Effects of Typical Karst Tourist Town on the Lijiang River Water: From Heavy Metals to N-Nitrosamines

Abstract

N-nitrosamines are nitrogenous organic pollutants with high carcinogenicity to humans. Heavy metal pollution in aquatic systems is currently a major environmental problem. Tourism in typical karst areas may influence the environment through wastewater discharge. However, it remains unclear whether these activities would cause water pollution. To evaluate the impact of tourism activities in typical tourist towns, this study investigated the occurrence and sources of 18 N-nitrosamines, eight heavy metals (HMs), and dissolved inorganic nitrogen (DIN) in the Lijiang River and its tributaries. Seven N-nitrosamines were detected, among which N-nitroso-N-ethylaniline (NEA, average of 24.8 ng/L) and N-nitroso-l-proline (NPRO, 20.4 ng/L) were the dominant compounds, while especially low concentrations of HMs (Mn, Cu, As, Ni, Cr, Co, Pb, and Cd) and DIN (NH₄⁺-N, NO₂⁻-N, and NO₃⁻-N) were observed. The most important influencing factors were seasonal factors, followed by land use type and mainstem and tributary factors. Principal component analysis revealed that in the city with developed tourism and relatively less heavy industry, aquaculture and agricultural wastewater were identified as the primary sources of N-nitrosamines. Meanwhile, domestic sewage and agricultural wastewater were found to be the main sources of HMs and DIN, respectively. The ecological risk assessments for all pollutants are relatively low (< 1). Therefore, N-nitrosamines, HMs, and DIN pollution caused by tourist activities pose a negligible risk to the Lijiang River.

Keywords

Lijiang River / N-nitrosamines / heavy metals / spatial distribution / water pollution

References

[1] An Y, Zhou S, Su C L, et al.. Heavy Metal Pollution of Sediments in Northern Jiaozhou Bay and the Influence of DOM on Their Environmental Behavior. Earth Science, 2024, 49(8): 2901-2913(in Chinese with English Abstract)

[2] Chen W W, Chen Y J, Huang H F, et al.. Occurrence of N-Nitrosamines in the Pearl River Delta of China: Characterization and Evaluation of Different Sources. Water Research, 2019, 164: 114896

[3] Chen W W, Li S Y, Huang H F, et al.. Occurrence and Transport of N-Nitrosamines in the Urban Water Systems of the Pearl River Delta, Southern China. Science of the Total Environment, 2023, 890: 164251

[4] Chen W W, Li X S, Huang H F, et al.. Comparison of Gas Chromatography-Mass Spectrometry and Gas Chromatography-Tandem Mass Spectrometry with Electron Ionization for Determination of N-Nitrosamines in Environmental Water. Chemosphere, 2017, 168: 1400-1410

[5] Chen Y J, Huang H F, Ding Y, et al.. Trace Metals in Aquatic Environments of a Mangrove Ecosystem in Nansha, Guangzhou, South China: Pollution Status, Sources, and Ecological Risk Assessment. Environmental Monitoring and Assessment, 2019, 191(10): 629

[6] Cope K, Seifried H, Seifried R, et al.. A Gas Chromatography-Mass Spectrometry Method for the Quantitation of N-Nitrosoproline and N-Acetyl-S-Allylcysteine in Human Urine: Application to a Study of the Effects of Garlic Consumption on Nitrosation. Analytical Biochemistry, 2009, 394(2): 243-248

[7] Dai N, Zeng T, Mitch W A. Predicting N-Nitrosamines: N-Nitrosodiethanolamine as a Significant Component of Total N-Nitrosamines in Recycled Wastewater. Environmental Science & Technology Letters, 2015, 2(3): 54-58

[8] Dong H, Guo X D, Xian Y P, et al.. A Salting Out-Acetonitrile Homogeneous Extraction Coupled with Gas Chromatography-Mass Spectrometry Method for the Simultaneous Determination of Thirteen N-Nitrosamines in Skin Care Cosmetics. Journal of Chromatography A, 2015, 1422: 82-88

[9] Fan C C, Lin T F. N-Nitrosamines in Drinking Water and Beer: Detection and Risk Assessment. Chemosphere, 2018, 200: 48-56

[10] GB 3838-2002. Environmental Quality Standards for Surface Water, 2002, Beijing, Ministry of Ecology and Environment of the People’s Republic of China(in Chinese)

[11] Huang B P, Wu Y G, Shen W T, et al.. Acute Toxicity and Safe Concentration of Arsenic and Fluoride to Daphnia Carinata. Guizhou Agricultural Sciences, 2011, 39(3): 106-110(in Chinese with English Abstract)

