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Liquid crystal monomers (LCMs) are a class of synthetic organic chemicals with a diphenyl or bicyclohexane backbone with hydrogen atoms on the phenyl rings replaced with functional groups such as bromine, chlorine, cyano groups, or fluorine. LCMs have been used widely in liquid crystal displays (LCDs) in electrical and electronic products such as computers, mobile phones, and televisions. The rapidly developed LCD industry has also led to a continuous increase in the annual production volume for LCMs around the world. It has been estimated that demand for LCMs use in LCDs have rose to - 1 300 t by 2021. It has recently been suggested that LCMs should be considered to be emerging persistent organic pollutants of the environment because they may be persistent, bioaccumulative, and toxic. LCMs are not covalently bonded to any of the other materials used in LCDs, so can be unintentionally released into the environment during manufacturing, use, disposal, and recycling of LCD devices and pose serious risks to ecology and human health. Environmental and toxicological research on LCMs in the scientific community has just recently been initiated, and information is deficient in many fields. In this paper, information published since 2018 about LCMs physicochemical properties, production, and emissions; analytical methods for accurately quantifying LCMs; LCMs concentrations, behaviors, and fates in various environmental matrices; and the risks posed by LCMs to humans is reviewed. Recent studies have mainly focused on target LCMs concentrations and distributions, and most studies have involved gas chromatography mass spectrometry with target ions or ion pairs monitored. Many unknown LCMs may be overlooked using such methods because data for LCMs production volumes and use in commercial LCDs are limited. It has previously been found that E-waste dismantling caused large amounts of LCMs in waste LCD panels to be emitted in E-waste recycling areas. LCMs have been detected in sediment, soil, municipal landfill leachate, indoor and outdoor dust, air, and other environmental media. This indicates widespread LCMs contamination of the environment, particularly in E-waste processing areas. Most LCMs are semi-volatile organic compounds, so air is expected to be the main medium in which LCMs released from e-products are transported to other areas. These results also provide indirect evidence that humans are exposed to LCMs in environmental media through ingestion, dermal contact, and inhalation. To date, LCMs have been detected in human tissues in only four studies, and the systematic exploration of bio-monitoring regarding LCMs in the human matrices is still scant. Fluorinated LCMs have been found to be the dominant LCMs in both environmental media and biota, and exhibit higher persistent, bioaccumulative, or even toxic potential than other LCMs. Future studies should focus on developing methods combining target and non-target analysis for identifying and quantifying novel LCMs. It is suggested that large-scale field research should be performed to investigate LCMs migration and transport mechanisms from E-waste recycling areas to other environmental matrices. Studies on bioaccumulation characteristics of LCMs in biota should also be performed to allow the risks posed by LCMs to humans to be effectively assessed. [ABSTRACT FROM AUTHOR]

People spend about one third of life time on sleeping, and exposure to semi-volatile organic compounds (SVOCs) in bedroom during the sleep may cause adverse health effects in humans. Dust is an important sink of indoor SVOCs, while levels of the SVOCs and corresponding health risks in the indoor dust are still unclear. Therefore, a comprehensive screening of the SVOCs is necessary to identify the dominant pollutants in indoor environment. In this study, settled dust samples were collected in bedrooms from 19 Chinese homes to investigate the occurrence, potential sources and health risks of the indoor SVOCs. Gas chromatography-mass spectrometry was used for high-throughput screening of 895 SVOCs in the indoor dust samples. Based on the health risk assessment method proposed by the United States Environmental Protection Agency, the health risks of the SVOCs with detection frequencies >10% to infants and adults were assessed, considering ingestion, inhalation and dermal absorption from dust. A total of 85 SVOCs were detected in the indoor dust samples, including 20 n-alkanes, 12 polycyclic aromatic hydrocarbons, 6 phthalates, 8 organophosphate esters, 7 alcohols, 6 substituted benzenes, 9 phenols, 9 pesticides, 4 esters, 2 fatty acids and 2 others, with the total concentrations ranging from 92 xgxg-1 to 1.4x103 xgxg-1 (median value: 4.3x102 μg·g-1 ). Among the 85 SVOCs, the phthalates were found to be the most abundant SVOCs in the dust, with the mean contribution of (40.9 ±11.7)% to the total SVOCs concentrations. Bis(2-ethylhexyl) phthalate (DEHP) was the predominant phthalate, accounting for (63.1±14.5)% of the total phthalate concentrations. The results of the health risk assessment indicated that the hazard index (HI) of SVOCs in the dust were negligible for adults. However, 4 SVOCs, including styrenated phenol (HI =7.2x10-2 ), DEHP (HI =3.8x10-2 ), myristic acid (HI = 2.2x10-2 ) and stearyl alcohol (HI =1.1x10-2 ), were found to pose low non-carcinogenic risks to infants via dust ingestion. In addition, the carcinogenic risks (CR) of fluoranthene (3.7 x10-6 ) and pyrene (2.8 x10-6 ) were found to exceed the acceptable risk level of 10-6 . The present study clarified the current pollution status of the SVOCs in indoor dust based on high-throughput screening method, and provided basic data for prevention and management of SVOCs risk in the indoor environment. [ABSTRACT FROM AUTHOR]

Brominated flame retardants 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl)2,3,4, 5-tetrabromophthalate (TBPH) have emerged as novel substitutes for legacy brominated flame retardant polybrominated diphenyl ethers (PBDEs), and are widely used in industrial and human daily life products. They have been frequently detected in various environmental matrices, organisms and even humans, and therefore have potential risks to the ecological environment and human health. This review summaries the latest ecotoxicological research progress of TBB and TBPH, mainly on their distribution and environmental fate in various environmental media and organisms, human exposure risks and related toxic effects. In addition, we combed and analyzed the weakness in the current TBB and TBPH studies, and put forward the research prospects in order to better carry out the environmental risk and human health risk assessment of TBB and TBPH. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai University / Shanghai Daxue Xuebao is the property of Journal of Shanghai University (Natural Sciences) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although non-phthalate plasticizers are widely used in various consumer products as substitutes for phthalates, currently little is known about their environmental occurrence and the risks of human exposure. To characterize the pollution and human exposure risk in indoor environments, house dust samples collected from 83 households in Guangzhou were analyzed for twelve typical non-phthalate plasticizers. Results showed that dioctyl terephthalate (DEHT), trioctyl trimellitate (TOTM), acetyl lemon tributyl ester (ATBC), heptylnonyl adipate, di(2-ethylhexyl) adipate, and trioctyl trimellitate were detected in all samples. The total concentrations of non-phthalate plasticizers ranged from 22.4 to 615 μg ·g -1 with a median of 101 μg ·g -1 . DEHT had the highest concentrations (9-487 μg ·g -1 ), followed by TOTM (0.3-87 μg ·g -1 ) and ATBC (1.7-50 μg ·g -1 ). Daily intakes via dust ingestion for adults and children were estimated based on the dust concentrations. The total daily intake of children was 367 ng ·(kg ·d) -1 , which was 8-9 times higher than that of adults[43 ng ·(kg ·d) -1 ]. Further risk assessment through the hazard quotient approach showed that the exposure of adults and children to non-phthalic plasticizers via dust ingestion was within an acceptable risk range.