Because of the Beijing Olympic Games, 72-year-old Guo Suying no longer has to deal with the irritating gasoline odor from a nearby filling station.

"This summer, we can open the window at any time without worrying the house would be filled with the smell," the Haidian district resident said.

The change was part of a large-scale Olympic campaign to curb emissions at gas stations across the capital to improve air quality.

Over the past 13 months, the campaign has extended to the city's 1,265 gas stations, 38 oil storehouses and 1,026 oil tank trucks, Beijing environmental protection bureau official Li Kunsheng said.

But it was only part of Beijing's broader push to fulfil the commitments it made seven years ago when it won the bid to host the 2008 Summer Olympics.

Beijing Shougang Group, one of China's leading steelmakers and a major polluter in the capital, has extinguished the fires in three of its four blast furnaces.

They have slashed monthly production to 200,000 tons in the third quarter, or 29 percent of its normal output, group President Zhu Jimin said.

Air quality has been a major concern surrounding the Games.

Over the past decade, the municipal government has made pollution reduction a priority and has invested about 120 billion yuan ($17 billion) to this end.

Much improvement has been achieved through the closure and relocation of small, polluting factories, the substitution of coal with electricity in residential heating systems and a tightening of vehicle exhaust standards.

Consequently, the number of "blue sky" days - an indicator of air quality - in the city increased to 246 last year from 100 in 1998.

In the push to realize the "Green Olympics", the government increased the amount of afforested land in the capital by 10,000 hectares from 2001 to 2007, Wang Sumei, a municipal official, said.

Du Shaozhong, Beijing environmental protection bureau's deputy director, said that to ensure good air quality, neighboring regions, such as Tianjin municipality and Hebei province, will control dust, vehicle exhaust and industrial pollution before and during the Games.