing demand for electricity.

Meanwhile, air pollution, especially acid rain, posed great challenge to china’s goal of building a well-off society, SEPA officials said.

The degree of acid rain contamination had climbed up in 2005 and a SEPA study finds 357, or 51.3 per cent, of all the 696 cities and counties that carried out acid rain monitoring across the country had experienced the acid rain.