Marine microplastics bound dioxin-like chemicals: Model explanation and risk assessment

Microplastics have become one of the most pervasive emerging pollutants in the marine environment because of their
wide occurrence and high sorption ability for hydrophobic organic contaminants (HOCs). Among the associated
HOCs, dioxin-like chemicals (DLCs) can pose severe health risks; however, information on effects of microplastics
bound DLCs is lacking. To fill this knowledge gap, this study integrated chemical analysis and in vitro bioassays to
elucidate the potential dioxin-like effects of microplastics bound DLCs. Chemical analysis results demonstrated that
styrofoams possessed significantly greater DLCs than other coastal or open ocean plastic particles. This was probably
due to the presence of additives and greater sorption ability of expanded polystyrene. However, styrofoams did not
show as strong dioxin-like effects as predicted by the bioanalysis equivalent model in bioassays. This could be
attributed to the decreased DLC bioavailability and increased competition with the presence of styrene oligomers.
Besides, bioassay results also demonstrated that aging increased the associated DLC concentrations, since extra
sorption from surrounding environment occurred during prolonged retention periods. Finally, it was estimated that
the leaching of DLCs could induce dioxin-like effects in marine organisms under 100% (11/11) and 18% (2/11)
scenarios for aged pellets and styrofoams through aqueous or dietary exposures.
Publication Name: 
Journal of Hazardous Materials
Year: 
2019
Volume: 
364
Page Number: 
82-90
Author: 
Chen, Qiqing; Zhang, Haibo; Allgeier, Annika; Zhou, Qian; Ouellet, Jacob D.; Crawford, Sarah E.; Luo, Yongming; Yang, Yi; Shi, Huahong; Hollert, Henner