IT does not take a genius to realise that pollution is worse at street level than four storeys up. To test this commonsense hypothesis just try breathing the air as you walk through Causeway Bay, for instance, and try again from a fourth floor window. Let your nose do the rest. Empirical evidence abounds.
Yet, until last week, the Environmental Protection Department seemed to treat this obvious fact as conjecture. Monitoring was conducted well above the street, on the spurious grounds that most people spent far more time in flats and offices than pounding the pavements. That would hardly fit the daily routine of ground-level shop-staff, professional drivers or even street-sleepers. Such judgments are based on official notions of average behaviour, not on real people.
The installation of monitoring systems which measured only 'ambient' pollution levels far above the ground, sparked a public outcry - including a campaign by the South China Morning Post. Yet it took until last year for the EPD to admit that street-level pollution was more serious than ambient pollution. Even then, officials continued to claim the difference would be about 20 per cent.
Now that equipment has finally been installed near the ground in Causeway Bay, Central and Mongkok, those complacent guesstimates appear seriously wide of the mark. Over the past week, the difference has been not 20 per cent but an average of 170 per cent.
It is time the Government woke up to reality. It is accepted that air pollution in Hong Kong causes 2,000 premature deaths a year and an array of chronic respiratory illnesses. Instead of relying on pedestrians to shield themselves with a hand placed across the mouth, the Government must push ahead with a determined programme to clean up the air.
The switch from diesel to petrol and LPG must be given new impetus, whatever the objections of taxi and minibus drivers. Tougher exhaust emission standards must be applied to all vehicles, public and private. Those which do not meet the targets must be taken off the road. Commercial fleets which persistently fail to keep engines tuned to the tightest standards must be subjected to heavier fines.
