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Xie JF, Gu JY, Li LZ, Guo Y, Liu LY. First report on liquid crystal monomers in tree barks surrounding a display manufacturer: Insights for atmospheric transport and establishment of priority list. JOURNAL OF HAZARDOUS MATERIALS 2024; 477:135372. [PMID: 39106723 DOI: 10.1016/j.jhazmat.2024.135372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 07/26/2024] [Accepted: 07/27/2024] [Indexed: 08/09/2024]
Abstract
Tree bark has been proven as an effective passive air sampler, particularly where access to active sampling methods is limited. In this study, 60 target liquid crystal monomers (LCMs; comprising 10 cyanobiphenyl and analogs (CBAs), 13 biphenyl and analogs (BAs), and 37 fluorinated biphenyl and analogs (FBAs)) were analyzed in 34 tree barks collected from the vicinity of a liquid crystal display (LCD) manufacturer situated in the Pearl River Delta, South China. The concentrations of LCMs in tree barks ranged from 1400 to 16000 ng/g lipid weight, with an average of 5900 ng/g lipid weight. Generally, bark levels of BAs exponentially decreased within 5 km of the LCD manufacturer. The profiles of LCMs in tree barks are similar to previously reported patterns in gaseous phase, suggesting bark's efficacy as a sampler for gaseous LCMs. The inclusion of different congeners in existing studies on the environmental occurrence of LCMs has hindered the horizontal comparisons. Therefore, this study established a list of priority LCMs based on environmental monitoring data and the publicly accessible production data. This list comprised 146 LCMs, including 63 REACH registered LCMs that haven't been analyzed in any study and 56 belonging to 4 types of mainstream LCMs.
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Affiliation(s)
- Jiong-Feng Xie
- Guangdong Key Laboratory of Environmental Pollution and Health, Scholl of Environment, Jinan University, Guangzhou 511443, China
| | - Jia-Yi Gu
- Guangdong Key Laboratory of Environmental Pollution and Health, Scholl of Environment, Jinan University, Guangzhou 511443, China
| | - Liang-Zhong Li
- Guangdong Provincial Key Laboratory of High-Quality Recycling of End-of-Life New Energy Devices, Guangzhou Institute of Energy Research, Chinese Academy of Sciences, Guangzhou 510630, China
| | - Ying Guo
- Guangdong Key Laboratory of Environmental Pollution and Health, Scholl of Environment, Jinan University, Guangzhou 511443, China
| | - Liang-Ying Liu
- Guangdong Key Laboratory of Environmental Pollution and Health, Scholl of Environment, Jinan University, Guangzhou 511443, China.
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He W, Yang H, Li Y, Cui Y, Wei L, Xu T, Li Y, Zhang M. Identifying the toxic mechanisms of emerging electronic contaminations liquid crystal monomers and the construction of a priority control list for graded control. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175398. [PMID: 39128516 DOI: 10.1016/j.scitotenv.2024.175398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2024] [Revised: 08/05/2024] [Accepted: 08/06/2024] [Indexed: 08/13/2024]
Abstract
Liquid crystal monomers (LCMs) are identified as emerging organic contaminations with largely unexplored health impacts. To elucidate their toxic mechanisms, support the establishment of environmental discharge and management standards, and promote effective LCMs control, this study constructs a database covering 20,545 potential targets of 1431 LCMs, highlighting 9 key toxic target proteins that disrupt the nervous system and metabolic functions. GO and KEGG pathway analysis suggests LCMs severely affect nervous system, linked to neurodegenerative diseases and mental health disorders, with toxicity variations driven by electronegativity and structural complexity of LCM terminal groups. To achieve tiered control of LCMs, construct toxicity risk control lists for 9 key toxic target proteins, suitable for the graded control of LCMs, management recommendations are provided based on toxicity levels. These lists were validated for reliability and offer reliable toxicity predictions for LCMs. SHAP analysis points to electronic properties, molecular shape, and structural characteristics of LCMs as primary health impact factors. As the first study integrating machine learning with computational toxicology to outline LCMs health impacts, it aims to enhance public understanding of LCM toxicity risks and support the development of environmental standards, effective management of LCM production and emissions, and reduction of public exposure risks.
