Tracking Source Variations of Inhalation Cancer Risks and Ozone Formation Potential in Hong Kong over Two Decades (2000-2020) Using Toxic Air Pollutant Monitoring Data

Yee Ka Wong; Wai Wai Chan; Dasa Gu; Jian Zhen Yu; Alexis K H Lau

doi:10.1021/envhealth.3c00209

Tracking Source Variations of Inhalation Cancer Risks and Ozone Formation Potential in Hong Kong over Two Decades (2000-2020) Using Toxic Air Pollutant Monitoring Data

Environ Health (Wash). 2024 May 23;2(6):411-421. doi: 10.1021/envhealth.3c00209. eCollection 2024 Jun 21.

Authors

Yee Ka Wong¹, Wai Wai Chan², Dasa Gu¹, Jian Zhen Yu^{1

2

3}, Alexis K H Lau^{1

2

4}

Affiliations

¹ Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 000000, China.
² Institute for the Environment, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 000000, China.
³ Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 000000, China.
⁴ Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 000000, China.

Abstract

Toxic air pollutants (TAPs) are a class of airborne chemicals known or suspected to cause serious health issues. This study, applying positive matrix factorization and inhalation unit risk estimates of TAPs, quantifies the changes in significant sources contributing to inhalation cancer risks (ICRs) from 2000 to 2020 in Hong Kong, China. Total ICR decreased from 1701 to 451 cases per million between 2000-2004 and 2016-2020, largely attributed to the reduction in diesel particulate matter (DPM), gasoline and solvent use-related volatile organic compounds (VOCs), and coal/biomass combustion-related polycyclic aromatic hydrocarbons and metal(loid)s. The regional contribution of VOCs associated with industrial and halogenated solvent sources increased substantially, representing the largest non-DPM ICR contributor (37%) in 2016-2020, stressing the need for a more comprehensive risk evaluation across the fast-growing and densely populated Greater Bay Area (GBA). ICRs in Hong Kong and the GBA will likely remain over 100 cases per million by 2050. The contributions to ozone formation potential of VOC/carbonyl sources were quantified, which show a notable shift from being solvent/gasoline-dominant in 2000-2004 to being more evenly shared by various sources in 2016-2020. Establishing a similar TAP monitoring network in the GBA is anticipated to provide the monitoring data needed to facilitate the development of more informed air quality management strategies.