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The Environmental Protection Department (EPD) of the Government of the Hong Kong Special Administrative Region and the Department of Environmental Protection of Guangdong Province (GDEPD) today (April 29) announced the report on the monitoring results of four major air pollutants (sulphur dioxide, nitrogen dioxide, ozone, and respirable suspended particulates) measured by the Pearl River Delta Regional Air Quality Monitoring Network for 2009. The report, which covers the air quality conditions in the Pearl River Delta (PRD) Region (including the HKSAR and PRD Economic Zone) for the full year of 2009, is available at both the GDEPD's website (www.gdepb.gov.cn) and the EPD's website (www.epd.gov.hk).
In general, the overall concentrations of most pollutants were lower in the summer months (e.g. June to August), while higher concentration levels were recorded in the winter months (e.g. January to March and October to December). Apart from heavier rainfall and higher mixing layer, the relatively clean maritime air stream that prevailed in the PRD region under the influence of the southern monsoon also accounts for a lower level of pollution in summer. Geographically, air quality in the coastal areas was better compared with that in the north-west areas of the region, probably as a result of relatively more favourable conditions for dispersion of pollutants in the former.
Since the operation of the Network, the average annual concentration of sulphur dioxide, nitrogen dioxide and respirable suspended particulates in the PRD region has decreased by 38%, 9% and 7% respectively in 2009 compared to the 2006 levels. Moreover, the concentration levels of sulphur dioxide and nitrogen dioxide decreased by 26% and 7% respectively in 2009 compared to the 2008 levels amid continuing growth of the economy in the region in 2009. These reductions are attributable to implementation of enhanced emission reduction measures by both sides. As for ozone, its concentration level increased by 10% compared to the 2008 level. Ozone formation is dependent on photochemical activities. The higher concentration level in 2009 is probably caused by stronger photochemical activities in 2009 as a result of stronger solar radiation and less rainfall.
Overall, 75% of the Regional Air Quality Index as recorded by the Network in 2009 were within Grade II, meaning the pollutant concentrations were within Class 2 National Ambient Air Quality Standards (NAAQS - applicable to general residential areas). Intermittent high levels of pollutants exceeding Class 2 NAAQS was recorded in all monitoring locations of the Network in the reporting period, which could have been triggered by meteorological conditions unfavourable to pollutant dispersion.
The Network is one of the major achievements of co-operation between the two sides in environmental protection. It comprises 16 automatic ambient monitoring stations scattered over the region, 13 of which are in the PRD Economic Zone, i.e. Guangzhou, Shenzhen, Zhuhai, Foshan, Zhongshan, Huizhou, Dongguan, Jiangmen, Zhaoqing, Shunde, Huiyang, Panyu and Conghua, and three are in Tsuen Wan, Tung Chung and Tap Mun in Hong Kong. The Guangdong Provincial Environmental Monitoring Centre and the EPD are responsible for the co-ordination, management and operation of the monitoring stations of each side.
During the reporting period, the Network operated smoothly in accordance with the Quality Assurance/Quality Control (QA/QC) operating procedures, which ensure that air quality data from the monitoring stations are of a high degree of precision and accuracy.
The environmental monitoring authorities of the two sides will continue to monitor regional air quality and regularly announce the latest monitoring results. The monitoring results for the first half of 2010 are expected to be available in October 2010.
Ends/Thursday, April 29, 2010
Issued at HKT 15:34
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