Deposition history of polycyclic aromatic hydrocarbons in tibetan lakes indicate the effectiveness of protected area establishment

Songhan Li; Xiyu Ban; He Zhang; Yaxin Xiong; Jun Li; Guo-Li Yuan

doi:10.1016/j.jenvman.2024.124004

Deposition history of polycyclic aromatic hydrocarbons in tibetan lakes indicate the effectiveness of protected area establishment

J Environ Manage. 2025 Jan 3:373:124004. doi: 10.1016/j.jenvman.2024.124004. Online ahead of print.

Authors

Songhan Li¹, Xiyu Ban¹, He Zhang¹, Yaxin Xiong², Jun Li³, Guo-Li Yuan⁴

Affiliations

¹ School of the Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China.
² School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China; Department of Environmental Sciences, University of California, Riverside, CA, 92521, USA.
³ School of the Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China. Electronic address: Junli@cugb.edu.cn.
⁴ School of the Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China.

PMID: 39754811
DOI: 10.1016/j.jenvman.2024.124004

Abstract

The effectiveness of protected areas in mitigating human impacts remains uncertain due to limited in-situ data; however, atmospheric micropollutant deposition in alpine lakes may provide a quantitative approach to evaluate anthropogenic pressures and threats. In this study, the temporal changes of polycyclic aromatic hydrocarbons (PAHs) inside/outside the Siling Co protected area, Tibet were reconstructed. The varying anthropogenic impact history suggested that, unlike the dominance of residential activities (i.e., biomass burning) outside the protected area, the protected area establishment significantly curtailed grazing and resource exploitation, leading to a sharp decline in atmospheric PAHs during the middle-1980. However, the PAH deposition increased rapidly after the 2000s, coinciding with the expansion of transportation networks in Tibet. The important contributions from gasoline/diesel exhaust and tire/asphalt dust in this period, as deciphered by the newly developed source-sample similarity index, emphasized the tourism activities as a point of concern for preserving the alpine ecosystem post-establishment. The observed delayed but notable increase in human impacts within the Siling Co protected area highlighted the need for long-term atmospheric monitoring to provide robust and reproducible data on anthropogenic pressures.

Keywords: PAHs; Protected area; Sediment core; Source similarity; Tibetan plateau.