[Immediate Release]

17th January, 2019

Clean Air Network 2018 Annual Air Quality Review & Response to Air Quality Objectives (AQOs) Review

Sacrificing Public Health and Failing to Achieve 2020 Targets

Clean Air Network 2018 Annual Air Quality Review


  1. The air quality in 2018 resulted in severe health hazard: If the air quality doesn’t get better and we fail to achieve the emission reduction targets in 2020 as set by the Clean Air Plan, there will be 493 premature deaths, 90 thousands upper respiratory tract infection cases, 542 emergency admissions to hospitals, 9 billion HKD direct economic loss, 1 billion HKD medical cost and productivity loss every year in Hong Kong.
  2. Over the past three years (2016-2018), the concentration of PM10 and ozone has increased significantly. The Government refuses to tighten up the Air Quality Objectives (AQOs) for both pollutants since their predicted levels in 2025 will exceed the AQOs if tightened.
  3. The level of PM2.5 has generally decreased (2016-2018), except for roadside monitoring stations. The Government proposes to tighten up the AQO for PM2.5 as its level in 2025 will be expected to comply with the new AQO. However, the no. of exceedance allowed per year for PM2.5 will be greatly relaxed from 9 times currently, to 35 times.
  4. The World Health Organization (WHO) suggests a much stricter guideline regarding the notion of exceedance allowed for air pollutants. The WHO advisory did not make any provision for allowable exceedances for SO2, NO2 and ozone, and allows only 3 exceedances for PM2.5 and PM10 per year. The suggestion to relax allowable exceedances clearly violates WHO’s health-first principle and seems to conflict with Hong Kong Air Pollution Control Ordinance’s (APCO) interpretation on public interest.
  5. The proposed AQOs fail to protect Hongkoners’ health from air pollution. The Government even stated that the health impact assessment in the review serves only as a “reference purpose” and is not used “for prioritizing or justifying the (policy) measures”. The main purpose of AQOs, according to the Government, is to “serve as a benchmark for designated projects under the statutory Environmental Impact Assessment (EIA) process”.
  6. Figures presented to the AQO Review Working Group show that the areas where NO2 levels are predicted to exceed AQOs in 2025, are the same areas where the Government proposes phased reclamation for the Lantau Tomorrow Vision project. It is likely that the Government will issue a waiver for future infrastructure projects, allowing them to adopt the older (hence “more lax”) AQOs.  This will ensure tighter air standards would not impede infrastructure projects.
  7. In projecting the 2025  air quality, the Government chose not to include more radical and effective short-, medium- and long-term policies to fight for a better air quality scenario. For all 14 short-term measures targeting at roadside emissions, only “enhancing district-based publicity on bus route rationalization” has been quantified and included in the projection of the air quality in 2025.


APCO – Air Pollution Control Ordinance

AQGs – Air Quality Guidelines (WHO)

AQO – Air Quality Objective

EIA – Environmental Impact Assessment

HEIA – Health and Economic Impact Assessment

WHO – World Health Organization

5 major air pollutants:

NO2 Nitrogen Dioxide
PM2.5 Fine Suspended Particles
PM10 Respiratory Suspended Particles
O3 Ozone
SO2 Sulfur Dioxide

Shifting the goalposts to attain Hong Kong AQOs

The air quality in 2018 has remained in similar level as compared to previous years. Major roadside pollutant nitrogen dioxide (NO2) continued to be exceeding the Hong Kong standard by 100%. Here is the 3-year comparison for the changes of the 5 major air pollutants:

Percentage change in the concentration of the 5 air pollutants

Table 1: Percentage change in the concentration of the 5 air pollutants, comparing 2018 with 2017 & 2016 (red cells – increased concentration; green cells – reduced concentration)

As shown in Table 1, we are seeing an upward trend in the PM10 and ozone levels, particularly the ozone level. Levels of SO2, NO2 and PM2.5 have all been dropping, apart from roadside monitoring stations.

It is worth noting that, in the upcoming AQO review, the Government recommends only tightening the concentration limits for PM2.5 and SO2, but not PM10 and ozone. The reason for this is simple: The Government projected that the level of SO2 and PM2.5 can attain the tightened level in 2025, thus recommended the tightening of the two pollutants. Since their projection showed that the concentration of PM10 and Ozone would be increasing in the future, further tightening on the two pollutants was therefore, not suggested.

