The proposed HKSAR AQO are not fit for health protection
The government’s repeated emphases on benchmarking the WHO Air Quality Guideline (AQG) is misleading because, except for the annual AQG for NO2, none of them are directly derived from WHO. According to the WHO, all short-term AQG for gaseous pollutants (NO2, SO2, O3) should not be exceeded once in a year and the AQG for particulate matter (PM10 and PM2.5) should not be exceeded on more than three days a year. The government’s proposed Hong Kong Air Quality Objectives (HKAQO) with adoption of "interim targets" or any limit values higher than the full WHO guideline values, or additional lax arbitrary modifications of allowable exceedances, will only create pseudo air quality limits that will never protect our heart, lungs and other body systems. Most importantly lax air quality controls will compromise child health with life time consequences for those affected.
The government’s repeated emphases on benchmarking the WHO Air Quality Guideline (AQG) is misleading because, except for the annual AQG for NO2, none of them are directly derived from WHO. According to the WHO, all short-term AQG for gaseous pollutants (NO2, SO2, O3) should not be exceeded once in a year and the AQG for particulate matter (PM10 and PM2.5) should not be exceeded on more than three days a year. The government’s proposed Hong Kong Air Quality Objectives (HKAQO) with adoption of "interim targets" or any limit values higher than the full WHO guideline values, or additional lax arbitrary modifications of allowable exceedances, will only create pseudo air quality limits that will never protect our heart, lungs and other body systems. Most importantly lax air quality controls will compromise child health with life time consequences for those affected.
We have demonstrated, in a recent analysis and publication, that two proposed HKAQO (PM2.5 and SO2) are either even worse than the most permissive WHO limits (only intended as entry level targets for poor low technology developing countries) or even poorer than the air quality in Hong Kong in 2010. In other words there is little or no scope for improvement through compliance with the new objectives. (www.hku.hk/press/news_detail_6375.html).
We can also show that the WHOAQG for NO2 is very unlikely to be achievable in Hong Kong because the government proposes to permit an increased number of exceedances of the 1 hour limit, leading to discordance between the short- and long-term limits (Lai et al 2010). These contrived new limits are not evidence based and will not work to improve air quality in Hong Kong's highly polluted environment. The HKSAR government should also learn critically from overseas experience and avoid attempts to reinvent invalid decision rules (the new AQO), which are only intended to accomodate (that is legitimate) Hong Kong's high pollution in terms of the air pollution control ordinance.
Edited by AJH
Reference:
Reference:
Lai HK, Wong CM, McGhee SM, Hedley AJ. Assessment of the health impacts and economic burden arising from proposed new air quality objectives in a high pollution environment. Open Epidemiology. 2011;4:106-122. http://www.benthamscience.com/open/toepij/articles/V004/SI0001TOEPIJ/106TOEPIJ.pdf