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Affiliation(s)
- Wei He
- MOE Key Laboratory of Resources Environmental Systems Optimization, North China Electric Power University, Beijing, China
| | - Hao Yang
- MOE Key Laboratory of Resources Environmental Systems Optimization, North China Electric Power University, Beijing, China
| | - Yunxiang Li
- MOE Key Laboratory of Resources Environmental Systems Optimization, North China Electric Power University, Beijing, China
| | - Yuhan Cui
- MOE Key Laboratory of Resources Environmental Systems Optimization, North China Electric Power University, Beijing, China
| | - Luanxiao Wei
- MOE Key Laboratory of Resources Environmental Systems Optimization, North China Electric Power University, Beijing, China
| | - Tingzhi Xu
- MOE Key Laboratory of Resources Environmental Systems Optimization, North China Electric Power University, Beijing, China.
| | - Yu Li
- MOE Key Laboratory of Resources Environmental Systems Optimization, North China Electric Power University, Beijing, China
| | - Meng Zhang
- College of Environmental Sciences and Engineering, State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Peking University, Beijing 100871, China; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, International Joint Laboratory for Regional Pollution Control, Ministry of Education, Beijing 100871, China.
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3
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Stadelmann B, Leonards PEG, Brandsma SH. A new class of contaminants of concern? A comprehensive review of liquid crystal monomers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 947:174443. [PMID: 38964401 DOI: 10.1016/j.scitotenv.2024.174443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/26/2024] [Accepted: 06/30/2024] [Indexed: 07/06/2024]
Abstract
Liquid crystal monomers (LCMs) are a class of emerging contaminants of concern predicted to be persistent, bioaccumulative and toxic (PBT). Being one of the key components in liquid crystal displays (LCDs), the disposal of LCD containing devices is closely related to the emission of LCMs into the environment. LCMs have been detected in a wide range of environmental matrices including dust, sediment, soil, sewage leachate, and air, with concentration ranges between 17 and 2121 ng/g found in indoor residential dust. Furthermore, they have been detected on human skin at concentrations up to 2,071,000 ng/m2 and in the serum of e-waste dismantling workers, at concentrations ranging from 3.9 to 276 ng/mL. Despite the far-reaching contamination of these compounds, there is limited knowledge of their environmental behaviour, fate, and toxicity. Model predictions show that 297 of 330 LCMs are persistent and bioaccumulative compounds, with many more indicated as being toxic. However, current knowledge of their physicochemical and PBT properties is largely restricted to theoretical predictions and limited to a small number of experimental toxicity studies. As an emerging class of contaminants of concern, a lack of standardisation between studies was identified as a key challenge to advancing the state of knowledge of these compounds. Not only are harmonised analytical methods for their determination and quantification in environmental media yet to be established, but there is also a need for a universal abbreviation system. To further harmonise the reporting of data on LCMs we propose reporting the sum concentration of ten priority LCMs, selected on the basis detection frequency, toxicity and potential for human exposure. Of the ten priority LCMs five are fluorinated biphenyls and analogues, four are biphenyls/bicyclohexyls and analogues and one is a cyanobiphenyl.
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Affiliation(s)
- Bianca Stadelmann
- Institute Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam, PO Box 94240, 1090 GE Amsterdam, the Netherlands.
| | - Pim E G Leonards
- Amsterdam Institute for Life and Environment, Chemistry for Environment & Health, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, the Netherlands
| | - Sicco H Brandsma
- Amsterdam Institute for Life and Environment, Chemistry for Environment & Health, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, the Netherlands
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Ge Y, Cui J, Zhang L, Zhang S, Baqar M, Cheng Z. Informal E-waste dismantling activities accelerated the releasing of liquid crystal monomers (LCMs) in Pakistan: Occurrence, distribution, and exposure assessment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 932:172987. [PMID: 38734084 DOI: 10.1016/j.scitotenv.2024.172987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/28/2024] [Accepted: 05/02/2024] [Indexed: 05/13/2024]
Abstract
Liquid crystal monomers (LCMs) are emerging contaminants characterized by their persistence, bioaccumulation potential, and toxicity. They have been observed in several environmental matrices associated with electronic waste (e-waste) dismantling activities, particularly in China. However, there is currently no information on the pollution caused by LCMs in other developing countries, such as Pakistan. In this study, we collected soil samples (n = 59) from e-waste dismantling areas with different functions in Pakistan for quantification analysis of 52 target LCMs. Thirty out of 52 LCMs were detected in the soil samples, with the concentrations ranging from 2.14 to 191 ng/g (median: 16.3 ng/g), suggesting widespread contamination by these emerging contaminants. Fluorinated LCMs (median: 10.4 ng/g, range: 1.27-116 ng/g) were frequently detected and their levels were significantly (P < 0.05) higher than those of non-fluorinated LCMs (median: 6.11 ng/g, range: not detected (ND)-76.7 ng/g). The concentrations and profiles of the observed LCMs in the soil samples from the four functional areas varied. The informal dismantling of e-waste poses a potential exposure risk to adults and infants, with median estimated daily intake (EDI, ng/kg bw/day) values of 0.0420 and 0.1013, respectively. Calculation of the hazard quotient (HQ) suggested that some LCMs (e.g., ETFMBC (1.374) and EDFPB (1.257)) may pose potential health risks to occupational workers and their families. Considering the widespread contamination and risks associated with LCMs, we strongly recommend enhancing e-waste management and regulation in Pakistan.
