Following is a question by the Hon Fred Li and a written reply by the Secretary for the Environment, Transport and Works, Dr Sarah Liao, at the Legislative Council meeting today (February 4) :
Question:
It has been reported that according to the records of the Environmental Protection Department's general station in Kwun Tong, the air pollution level in the district was "very high" for a total of 18 hours in 2001, and the respective figures for 2002 and 2003 were 64 and 136 hours, which shows that air pollution in the district has been worsening; and based on the total number of hours per annum for which the air pollution level was "very high", the air pollution level in Kwun Tong was the most serious among all districts in the territory in 2003. In this connection, will the Government inform this Council:
(a) of the hours of the day, weather and environmental conditions in which the air pollution in Kwun Tong was often more serious;
(b) as quite a number of industrial buildings in the district have been converted to non-industrial uses in recent years, whether it has studied why air pollution in the district has worsened instead; if it has, of the study results; and
(c) whether it has established a long-term strategy to reduce air pollution in the district; if it has, of the details of the strategy; if not, the reasons for that?
Reply:
Madam President,
(a) Air pollution is a complex phenomenon. The concentration of air pollutants at a particular place and at a particular time in Hong Kong is affected by many factors. These include emissions from sources at that particular place, other areas in Hong Kong and the Mainland part of the Pearl River Delta (PRD) Region. Moreover, the density of urban development, topography and meteorology can all affect the movement and dispersion of air pollutants, and hence their concentration.
Generally speaking, taking aside meteorological factors, the situation in Kwun Tong District is similar to that in most other urban areas in Hong Kong in that it is exposed to a higher level of air pollution during daytime (especially in the early morning and the evening rush hours) when there are more traffic and commercial and industrial activities. As mentioned in the foregoing paragraph, meteorological conditions can have a significant impact on the concentration of pollutants. For instance, hot weather and rising air can help dispersion of air pollutants; rainfall can wash out certain pollutants in the air; an occasional phenomenon known as temperature inversion can trap air pollutants in the lower atmosphere; and still wind conditions can inhibit effective dispersion of air pollutants. Moreover, when a weak northerly wind prevails in Southern China, the impact of regional air pollution on Hong Kong will become more serious.
(b) & (c) The station in Kwun Tong is a general air quality monitoring station. The data collected at the station in 2003 show an upward trend of air pollutant concentrations similar to that recorded at the general air quality monitoring station in Kwai Chung, a district with land use (an urban area with mixed residential, commercial and industrial developments) similar to that in Kwun Tong. Therefore, the upward trend of ambient air pollution is not a localised phenomenon peculiar to a particular district.
In fact, the total number of hours of "Very High" air pollution level recorded at the roadside air quality monitoring stations has dropped by 35% compared with 1999. However, the same for the general air quality monitoring stations has increased by 8%. This demonstrates that on the whole, while the roadside air quality in Hong Kong has improved since the implementation of the measures to reduce motor vehicle emissions in 1999, the regional air pollution problem has remained serious and occasionally affects Hong Kong's local air quality.
To arrest the deterioration of air quality in the PRD Region, the Hong Kong SAR Government and the Guangdong Provincial Government reached a consensus in April 2002 to reduce, on a best endeavour basis, by 2010 the regional emissions of sulphur dioxide (SO2), nitrogen oxides (NOx), respirable suspended particulates (RSP) and volatile organic compounds (VOCs) by 40%, 20%, 55% and 55% respectively, using 1997 as the base year. Achieving the targets will enable Hong Kong to meet its current air quality objectives and also significantly improve the air quality in the whole of the PRD Region.
To work out air pollution control measures and monitor the progress of their implementation, the two Governments have set up a "Pearl River Delta Air Quality Management and Monitoring Special Panel" under the Hong Kong/Guangdong Joint Working Group on Sustainable Development and Environmental Protection. The Special Panel is responsible for working out a regional air quality management plan for achieving the emission reduction targets.
The regional air quality management plan has now been drawn up. The details of the enhanced pollution control measures to be implemented in Hong Kong and Guangdong are set out at the Annex.
Ends/Wednesday, February 4, 2004
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