Christine Loh, SCMP

There’s no avoiding the fact that roadside air pollution is so high it’s a major threat to our health

Can there really be any doubt that street-level pollution in Hong Kong comes almost wholly from the vehicles on our roads? It’s definitely not from across the border. But it is frighteningly high, and presents a major threat to public health. Roadside air monitoring stations showed that levels so far this year are much worse than they were in the same period in 2005.

The South China Morning Post (SEHK: 0583, announcements, news) reported on Wednesday that the stations in Central, Causeway Bay and Mong Kok recorded the equivalent of 44 days – or 1,066 hours – of “very high” pollution levels, using the government’s outmoded Air Pollution Index (API).

To really understand the true costs of air pollution in Hong Kong, we should be looking at the Hedley Environmental Index. This monitors and publishes in real-time the economic costs of Hong Kong’s air pollution in terms of public health impacts and their monetary value.

What most people do not know is that even at “high” or “medium” API levels, the pollution is bad enough to affect our health. That’s because the API is based on a set of outdated air quality objectives. These have not been revised since 1987 – yet health science has advanced a lot since then and much more is now known about the impact pollution has on people. Clearly, then, these objectives cannot protect our health; air quality that meets them just isn’t good enough. Worse, not meeting these objectives presents an enormous health hazard.

Almost on a daily basis, roadside air pollution levels are “medium” to “high”, and quite regularly reach “very high”. We have just three roadside monitoring stations – in Central, Causeway Bay and Mong Kok – so people naturally assume these must be the most polluted areas. This is not necessarily true; we just happen to measure pollution levels there. They were chosen because they are areas with a high density of population and traffic, yet there are other, just as busy, places where the pollution may be even worse. We don’t know, because we are not measuring the levels.

The bottom line is that pollution from vehicles poses a severe health threat to a very large number of citizens. Just how many people? Well, consider all the streets where the “canyon effect” traps pollution between buildings. Now think of all the people who live in low-rise, older buildings or on the lower floors of high-rises, as well as those who attend schools and clinics in some of the most densely populated areas of town. Then there are the people who work in such areas, particularly those in shops and cafes that open onto busy streets. And, let’s not forget drivers, street vendors, street cleaners, postmen and police officers on the beat. The number of people exposed to very high levels of roadside air pollution for a significant time every day must be enormous, perhaps in the millions.

The government’s response is that there have been improvements. Officials say some of the pollutant levels – those for sulphur dioxide, particulates and nitrogen oxides – have been reduced by 20 per cent since 1999. Hong Kong’s leading air-pollution and public-health experts continue to debate with officials about the significance of such claims. Even if we agree there have been “improvements”, they need to be seen in context.

It is undeniable that street-level pollution is extremely high. It was so in 1999; it remains so today. The so-called improvements are insignificant when it comes to our health.

If we use the World Health Organisation’s guidelines as the yardstick – rather than our own lax objectives – our roadside pollution is so bad that we have only one choice: clean it up, to protect public health, and do so quickly. It is the government’s duty.

People want to know what can be done. Here are a few measures to consider:

• The government must adopt a new policy goal to improve air quality to the point where pollution no longer poses a significant health risk. All bureaus and departments must work together on this.
• Our air quality objectives must be revised using the WHO standards, and implementation plans with timelines must accompany interim targets.
• Officials should devise a scheme to switch diesel and petrol vehicles to natural gas and environmentally sustainable biofuels while using electric-powered transport where appropriate.
• Highways and transport officials must not be allowed to dictate – as they do today – road designs without considering environmental and health factors.
• Traffic flows need to be managed more efficiently, using information technology, and the number of vehicles on our roads must be reduced.
• Finally, vehicle tax and licence fees should be set according to the amount of emissions produced.

A new mindset is needed, to put people before cars, and plan the city accordingly. The last thing Hong Kong should do is blame its roadside pollution on someone else.

Christine Loh Kung-wai is chairwoman of the new Clean Air Network (CAN), and CEO of the non-profit think tank Civic Exchange. For the Hedley Environmental Index, see: http://hedleyindex.sph.hku.hk.