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Affiliation(s)
- Yanhui Ge
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Jingren Cui
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China; MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Lianying Zhang
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Shaohan Zhang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Mujtaba Baqar
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan
| | - Zhipeng Cheng
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
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He S, He J, Ma S, Wei K, Wu F, Xu J, Jin X, Zhao Y, Martyniuk CJ. Liquid crystal monomers disrupt photoreceptor patterning of zebrafish larvae via thyroid hormone signaling. ENVIRONMENT INTERNATIONAL 2024; 188:108747. [PMID: 38761427 DOI: 10.1016/j.envint.2024.108747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/12/2024] [Accepted: 05/10/2024] [Indexed: 05/20/2024]
Abstract
Liquid crystal monomers (LCMs) are the raw material for liquid crystal displays, and their use is steadily increasing in electronic products. Recently, LCMs have been reported to be novel endocrine disrupting chemicals, however, the mechanisms underlying their potential for thyroid hormone disruption and visual toxicity are not well understood. In this study, six widely used fluorinated LCMs (FLCMs) were selected to determine putative mechanisms underlying FLCM-induced toxicity to the zebrafish thyroid and visual systems. Exposure to FLCMs caused damage to retinal structures and reduced cell density of ganglion cell layer, inner nuclear layer, and photoreceptor layer approximately 12.6-46.1%. Exposure to FLCMs also disrupted thyroid hormone levels and perturbed the hypothalamic-pituitary-thyroid axis by affecting key enzymes and protein in zebrafish larvae. A thyroid hormone-dependent GH3 cell viability assay supported the hypothesis that FLCMs act as thyroid hormone disrupting chemicals. It was also determined that FLCMs containing aliphatic ring structures may have a higher potential for T3 antagonism compared to FLCMs without an aliphatic ring. Molecular docking in silico suggested that FLCMs may affect biological functions of thyroxine binding globulin, membrane receptor integrin, and thyroid receptor beta. Lastly, the visual motor response of zebrafish in red- and green-light was significantly inhibited following exposure to FLCMs. Taken together, we demonstrate that FLCMs can act as thyroid hormone disruptors to induce visual dysfunction in zebrafish via several molecular mechanisms.
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Affiliation(s)
- Shan He
- College of Geo-exploration Science and Technology, Jilin University, Changchun 130026, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jia He
- Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology, College of Water Sciences, Beijing Normal University, Beijing 100875, China.
| | - Siying Ma
- Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology, College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Kunyu Wei
- Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology, College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Fengchang Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Jian Xu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xiaowei Jin
- China National Environmental Monitoring Centre, Beijing 100012, China
| | - Yuanhui Zhao
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, Jilin 130117, China
| | - Christopher J Martyniuk
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, UF Genetics Institute, Interdisciplinary Program in Biomedical Sciences, University of Florida, Gainesville, FL 32611, USA
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Zheng S, Wang J, Luo K, Gu X, Yuan G, Wei M, Yao Y, Zhao Y, Dai J, Zhang K. Comprehensive Characterization of Organic Light-Emitting Materials in Breast Milk by Target and Suspect Screening. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5103-5116. [PMID: 38445973 DOI: 10.1021/acs.est.3c08961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Organic light-emitting materials (OLEMs) are emerging contaminants in the environment and have been detected in various environment samples. However, limited information is available regarding their contamination within the human body. Here, we developed a novel QuEChERS (quick, easy, cheap, effective, rugged, and safe) method coupled with triple quadrupole/high-resolution mass spectrometry to determine OLEMs in breast milk samples, employing both target and suspect screening strategies. Our analysis uncovered the presence of seven out of the 39 targeted OLEMs in breast milk samples, comprising five liquid crystal monomers and two OLEMs commonly used in organic light-emitting diode displays. The cumulative concentrations of the seven OLEMs in each breast milk sample ranged from ND to 1.67 × 103 ng/g lipid weight, with a mean and median concentration of 78.76 and 0.71 ng/g lipid weight, respectively, which were higher compared to that of typical organic pollutants such as polychlorinated biphenyls and polybrominated diphenyl ethers. We calculated the estimated daily intake (EDI) rates of OLEMs for infants aged 0-12 months, and the mean EDI rates during lactation were estimated to range from 30.37 to 54.89 ng/kg bw/day. Employing a suspect screening approach, we additionally identified 66 potential OLEMs, and two of them, cholesteryl hydrogen phthalate and cholesteryl benzoate, were further confirmed using pure reference standards. These two substances belong to cholesteric liquid crystal materials and raise concerns about potential endocrine-disrupting effects, as indicated by in silico predictive models. Overall, our present study established a robust method for the identification of OLEMs in breast milk samples, shedding light on their presence in the human body. These findings indicate human exposure to OLEMs that should be further investigated, including their health risks.
