The Government's advice after yesterday's record pollution index reading of 167 in Causeway Bay was misleading. It said pollution at that level would have 'little effect on a healthy person', but that people with existing heart or respiratory illnesses should stay away or minimise physical exercise. That is only half the story. It must be clear to even the most smog-fuddled brain that pollution serious enough to affect the weak immediately will affect the healthy more slowly, unless they also limit their exposure. Pollution can no longer be dismissed as someone else's problem. It affects the economy, through working days lost and medical and hospital charges. It makes the most important tourist and commercial centres less attractive to visitors. And it makes Hong Kong a less pleasant place to live and work. No society has achieved a pollution-free environment, but many have worked harder at improving air quality. The Government could head off political confrontation over the switch to cleaner, but more expensive, fuels by increasing the differentials in duty between diesel, petrol and LPG. It must slash fees and taxes on LPG vehicles. The Citizens Party's call for pedestrianisation of busy shopping districts should be taken seriously. Electronic road pricing should be introduced as a matter of urgency. Cross-border co-ordination on air and sea pollution must be accelerated and intensified. Above all, businesses in Guangdong must be brought on board. Dirty air is as much a problem for them as it is for the rest of the population. Pollution does not respect borders. Hong Kong companies which pollute in southern China are rubbishing their home as effectively as if they were polluting in Sha Tin. That is a lesson they have to learn.