[12] Huang H W, Xiao H, Wang D Q, et al.. Pollution Characteristics and Health Risk Assessment of Heavy Metals in the Water of Lijiang River Basin. Huanjing Kexue, 2021, 42(4): 1714-1723(in Chinese with English Abstract)

[13] Krasner S W, Westerhoff P, Chen B Y, et al.. Occurrence of Disinfection Byproducts in United States Wastewater Treatment Plant Effluents. Environmental Science & Technology, 2009, 43(21): 8320-8325

[14] Krumlinde P, Ek S, Tunestál E, et al.. Synthesis and Characterization of Novel Stabilizers for Nitrocellulose-Based Propellants. Propellants, Explosives, Pyrotechnics, 2017, 42(1): 78-83

[15] Li M X, Chen Y J, Liu Z J, et al.. The Distribution, Sources and Health Risk of N-Nitrosamines in Karst Dominated Water of Liujiang River, Southwest China. Applied Geochemistry, 2023, 158: 105796

[16] Li Z G, Song G F, Bi Y H, et al.. Occurrence and Distribution of Disinfection Byproducts in Domestic Wastewater Effluent, Tap Water, and Surface Water during the SARS-CoV-2 Pandemic in China. Environmental Science & Technology, 2021, 55(7): 4103-4114

[17] Lou B F, Zhuo H H, Zhou Z, et al.. Analysis on Alteration of Water Quality and Pollutant Fluxes in the Yangtze Mainstem during Recently 18 Years. Research of Environmental Sciences, 2020, 33(5): 1150-1162(in Chinese with English Abstract)

[18] Lu Y J, Chen W W, Chen Y J, et al.. Analysis on the Characteristics of Nitrogen Compounds and Bacteria Communities in Lijiang River Basin. Environmental Science & Technology, 2019, 42(10): 34-41(in Chinese with English Abstract)

[19] Mao L F, Fu S, Liu H, et al.. Analysis of Recharge Source of Karst Spring Water Based on Stable Hydrogen and Oxygen Isotopes. Earth Science, 2023, 48(9): 3480-3493(in Chinese with English Abstract)

[20] Ng K, Alygizakis N, Androulakakis A, et al.. Target and Suspect Screening of 4777 Per- and Polyfluoroalkyl Substances (PFAS) in River Water, Wastewater, Groundwater and Biota Samples in the Danube River Basin. Journal of Hazardous Materials, 2022, 436: 129276

[21] Orias F, Bony S, Devaux A, et al.. Tamoxifen Ecotoxicity and Resulting Risks for Aquatic Ecosystems. Chemosphere, 2015, 128: 79-84

[22] Pan, W. Y., Yin, R. L., Liu, F. S., et al., 2026. Spatio-temporal Variation Characteristics of Water Quality and Pollutant Source Apportionment in the Xiaoqing River Mainstream. Earth Science. Online First (in Chinese with English Abstract)

[23] Peng C, Gong K L, Li Q N, et al.. Simultaneous Immobilization of Arsenic, Lead, and Cadmium in Soil by Magnesium-Aluminum Modified Biochar: Influences of Organic Acids, Aging, and Rainfall. Chemosphere, 2023, 313: 137453

[24] Prasad Ahirvar B, Das P, Srivastava V, et al.. Perspectives of Heavy Metal Pollution Indices for Soil, Sediment, and Water Pollution Evaluation: An Insight. Total Environment Research Themes, 2023, 6: 100039

[25] Raj A R A, Mylsamy P, Sivasankar V, et al.. Heavy Metal Pollution of River Water and Eco-Friendly Remediation Using Potent Microalgal Species. Water Science and Engineering, 2024, 17(1): 41-50

[26] Ren K, Pan X D, Yuan D X, et al.. Nitrate Sources and Nitrogen Dynamics in a Karst Aquifer with Mixed Nitrogen Inputs (Southwest China): Revealed by Multiple Stable Isotopic and Hydro-Chemical Proxies. Water Research, 2022, 210: 118000

[27] Renman A, Renman G, Gustafsson J P, et al.. Metal Removal by Bed Filter Materials Used in Domestic Wastewater Treatment. Journal of Hazardous Materials, 2009, 166(2/3): 734-739

[28] Shen H Y, Jiang G H, Guo F, et al.. Distribution Characteristics and Influence Factors of the Ammonia, Nitrite and Nitrate in the Lijiang River, Guilin City. Carsologica Sinica, 2015, 34(4): 369-374(in Chinese with English Abstract)