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Affiliation(s)
- Shuping Zheng
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Jingsheng Wang
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Kai Luo
- Key Laboratory of Environment Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Xiaoxia Gu
- Zhongda Hospital, Southeast University, Nanjing 210009, China
| | - Guanxiang Yuan
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Meiting Wei
- Department of Preventive Medicine, Shantou University Medical College, Shantou 515041, Guangdong, China
| | - Yao Yao
- The Genetics Laboratory, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City, Longgang Maternity and Child Institute, Shantou University Medical College, Shenzhen 518172, Guangdong, China
| | - Yanbin Zhao
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Jiayin Dai
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Kun Zhang
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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Xie JF, Wei GL, Zeng LX, Liu LY. Liquid crystal monomers in soils near the e-waste recycling site and liquid crystal display manufacturer: Exponential decrease with distance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 909:168428. [PMID: 37972771 DOI: 10.1016/j.scitotenv.2023.168428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/02/2023] [Accepted: 11/06/2023] [Indexed: 11/19/2023]
Abstract
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.
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Affiliation(s)
- Jiong-Feng Xie
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
| | - Gao-Ling Wei
- 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
| | - Li-Xi Zeng
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
| | - Liang-Ying Liu
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
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Zhu X, Yu Y, Meng W, Huang J, Su G, Zhong Y, Yu X, Sun J, Jin L, Peng P, Zhu L. Aerobic Microbial Transformation of Fluorinated Liquid Crystal Monomer: New Pathways and Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:510-521. [PMID: 38100654 DOI: 10.1021/acs.est.3c04256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Fluorinated liquid crystal monomers (FLCMs) have been suggested as emerging contaminants, raising global concern due to their frequent occurrence, potential toxic effects, and endurance capacity in the environment. However, the environmental fate of the FLCMs remains unknown. To fill this knowledge gap, we investigated the aerobic microbial transformation mechanisms of an important FLCM, 4-[difluoro(3,4,5-trifluorophenoxy)methyl]-3, 5-difluoro-4'-propylbiphenyl (DTMDPB), using an enrichment culture termed as BG1. Our findings revealed that 67.5 ± 2.1% of the initially added DTMDPB was transformed in 10 days under optimal conditions. A total of 14 microbial transformation products obtained due to a series of reactions (e.g., reductive defluorination, ether bond cleavage, demethylation, oxidative hydroxylation and aromatic ring opening, sulfonation, glucuronidation, O-methylation, and thiolation) were identified. Consortium BG1 harbored essential genes that could transform DTMDPB, such as dehalogenation-related genes [e.g., glutathione S-transferase gene (GST), 2-haloacid dehalogenase gene (2-HAD), nrdB, nuoC, and nuoD]; hydroxylating-related genes hcaC, ubiH, and COQ7; aromatic ring opening-related genes ligB and catE; and methyltransferase genes ubiE and ubiG. Two DTMDPB-degrading strains were isolated, which are affiliated with the genus Sphingopyxis and Agromyces. This study provides a novel insight into the microbial transformation of FLCMs. The findings of this study have important implications for the development of bioremediation strategies aimed at addressing sites contaminated with FLCMs.
