Air pollution management and the city’s air quality standards interlinks with each other in determining whether more aggressive reduction measures are needed as well as indicating the effectiveness of the implemented policy. Often, air quality standards are set with reference to the World Health Organization (WHO) Air Quality Guidelines (AQGs) and its interim targets which was recently updated in 2021 from its previous guidelines in 2006. Currently, air pollution standards continue to use a reference-based standard where individual pollutants are viewed with individualized standards. Air pollution communication methods in the majority of cities also use a reference-based method to communicate air quality status to the public. However, air pollution exists in the atmosphere as a collecti...[ Read more ]

Air pollution management and the city’s air quality standards interlinks with each other in determining whether more aggressive reduction measures are needed as well as indicating the effectiveness of the implemented policy. Often, air quality standards are set with reference to the World Health Organization (WHO) Air Quality Guidelines (AQGs) and its interim targets which was recently updated in 2021 from its previous guidelines in 2006. Currently, air pollution standards continue to use a reference-based standard where individual pollutants are viewed with individualized standards. Air pollution communication methods in the majority of cities also use a reference-based method to communicate air quality status to the public. However, air pollution exists in the atmosphere as a collective risk and should be addressed holistically rather than individualized. A risk-based approach to air pollution management and communication is advantageous by tackling air pollution as a holistic matter rather than its individual pollutants. Thus, this research will first cover the update on the short-term air quality health index (SAQHI) for the excess health risk from short-term air pollution exposure as well as proposing a new long-term air quality health index (LAQHI) for health risk communication due to long-term air pollution exposure. Other than risk communication, a new short-term and long-term risk-based air quality standard (SRAQS, LRAQS) is proposed by combining the excess health risk (%ER) of the criteria pollutants to form a single SRAQS and LRAQS value to represent the overall air quality standard to be in place of the current reference-based framework. Historical air quality data in Hong Kong will be used throughout this research and converted into a percentage excess health risk using short-term and long-term risk factors. 2021 WHO AQGs concentrations and its interim targets (ITs) will be used as the reference concentrations to set the risk standards and its interim standards making it implementable to different cities that want to implement a risk-based approach. When converted into a risk-based approach, it provides a more comprehensive approach to air quality management that can convert from focusing on the pollutant’s concentration to focusing on decreasing the risk to human health. This change in both AQHI and RAQS brings light to advancing air pollution reduction more effectively than the current reference-based method, specifically highlighting pursuing air pollution reduction as a holistic matter rather than single-pollutant focused. Today’s air quality situation is significantly better than in 1970 when the Clean Air Act (CAA) was established. With the major reduction in air pollution concentrations, it is imperative to address air pollution as a collective risk, with future research, the risk-based AQHI and RAQS is also highly adaptable for worldwide use and for incorporation of other air toxins that may pose significant health threats making the risk-based approach an even more desirable and effective framework for both air pollution and climate control.