Xie Jiong-Feng, Wei Gao-Ling, Zeng Li-Xi, Liu Liang-Ying
Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China.
Sci Total Environ. 2024 Jan 20;909:168428. doi: 10.1016/j.scitotenv.2023.168428. Epub 2023 Nov 14.
Liquid crystal monomers (LCMs) have been recognized as contaminants of emerging concerns. E-waste recycling sites and liquid crystal displays (LCDs) manufacturers are supposed to be critical sources. However, information regarding LCM contaminations in soils surrounding these sites are currently unavailable. In this study, soil samples were collected from two distinct areas in South China: e-waste recycling area (n = 36) and LCD manufacturer (n = 41), and 60 target LCMs (including 13 biphenyl and analogs (BAs), 10 cyanobiphenyl and analogs (CBAs), and 37 fluorinated biphenyl and analogs (FBAs)) were determined. The concentrations of LCMs in the soils from near the e-waste recycling area (0.32-18 ng/g, average: 4.2 ng/g) were higher than those surrounding the LCD manufacturer (ND - 7.2 ng/g, average: 1.5 ng/g). The compositional profiles of LCMs in soil samples from these two typical point sources were considerably different. The concentrations of FBAs exponentially decreased with distance from the e-waste recycling park, by >90 % within 2 km. The levels of BAs exhibited a similar exponential decrease with distance from the LCD manufacturer. The inventories of LCMs were estimated to be 21.0 kg in the e-waste recycling area and 10.8 kg in the LCD manufacturer area. Remarkably, the inventory of LCMs in soils from e-waste recycling area was one order of magnitude larger than that of hexabromocyclododecanes (HBCDs) in the same region, and 0.2 to 20 times the annual global emissions of LCMs from discarded LCD panels. More studies are required to elucidate the environmental occurrence, behavior, and fate of LCMs in multimedia environment surrounding typical point sources.
液晶单体（LCMs）已被视为新出现的受关注污染物。电子垃圾回收场地和液晶显示器（LCD）制造商被认为是主要来源。然而，目前尚无关于这些场地周边土壤中LCM污染的信息。在本研究中，从中国南方两个不同区域采集了土壤样本：电子垃圾回收区（n = 36）和LCD制造商区域（n = 41），并测定了60种目标LCMs（包括13种联苯及其类似物（BAs）、10种氰基联苯及其类似物（CBAs）和37种氟化联苯及其类似物（FBAs））。电子垃圾回收区附近土壤中LCMs的浓度（0.32 - 18 ng/g，平均：4.2 ng/g）高于LCD制造商周边土壤中的浓度（未检出 - 7.2 ng/g，平均：1.5 ng/g）。来自这两个典型点源的土壤样本中LCMs的组成特征有很大差异。FBA的浓度随与电子垃圾回收园区距离的增加呈指数下降，在2公里内下降超过90%。BA的含量随与LCD制造商距离的增加也呈现类似的指数下降。估计电子垃圾回收区LCMs的存量为21.0千克，LCD制造商区域为10.8千克。值得注意的是，电子垃圾回收区土壤中LCMs的存量比同一区域的六溴环十二烷（HBCDs）存量高一个数量级，是废弃LCD面板全球LCMs年排放量的0.2至20倍。需要更多研究来阐明LCMs在典型点源周边多介质环境中的环境存在、行为和归宿。
