Source apportionment of polychlorinated dibenzo-p-dioxin/furans and polychlorinated biphenyls in soil from the Gyirong Valley in the Himalayas

Qingyu Guo; Mingxuan Wang; Yujue Yang; Guorui Liu; Qiuting Yang; Linjun Qin; Lili Yang; Minghui Zheng

doi:10.1016/j.envpol.2025.126066

Source apportionment of polychlorinated dibenzo-p-dioxin/furans and polychlorinated biphenyls in soil from the Gyirong Valley in the Himalayas

Environ Pollut. 2025 May 1:372:126066. doi: 10.1016/j.envpol.2025.126066. Epub 2025 Mar 13.

Authors

Qingyu Guo¹, Mingxuan Wang¹, Yujue Yang¹, Guorui Liu², Qiuting Yang¹, Linjun Qin¹, Lili Yang³, Minghui Zheng⁴

Affiliations

¹ State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
² State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China; College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, 310024, China.
³ State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address: llyang@rcees.ac.cn.
⁴ State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China; Jianghan University, Wuhan, 430056, China.

PMID: 40089140
DOI: 10.1016/j.envpol.2025.126066

Abstract

The Tibetan Plateau is an important area for persistent organic pollutants (POPs) research because of high-altitude condensation and global distillation. However, the sources of the POPs in remote regions have not been quantified, which is critical for global control of POPs. The Gyirong Valley in the Himalayas bordering Nepal serves as an important pathway for cross-border transport of POPs to the Tibetan Plateau. In this study, the occurrences of polychlorinated dibenzo-p-dioxin/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) as typical POPs were investigated in surface soil samples collected along the Gyirong Valley. The PCDD/F and PCB congener profiles and positive matrix factorization were used to identify sources and quantify their contribution to PCDD/Fs and PCBs in the valley. The main source of PCDD/Fs was long-range atmospheric transport (LRAT), while the main sources of PCBs were domestic burning of coal and wood (27.3 %), LRAT (23.7 %), by-products from pigments, paints, and dyes (42.4 %) and industrial activities related to maintenance, disassembly or accidental releases of electrical equipment (6.5 %). A backward trajectory simulation indicated that the Indian monsoon played a dominant role in facilitating the transport of POPs from Nepal through the Gyirong Valley to the Tibetan Plateau. These results for the occurrences, distribution characteristics, and primary sources of PCDD/Fs and PCBs in the Himalayas will be helpful for POPs risk assessments and control in remote regions.

Keywords: Long-range atmospheric transport; Persistent organic pollutants; Positive matrix factorization; Tibetan Plateau.

MeSH terms

Environmental Monitoring*
Himalayas
Nepal
Persistent Organic Pollutants
Polychlorinated Biphenyls* / analysis
Polychlorinated Dibenzodioxins* / analysis
Soil / chemistry
Soil Pollutants* / analysis
Tibet

Substances

Polychlorinated Biphenyls
Soil Pollutants
Polychlorinated Dibenzodioxins
Soil
Persistent Organic Pollutants