Communicating serious health hazards of Hong Kong air - A new version of the Hedley Environmental Index

Abstract

Hong Kong’s air quality has been deteriorating over 20 years and today presents a serious daily threat to the health of the public and for future generations. The Environmental Protection Department of the Hong Kong SAR Government relies on the Air Pollution Index (HKAPI) to communicate the health hazards of pollution to the public. However, the HKAPI is 25 years out of date, primitive and seriously misleading. The risk categories in the HKAPI bear no relationship to the currently measured bad health outcomes in the population. In order to create a new approach to health risk communication and to inform and assist the public in the interpretation of pollution levels, a group of researchers at The University of Hong Kong School of Public Health developed the Hedley Environmental Index (HEI) in 2008 and launched an updated version today (January 17, 2012) to improve the hourly estimation of air pollution impacts on bad health outcomes and economic costs. The new HEI is evidence-based and referenced to the World Health Organization (WHO) Air Quality Guidelines (AQG). The HEI was originally established by the School of Public Health, HKU in 2008 with funding from the Fu Tak Iam Foundation and ADM Capital Foundation and project management from Civic Exchange. Fu Tak Iam Foundation continues to be the founding funder of this new HEI. The new version of the HEI is launched with the aim to enhance health risk communication and to inform and assist the public in the interpretation of pollution levels which exceed the WHO AQG, particularly in relation to bad health outcomes and economic costs. The updated version of HEI offers several new functions and modifications including: (1) A real-time health risk warning meter with 5 risk categories based on WHO guidelines which can be distributed by web-based social networks. (2) A HKSAR real-time pollution map showing the levels of four pollutants at 14 monitoring stations. A visual representation of pollution levels by colours, spatial distribution and numerical values provides an instant overall picture of our air quality at any point in time. (3) A new graphical display of the recent harm to the community health in terms of doctor visits, hospital admissions and deaths. (4) A summary report showing the number of clear and polluted days we have been exposed to, using the WHO guidelines for safer air quality as our reference. (5) A rolling meter counting the hourly dollar cost of the pollution impact on health care and lost productivity, and the population willingness to pay to avoid a day’s illness, hospital admission or death. (6) A revised and more comprehensive approach to calculating health risks including doctor visits , hospital bed days and deaths. (7) A new analytical tool for users of the Index to gain an in depth understanding of trends and summary statistics of the recent and long term historical data in the index archives. [This revision has led to a significant upward adjustment of the estimation of deaths and other health impacts published by the Index. The Index remains valid and conservative indicator of the harm to our community caused by pollution. It is now possible to analyze and display cumulative pollutant trends, estimated bad health outcomes including deaths, and economic loss to the HKSAR.]