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Xing Y, Ge Y, Lu S, Yang T, Peng X. Dimethylcyclosiloxanes in Mobile Smart Terminal Devices: Concentrations, Distributions, Profiles, and Environmental Emissions. TOXICS 2024; 12:287. [PMID: 38668510 PMCID: PMC11053745 DOI: 10.3390/toxics12040287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 04/29/2024]
Abstract
Dimethylcyclosiloxanes (DMCs) are utilized as vital monomers in the synthesis of organosilicon compounds, integral to the manufacture of mobile smart terminal devices. Toxicological studies have revealed potential endocrine-disrupting activity, reproductive toxicity, neurotoxicity, and other toxicities of the DMCs. This study investigated the concentrations and composition profiles of seven DMCs, including hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and tetradecamethylcycloheptasiloxane (D7), hexadecamethylcyclooctasiloxane (D8), and octadecamethylcyclononasiloxane (D9) in three types of mobile smart terminal device components (silicone rubber, adhesive, and plastics). Environmental emissions of DMCs from silicone rubber materials were also estimated to improve the recognition of their potential fate within the environment. D5-D9 were widely present in silicone rubber and adhesives with detection rates ranging from 91-95.5% and 50-100%, respectively, while D3 and D4 were more frequently detected in plastics, both showing a detection rate of 61.1%. Silicone rubber had the highest total DMCs (∑7DMCs) and a concentration of 802.2 mg/kg, which were dominated by D7, D8, and D9. DMCs detected in adhesives were dominated by D4, D5, and D6. The estimated emission of ∑DMCs released into the environment in China from silicone rubber used in mobile smart terminal devices exceeds 5000 tons per year. Further studies are needed on the presence of DMCs in various commodities and environmental media to assess their ecological and human health impacts, as well as the toxicological effects of D7-D9 for the appropriate regulation of these chemicals.
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Affiliation(s)
- Yuanna Xing
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiming Ge
- School of Public Health (Shenzhen), Shenzhen Campus of SunYat-sen University, Shenzhen 518107, China; (Y.G.); (S.L.)
| | - Shaoyou Lu
- School of Public Health (Shenzhen), Shenzhen Campus of SunYat-sen University, Shenzhen 518107, China; (Y.G.); (S.L.)
| | - Tao Yang
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xianzhi Peng
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
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Sultan MB, Anik AH, Rahman MM. Emerging contaminants and their potential impacts on estuarine ecosystems: Are we aware of it? MARINE POLLUTION BULLETIN 2024; 199:115982. [PMID: 38181468 DOI: 10.1016/j.marpolbul.2023.115982] [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: 09/18/2023] [Revised: 12/21/2023] [Accepted: 12/23/2023] [Indexed: 01/07/2024]
Abstract
Emerging contaminants (ECs) are becoming more prevalent in estuaries and constitute a danger to both human health and ecosystems. These pollutants can infiltrate the ecosystem and spread throughout the food chain. Because of the diversified sources and extensive human activities, estuaries are particularly susceptible to increased pollution levels. A thorough review on recent ECs (platinum group elements, pharmaceuticals and personal care products, pesticides, siloxanes, liquid crystal monomers, cationic surfactant, antibiotic resistance genes, and microplastics) in estuaries, including their incidence, detection levels, and toxic effects, was performed. The inclusion of studies from different regions highlights the global nature of this issue, with each location having its unique set of contaminants. The diverse range of contaminants detected in estuary samples worldwide underscores the intricacy of ECs. A significant drawback is the scarcity of research on the toxic mechanisms of ECs on estuarine organisms, the prospect of unidentified ECs, warrant research scopes.
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Affiliation(s)
- Maisha Binte Sultan
- Laboratory of Environmental Health and Ecotoxicology, Department of Environmental Sciences, Jahangirnagar University, Dhaka 1342, Bangladesh; Department of Environmental Science, Bangladesh University of Professionals (BUP), Dhaka-1216, Bangladesh
| | - Amit Hasan Anik
- Department of Environmental Science, Bangladesh University of Professionals (BUP), Dhaka-1216, Bangladesh
| | - Md Mostafizur Rahman
- Laboratory of Environmental Health and Ecotoxicology, Department of Environmental Sciences, Jahangirnagar University, Dhaka 1342, Bangladesh; Department of Environmental Science, Bangladesh University of Professionals (BUP), Dhaka-1216, Bangladesh; Department of Environmental Sciences, Jahangirnagar University, Dhaka 1342, Bangladesh.
