Total gaseous mercury in Kathmandu, a South Asian metropolis: Temporal variations, sources apportionment and health risk assessment

被引：2

作者：

Rawat, Bakhat ^{[1
,3
,4
]}

Yin, Xiufeng ^{[1
,2
]}

Sharma, Chhatra Mani ^{[5
]}

Tripathee, Lekhendra ^{[2
]}

Truong, Minh Tri ^{[6
]}

Tiwari, Pravash ^{[7
]}

Kandel, Kshitiz ^{[1
,3
]}

Kang, Shichang ^{[2
,3
]}

Zhang, Qianggong ^{[1
,3
]}

机构：

[1] Chinese Acad Sci, Inst Tibetan Plateau Res, State Key Lab Tibetan Plateau Earth Syst, Environm & Resources TPESER, Beijing 100101, Peoples R China

[2] Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, Key Lab Cryospher Sci & Frozen Soil Engn, Lanzhou 730000, Peoples R China

[3] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

[4] Univ Wollongong UOW, Ctr Atmospher Chem, Wollongong, NSW 2522, Australia

[5] Tribhuvan Univ, Cent Dept Environm Sci, Kathmandu 44613, Nepal

[6] Univ Virginia, Dept Environm Sci, Charlottesville, VA 22904 USA

[7] China Univ Min & Technol, Sch Environm & Spatial Informat, Xuzhou 221116, Peoples R China

来源：

JOURNAL OF HAZARDOUS MATERIALS | 2025年 / 483卷

基金：

中国国家自然科学基金;

关键词：

Total gaseous mercury; Seasonal and diurnal variation; Potential sources; Influencing factors; South Asia; SPECIATED ATMOSPHERIC MERCURY; EXPERIMENT NAMASTE EMISSIONS; PARTICULATE MATTER; TIBETAN PLATEAU; ELEMENTAL MERCURY; BRICK KILNS; AIR-QUALITY; EAST CHINA; VALLEY; NEPAL;

D O I：

10.1016/j.jhazmat.2024.136644

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

South Asia is a global hotspot of air pollution gaining attention due to its severe implications, in which atmospheric mercury (Hg) could cause detrimental health effects in metropolitan areas. In this study, first-time yearround (January - December 2019) mean total gaseous mercury (TGM) concentration at Kathmandu, Nepal- a sub-tropical city in South Asia was reported at 9.9 +/- 10.0 ng m-3. Seasonal TGM variation at Kathmandu showed highest concentration in winter (16.8 +/- 16.9 ng m-3) and lowest in summer (2.9 +/- 2.1 ng m-3). Generally higher daytime TGM concentration as opposed to night-time TGM indicated Hg build-up within atmospheric boundary layer due to low wind speed and high humidity. Events with high wind speed (> 30 m s-1) induced regional pollutant transport from nearby brick kilns and cement factories. Principal component analysis associated a major part of TGM with PM 2.5 and CO and indicated the remarkable influence of fuel combustion and vehicular emissions. Backward trajectory and potential source contribution factor analysis further indicate the impact of regional Hg emissions and transboundary emissions from India towards Nepal, which expands beyond the Himalayas and the Tibetan Plateau. Prominent low-grade coal burning and kilning activities in winter spiked up TGM concentrations, resulting in the highest health quotient (HQ = 0.24) value, which could significantly impact public health. Our study presented the most comprehensive set of continuous annual atmospheric Hg monitoring data from Nepal in the South Asian region. The results serve as a baseline for regional atmospheric Hg levels and offer a critical reference for assessing and addressing air pollution concerns in Nepal as well as throughout South Asia.

引用

页数：12