BEIJING • China faces difficulties in meeting its smog-fighting target for this year, its environmental protection minister said during a visit to four heavily industrialised provinces in northern China, where the country's air pollution problem is especially acute.

China has pledged to cut average concentrations of hazardous airborne particles known as PM2.5 by more than 15 per cent in 28 northern cities in the coming winter months from a year earlier.

"Currently, the air pollution control work is challenging and complex," Minister of Environmental Protection Li Ganjie said during a tour earlier this week of Hebei, Shanxi, Shandong and Henan provinces, according to a statement posted on the ministry's website on Wednesday.

He said air quality has fluctuated, with some areas seeing a significant slowdown in improvement and even a worsening. "The completion of the annual targets for air quality control faces huge difficulties," he added.

In the capital region, which includes Beijing, the surrounding Hebei province and the port city of Tianjin, air quality worsened in the area's 13 cities during August from a year earlier, with a 5.4 per cent increase in concentrations of PM2.5, according to recent ministry data.

Air quality in China's 338 largest cities on average deteriorated in the first six months of this year, ministry data showed, with 74.1 per cent of all days during the period experiencing clean air, down 2.6 percentage points from a year earlier.

Mr Li urged local governments to step up enforcement of environmental laws and regulations.

China has promised to close twice as many factories and enforce bigger emission cuts in coming months in a bid to avoid a repeat of the near-record levels of choking smog that enveloped key northern regions at the start of the year.

State news agency Xinhua reported earlier that Hebei, home to several of China's most polluted cities, is taking measures to tackle air pollution ahead of the four-month winter heating season that usually starts on Nov 15.

Its rural regions surrounding Beijing were ordered to use electricity and natural gas to replace coal burning, a major cause of smog in winter. By the end of next month, raw coal burning in rural homes will be banned in 18 counties and districts.

In other regions, at least 1.8 million households must also replace traditional coal-fired heating sources.

Hebei province is also improving energy efficiency and replacing coal with clean energy in the industrial sector by ordering heavily polluting industries to restrict production and cut their emissions of industrial pollutants.

REUTERS, XINHUA