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Chen W, Lee S, Moon HB. Cyclic and linear siloxane contamination in sediment and invertebrates around a thermal power plant in Korea: Source impact, distribution, seasonal variation, and potential for bioaccumulation. CHEMOSPHERE 2024; 349:140779. [PMID: 38008296 DOI: 10.1016/j.chemosphere.2023.140779] [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: 09/06/2023] [Revised: 11/19/2023] [Accepted: 11/20/2023] [Indexed: 11/28/2023]
Abstract
Siloxanes have been commonly used as additives in a variety of industrial and consumer products. Media and government investigations have revealed that defoamers containing siloxanes are used in the effluent of thermal power plants in Korea. However, investigations of the source impact of siloxane contamination from the discharge of thermal power plants into coastal environments are scarce. In this study, sediment and invertebrates were collected around a thermal power plant to assess source impact, seasonal variation, and a potential for bioaccumulation. Although siloxanes were detectable in sediment and invertebrates, the spatial distribution and composition (which differed between the siloxanes found in sediment and invertebrates and those in defoamer used in the plant) suggest they were likely transported by long-distance migration as well as the discharge of thermal power plant. Seasonal differences might affect sedimentary contamination and the bioaccumulation potential of siloxanes. Specifically, octamethylcyclotetrasiloxane (D4) may have limited adsorption capacity and potential for long-distance migration, as its contribution in sediment far from the coastline was greater than that of decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). However, higher D5 accumulation in invertebrates, and D5 has a potential bioaccumulation. A molecular docking analysis showed that the binding affinity between D5 and the cytochrome enzyme in invertebrates was weaker than that with other siloxanes, which could lead to higher D5 accumulation in invertebrates.
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Affiliation(s)
- Wenming Chen
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, Hainan, 571158, China.
| | - Sunggyu Lee
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan, 15588, Republic of Korea
| | - Hyo-Bang Moon
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan, 15588, Republic of Korea.
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Kang Y, Lee S, Chen W, Moon HB. Factors determining contamination and time trends in cyclic and linear siloxanes in sediments from an industrialized lake in Korea. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 269:115817. [PMID: 38103470 DOI: 10.1016/j.ecoenv.2023.115817] [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: 07/10/2023] [Revised: 12/08/2023] [Accepted: 12/09/2023] [Indexed: 12/19/2023]
Abstract
Siloxanes, widely used in various consumer and industrial products, are emerging concerns of contaminants. Despite this, limited studies have been conducted on contamination and time trends on siloxanes in coastal environments. In the present study, four cyclic and 15 linear siloxanes were measured in sediments collected from an artificial saltwater lake in Korea during 2001-2016 to investigate contamination, time trends, and ecotoxicological concerns. Cyclic siloxanes were detected in all sediment samples, whereas linear siloxanes were not frequently detected. The highest siloxane concentrations were observed in creeks passing through various industrial complexes, indicating that industrial activities predominantly contributed to siloxane contamination in coastal environments. Decamethylcyclopentasiloxane (D5) and dodecylcyclohexasiloxane (D6) were predominant siloxanes in sediments over the last two decades. Siloxane concentrations significantly increased in creek sediments from 2008 to 2016, whereas those in inshore and offshore regions significantly decreased due to a strong dilution effect by the operation of tidal power plant. This suggests that consumption patterns and coastal development activities are crucial factors determining the contamination and time trends in the sedimentary siloxanes. The sedimentary concentrations of octamethylcyclotetrasiloxane (D4) and D5 exceeded several thresholds, raising the potentials for ecological risks to aquatic organisms.
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Affiliation(s)
- Yujin Kang
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Sunggyu Lee
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Wenming Chen
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158, China
| | - Hyo-Bang Moon
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea.
