Distribution characteristics of volatile methylsiloxanes in Tokyo Bay watershed in Japan: Analysis of surface waters by purge and trap method

Horii, Yuichi; Minomo, Kotaro; Ohtsuka, Nobutoshi; Motegi, Mamoru; Nojiri, Kiyoshi; Kannan, Kurunthachalam

doi:10.1016/j.scitotenv.2017.02.014

Cited by 47 publications

(9 citation statements)

References 39 publications

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“…They are used in the production of silicone polymers, and have a range of industrial applications, including pharmacy and medicine [ 3 , 4 , 5 , 6 ]. For many years, their use was considered safe for humans [ 3 , 7 ]; however, in recent years, it has been shown that they cause environmental pollution [ 1 , 2 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. In addition, these compounds can bioaccumulate in the living organisms [ 17 , 18 , 19 , 20 ], in the ecosystem with significant durability and the ability to transport to very remote areas, including the Arctic region [ 20 , 21 , 22 ].…”

Section: Introductionmentioning

confidence: 99%

Ex Vivo Human Skin is not a Barrier for Cyclic Siloxanes (Cyclic Silicones): Evidence of Diffusion, Bioaccumulation, and Risk of Dermal Absorption Using a New Validated GC-FID Procedure

Krenczkowska

Mojsiewicz‐Pieńkowska

Wielgomas

et al. 2020

Pharmaceutics

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Cyclic methylsiloxanes D4, D5, D6 (also called cyclic silicones) are widely used in various dermatological products and cosmetics, both for children and adults. As a result of their unique physicochemical properties, the production of cyclic methylsiloxanes has greatly increased over the last few years, which has resulted in increased exposure to mankind. The validated quantitative for gas chromatography-flame ionization detector (GC-FID) analysis with using the transdermal diffusion system with vertical Franz cells demonstrated that ex vivo human skin is not a barrier to cyclic siloxanes. D4, D5, and D6 have a specific affinity to stratum corneum (SC) (especially D6), and can even diffuse into the deeper layers of the skin (epidermis (E) and dermis (D)), or into the receptor fluid as well. An important achievement of this work was the observation of the characteristic ratio partitioning D4, D5, and D6 in skin layers and receptor fluid (RF). The studies have shown that, in order to thoroughly understand the mechanism, it is important to determine not only the differences in the amounts of cumulated doses in total in all skin layers and receptor fluid, but also the mutual ratios of analyte concentrations existing between matrices. For example, in the case of the stratum corneum, the cumulative doses of D4, D5, and D6 were 27.5, 63.9, and 67.2 µg/cm2/24 h, respectively, and in the epidermis, they were 6.9, 29.9, and 10.7 µg/cm2/24 h, respectively, which confirmed the highest affinity of D6 to stratum corneum as the amount diffused into the epidermis was 2.8 times smaller compared to D5. The calculated epidermis-to-stratum corneum ratios of analyte concentrations also confirm this. The largest ratio was identified for D5 (E/SC = 47), followed by D4 (E/SC = 25), and finally by D6 (E/SC = 16). The analysis of the next stage of diffusion from epidermis to dermis revealed that in dermis the highest cumulative dose was observed for D5 (13.9 µg/cm2/24 h), while the doses of D4 and D6 were similar (5.1 and 5.3 µg/cm2/24 h). Considering the concentration gradient, it can be concluded that the diffusion of D5 and D6 occurs at a similar level, while D4 diffuses at a much higher level. These observations were also confirmed by the dermis-to-epidermis concentration ratios. The final stage of diffusion from dermis to the receptor fluid indicated that D4 was able to permeate easily, while D5 exhibited a difficult diffusion and the diffusion of D6 was limited. The receptor fluid-to-dermis concentration ratios (RF/D) were calculated for D4, D5, and D6: 80, 53, and 17, respectively. Our results also revealed the increased risk of D4 and D5 absorption into the blood and lymphatic systems, whereas D6 demonstrated the lowest risk. Therefore, we can argue that, among the three tested compounds, D6 is the safest one that can be used in dermatological, cosmetic, and personal care products. This study demonstrates that the stratum corneum, epidermis, and dermis can be also considered reservoirs of cyclic methylsiloxanes. Therefore, these compounds can demonstrate potential long-term bioaccumulation, and can be absorbed to the bloodstream in a long-term and uncontrolled process.

