ENG-1998 — Page 461

THE ENVIRONMENT

were 102 micrograms per cubic metre of total suspended particulates (dust) and 63 micrograms per cubic metre of respirable suspended particulates (fine dust and smoke). The concentrations of nitrogen dioxide measured at roadsides also exceeded the objective for a few days in the year.

Hong Kong's objectives for air quality are comparable with standards adopted in developed countries. The Environmental Protection Department (EPD) completed a review of these objectives in 1998, and will make its recommendations in 1999. News media reports during the year concerning Hong Kong's air quality were notable for error and overstatement. To keep matters in perspective, Hong Kong has less than a quarter the level of respirable particulates found in Mexico City and lower than the levels in Philadelphia and Barcelona. Carbon monoxide levels are about one-tenth that found in Mexico City, nitrogen dioxide a quarter, sulphur dioxide just over a quarter and ozone less than half. Ozone levels are better than those found in Chicago, Philadelphia, Geneva, Paris, Atlanta, Houston and Los Angeles; sulphur dioxide. levels are better than in Tokyo, Washington DC, Singapore and New York. Nitrogen dioxide levels are better than in Boston, London, New York and Rome.

Water pollution has also increased with urban development. The lack of proper treatment for most sewage generated from the urban area around Victoria Harbour has resulted in poor water quality there. The concentration of sewage bacteria (E. coli) in the central harbour in 1998 was about 7 000/100ml, somewhat better than the average concentration in 1997 but still a very high level that poses a potential health hazard to the community.

A new sewerage system and a sewage improvement scheme are making progress in tackling the problem. More progress has been made at bathing beaches, where small, private sewage-treatment facilities are often the dominant source of pollution. A combination of effective control and the provision of new sewerage has reversed a recent declining trend in the water quality at beaches.

The Environment of Rural Areas and New Towns

Some waterways in the New Territories are still severely polluted. A few rivers in the Deep Bay area remain little better than open sewers. They lack normal aquatic life and their pollution can be harmful to people coming into direct contact with them. Such rivers are a serious public health hazard where they pass through villages and new towns. However, pollution control is now having a positive effect, and river quality is slowly improving. The percentage of rivers in the 'good' and 'excellent' categories increased from 27 per cent in 1986 to 70 per cent in 1998, and the percentage in the 'bad' and 'very bad' categories fell from 52 per cent in 1986 to 17 per cent in 1998.

Bathing beaches are an important recreational resource. To safeguard the public against swimming in polluted waters, the government has adopted strict standards for water quality control in bathing beaches. These standards relate to pollution measured as E. coli (bacteria that can indicate the presence of sewage) and were devised after a very thorough study of the health risk facing local bathers. The following table shows how beaches were classified in 1997 and 1998. Beaches in the 'good' and 'fair' categories meet the government's water quality objective for bathing.

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