TY - JOUR
T1 - Do microplastics mediate the effects of chemicals on aquatic organisms?
AU - Marchant, Danielle J.
AU - Iwan Jones, J.
AU - Zemelka, Gabriela
AU - Eyice, Ozge
AU - Kratina, Pavel
N1 - Funding Information:
This research was funded by the EU INTERREG France (Channel) England project “Preventing Plastic Pollution” co-financed by the European Regional Development Fund. JIJ acknowledges funding from Defra (Project No. WT15112, Evidence Reviews on Analysis, Prevalence and Impact of Microplastics in Freshwater Environments). PK acknowledges funding from the Royal Society, Newton Advanced Fellowship (Grant No. NAF/R2/180791).We thank John F. Murphy, Amanda Arnold, James L. Pretty, Kate Spencer, Adriaan A. Markus and. Andre D. Vethaak for their help with data collection and Marina Resmini, Kate Heppell and Mark Trimmer for comments on an earlier draft. We also thank two anonymous reviewers for their constructive feedback.
Publisher Copyright:
© 2021
PY - 2022/1/1
Y1 - 2022/1/1
N2 - Microplastics are ubiquitous in both marine and freshwater ecosystems, where they can act as a physical contaminant, as well as interact with chemicals present in the environment. It has been suggested that chemical contaminants can sorb to microplastics, such that microplastics act as a vector for chemicals into aquatic biota and enhance their negative effects. It has been repeatedly suggested that the main factors underpinning the binding of chemicals to microplastics are hydrophobic partitioning and the size of microplastic particles. Therefore, we used the hydrophobicity of chemicals, as log Kow, as well as the size of microplastic particles to conduct a quantitative analysis of published results to evaluate the influence of microplastics on chemical toxicity. We collated data from 39 laboratory studies that assessed the effects of microplastics, chemicals and their combination on several ecotoxicological responses of freshwater and marine organisms. Each chemical was assigned the relevant octanol / water partition coefficient (log KOW) as a measure of its hydrophobicity, and the mean size of microplastics particles used in each study was recorded. We found no effect of log KOW or the size of microplastic particles on the interaction between microplastics and chemicals with regards to any of the relevant ecotoxicological responses (behaviour, growth, survival and cellular) considered in this study. These findings are significant in showing that the effect of microplastics on the toxicity of chemicals is more complex than just considering hydrophobicity of chemicals and size of microplastics. We call for more mechanistic experiments to motivate a robust risk assessment and mitigation of microplastic toxicity in the environment.
AB - Microplastics are ubiquitous in both marine and freshwater ecosystems, where they can act as a physical contaminant, as well as interact with chemicals present in the environment. It has been suggested that chemical contaminants can sorb to microplastics, such that microplastics act as a vector for chemicals into aquatic biota and enhance their negative effects. It has been repeatedly suggested that the main factors underpinning the binding of chemicals to microplastics are hydrophobic partitioning and the size of microplastic particles. Therefore, we used the hydrophobicity of chemicals, as log Kow, as well as the size of microplastic particles to conduct a quantitative analysis of published results to evaluate the influence of microplastics on chemical toxicity. We collated data from 39 laboratory studies that assessed the effects of microplastics, chemicals and their combination on several ecotoxicological responses of freshwater and marine organisms. Each chemical was assigned the relevant octanol / water partition coefficient (log KOW) as a measure of its hydrophobicity, and the mean size of microplastics particles used in each study was recorded. We found no effect of log KOW or the size of microplastic particles on the interaction between microplastics and chemicals with regards to any of the relevant ecotoxicological responses (behaviour, growth, survival and cellular) considered in this study. These findings are significant in showing that the effect of microplastics on the toxicity of chemicals is more complex than just considering hydrophobicity of chemicals and size of microplastics. We call for more mechanistic experiments to motivate a robust risk assessment and mitigation of microplastic toxicity in the environment.
KW - Aquatic organisms
KW - Chemical toxicity
KW - Hydrophobicity
KW - Microplastic pollution
KW - Multiple stressors
UR - http://www.scopus.com/inward/record.url?scp=85119930893&partnerID=8YFLogxK
U2 - 10.1016/j.aquatox.2021.106037
DO - 10.1016/j.aquatox.2021.106037
M3 - Article
C2 - 34844050
AN - SCOPUS:85119930893
SN - 0166-445X
VL - 242
JO - Aquatic Toxicology
JF - Aquatic Toxicology
M1 - 106037
ER -