DEAD SEA, Jordan - The International Olympic Committee (IOC) president Jacques Rogge on Saturday said that China is making big strides in clearing up its air quality ahead of the 2008 Olympics.

During the opening ceremony of the 4th World Conference on Women and Sports, which was opened in the sort of Dead Sea, Jordan, Rogge told some reporters that "we will see that Beijing has made major progress."

China has taken some measures, including switching from coal to gas energy, closing 10 percent of its gas stations, and planting millions of trees to improve its air quality, said Rogge.

He also said he was pleased that more female athletes than ever, about 45 percent of the 10,500 participants, will compete in the Beijing Games.

On Friday, Beijing launched its first census of pollution sources for accurate statistics, amid a green drive to improve environment ahead of the Olympics.

The survey will cover 90,000 sources of pollution, among which 24,000 are industrial sources, 45,000 residential, 21,000 agricultural and 128 facilities for centralized treatment of pollutants, according to the city's bureau of environmental protection.

Beijing authorities said last month that major pollutants in Beijing were down and air quality in the city had improved for a ninth consecutive year, but experts warned that the government should prepare for a long and tough fight against air pollution, citing inhalable particles and ozone as major obstacles for Beijing to achieve its "Green Olympics" goal.

China started its first national census of pollution sources in February, focusing on industrial sources including metallurgy, chemistry, construction materials, power plants, paper-making, pharmaceuticals and mining.

The central government planned to finish data collection and analysis this year and approve the findings in the first half of 2009.