SCMP | Updated on Oct 25, 2008
The announcement by the chief executive that the government will adopt the very lowest tier of the World Health Organisation air quality interim targets, rather than the WHO guidelines, will not help clean up Hong Kong’s air and may even cause further deterioration (“Beginner air quality standards criticised“, October 16).
We should be concerned about this move.
The low tiers of interim targets are there to help poor countries with low levels of expertise move to an entry level for environmental management, not regions with a high gross domestic product and capable of making urgent radical interventions.
The 24-hour target for particulates of 150 micrograms per cubic metre is so permissive it is 15 micrograms per cubic metre above the maximum level observed in 99 per cent of days in 2006. Compliance will not lead to any improvement in the present high average annual levels of pollution.
There is a real risk that retaining a permissive target level will lead to further increases in pollution as has happened with the present inadequate air quality objectives.
Hong Kong’s typical daily levels of pollution, particularly in the cool season, are consistently so high that they always exceed the WHO annual guidelines by several hundred per cent.
These current annual levels of pollution are associated with our very high burden of avoidable illness, premature deaths and community costs due to health care and lost productivity. There will be no reduction of this burden without more stringent regulations.
The 24-hour targets are not intended to be used in the absence of an appropriate annual target which would improve air quality across the year.
The WHO 24-hour guidelines should be applied together with the annual guidelines in order to maximise health benefits and reduce both short-term and longer-term morbidity and mortality. The chief executive’s proposal appears to pre-empt the outcome of the government’s current review of our outdated air quality objectives, but it is clearly not part of a strategy for air quality improvement in the foreseeable future.
Anthony J. Hedley, Wong Chit-ming, school of public health, University of Hong Kong