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Section: Introductionmentioning

confidence: 99%

Ex Vivo Human Skin is not a Barrier for Cyclic Siloxanes (Cyclic Silicones): Evidence of Diffusion, Bioaccumulation, and Risk of Dermal Absorption Using a New Validated GC-FID Procedure

Krenczkowska

Mojsiewicz‐Pieńkowska

Wielgomas

et al. 2020

Pharmaceutics

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“…Previous studies have indicated that WWTPs are substantial sources of VMS into the surface waters and the atmosphere. 33,40,41 It was suggested that D3 may be formed through the degradation of highermolecular-weight cyclic VMS in wastewater. 41 This mechanism may explain the occurrence of the highest atmospheric D3 levels around the WWTP in the present study.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…33,40,41 It was suggested that D3 may be formed through the degradation of highermolecular-weight cyclic VMS in wastewater. 41 This mechanism may explain the occurrence of the highest atmospheric D3 levels around the WWTP in the present study. Average concentrations of D4 were 102, 36.9, 32.1, 19.2, 14.2, and 3.59 ng/m 3 at the landfill, WWTP, urban, suburban, industrial, and rural areas, respectively.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Development of a New Passive Sampling Method for the Measurement of Atmospheric Linear and Cyclic Volatile Methyl Siloxanes

Okan

Odabaşı

Yaman

et al. 2021

Environ. Sci. Technol.

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A new passive sampling method was developed and characterized to measure atmospheric volatile methyl siloxanes (VMS). The infrastructure of a commercial passive air sampler (PAS) was used along with XAD-2 resin as the adsorbent. Experimental sampling rates (SR) determined using collocated active and passive samplers ranged between 0.0363 (L5) and 0.0561 (D3) m 3 /day and agreed well with the theoretical ones. VMS uptake was highly linear for eight weeks. The precision of the method was very good (<10%). Compared to the other PASs used for VMS, the new method has several advantages (i.e., the sampler is much smaller, it has commercially available components, and the solvent requirement, equipment needed for extraction, and steps for sample preparation are minimal) while achieving similar or lower method detection limits. The developed method was applied to investigate the spatial distribution and possible sources of atmospheric VMS in the Izmir region. Field sampling covered 42 sites representing different source and land use areas. ΣVMS concentrations ranged between 41.4 and 981 ng/m 3 . The dominant VMS was D5 followed by D3 and D4. Spatial distributions indicated that the main VMS sources in the area were urban areas, wastewater treatment plants, and landfills where the VMS-containing products are used and disposed.

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“…The primary product of this process is dimethylsilandiol, which can evaporate in the atmosphere and subsequently get oxidized in the presence of sunlight [ 53 ]. Regarding the SiO 2 nanoparticles, the toxicologists believe that their effect on the human organism may have other adverse effects compared to micron-sized silica due to their small size: in vitro and in vivo studies have shown that they can cause different side effects [ 54 , 55 , 56 , 57 , 58 ].…”

Section: Anti-icing Hydrophobic Compoundsmentioning

confidence: 99%

A Mini-Review on Recent Developments in Anti-Icing Methods

et al. 2021

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An aggressive impact of the formed ice on the surface of man-made objects can ultimately lead to serious consequences in their work. When icing occurs, the quality and characteristics of equipment, instruments, and building structures deteriorate, which affects the durability of their use. Delays in the adoption of measures against icing endanger the safety of air travel and road traffic. Various methods have been developed to combat de-icing, such as mechanical de-icing, the use of salts, the application of a hydrophobic coating to the surfaces, ultrasonic treatment and electric heating. In this review, we summarize the recent advances in the field of anti-icing and analyze the role of various additives and their operating mechanisms.

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Distribution characteristics of volatile methylsiloxanes in Tokyo Bay watershed in Japan: Analysis of surface waters by purge and trap method

Cited by 47 publications

References 39 publications

Ex Vivo Human Skin is not a Barrier for Cyclic Siloxanes (Cyclic Silicones): Evidence of Diffusion, Bioaccumulation, and Risk of Dermal Absorption Using a New Validated GC-FID Procedure

Ex Vivo Human Skin is not a Barrier for Cyclic Siloxanes (Cyclic Silicones): Evidence of Diffusion, Bioaccumulation, and Risk of Dermal Absorption Using a New Validated GC-FID Procedure

Development of a New Passive Sampling Method for the Measurement of Atmospheric Linear and Cyclic Volatile Methyl Siloxanes

A Mini-Review on Recent Developments in Anti-Icing Methods

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