A major positive step was taken in 2014 when a new legal mandate was put in place requiring the government to review Hong Kong's Air Quality Objectives at least once every five years. The purpose of requiring periodic review is to improve public health. Previously, the AQOs had not been reviewed for many years, and was a great source of public criticism.
A new legal mandate requires a new process to assess the extent to which the AQOs could be tightened.
The World Health Organization's air quality guidelines are the international benchmark to strive for because they are set according the latest science on air pollution's harm to public health.
Its guidelines can be used as a reference for governments in setting their own air quality standards.
The SAR government looked at how other jurisdictions conducted their air quality standards review and created an organized process.
In 2016, it established the AQO Review Working Group to appraise development in air science and health effects of air pollution, examine air pollution levels and trends, identify improvement measures, develop an air quality management plan for improvements, and assess air quality in future under different control scenarios, and the scope for further tightening the AQOs. The working group also established sub-groups to engage many groups of stakeholders, including air scientists, health experts, academics, professionals, green groups, community leaders, and the business sector to deliberate on key aspects of the review.
Many rounds of meetings were held, and experts were contracted to work on specific assessments. Public engagement sessions were also held in 2017.
The government will have to decide in the foreseeable future whether and to what extent the AQOs could be tightened. Recommendations can be expected in due course. Having been the undersecretary for the environment at the time when the review process was put in place, and having chaired the working group up until June 30, 2017, there are several obvious issues the government will have to address.
Hong Kong's ambition must be to develop the most robust review process over time - this was just the first time.
The government will have to tighten the AQOs. Where air pollutant level has decreased, such as with sulphur dioxide and PM2.5, the public expects the relevant objectives to be tightened.
This will have the effect of requiring infrastructure projects in Hong Kong to meet more stringent requirements, such as when a new highway is built.
And this is quite right.
The review process itself should be examined. Having gone through it once, the next time around, the process should be backed by more research so that working group members could know the magnitude of health improvements from various control measures.
This can be done through early commissioning of relevant research.
Lastly, Hong Kong should estimate the air quality improvements brought about by the mainland's control measures in Guangdong province, since their efforts have a tremendous beneficial impact on Hong Kong, and estimating their efforts makes every sense.
Christing Loh is Adjunct Professor of Environment and Sustainability, HKUST