[29] Sheng D R, Meng X H, Wen X H, et al.. Contamination Characteristics, Source Identification, and Source-Specific Health Risks of Heavy Metal(Loid)s in Groundwater of an Arid Oasis Region in Northwest China. Science of the Total Environment, 2022, 841: 156733

[30] Sun W Q, Xu X D, Lv Z Q, et al.. Environmental Impact Assessment of Wastewater Discharge with Multi-Pollutants from Iron and Steel Industry. Journal of Environmental Management, 2019, 245: 210-215

[31] Wang W F, Ren S Y, Zhang H F, et al.. Occurrence of Nine Nitrosamines and Secondary Amines in Source Water and Drinking Water: Potential of Secondary Amines as Nitrosamine Precursors. Water Research, 2011, 45(16): 4930-4938

[32] Wang X H, Xu Y J, Zhang L. Watershed Scale Spatiotemporal Nitrogen Transport and Source Tracing Using Dual Isotopes among Surface Water, Sediments and Groundwater in the Yiluo River Watershed, Middle of China. Science of the Total Environment, 2022, 833: 155180

[33] Wang X Z, Liu Z M, Wang C, et al.. Occurrence and Formation Potential of Nitrosamines in River Water and Ground Water along the Songhua River, China. Journal of Environmental Sciences, 2016, 50: 65-71

[34] Wang Y G, Yang Y Q, Li Q, et al.. Early Warning of Heavy Metal Pollution after Tailing Pond Failure Accident. Journal of Earth Science, 2022, 33(4): 1047-1055

[35] Wang, Z. Q., Liu, Y. L., Qian, K., et al., 2026. Calcium, Magnesium, and Their Ratio in Drinking Water: Health Effects and Distribution Patterns in China. Journal of Earth Science. https://doi.org/10.1007/s12583-025-0402-3

[36] Wu A M, Wei J B, Lai C S, et al.. A Study of Acute Toxicity of Heavy Metals in Cultured Water to Zebra Fish. Journal of Foshan University (Natural Sciences Edition), 2016, 34(5): 71-75(in Chinese with English Abstract)

[37] Xie F Y, Yu M C, Yuan Q K, et al.. Spatial Distribution, Pollution Assessment, and Source Identification of Heavy Metals in the Yellow River. Journal of Hazardous Materials, 2022, 436: 129309

[38] Xiu R Q, Xu Y X, Gao S R, et al.. Joint Toxicity Test of Arsenic with Cadmium and Zinc Ions to Zebrafish, Brachynanio Rerio. China Environmental Science, 1998, 18(4): 349-352(in Chinese with English Abstract)

[39] Xu L, Qu Y H, Chu X D, et al.. Urinary Levels of N-Nitroso Compounds in Relation to Risk of Gastric Cancer: Findings from the Shanghai Cohort Study. PLoS One, 2015, 10(2): e0117326

[40] Yan H, Pan G, Huo R L. Oxic Effects of Copper, Zinc and Manganese on the Inhibition of the Growth of Closterium Lunula. Acta Scientiae Circumstantiae, 2001, 21(3): 328-332(in Chinese with English Abstract)

[41] Zhang H G, Cui B S, Xiao R, et al.. Heavy Metals in Water, Soils and Plants in Riparian Wetlands in the Pearl River Estuary, South China. Procedia Environmental Sciences, 2010, 2: 1344-1354

[42] Zhang Z Y, Dai J F, Xie X L, et al.. Temporal and Spatial Variability of Nitrogen and Phosphorus Concentration in Jingui River Region of the Upper Reaches of Lijiang River. China Rural Water and Hydropower, 2021, 2021(7): 101-112(in Chinese with English Abstract)

[43] Zhao C, Lu Q, Gu Y, et al.. Distribution of N-Nitrosamines in Drinking Water and Human Urinary Excretions in High Incidence Area of Esophageal Cancer in Huai’an, China. Chemosphere, 2019, 235: 288-296

[44] Zhao Y Q, Xia Y Q, Kana T M, et al.. Seasonal Variation and Controlling Factors of Anaerobic Ammonium Oxidation in Freshwater River Sediments in the Taihu Lake Region of China. Chemosphere, 2013, 93(9): 2124-2131

[45] Zhou Q L, McCraven S, Garcia J, et al.. Field Evidence of Biodegradation of N-Nitrosodimethylamine (NDMA) in Groundwater with Incidental and Active Recycled Water Recharge. Water Research, 2009, 43(3): 793-805

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