Atmospheric particulate-bound mercury (PBM10) in a Southeast Asia megacity: Sources and health risk assessment

Ly Sy Phu Nguyen; To Thi Hien; Minh Tri Truong; Nguyen Doan Thien Chi; Guey-Rong Sheu

doi:10.1016/j.chemosphere.2022.135707

Atmospheric particulate-bound mercury (PBM₁₀) in a Southeast Asia megacity: Sources and health risk assessment

Chemosphere. 2022 Nov;307(Pt 1):135707. doi: 10.1016/j.chemosphere.2022.135707. Epub 2022 Jul 13.

Authors

Ly Sy Phu Nguyen¹, To Thi Hien², Minh Tri Truong², Nguyen Doan Thien Chi², Guey-Rong Sheu³

Affiliations

¹ Faculty of Environment, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam. Electronic address: nlsphu@hcmus.edu.vn.
² Faculty of Environment, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam.
³ Department of Atmospheric Sciences, National Central University, Taoyuan, Taiwan; Center for Environmental Monitoring and Technology, National Central University, Taoyuan, Taiwan. Electronic address: grsheu@atm.ncu.edu.tw.

PMID: 35842046
DOI: 10.1016/j.chemosphere.2022.135707

Abstract

Particulate-bound mercury (PBM) is a global environmental concern owing to its large dry deposition velocities and scavenging coefficients, both of which drive Hg into terrestrial and marine ecosystems. PBM observation studies have been widely conducted over East Asia, but comparable studies in Peninsular Southeast Asia (PSEA) remain scarce. This is the first study reporting PBM concentrations for Ho Chi Minh City (HCMC), the biggest metropolitan area in Vietnam. A total of 222 samples were collected in 2018 and contained an average PBM₁₀ (particulate matter - PM with diameter ≤10 μm) concentration and Hg mass fraction (i.e. PBM/PM) of 67.3 ± 45.9 pg m^-3 and 1.18 ± 1.12 μg g^-1, respectively. Although PBM concentration was lower than those reported in Chinese megacities, the Hg mass fraction was similar to those in China, suggesting strong enrichment from anthropogenic Hg emissions in HCMC. Traffic-induced particulate emission and deposition processes were major factors governing PBM temporal variation at our site. In addition, the prevailing southwest monsoon winds brought air masses that passed through industrial areas and were associated with a higher Hg mass fraction. Statistically significant positive correlations (R² = 0.11-0.52, p < 0.01) were observed for PBM with PM and the Hg mass fraction, indicating similar PM and Hg sources or oxidized Hg adsorption onto PM via gas-particle partitioning. Moreover, PCA results revealed a higher contribution of primary sources than secondary sources to PBM concentration variability in HCMC. A health risk assessment indicated that the PBM concentrations at HCMC posed minimal non-carcinogenic risks (HI < 1) for children and adults, but dermal contact may act as an important exposure route since lightweight clothing is common among residents. This PBM dataset over PSEA, a region with high atmospheric Hg emissions, provides a valuable resource for the Hg scientific community to improve our understanding of Hg biogeochemical cycle.

Keywords: Health risk; Ho Chi Minh City; Particulate-bound mercury; Source apportionment; Southeast Asia.

MeSH terms

Air Pollutants* / analysis
Asia, Southeastern
Child
Dust / analysis
Ecosystem
Environmental Monitoring / methods
Humans
Mercury* / analysis
Particulate Matter / analysis
Risk Assessment
Streptothricins

Substances

Air Pollutants
Dust
Particulate Matter
phytobacteriomycin
Streptothricins
Mercury