Microplastics altered contaminant behavior and toxicity in natural waters

Tengda Ding; Liyan Wei; Zhangming Hou; Juying Li; Chunlong Zhang; Daohui Lin

doi:10.1016/j.jhazmat.2021.127908

Microplastics altered contaminant behavior and toxicity in natural waters

J Hazard Mater. 2022 Mar 5:425:127908. doi: 10.1016/j.jhazmat.2021.127908. Epub 2021 Nov 26.

Authors

Tengda Ding¹, Liyan Wei², Zhangming Hou², Juying Li², Chunlong Zhang³, Daohui Lin⁴

Affiliations

¹ Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China. Electronic address: dingtenda@szu.edu.cn.
² Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
³ Department of Environmental Sciences, University of Houston-Clear Lake, 2700 Bay Area Blvd., Houston 77058, TX, United States.
⁴ Department of Environmental Sciences, Zhejiang University, Hangzhou 310058, China.

PMID: 34883377
DOI: 10.1016/j.jhazmat.2021.127908

Abstract

Microplastics (MPs) have received an increasing attention because of their ubiquitous presence and aquatic toxicity associated with MPs and MP-bound contaminants in the natural water. This review is to critically examine the chemical additives leached from MPs, the altered contaminant behaviors and the resulting changes in their aquatic ecotoxicity. Available data suggest that heavy metals Zn, Cr, Pb, and Cd regulated and present in plastics at the sub-mg g^-1 to mg g^-1 level can leach a significant amount depending on MPs size, aging, pH, and salinity conditions. MP-bound organic contaminants are primarily additive-derived (e.g., brominated diphenyl ethers, nonylphenol, and bisphenol A) at the µg g^-1 to mg g^-1 level, and secondarily pyrogenic and legacy origins (e.g., PAHs and PCBs) in the range of ng g^-1 and mg g^-1. MPs tend to have higher but more variable sorption capacities for organic compounds than metals (1.77 ± 2.34 vs. 0.82 ± 0.94 mg g^-1). MPs alter the behavior of heavy metals through the electrostatic interactions and surface complexation, while the transport of additive derived organic compounds are altered primarily through hydrophobic effect as supported by a positive correlation (R² = 0.71) between the logarithmic MPs-adsorbed concentrations and octanol/water partition coefficients (K_OW) of organic compounds. MPs constitute less than 0.01% of the total mass of aquatic particulates in typical waters, but play a discernible role in the local partitioning and long-distance movement of contaminants. MPs alone exert higher toxicity to invertebrates than algae; however, when MPs co-occur with pollutants, both synergistic and antagonistic toxicities are observed depending mainly on the ingestibility of MPs, the extent of sorption, MPs as a transport vector or a sink to scavenge pollutants. We finally suggest several key areas of future research directions and needed data concerning the role of MPs in mitigating pollutant leaching, transport and risk under conditions mimicking natural and polluted waters.

Keywords: Chemical additives; Ecotoxicity; Heavy metals; Microplastics; Organic compounds.

Publication types

Research Support, Non-U.S. Gov't
Review

MeSH terms

Adsorption
Metals, Heavy* / toxicity
Microplastics
Plastics
Water Pollutants, Chemical* / analysis
Water Pollutants, Chemical* / toxicity

Substances

Metals, Heavy
Microplastics
Plastics
Water Pollutants, Chemical