Impacts of road traffic on the environment of Hong Kong

Many megacities in the world face similar problems of pollution and traffic congestion which significantly affect the quality of life.; Traffic congestion has always been seriously criticized by the people of Hong Kong. Although the time lost in traffic congestion has not been officially estimated, it is expected to be enormous and people always complain about the poor traffic management and unreliable public transportation.; Too many vehicles bustling on roads is the main cause of traffic congestion in Hong Kong. As emphasized by the Environmental Protection Department, vehicle emission is the main cause of pollution. It causes the air pollution and furthermore acid rain produced may further deteriorate the quality of surface water collected for our public water supply.; In the present work, the air quality in Hong Kong was investigated. Bauhinia blakeana was selected as the biomonitor to monitor the air quality in Hong Kong. The sulphate, potassium, calcium, copper, lead, iron and zinc in the leaf samples were analysed. Good correlation was observed between the ambient concentrations and those in the leaves. Therefore it is possible to estimate the time-averaged pollutants' concentrations in different areas. On the other hand empirical formulae were derived to estimate the pollutants' concentrations along the road, which were only based on the traffic density, distance from the road, background pollutant concentration, the ratio of the number of diesel engines to total number of vehicles, traffic speed and the fuel composition.; Surface water in Hong Kong is scarce. About 70% of raw water for public water supply comes from China. Protecting the surface water from pollution is thus important for conserving our fresh water resources. Pollutants such as sulphur dioxide and lead from vehicles emission may pollute the water collected to the impounding reservoirs. Studies were made including literature survey and analysing the tap waters, and raw water from reservoirs to estimate the extent of pollution to raw water caused by the traffic flow.; People always have the idea that bottled waters, e.g. mineral water, are safer than tap waters. However, manufacturing bottled water usually consume more energy and water resources than equal amount of tap water. The strong preference of drinking bottled water is actually generating stress to our environment. In the present research, tap water samples and mineral water samples were analysed for their inorganic contents. The conclusion was made that the quality of mineral waters were not found to be better than those of tap waters.; Information about other impacts of traffic congestion, such as noise, solid waste and economic loss were also collected and briefly discussed. The impacts estimated suggest that urgent remedial actions are needed to alleviate the problem.; As road traffic in Hong Kong is a major cause of pollution and traffic congestion, solutions to solve this problem were suggested with reference to the experience from Singapore. “Users and polluters pay principle”, change in management hierarchy and improvement in public transport facilities were proposed to mitigate the pollution from vehicles.