Lai See | How much longer for action on roadside pollution?

The Environmental Protection Department issued a statement yesterday morning pointing out that its air pollution indices at roadside air quality monitoring stations reached a "very high" level. However, turning to the Hedley Environmental Index (HEI), we see that it described air pollution over Hong Kong more graphically as being "very dangerous".

The HEI is linked to World Health Organisation (WHO) guidelines which indicate the levels beyond which air pollution begins to affect health.

In Causeway Bay, the hourly concentration of nitrogen dioxide at 5pm was 259ìg/m3 (micrograms per cubic metre), compared with the WHO guideline average level for a 24-hour period of 140ìg/m3 - i.e. 85 per cent over the WHO limit. At the roadside in Central, the nitrogen dioxide level was 338ìg/m3. The PM10 respirable particles were 99ìg/m3 and 105ìg/m3 at Causeway Bay and Central respectively, compared with the WHO short-term guide of 50ìg/m3.

Levels of the much more dangerous PM2.5 particles, which can enter the lungs, were also dangerously high at 65ìg/m3 and 61ìg/m3 in Causeway Bay and Central, compared with the WHO guideline of 25ìg/m3. These figures are way above WHO guideline levels.

We are told weather conditions have exacerbated the high levels of pollution. But the street level pollution is produced locally. The absence of strong winds with the canyon effect created by skyscrapers means that the pollution is not being dispersed. This is not a new problem. A year ago we were promised action on this problem by taking old diesel-engined vehicles off the streets. We're still waiting. Meanwhile, thousands of unnecessary deaths are occurring every year due to our dirty air. Surely this is one area where the government can take resolute action without fearing street protests. `