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Chen X, Lv Z, Yang Y, Yang R, Shan G, Zhu L. Screening Novel Per- and Polyfluoroalkyl Substances in Human Blood Based on Nontarget Analysis and Underestimated Potential Health Risks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:150-159. [PMID: 38153813 DOI: 10.1021/acs.est.3c06675] [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: 12/30/2023]
Abstract
Nontarget analysis has gained prominence in screening novel perfluoroalkyl and polyfluoroalkyl substances (PFASs) in the environment, yet remaining limited in human biological matrices. In this study, 155 whole blood samples were collected from the general population in Shijiazhuang City, China. By nontarget analysis, 31 legacy and novel PFASs were assigned with the confidence level of 3 or above. For the first time, 11 PFASs were identified in human blood, including C1 and C3 perfluoroalkyl sulfonic acids (PFSAs), C4 ether PFSA, C8 ether perfluoroalkyl carboxylic acid (ether PFCA), C4-5 unsaturated perfluoroalkyl alcohols, C9-10 carboxylic acid-perfluoroalkyl sulfonamides (CA-PFSMs), and C1 perfluoroalkyl sulfonamide. It is surprising that the targeted PFASs were the highest in the suburban population which was impacted by industrial emission, while the novel PFASs identified by nontarget analysis, such as C1 PFSA and C9-11 CA-PFSMs, were the highest in the rural population who often drank contaminated groundwater. Combining the toxicity prediction results of the bioaccumulation potential, lethality to rats, and binding affinity to target proteins, C3 PFSA, C4 and C7 ether PFSAs, and C9-11 CA-PFSMs exhibit great health risks. These findings emphasize the necessity of broadening nontarget analysis in assessing the PFAS exposure risks, particularly in rural populations.
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Affiliation(s)
- Xin Chen
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Zixuan Lv
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Yi Yang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Rongyan Yang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Guoqiang Shan
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Lingyan Zhu
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, P. R. China
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Wang WL, Zhang Y, Sun DM, Chen ZY, Qian M, Zhou Y, Feng XS, Zhang XY. Volatile Methylsiloxanes in Complex Samples: Recent Updates on Pretreatment and Analysis Methods. Crit Rev Anal Chem 2023:1-21. [PMID: 37603425 DOI: 10.1080/10408347.2023.2245050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Volatile methylsiloxanes (VMSs) are massively produced chemicals having applications in industry and home because of their physical and chemical characteristics. They are used in personal care products such as cosmetics, household coatings, cleaners, skin care products, and others. Resultantly, large number of VMSs are discharged into air where they can be subjected to atmospheric migrations over long distances causing toxic and estrogenic effects, persistence, and bioaccumulations. Many institutions have taken measures to control VMSs. They require accurate, rapid, and sensitive pretreatment and analysis methods for diverse samples. Herein, the pretreatment and determination methods of VMSs as reported in recent years are reviewed and summarized. Pretreatments include commonly methods such as membrane-assisted solvent extraction, liquid-liquid extraction, and others, while novel methods are solid phase extraction, solid phase microextraction, diverse liquid phase microextraction and others. Analyses are made through gas chromatography-based methods. In addition, the advantages, and disadvantages of techniques are compared, and the prospects of pretreatment and analysis methods are discussed.
