Polycyclic aromatic hydrocarbons in remote lakes from the Tibetan Plateau: Concentrations, source, ecological risk, and influencing factors

Yixin Bai; Heyu Yu; Kunlin Shi; Nana Shang; Yao He; Lize Meng; Tao Huang; Hao Yang; Changchun Huang

doi:10.1016/j.jenvman.2022.115689

Polycyclic aromatic hydrocarbons in remote lakes from the Tibetan Plateau: Concentrations, source, ecological risk, and influencing factors

J Environ Manage. 2022 Oct 1:319:115689. doi: 10.1016/j.jenvman.2022.115689. Epub 2022 Jul 8.

Authors

Yixin Bai¹, Heyu Yu¹, Kunlin Shi¹, Nana Shang¹, Yao He¹, Lize Meng¹, Tao Huang², Hao Yang², Changchun Huang³

Affiliations

¹ School of Geography, Nanjing Normal University, Nanjing 210023, PR China.
² School of Geography, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Ministry of Education, Nanjing 210023, PR China; State Key Laboratory Cultivation Base of Geographical Environment Evolution (Jiangsu Province), Nanjing 210023, PR China.
³ School of Geography, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Ministry of Education, Nanjing 210023, PR China; State Key Laboratory Cultivation Base of Geographical Environment Evolution (Jiangsu Province), Nanjing 210023, PR China. Electronic address: huangchangchun_aaa@163.com.

PMID: 35816959
DOI: 10.1016/j.jenvman.2022.115689

Abstract

Polycyclic aromatic hydrocarbons (PAHs) have received worldwide attention due to their potential teratogenic, persistent, and carcinogenic characteristics. In this study, the PAHs concentrations in two dated sediment cores taken from central Tibetan Plateau (TP) were analyzed to study the deposition history, potential sources, ecological risks, and influencing factors. Total concentration of PAHs (∑PAHs) ranged from 50.0 to 195 ng g^-1 and 51.9-133 ng g^-1 in sediments of Pung Co (PC) and Dagze Co (DZC), respectively. 2-3-ring PAHs were dominant in the two lake sediments, accounting for an average of 77.5% and 80.1%, respectively. The historical trends of ∑PAHs in the two lakes allowed to distinguish three periods, namely, relative stability before the 1950s, a gradual increase between the 1950s and the 1990s, and then a decline to the present-day. In addition, the trend in the concentration level of each PAH composition was consistent with ∑PAHs before the 1990s, while they exhibited different trends since the 1990s, which may be the result of a combination of anthropogenic activities and climate change in recent years, whereas before the 1990s the PAH profile was mainly influenced by atmospheric deposition. The results of source apportionment examined according to diagnostic ratios and positive matrix factorization were consistent and revealed that PAHs were primarily derived from biomass and coal combustion. Significant correlations between PAHs and organic carbon (OC) indicate that OC might be a key factor influencing the concentration of PAHs in sediments. The ecological risk assessment demonstrated that PAHs in TP sediments occurred at a low risk level. Results of this study could be helpful to develop a deeper insight into the deposition history of PAHs in remote lakes of the TP region and explore the response of these variations to climate change and human activities.

Keywords: Anthropogenic activities; Ecological risk; Polycyclic aromatic hydrocarbons; Sediment core; Tibetan plateau.

MeSH terms

China
Environmental Monitoring / methods
Geologic Sediments
Humans
Lakes
Polycyclic Aromatic Hydrocarbons*
Tibet
Water Pollutants, Chemical* / analysis

Substances

Polycyclic Aromatic Hydrocarbons
Water Pollutants, Chemical