TY - JOUR
T1 - Questioning the suitability of available microplastics models for risk assessment – A critical review
AU - Rubin, Andrey Ethan
AU - Sarkar, Amit Kumar
AU - Zucker, Ines
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/9/20
Y1 - 2021/9/20
N2 - The rise of microplastic (MP) pollution in the environment has been bolstering concerns regarding MPs' unknown environmental fate, transport, and potential toxicity toward living forms. However, the use of real environmental plastics for risk assessment is often hindered due to technical and practical challenges such as plastics' heterogeneity and their wide size distribution in the environment. To overcome this issue, most available data in the field is generated using plastic models as surrogates for environmental samples. In this critical review, we describe the gaps in risk assessments drawn from these plastic models. Specifically, we compare physicochemical properties of real environmental plastic particles to synthesized polymeric micro-beads, one of the most commonly used plastic models in current literature. Several surface and bulk characteristics including size, surface chemistry, polymer type, and morphology are shown to not only be inherently different between environmental MP's and synthesized micro-beads, but also drive behavior in fate, transport, and toxicity assays. We highlight the importance of expressing real-world physicochemical characteristics in representative MP models and outline how current state-of-the-art models are limited in this regard. To address this issue, we suggest future areas of research such as combinations of mechanical, photochemical, and thermal degradation processes to simulate real-world weathering, all in an effort to increase realism of plastic modeling and allow more robust and reliable environmental MP risk assessment in the future.
AB - The rise of microplastic (MP) pollution in the environment has been bolstering concerns regarding MPs' unknown environmental fate, transport, and potential toxicity toward living forms. However, the use of real environmental plastics for risk assessment is often hindered due to technical and practical challenges such as plastics' heterogeneity and their wide size distribution in the environment. To overcome this issue, most available data in the field is generated using plastic models as surrogates for environmental samples. In this critical review, we describe the gaps in risk assessments drawn from these plastic models. Specifically, we compare physicochemical properties of real environmental plastic particles to synthesized polymeric micro-beads, one of the most commonly used plastic models in current literature. Several surface and bulk characteristics including size, surface chemistry, polymer type, and morphology are shown to not only be inherently different between environmental MP's and synthesized micro-beads, but also drive behavior in fate, transport, and toxicity assays. We highlight the importance of expressing real-world physicochemical characteristics in representative MP models and outline how current state-of-the-art models are limited in this regard. To address this issue, we suggest future areas of research such as combinations of mechanical, photochemical, and thermal degradation processes to simulate real-world weathering, all in an effort to increase realism of plastic modeling and allow more robust and reliable environmental MP risk assessment in the future.
KW - Environmental relevancy
KW - Microplastic
KW - Microplastic models
KW - Spherical micro-beads
KW - Surface properties
UR - http://www.scopus.com/inward/record.url?scp=85106955948&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.147670
DO - 10.1016/j.scitotenv.2021.147670
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C2 - 34029818
AN - SCOPUS:85106955948
SN - 0048-9697
VL - 788
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 147670
ER -