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Affiliation(s)
- Wei-Lai Wang
- School of Pharmacy, China Medical University, Shenyang, China
| | - Yuan Zhang
- School of Pharmacy, China Medical University, Shenyang, China
| | - De-Mei Sun
- School of Pharmacy, China Medical University, Shenyang, China
| | - Zu-Yi Chen
- School of Pharmacy, China Medical University, Shenyang, China
| | - Min Qian
- School of Pharmacy, China Medical University, Shenyang, China
| | - Yu Zhou
- Department of Pharmacy, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xue-Song Feng
- School of Pharmacy, China Medical University, Shenyang, China
| | - Xin-Yuan Zhang
- School of Forensic Medicine, China Medical University, Shenyang, China
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Liu N, Zhang J, He X, Xu L, Cai Y. Occurrence and fate of chlorinated methylsiloxanes in surrounding aqueous systems of Shengli oilfield, China. J Environ Sci (China) 2023; 125:332-339. [PMID: 36375918 DOI: 10.1016/j.jes.2021.11.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/22/2021] [Accepted: 11/22/2021] [Indexed: 06/16/2023]
Abstract
Mono-chlorinated products of cyclic volatile methylsiloxanes (cVMS), i.e., Monochlormet-hylheptamethylcyclotetrasiloxane [D3D(CH2Cl)], monochlormethylnonamethylcyclopenta-siloxane [D4D(CH2Cl)], and monochlormethylundemethylcyclohexasiloxane [D5D(CH2Cl)], were detected in water [<LOQ (Limit of quantitation) -86.3 ng/L, df (detection frequency) = 23%-38%, n=112] and sediment samples [<LOQ-504 ng/g dw (dry weight), df = 33%-38%, n=112] from 16 lakes located in Shengli oilfield of China, and had apparent increasing trends (31%-34% per annum) in sediments during Year 2014-2020. Simulated experiments showed that chloro-cVMS in sediment-water system had approximately 1.7-2.0 times slower elimination rates than parent cVMS. More specifically, compared with those of parent cVMS, volatilization (86-2558 days) and hydrolysis (135-549 days) half-lives of chloro-cVMS were respectively 1.3-2.0 and 1.8-2.1 times longer. In two species of freshwater mussels (n=1050) collected from six lakes, concentrations of chloro-cVMS ranged from 9.8-998 ng/g dw in Anodonta woodiana and 8.4-970 ng/g dw in Corbicula fluminea. Compared with parent cVMS, chloro-cVMS had 1.1-1.5 times larger biota-sediment accumulation factors (2.1-3.0) and 1.1-1.7 times longer half-lives (13-42 days). Their stronger persistence in sediment and bioaccumulation in freshwater mussels suggested that environmental emission, distribution and risks of chloro-cVMS deserve further attention.
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Affiliation(s)
- Nannan Liu
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
| | - Jie Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
| | - Xudan He
- Institute of Resources and Environment, Beijing Academy of Science and Technology, Beijing 100089, China
| | - Lin Xu
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China.
| | - Yaqi Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China; University of Chinese Academy of Sciences, Beijing 100049, China
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Zhang J, Liu N, Ren J, Xu L, Cai Y. Vinylmethylsiloxanes in Municipal Wastewater Treatment Plant and Biosolid-Amended Soils: Their Distribution and Backbone/Vinyl Branch Degradation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:10691-10698. [PMID: 35833964 DOI: 10.1021/acs.est.2c01400] [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: 06/15/2023]
Abstract
This study is the first to investigate the emission and environmental fate of one type of modified methylsiloxane with double-bond (vinyl) groups. During 2018-2020, 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane (V3), 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (V4), and 2,4,6,8,10-pentavinyl-2,4,6,8,10-pentamethylcyclopentasiloxane (V5) were found in aqueous (<LOD-72.9 ng/L) and solid [13.0-371 ng/g dw (dry weight)] phases of wastewater samples from one Chinese municipal wastewater treatment plant (WWTP) as well as the corresponding biosolid-amended soils [<LOD-36.9 ng/g dw, df (detection frequency) = 37.5-41.7%, n = 48]. Based on the measure of environmental samples, simulated experiment, and product analysis by ESI-FT-ICR-MS, it was found that (1) in addition to sorption to sludge, abiotic degradation of vinylmethylsiloxanes (especially V3, t1/2 = 0.5-1.9 h at pH = 5.2-9.2) should have an important contribution to their sufficient removal in WWTP; (2) different from siloxane analogues with saturated branches and aromatic branches, abiotic degradation pathways of vinylmethylsiloxane might include both the hydrolysis of Si-O backbone and the oxidation/addition reactions of vinyl branches; (3) although vinylmethylsiloxanes in wastewater could be transferred to soil by biosolids application, these compounds had no accumulation in soil, which should arise from their fast elimination, such as volatilization (t1/2 = 3.2 h-20.9 days) and degradation (t1/2 =9.1 h-96.3 days); and (4) degradation of the Si-O backbone and vinyl branches had slowing trends with the increase in the soil organic matter.