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Affiliation(s)
- Xifen Zhu
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, China
| | - Yuanyuan Yu
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, China
| | - Weikun Meng
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
| | - Jiahui Huang
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, China
| | - Guanyong Su
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
| | - Yin Zhong
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China
| | - Xiaolong Yu
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, China
| | - Jianteng Sun
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, China
| | - Ling Jin
- Department of Civil and Environmental Engineering and Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Kowloon 999077, Hong Kong
| | - Ping'an Peng
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China
| | - Lizhong Zhu
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
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Zhan Y, Jin Q, Lin H, Tao D, Law LY, Sun J, He Y. Occurrence, behavior and fate of liquid crystal monomers in municipal wastewater. WATER RESEARCH 2023; 247:120784. [PMID: 37950950 DOI: 10.1016/j.watres.2023.120784] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 11/13/2023]
Abstract
Liquid crystal monomers (LCMs), the essential substances used in the display screen of electronic devices, have been proposed as a class of emerging chemicals of concern. Despite their detection in various environmental matrices, little is known about the presence of LCMs in municipal sewage systems. This study aimed to investigate the occurrence, distribution, and fate of 64 LCMs released into the aqueous environment from a municipal wastewater treatment plant (WWTP) in Hong Kong, China. In total 14 LCMs were detected in WWTP samples. Specifically, the Σ14LCMs concentrations in crude influent, final effluent, and final sludge were found to be 16.8 ± 0.3 ng/L, 2.71 ± 0.05 ng/L, and 19.2 ± 1.0 ng/g dry weight, respectively. Among them, 10 fluorinated LCMs (F-LCMs) were determined to be present at concentrations of 8.90 ± 0.10 ng/L, 1.69 ± 0.05 ng/L, and 9.94 ± 1.00 ng/g dry weight, respectively. The predominant non-fluorinated LCMs (NF-LCMs) detected in all samples were 3OCB and EPhEMOB, while 2OdF3B was the dominant F-LCM. The overall removal rate of total LCMs was 83.8 ± 0.3 %, with 25.4 ± 4.8 % being removed by biodegradation and UV treatment. Compared to NF-LCMs, F-LCMs were more resistant to biodegradation. Despite the significant removal of LCMs through WWTP, the remaining LCMs in final effluent could result in an annual emission of 3.04 kg of total LCMs from the population of Hong Kong. This study provides the first evidence of LCMs contamination in municipal wastewater, possibly arising from routine electronic devices usage. Further investigation is needed to elucidate the potential impact of LCMs emission via WWTP effluent on the aquatic receiving ecosystem.
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Affiliation(s)
- Yuting Zhan
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Qianqian Jin
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
| | - Huiju Lin
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Danyang Tao
- State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Lok Yung Law
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Jiaji Sun
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Yuhe He
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China.
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Jin Q, Fan Y, Lu Y, Zhan Y, Sun J, Tao D, He Y. Liquid crystal monomers in ventilation and air conditioning dust: Indoor characteristics, sources analysis and toxicity assessment. ENVIRONMENT INTERNATIONAL 2023; 180:108212. [PMID: 37738697 DOI: 10.1016/j.envint.2023.108212] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 08/25/2023] [Accepted: 09/14/2023] [Indexed: 09/24/2023]
Abstract
Indoor dust contaminated with liquid crystal monomers (LCMs) released from various commercial liquid crystal display (LCD) screens may pose environmental health risks to humans. This study aimed to investigate the occurrence of 64 LCMs in ventilation and air conditioning filters (VACF) dust, characterize their composition profiles, potential sources, and associations with indoor characteristics, and assess their in vitro toxicity using the human lung bronchial epithelial cells (BEAS-2B). A total of 31 LCMs with concentrations (ΣLCMs) ranging from 43.7 ng/g to 448 ng/g were detected in the collected VACF dust. Additional analysis revealed the potential interactions between indoor environmental conditions and human exposure risks associated with the detected LCMs in VACF dust. The service area and working time of the ventilation and air conditioning system, and the number of indoor LCD screens were positively correlated with the fluorinated ΣLCMs in VACF dust (r = 0.355 ∼ 0.511, p < 0.05), while the associations with the non-fluorinated ΣLCMs were not found (p > 0.05), suggesting different environmental behavior and fates of fluorinated and non-fluorinated LCMs in the indoor environment. Four main indoor sources of LCMs (i.e., computer (37.1%), television (28.3%), Brand A smartphone (21.2%) and Brand S smartphone (13.4%)) were identified by positive matrix factorization-multiple linear regression (PMF-MLR). Exposure to 14 relatively frequently detected LCMs, individually and in the mixture, induced significant oxidative stress in BEAS-2B cells. Among them, non-fluorinated LCMs, specifically 3cH2B and MeP3bcH, caused dominant decreased cell viability. This study provides new insights into the indoor LCMs pollution and the associated potential health risks due to the daily use of electronic devices.
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Affiliation(s)
- Qianqian Jin
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
| | - Yinzheng Fan
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Yichun Lu
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Yuting Zhan
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Jiaji Sun
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Danyang Tao
- State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Yuhe He
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China.
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