Let us begin with the cause of the problems, which includes three main aspects: vehicle emissions, unplanned use of land, and cross-border pollution.
The first aspect concerns the vehicle emissions. With the increasing number of private cars, and the slow introduction of environmentally friendly fuels, the amount of air pollutants released by vehicles keeps increasing, thereby tarnishing the air quality.
Secondly, the unplanned use of land can also account for the problems. Due to the limited land supplied, Hong Kong tends to be densely populated while the buildings are usually designed to be as tall as possible. All the buildings therefore form a physical barrier to block the ventilation of air. Consequently, pollutants like suspended particles are trapped in air, causing the air to be polluted.
Cross-border pollution is the third aspect. There are currently numerous factories built in Mainland in Guangdong Province. The industrial air pollutants can be carried to Hong Kong by winds. Especially in winter, when much pollution is brought by the northern monsoon, the air quality is exceptionally terrible.
To tackle the problem, we should focus on the causes and design solutions accordingly.
To deal with the first cause, which is related to traffic, the amount of vehicle emissions should be controlled properly. Actually, this has been implemented before, for example,