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Affiliation(s)
- Jie Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Nannan Liu
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Juntao Ren
- Dongying Eco-Environment Monitoring Center of Shandong Province, Dongying 257091, China
| | - Lin Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China
| | - Yaqi Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Hubei Key Laboratory of Environmental and Health Effects of Persistence Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan 430056, China
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Huang J, Ye L, Fang M, Su G. Industrial Production of Organophosphate Flame Retardants (OPFRs): Big Knowledge Gaps Need to Be Filled? BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2022; 108:809-818. [PMID: 35080673 DOI: 10.1007/s00128-021-03454-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 12/30/2021] [Indexed: 06/14/2023]
Abstract
Since the phase-out of traditional halogenated flame retardants (HFRs), interests of research are gradually being shifted to organophosphate flame retardants (OPFRs), and this can be reflected by the increasing number of publications on OPFRs year by year. Here, an extensive survey is conducted in an attempt to generate a list of OPFRs that are being produced in factories, and to investigate the annual production volume (APV). This survey suggests that at least n = 56 OPFR monomers and n = 62 OPFR mixtures are being currently produced in 367 factories around the world, and 201 out of them are in Mainland China. APV of OPFRs was estimated as 598,422 metric tons, and this number could be underestimated due to the limitation of available information. We also notice that current researches are confined to a limited number of OPFRs, especially for OP esters (OPEs), and other OPFRs with different structures from OPEs has been rarely studied. Based on all the collected datasets, we provide five recommendations for how to proceed with future research to more comprehensively understand the currently-produced OPFRs in the environment.
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Affiliation(s)
- Jianan Huang
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, People's Republic of China
| | - Langjie Ye
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, People's Republic of China
| | - Mingliang Fang
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
| | - 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, People's Republic of China.
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6
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Liu N, Zhao X, Xu L, Cai Y. Temporal and spatial variation, input fluxes and risk assessment of cyclic methylsiloxanes in Rivers-Bohai Sea System. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 231:113169. [PMID: 35032727 DOI: 10.1016/j.ecoenv.2022.113169] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 12/23/2021] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
In the present study, the total concentrations of three cyclic methylsiloxanes (ΣCMSs), including octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6), in surface water and sediment samples of five main rivers draining into the Bohai Sea were in the range of 1.62-1.39 × 103 ng/L and 1.92-1.69 × 103 ng/g dw, respectively. Riverine input had great influence on the coastal distribution of siloxanes in the Bohai Sea. The concentrations of ΣCMSs in coastal sediments farthest away (40-50 Km) from the estuaries were only 4-33% of those close to the estuaries. But surprisingly, compared with those in coastal sediments (1.03-1.44 × 103 ng/g dw), the concentrations of CMSs (1.56-2.67 × 103 ng/g dw) in some deep-sea sediments were higher, and certain positive correlation existed between sediment ΣCMSs in this area with the total petroleum hydrocarbons concentration (R2 = 0.92, p < 0.05) suggested offshore oil exploitation as one important emission source of siloxanes. Overall, calculated based on their sediment concentrations, D4-D6 had negligible ecological risks to the benthic organisms in river-Bohai Sea system, i.e. HQs < 1. However, sediment-accumulation of siloxanes should be paid attention, especially for some deep-sea sediments nearby drilling platforms, where it will take only less than 1 year for D4 to reach its threshold.
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Affiliation(s)
- Nannan Liu
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
| | - Xuesheng Zhao
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, Tianjin 300384, China
| | - Lin Xu
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China.
| | - Yaqi Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China; University of Chinese Academy of Sciences, Beijing 100049, China
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8
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Xiang X, Liu N, Xu L, Cai Y. Review of recent findings on occurrence and fates of siloxanes in environmental compartments. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 224:112631. [PMID: 34416634 DOI: 10.1016/j.ecoenv.2021.112631] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 08/08/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
In view of their vast global usage in both consumer products and industrial processes, environmental emission and fates of siloxanes have become concerned issue. This review summarized the research progress, especially in the last decade, on production/consumption data, toxicities, analysis methods, environmental distribution, migration and degradation/transformation of both dimethylsiloxanes and modified siloxanes in atmospheric, aquatic and terrestrial compartments from various areas (especially in China). In spite of their fast degradation (hydrolysis and hydroxylation, etc) in various matrices (except sediment), dimethylsiloxane oligomers have been found in various environmental matrices from many countries due to their constant usage and emission. Moreover, recent literatures have paid attention to behaviors of dimethylsiloxanes in industrial areas, e.g., their higher residual levels compared with residential areas and unique transformed products (such as halogenated products) arose from special industrial production scenarios. Meanwhile, although most prior studies focused on dimethylsiloxanes, identification of modified-siloxanes with other functional groups in environment have been beginning to attract the attention of scientists. Furthermore, related literatures indicated that compared with dimethylsiloxanes, both halogenated-dimethylsiloxanes and modified methylsiloxanes (phenylsiloxanes and trifluoropropylsiloxanes) could have stronger persistence due to their weaker volatilization and degradation, especially in terrestrial matrices.
