It says something about Hong Kong's pollution that many people have greeted the city's new Air Quality Health Index (AQHI) and bad-air smartphone alert app launched on Monday with a shrug of the shoulders. A typical reaction was that the air was always bad and the new index would not improve it. The first results tended to support the first part. After officials predicted "moderate to very high" health risk, official readings under the new system at three roadside monitoring stations at Causeway Bay, Central and Mong Kok hit 10 by 6pm. This meant the health risk was "very high", with the level of suspended particles harmful to health more than double the highest the World Health Organisation considers safe. Officials attributed the higher readings to bad roadside air quality mixed with secondary background pollution from the Pearl River Delta. On the other hand, a trial run of the new system at nine general monitoring systems showed that three "highs" under the old system had become "moderate" under the new one.
However, Friends of the Earth agreed that the new index reflected the public health risk more accurately, although it failed to stipulate that the government take counter measures against severe pollution, such as restricting traffic in the streets. Whereas the old Air Quality Index, in use since 1995, simply reflected the intensity of air pollution, the AQHI reflects the health risk in five categories from low to serious.
Anything that increases transparency about air quality and results in a better informed public will help bring a greater sense of urgency over clean-fuel measures for shipping and diesel vehicles, low-emission zones for buses and strengthened emission controls for petrol and LPG vehicles, all revealed in a government plan last April. As suggested at the time by environment undersecretary Christine Loh Kung-wai, it should also prompt consideration of more pedestrian-only areas or traffic diversions to tackle nitrogen dioxide pollution. Ultimately, pressure will grow for consensus about electronic road pricing, which has proved effective in easing congestion and reducing emissions elsewhere.