著者

岩崎 雄一 眞野 浩行 林 彬勒 内藤 航

出版者

日本環境毒性学会

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.24, pp.53-61, 2021-08-12 (Released:2021-08-12)

参考文献数

45

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Microplastic contamination in the environment is an emerging concern worldwide. In this review, by putting a particular focus on the ecological risk assessment of microplastic particles, we introduced several results of hazard assessments that have focused on the hazardous concentration for 5% of the species (HC5) estimated using species sensitivity distribution. In these previous studies, point estimates (mean/median) for HC5 were derived on the order of 0.01–1 µg/L (based on particle number, 105–106 particles/m3). We then summarized and discussed the relevant issues on the hazard assessments for microplastic particles: (1) identification of effect mechanisms relevant for risk assessment, (2) consideration of the influences of microplastic properties on effect concentrations, (3) identification of a proper concentration unit (i.e., mass-based or particle-based concentration), (4) handling of effect concentrations obtained from experiments that failed to establish concentration-response relationships, (5) consideration of bioavailability of microplastic particles, (6) consideration of environmentally realistic exposure conditions, (7) consideration of naturally occurring particles, (8) consideration of the influences of chemical additives and preservatives on effect concentrations, and (9) application of uncertainty factors to effect concentrations.

著者

田井 梨絵 小倉 勇 眞野 浩行

出版者

日本環境毒性学会

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.25, pp.32-47, 2022-06-07 (Released:2022-06-07)

参考文献数

51

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To develop ecotoxicity test methods for the ecological impact assessment of cellulose nanofibers (CNFs) in aquatic environments, we summarized the methods and results of ecotoxicity tests used in published articles. We also discussed the points to be considered while conducting ecotoxicity tests for CNFs using aquatic organisms based on the Organisation for Economic Co-operation and Development (OECD) guidance document No. 317 for ecotoxicity testing of nanomaterials. In some published articles, no ecological effects of CNFs on aquatic organisms were observed, even when they were exposed to high concentrations of CNFs. In these studies, test organisms may not have been exposed to nominal concentrations of CNFs because of CNF agglomeration and settling caused due to the low dispersion stability of CNFs resulting from the water quality of the test medium. According to the OECD guidance document, attention must be paid toward dispersibility and dispersion stability, effects of feeding, and factors related to adverse effects, analysis, and measurement of CNFs. No literature was found that reported on all these aspects of testing. Future examination of ecological effects of CNFs needs to consider measuring actual exposure concentrations by evaluating dispersibility and dispersion stability of CNFs.