Fog shrouds the Temple of Heaven in Beijing, capital of China, July 3, 2014. [Photo: Xinhua/Li Wen]

New stats show PM2.5 levels in the Beijing-Tianjin-Hebei region have dipped by nearly 20-percent so far this year.

Municipal authorities in Beijing suggest one of the main reasons for the sharp decrease in air pollution in the capital so far this year is through the replacement of coal-fired power plants with gas-powered facilities.

Coal consumption in the region has been cut by some 4.6-million tonnes through the first quarter.

This has cut sulphur dioxide levels by well-over 40-percent compared with the same period last year.

Li Xiang with the Beijing Environment Bureau says other steps are also being taken to try to clean up the air in the region.

"For example, we have scraped nearly 500-thousand old vehicles over the past year and upgraded 6,500 ton-per-hour coal burning boilers. It is the biggest move in the history. The city's concentration level of sulphur dioxide reached a record low, and is now the lowest in northern China."

One of the new gas-fired plants is the Jingxi facility in northwestern Beijing.

Plant manager Zhao Jianbo says his operation is far more efficient than the older power plants now being replaced.

"At the moment, we're a natural-gas powered plant with an installed capacity of 1.3 gigawatts. We have an expanded installed capacity. In terms of clean emissions, as we just said, comparing natural gas plants with coal-powered plants, we are cutting 4.37 million tonnes of coal every year."

So far around 30-percent of Beijing's power is produced from plants like Jingxi.

However, the rest is still generated from power plants outside the city, most of which are still run on coal.

Ahead of the 2008 Olympic Games in Beijing, authorities simply shut down production at high-polluting industrial facilities as a stop-gap measure to ensure a clean-air Olympics.

However, as part of the plans for the 2020 Winter Games, authorities have revealed longer-term plans to try to ensure the air in-and-around the Chinese capital remains clean before, during and after the Olympic flame is put out.