Expert is worried about record levels of particulates found in some HK areas The deterioration of air quality is not likely to level off soon, after the highest level of particulates was recorded in some districts last year, according to a leading scientist on air pollution. Data obtained from the Environmental Protection Department shows the annual average level of respirable suspended particulates (RSP) in Central and Western, Tung Chung and Yuen Long last year were the highest since 1996. These stations are on the western side of the city, which experts say is more prone to the impact of pollution from the mainland. The disclosure came after the Hong Kong Observatory reported the worst visibility on record in 2004, after an increase in suspended particulates in the air. In Yuen Long, the average RSP level hit 71 micrograms per cubic metre of air, up 16 per cent from the previous year. Tung Chung also recorded a 14 per cent increase to 62 micrograms, the worst since monitoring started in 1999. Central and Western also saw the level hitting 59 micrograms. All of these readings breached the annual air quality objective of 55 micrograms. The EPD has yet to compile the monthly and annual average for the remaining 11 monitoring stations. RSPs, or pollutants with a size smaller than 10 microns, are health hazards, potentially leading to respiratory or lung diseases. Most of these particulates are generated from the combustion processes of power plants, vehicles, factories, and open burning in the region. Apart from the annual performance, the monthly average data also revealed a disturbing trend of air quality deterioration during the months from June to October, when sea breezes should have brought in fresh air. For instance, the Tung Chung reading jumped from 17 micrograms in June 2002 to 35 in 2003, and 45 micrograms in 2004. The last two months, however, showed some relief with the average monthly figures generally lower than in 2003, though they were still significantly higher than 2002. Alexis Lau Kai-hon, acting director of the Centre for Coastal and Atmospheric Research, said: 'There is no evidence to suggest the deterioration has levelled off. Instead, we have seen continuing bad air quality in early January.' EPD data showed that RSP readings in Tung Chung and Yuen Long hit a very high level of over 260 micrograms for some hours between January 3 and 5. Professor Lau believes the deterioration was caused by increasing emissions in the region while rapid urbanisation in the delta region helped trap the pollutants, preventing dispersion. Raymond Leung Pak-ming, EPD principal environmental protection officer, said that it was still too early to predict the air quality, as the data could vary from year to year.