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Chen W, Kang YJ, Lee HK, Lee M, Moon HB. Nationwide monitoring of cyclic and linear siloxanes in sediment and bivalves from Korean coastal waters: Occurrence, geographical distribution, and bioaccumulation potential. MARINE POLLUTION BULLETIN 2022; 185:114201. [PMID: 36257246 DOI: 10.1016/j.marpolbul.2022.114201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
Contamination of coastal environments by siloxanes is of growing concern. Sediment and bivalves were collected from 50 locations along the Korean coast to assess the geographical distribution, sources, and bioaccumulation potential of siloxanes. Cyclic and linear siloxanes were detectable in all sediment and bivalve samples. The highest siloxane concentrations were detected in sediment (656 ng/g dw) and bivalves (3273 ng/g dw) from highly industrialized bays and harbor-zones, suggesting that industrial and shipping activities are major sources of siloxanes in coastal environment. The geographical distribution of siloxanes was similar in sediment and bivalves. Sedimentary siloxanes were dominated by cyclic siloxanes, while linear siloxanes were predominant in bivalves. Bioaccumulation of linear siloxanes in bivalves originated mainly from the sedimentary environment. Mean biota-sediment accumulation factors (BSAFs) of seven siloxanes ranged from 1.26 to 6.03, indicating potential for bioaccumulation. This is the first report on the nationwide survey on siloxanes in Korean coastal waters.
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Affiliation(s)
- Wenming Chen
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, PR China
| | - Yu-Jin Kang
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Hyun-Kyung Lee
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Moonjin Lee
- Maritime Safety and Environmental Research Division, Korea Research Institute of Ships and Ocean Engineering, Daejeon 34103, Republic of Korea
| | - Hyo-Bang Moon
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea.
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Horii Y, Ohtsuka N, Nishino T, Kuroda K, Imaizumi Y, Sakurai T. Spatial distribution and benthic risk assessment of cyclic, linear, and modified methylsiloxanes in sediments from Tokyo Bay catchment basin, Japan: Si-based mass profiles in extractable organosilicon. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:155956. [PMID: 35580679 DOI: 10.1016/j.scitotenv.2022.155956] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
We investigated the spatial distribution, mass profiles, and benthic risk assessment of a wide range of methylsiloxanes (MSs), including 7 cyclic MSs (CMSs; D3-D9; the number refers to the number of SiO bonds), 13 linear MSs (LMSs; L3-L15), and 15 modified and other MSs (MMSs) in sediments from the Tokyo Bay catchment basin, Japan. We observed widespread distribution of MSs (ΣCMS, ΣLMS, and ΣMMS) in the sediment samples, with concentrations of 1.0-6180 ng/g dry weight (dw), 1.8-10,100 ng/g dw, and < 0.31-210 ng/g dw, respectively. Our study is the first to measure various MMSs modified with hydrogen, vinyl, or phenyl groups; however, only methyltris(trimethylsiloxy)silane and phenyltris(trimethylsiloxy)silane were detected with high occurrence frequency. Notably, no elevated concentrations of MSs were observed downstream of silicone manufacturers, whereas the sediment was characterized by a specific D4/D5 ratio. With the Si-based mass profiles in extractable organosilicon (EOSi), the measured CMSs, LMSs, and MMSs accounted for 5.4%, 7.8%, and 0.2%, respectively. Unidentified EOSi (unknown fraction) constituted a major proportion of the EOSi in the sediment, with a mean of 87%, suggesting that the organosilicon environmental emissions were more than the measured MSs. In risk assessment of the adverse effects of D4, D5, and D6 in sediment on benthic organisms, the respective distributions indicated no overlap between the 95th percentile field sediment concentration and the 5th percentile chronic sediment no-effect concentration in organic carbon-normalized concentration. Although the hazard quotient compared with the predicted no-effect concentration for D5 and D6 exceeded the threshold level (hazard quotient ≥1), the results of probabilistic risk assessment for the three CMSs were not high enough to indicate a threat to benthic organisms in the study area.
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Affiliation(s)
- Yuichi Horii
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan.
| | - Nobutoshi Ohtsuka
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
| | - Takahiro Nishino
- Tokyo Metropolitan Research Institute for Environmental Protection, 1-7-5 Shinsuna, Koto, Tokyo 136-0075, Japan
| | - Keisuke Kuroda
- Department of Environmental and Civil Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Yoshitaka Imaizumi
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Takeo Sakurai
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
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Comment on Hossain et al. Exposure to Dodecamethylcyclohexasiloxane (D6) Affects the Antioxidant Response and Gene Expression of Procambarus clarkii. Sustainability 2021, 13, 3495. SUSTAINABILITY 2022. [DOI: 10.3390/su14148519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hossain et al. [...]
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