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Affiliation(s)
- Xiaoling Xiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Hubei Key Laboratory of Environmental and Health Effects of Persistence Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan 430056, China
| | - Nannan Liu
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Lin Xu
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China.
| | - Yaqi Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Hubei Key Laboratory of Environmental and Health Effects of Persistence Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan 430056, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China
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Cheng Z, Qiu X, Shi X, Zhu T. Identification of organosiloxanes in ambient fine particulate matters using an untargeted strategy via gas chromatography and time-of-flight mass spectrometry. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 271:116128. [PMID: 33421844 DOI: 10.1016/j.envpol.2020.116128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 06/12/2023]
Abstract
Organosilicons are widely used in consumer products and are ubiquitous in living environments. However, there is little systemic information on this group of pollutants in ambient particles. This study proposes a novel untargeted strategy based mainly on the mass difference of three silicon isotopes to screen organosilicon compounds from 2-year PM2.5 samples of Beijing using gas chromatography and high-resolution time-of-flight mass spectrometry. 61 organosilicons were filtered from 1019 peaks, and 35 ones were identified as organosiloxanes including 17 methylsiloxanes and 18 phenylmethylsiloxanes, of which 6 and 3 species were confirmed using reference standards, respectively. These organosiloxanes could be clustered into three groups: low-silicon-number methylsiloxanes, high-silicon-number methylsiloxanes, and phenylmethylsiloxanes. Low-silicon-number methylsiloxanes showed high abundance in the heating season but low abundance in the non-heating season, whereas high-silicon-number methylsiloxanes showed the opposite seasonal variation. This study provides a promising strategy for screening organosilicon compounds through an untargeted approach and gives insights for further investigation of the sources and health risks of organosiloxanes.
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Affiliation(s)
- Zhen Cheng
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, And Center for Environment and Health, Peking University, Beijing, 100871, PR China
| | - Xinghua Qiu
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, And Center for Environment and Health, Peking University, Beijing, 100871, PR China.
| | - Xiaodi Shi
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, And Center for Environment and Health, Peking University, Beijing, 100871, PR China
| | - Tong Zhu
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, And Center for Environment and Health, Peking University, Beijing, 100871, PR China
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Zhi L, Sun H, Xu L, Cai Y. Distribution and Elimination of Trifluoropropylmethylsiloxane Oligomers in Both Biosolid-Amended Soils and Earthworms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:985-993. [PMID: 33356203 DOI: 10.1021/acs.est.0c05443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
During a primary screening in 2015 and 2016, tris(trifluoropropyl)trimethylcyclotrisiloxane (D3F) and cis-/trans-tetrakis(trifluoropropyl)tetramethylcyclotetrasiloxane isomers (cis-D4F, trans-D4Fa,b,c) were detected in 12 biosolid-amended soils from Laixi and Shijiazhuang Cities of China, with mean concentrations being 10.3 ng/g dry weight (dw) and 2.7 ng/g dw for D3F and D4F, respectively. Subsequently, one further systematical survey found that although repeatedly amended by biosolids containing trifluoropropylmethylsiloxanes (4.2-724 ng/g dw), these compounds had no increasing trend in biosolid-amended soils (n = 100) collected from Laixi City at five sampling events from February 2017 to June 2019. Simulated experiments indicated that hydrolysis half-lives (1.8-28.0 days) of trifluoropropylmethylsiloxanes in soils were 3.0-18.3 times shorter than volatilization half-lives (7.4-362 days). Compared with those of octamethylcyclotetrasiloxane (D4), the hydrolysis rates of D4F isomers were faster in soils with total organic carbon (TOC) ≤80 mg/g but lower in soils with TOC ≥ 150 mg/g. In earthworm bodies, trifluoropropylmethylsiloxanes had 1.03-1.5 times lower biota-soil accumulation factors (1.3-3.2) but 1.4-3.0 times longer half-lives (2.6-5.7 days) than D4. The stronger persistence of fluorinated-siloxane than the corresponding dimethylsiloxane in both soils (at high TOC levels) and earthworms indicated that environmental risks of these compounds deserve further investigation.
