High levels of air pollution persist in Hong Kong

25 November 1998

The air pollution has reached alarmingly high levels in Hong Kong. According to press reports, the Hong Kong lawmakers voted overwhelmingly to prod their government to accelerate plans to clean up the territory's polluted air. The proposed measures would include offering incentives to operators of diesel-powered taxis to switch to liquefied petroleum gas (LPG), planting more trees, studying the use of cleaner fuels, reduction of cross-border pollution, increased vehicle inspections, increased fines on smoky vehicles and ban on leaded gasoline sales in 1999.

Hong Kong has been experiencing months of persistently high levels of air pollution recorded in its urban areas. The air pollution index (API) hit 167 on September 21, the highest recorded this year, and has since frequently hovered around 100.

The API figures are calculated by comparing the concentrations of 5 air pollutants, including nitrogen dioxide, sulfur dioxide, ozone, carbon monoxide, and respirable suspended particulates with respective Hong Kong Air Quality Objectives (AQO). The API can range from 0 to 500. The API is divided into five categories: low (0 to 25), medium (26 to 50), high (51 to 100), very high (101 to 200) and severe (201 to 500).

The Hong Kong government, which ignored the problem for years while under British colonial rule, recently blamed it on diesel-powered vehicles. The government has proposed to replace diesel- with LPG-powered taxis by 2005, and make LPG gas usage mandatory for all new taxis from 2001 onwards.

Hong Kong air quality data indicates that while the levels of sulfur dioxide, nitrogen dioxide, carbon monoxide and ozone are comparable to those in London, New York, Boston and many other cities, the level of particulates is higher than elsewhere.

On several occasions people in Hong Kong took to the streets to express their discontent. Earlier this week, dozens of school children, wearing masks and armed with a petition of 30,000 signatures, marched to government headquarters in Central district to urge the government into action.

Source: Hong Kong API