China’s industrial heartland of Guangdong, which borders Hong Kong, recorded an average of 75.7 days of haze in 2007, the highest level since the Communists came to power in 1949 and a ‘marked increase’ over normal years, according to a new report released by Guangdong’s meteorological bureau, Xinhua said.

The report found the industrial heartland of the Pearl River Delta, whose factories have powered China’s export growth, fared the worst.

Provincial blackspots included Enping with 240 hazy days, Dongguan with 213 and Xinhui City with 238, Xinhua added.

‘It may take at least 20 or 30 years to bring the haze under control. Cities in the delta region should join in fighting air pollution instead of acting by themselves,’ Wu Dui, an atmospheric studies expert from the Guangdong Provincial Meteorological Bureau, was quoted by Xinhua as saying.

Neighbouring Hong Kong has also grappled with chronic air pollution, partly from industrial smog blown in from Guangdong, but also from coal-fired power stations.

The city’s picturesque harbour is now regularly shrouded in a thick smog, particularly during the winter months.

The Environmental Protection Department found that for the last quarter in 2007, roadside air monitoring stations recorded ‘high’ air pollution index readings 85 per cent of the time, and ‘very high’ readings 11 per cent of the time.

Hong Kong and Guangdong have committed to ambitious air-quality reduction targets by 2010, including cutting sulphur dioxide and suspended particulate emissions by upwards of 50 per cent compared with 1997 levels.

But green groups and scientists have expressed scepticism the targets will be met.