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Affiliation(s)
- Liqin Zhi
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
- Environmental Protection Research Institute of Light Industry, Beijing 100089, China
| | - Hongyu Sun
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Lin Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
| | - Yaqi Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
- Hubei Key Laboratory of Environmental and Health Effects of Persistence Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan 430056, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China
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Huang Z, Xiang X, Xu L, Cai Y. Phenylmethylsiloxanes and trifluoropropylmethylsiloxanes in municipal sludges from wastewater treatment plants in China: Their distribution, degradation and risk assessment. WATER RESEARCH 2020; 185:116224. [PMID: 32758790 DOI: 10.1016/j.watres.2020.116224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/13/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Based on wastewater and raw/digested sludge samples from 29 wastewater treatment plants in 25 Chinese cities, the nationwide profiles of cis- and trans- isomers of phenylmethylsiloxanes (P3 and P4) and trifluoropropylmethylsiloxanes (D3F and D4F) were investigated. Calculated with paired influents/sludges positive for these compounds, majority (93% at mean) of them were found accumulating in raw sludges [<LOQ-188 ng/g dw (dry weight), df (detection frequency) = 0-96.6%, n = 58] during wastewater treatment. Overall, trifluoropropylmethylsiloxanes were merely found in 6 cities, while phenylmethylsiloxanes were found in all cities distributed over seven geographic regions of China. Sludge emissions of phenylmethylsiloxanes in each region correlated with their reported consumption volume (R2 = 0.81, except for the Southwest China), per capita gross domestic products (R2 = 0.20), and annual average temperature (R2 = 0.63). Although not found in wastewater biological treatment processes, degradation of phenylmethylsiloxanes and trifluoropropylmethylsiloxanes was apparent (3.0-25.9%) during sludge-digestion processes. In digestion experiments, detection of silanediols and silanetriols indicated possible biodegradation pathway, i.e., hydrolysis of Si-O and Si-C bones, with half-lives ranging from 33.7-57.7 d The calculated hazard quotients of these compounds in soils undergoing one year sludge-fertilization were less than 0.01, but their ecological risks should be further studied in view of their potential accumulation in soils.
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Affiliation(s)
- Zichun Huang
- Hubei Key Laboratory of Environmental and Health Effects of Persistence Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xiaoling Xiang
- Hubei Key Laboratory of Environmental and Health Effects of Persistence Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Lin Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Yaqi Cai
- Hubei Key Laboratory of Environmental and Health Effects of Persistence Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China
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Zhu B, Jiang W, Wang W, Lin Y, Ruan T, Jiang G. Occurrence and Degradation Potential of Fluoroalkylsilane Substances as Precursors of Perfluoroalkyl Carboxylic Acids. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:4823-4831. [PMID: 30999748 DOI: 10.1021/acs.est.9b00690] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Polyfluoroalkylsilanes (PFASis) are a class of artificial chemicals with wide applications in surface coating, which arouse attention due to their hydrophobic/oleophobic properties and potential biological effects. In this study, a robust high-resolution mass spectrometry method through direct injection into a Fourier transform ion cyclotron resonance instrument was established, with the aid of CF2-scaled Kendrick mass defect analysis and isotope fine structure elucidation. The occurrence of 8:2 polyfluoroalkyl trimethoxysilane (8:2 PTrMeOSi) and 8:2 polyfluoroalkyl triethoxysilane (8:2 PTrEtOSi), as well as their cationic adducts, solvent substitutions, and other compound analogues, were identified in commercial antifingerprint liquid products. In the hydroxyl radical-based total oxidizable precursor assay, differential molar yields of products were observed with regard to varied PFASi carbon-chain lengths and terminal groups. The yields of perfluoroalkyl carboxylic acids (PFCAs) from 8:2 PTrMeOSi conversion were the highest (92 ± 9%, n = 3), with the C ( n - 1) perfluoroheptanoic acid (PFHpA, 49 ± 11%, n = 3) as the dominating product. Distinct conversion of 8:2 PTrMeOSi in the simulated solar exposure experiments found that C ( n) perfluorooctanoic acid (PFOA, 0.6 ± 0.04 ‰, n = 3) was predominant, and 8:2 fluorotelomer carboxylic acid (8:2 FTCA, 0.59 ± 0.08‰, n = 3), 8:2 fluorotelomer unsaturated carboxylic acid (8:2 FTUCA, 0.09 ± 0.00‰, n = 3) intermediates were also observed. To our knowledge, this is the first report regarding the occurrence and degradation potential of several fluoroalkylsilane substances as PFCA precursors.
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Affiliation(s)
- Bao Zhu
- Environment Research Institute , Shandong University , Binhai Road 72 , Qingdao 266237 , P. R. China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
| | - Wei Jiang
- Environment Research Institute , Shandong University , Binhai Road 72 , Qingdao 266237 , P. R. China
| | - Wenxing Wang
- Environment Research Institute , Shandong University , Binhai Road 72 , Qingdao 266237 , P. R. China
| | - Yongfeng Lin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
| | - Ting Ruan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
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