Prof.  Ruilian  Yu
College of Chemical Engineering, Huaqiao University, Xiamen,  China

Title: Pollution, source, transfer and potential risk of rare earth elements in the soil-dust-plant system of parks in a tourist city, southeast China

Abstract:

Urban parks, as important public activity spaces, are vulnerable to contamination by heavy metals including rare earth elements (REEs), which are regarded as emerging contaminants. However, the occurrence characteristics, sources, migration pathway, and risk levels in park ecosystems remain poorly understood. In this study, 14 REEs were systematically investigated by analyzing their total concentrations, chemical speciation, geochemical characteristics, spatial and seasonal distribution patterns, migration and transformation behaviors, pollution levels, and ecological and human health risks. The results showed that the mean REE concentrations in park soil predominantly exceeded the background values, with relatively uniform spatial distributions. According to the results of BCR sequential extraction, the REEs in park soil were concentrated in the residual fraction, whereas only 1% were found in the weak-acid extractable fraction, indicating low bioavailability and mobility. Overall, the geo-accumulation and ecological risk index results indicated no significant pollution or ecological risk; however, moderate to high risk was observed at some sites. Seasonal variations significantly affected the spatial distribution and ecological risk of REEs in dust-fall. REEs in winter dust-fall exhibited greater ecological risk than those in summer. Most sampling sites showed low ecological risk, with lutetium (Lu) contributing more than 20% to the total potential ecological risk in both seasons. Health risks from dust-fall were lower than those from soils, and both exhibited relatively low impact on human health. The MixSIAR and random forest models indicated that some dust-fall points were strongly influenced by metallurgical and automotive exhaust, with industrial and traffic sources as the main contributors. Relatively low REE content was observed in the plant leaves. The leaves of Ficus spp. had slightly higher content compared to Schefflera. Quantitative modeling results indicated that the dust–plant migration pathway exhibited better predictive performance than the soil–plant pathway in Xiamen City Park.

Keywords: City park; Rare earth elements; Soil-dust-plant system; Migration characteristics; Source analysis

Biography:

Ruilian Yu, female, is a professor and doctoral supervisor at Huaqiao University. I was once a visiting scholar at the Key Laboratory of Surficial Geochemistry in Nanjing University, and the Department of Ecology and Environmental Sciences of Umea University in Sweden. I have been engaged in teaching and research in the field of environmental geochemistry for more than 27 years, and have trained about 30 graduate students. I am now an expert in environmental impact assessment, and hazardous waste environmental protection, in Fujian Province, and an expert in environmental monitoring and soil environmental management in Xiamen City. I have been the principal investigator for 2 projects of National Natural Science Foundation of China, and several natural science foundation projects in Fujian Province. and have participated in 6 projects of National Natural Science Foundation of China. I have published more than 100 academic papers in domestic and international journals such as Environmental Science ＆ Technology, Journal of Hazardous Materials, Plant and Soil, Catena, Environmental Pollution, Atmospheric Environment, Marine Pollution Bulletin, Journal of Soils and Sediments, and Applied Geochemistry, among which more than 60 have been indexed by SCI. I have obtained one authorized Chinese patent.