Cheung Chi-fai, SCMP – Apr 23, 2009
Environmental officials have claimed “huge” success in efforts to improve air quality in the Pearl River Delta, although they admit plummeting industrial production could have had something to do with it.
They say that after completion of major sulfur-reduction projects in Guangdong and a switch to cleaner industrial and vehicle fuel, concentrations of sulfur dioxide in the air fell by a third in the six months to March compared with a year earlier.
The drop was in line with a general improvement in air quality in the region as reported in the latest regional air quality monitoring results for last year, released yesterday.
A Hong Kong environmental official said factory closures could have been a factor and monitoring over a longer period was needed to be sure. “But so far we do not believe the financial tsunami alone could have brought such huge progress.”
The results showed that the annual average concentration for sulfur dioxide, a major pollutant from fuel combustion, dropped by 19 per cent compared with 2007, while the particulate matter level fell 11 per cent.
The levels of two other pollutants, nitrogen dioxide and ozone, however, remained largely the same as in the previous year.
It was the third report on the region’s air quality since a cross-border monitoring network, with 16 stations in Guangdong and Hong Kong, came into operation in late 2005. The network provides the regional air quality monitoring index daily on the websites of the Environmental Protection Department and Guangdong Environmental Protection Bureau.
The report showed that the proportion of days with the worst air quality dropped from 10.5 per cent in 2007 to 7.5 per cent last year, while good air quality days increased to 71 per cent, from 66 per cent in 2007.
Pollution also reduced significantly in individual areas, particularly in the black-spot cities of Foshan and Zhaoqing .
Despite the improvement, a Hong Kong environmental official was cautious about saying last year represented a watershed in the battle to reverse the trend of worsening air quality in the delta. “We need more monitoring data, say, for five years, to ascertain that,” he said.
The official attributed the change to the completion of desulfurisation projects at major power plants in Guangdong. Coal-fired plants with a total capacity of 26,000MW were fitted with sulfur scrubbers last year, more than double the capacity in late 2007. Smaller polluting generation units with a total capacity of 3,600MW have been closed down.
The official said upgrading vehicle fuel with less sulfur in Guangdong and using ultra-low-sulfur fuel for industries in Hong Kong also added to the progress. Sulfur dioxide and particulate levels in Hong Kong fell by 7 and 5 per cent last year, though the ozone level rose by 5 per cent, he said.
The sky has also cleared somewhat, with the number of hours with poor visibility falling to 1,100 last year, from nearly 1,300 hours in 2007, the Observatory has reported.