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
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
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日本东京湾流域沉积物中环状、线性和改性甲基硅氧烷的空间分布和底栖风险评估：可提取有机硅中的硅基质量分布
DOI：
10.1016/j.scitotenv.2022.155956
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发表时间：
2022
影响因子：
9.8
通讯作者：
Takeo Sakurai
中科院分区：
文献类型：
--
作者：
Yuichi Horii;Nobutoshi Ohtsuka;Takahiro Nishino;Keisuke Kuroda;Yoshitaka Imaizumi;Takeo Sakurai
我们调查了日本东京湾流域沉积物中广泛的甲基硅氧烷(MSS)的空间分布、质量分布和底栖生物风险评估，包括7个环状MSS(CMSS；D3-D9；数字指的是Sisingle Bondo键的数量)，13个线性MSS(LMSS；L3-L15)，以及15个修饰和其他MMS(MMS)。我们在沉积物样品中观察到广泛分布的MS(ΣCMS、ΣLMS和ΣMMS)，其浓度分别为1.0-6180 ng/g干重、1.8-10、100 ng/g dw和 <； 0.31-210 ng/g dw。我们的研究首次测量了各种氢基、乙烯基或苯基修饰的MMS，但只有甲基三(三甲基硅氧基)硅烷和苯基三(三甲基硅氧基)硅烷出现频率较高。值得注意的是，在有机硅制造商下游没有观察到MSS浓度升高，而沉积物具有特定的D4/D5比率。对于可提取有机硅(EOSi)中的硅基质量分布，测得的CMSS、LMSS和MMSS分别占5.4%、7.8%和0.2%。沉积物中未确认的有机硅(未知部分)占总有机硅的比例较大，平均为87%，表明有机硅的环境排放量大于实际测量的MSS。在沉积物中D4、D5和D6对底栖生物不利影响的风险评估中，各自的分布表明，在有机碳归一化浓度中，第95个百分位数的野外沉积物浓度和第5个百分位数的慢性沉积物无效浓度之间没有重叠。尽管D5和D6的危险商与预测的无影响浓度相比超过了阈值水平(危险商≥1)，但这三个CMSS的概率风险评估结果不足以表明对研究区域底栖生物的威胁。
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 Sisingle bondO 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.