Conservative projection for air quality in 2025

However, it is likely that the Government’s projection for the 2025 air quality has been underestimated. The AQO Review Working Group identified a total of 14 short-term new air quality improvement measures on road transportation. Among the 14 measures, the Government only quantified the reduction emission for one measure, which is the enhancement of district-based publicity on bus route rationalization. All other 13 measures, as well as the medium- and long-term measures, had not been quantified by the EPD and be included in their projection. Without reflecting the impact of these measures in the estimation, it is likely that the projected air quality in 2025 is underestimated substantially.

The reason behind this intended underestimation is to create a narrative that, concentration of certain air pollutants, such as PM10 and ozone, could not be reduced by simply tightening their AQOs.

Another reason to set a loose air quality standard is to ensure that development and infrastructure projects would not be affected by the statutory EIA. This is not the first time our Government manipulated with air policy for the sake of “development”. In the previous AQO review in 2013, the Government exempted the North East New Territories New Development Areas Planning project from the updated and tightened AQOs. The Project was only required to pass the 1987 AQOs, which were ridiculously loose at the time.

According to EPD’s AQO review document, in 2025, the annual NO2 level in the surrounding marine of Kau Yi Chau, where the proposed reclamation in the Lantau Tomorrow Vision project will take place, will be far exceeding the Hong Kong AQO. Will the Government issue a waiver again this time and sacrifice public health for the sake of infrastructure?


Image 1: Projected annual average NO2 concentration in 2025 (black shaded area: proposed reclamation area for Lantau Tomorrow; pink and orange shaded area: areas that will fail to achieve AQO)

Sacrificing public health and failing to achieve 2020 targets

The underestimated and conservative air quality projection comes with undesirable consequences. First, the increased number of allowable exceedances for PM2.5 will allow more frequent high air pollution episodes, according to a study in 2011 by Professor Anthony Hedley, HKU School of Public Health. WHO also states that the number of allowable exceedance for air pollutants should be kept to a minimum. By greatly relaxing the PM2.5 number of allowable exceedance from 9 times to 35 times, the Government not only goes against international guideline and practice, but also violates the “public interest” stated in the APCO. It is undebatable that increasing high pollution episodes causes adverse health impact for the population in Hong Kong, and is a clear violation of public interest.

Comparison of the no. of allowable exceedance in HKAQO

Table 2: Comparison of the no. of allowable exceedance in HKAQO, proposed AQO, and WHO guideline

Second, the projected air quality in 2020 is going to miss the targets set out in the Clean Air Plan, if we accept the conservative assumptions and policies suggested by EPD. According to EPD’s projection, levels of PM2.5 and PM10 in 2025 will be even higher than in 2018 and 2020. Weak air policies and measures will keep us from achieving the WHO AQG and worsen our current air quality.

Comparison of air quality

Failure to meet the 2020 Clean Air Plan targets would mean that public health is being put at severe risk and causing our society enormous economic loss and medical cost. Based on the HEIA conducted by the AQO Review Working Group, chaired by Under Secretary for the Environment, Clean Air Network estimated the health and economic impact in the scenario where Hong Kong missed the 2020 targets and maintained the poor air quality in 2018: there will be 493 premature deaths, over 90,000 new episodes of upper respiratory tract infections, 542 emergency hospital admissions, about HK$8.9 billion direct economic loss, and HK$ 1 billion medical cost and productivity loss every year. If the Government concentrates on transport policy to deal with roadside emission, it will not only reduce the levels of roadside NO2 and PM2.5, our society will also enjoy substantial health and economic benefits.


Image 2: Health and economic impact caused by air pollution if Hong Kong missed the 2020 target

For Media Enquiries:

Mr. Patrick FUNG (Chief Executive Officer, Clean Air Network)
Phone: 3971 0106 / 9834 8892
Email: patrick@hongkongcan.org

Mr. LOONG Tsz-Wai (Senior Community Relationship Manager, Clean Air Network)
Phone: 3971 0106 / 6256 2928
Email: loong@hongkongcan.org

Story posted on
17th Jan, 2019


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