0
Article Tier 2 Environmental Sources Remediation Sign in to save

Microplastics as a Vector for HOC Bioaccumulation in Earthworm Eisenia fetida in Soil: Importance of Chemical Diffusion and Particle Size

Environmental Science & Technology 2020 90 citations

AI summary Read the abstract

Researchers investigated whether microplastics act as vectors for hydrophobic organic contaminant (HOC) bioaccumulation in earthworms, testing two scenarios with polyethylene particles of different sizes and polychlorinated biphenyls in soil. Results showed that clean microplastics in contaminated soil reduced HOC bioaccumulation, while smaller precontaminated microplastics enhanced transfer of PCBs to earthworms, demonstrating that particle size and prior contamination status are critical factors.

The role of microplastics as a carrier in the bioaccumulation of hydrophobic organic contaminants (HOCs) in soil organisms is poorly understood. Two environmentally relevant scenarios, including earthworm Eisenia fetida exposed to contaminated soil amended with clean microplastics (S1) and clean soil introduced with precontaminated microplastics (S2), were simulated to estimate the importance of microplastics in bioaccumulation. Three polychlorinated biphenyls and polyethylene particles with different sizes were employed. The microplastics under the S1 scenario significantly decreased the polychlorinated biphenyl congener (PCB) bioaccumulation, whereas for the S2 scenario, the PCBs on the microplastics can be assimilated by earthworms. Compared to plastic-free treatments, the freely dissolved concentrations (Cfree) of PCBs were consistently lower in the soils amended with microplastics. Biodynamic model analysis suggested that the contribution of microplastic ingestion to bioaccumulation under the S2 scenario (mean 26.1%) was higher than that under S1 (8.7%), likely because of the slow chemical transfer between plastics and ambient media. These results indicated whether microplastics act as a source or a sink of HOCs depended strongly on the diffusion gradients between microplastics and soils. As ingestion of smallest particles (50-150 μm) showed the greatest contribution to bioaccumulation under S1 and S2 scenarios, the gradual breakdown of microplastics may increase their relative importance in contaminant transfer.

More Papers Like This

Article Tier 2

Accumulation of HOCs via Precontaminated Microplastics by Earthworm Eisenia fetida in Soil

AI summary Read the abstract

Researchers incubated earthworms in soil amended with five types of microplastics precontaminated with polychlorinated biphenyls and polycyclic aromatic hydrocarbons to assess whether pre-contaminated MPs enhance HOC transfer to terrestrial organisms. Results showed that precontaminated microplastics significantly increased earthworm accumulation of PCBs and PAHs compared to controls, demonstrating that the contamination history of MPs entering soil is a critical but overlooked factor in risk assessment.

Article Tier 2

Size-dependent vector effects of microplastics on bioaccumulation of hydrophobic organic contaminants in earthworm: A dual-dosing study

AI summary Read the abstract

Researchers developed a dual-dosing method to directly measure how microplastics act as carriers for hydrophobic organic contaminants in earthworms. The study found that smaller microplastic particles had greater vector effects, increasing bioaccumulation of pollutants, and that dermal uptake played a significant role in contaminant transfer from microplastics to organisms.

Article Tier 2

Assessing the role of polyethylene microplastics as a vector for organic pollutants in soil: Ecotoxicological and molecular approaches

AI summary Read the abstract

Polyethylene microplastics were shown to act as vectors for organic pollutants including pharmaceuticals and pesticides in soil, with earthworm bioaccumulation assays and molecular endpoints revealing that MPs increased contaminant uptake compared to soil exposure alone.

Article Tier 2

Size effects of microplastics on accumulation and elimination of phenanthrene in earthworms

AI summary Read the abstract

Researchers examined how microplastic particle size affects the accumulation and elimination of the pollutant phenanthrene in earthworms. They found that smaller microplastics enhanced phenanthrene uptake in earthworm tissues, while larger particles had a less pronounced effect. The study demonstrates that microplastic size influences how organic pollutants interact with soil organisms, with finer particles potentially increasing contaminant bioavailability.

Article Tier 2

Influence of polyethylene microplastics on the sorption of organic contaminants in soils

AI summary Read the abstract

A study examined how polyethylene microplastics in soil alter the sorption of organic contaminants, addressing concerns about microplastics acting as vectors for persistent pollutants in terrestrial environments. Results showed that microplastics can change the distribution and bioavailability of co-occurring organic chemicals in soil.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper