We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Strong but reversible sorption on polar microplastics enhanced earthworm bioaccumulation of associated organic compounds
Summary
Sorption experiments showed that organic compounds bound more strongly to polar biodegradable microplastics than to conventional polypropylene, but that strong binding reduced bioavailability to earthworms, with earthworm bioaccumulation of phenanthrene from MP-contaminated soil following patterns predicted by equilibrium partitioning rather than carrier effects.
Sorption/desorption of two organic compounds (OCs), phenanthrene (PHE), and 1-nitronaphthalene (1-Nnap) on three polar and one nonpolar polypropylene (PP) microplastics (MPs) and earthworm bioaccumulation of MP associated PHE were systematically studied. Poly-butylene succinate (PBS) with the lowest glass transition temperature (T) showed the highest sorption toward PHE and 1-Nnap (K: 25,639 ± 276 and 1673 ± 28.8 L kg, respectively), while polylactic acid (PLA) with the highest T showed the least sorption (182 ± 5 and near 0), confirming that hydrophobic partition was the main driving force of sorption. However, polar interactions also contributed to the preferential sorption of 1-Nnap on polar poly-hydroxyalkanoates (PHA). Moreover, small particle size favored the sorption of MPs and simulated weathering enhanced sorption on MPs with medium/high T As for desorption, slight hysteresis was observed in most cases with near-zero hysteresis index (HI), and PHE generally had higher HI than 1-Nnap. The simulated digestive solution could further promote the desorption of PHE. The PHE concentrations in earthworms with the presence of 5% PBS or PP MPs in soil were 1.50-2.35 or 1.59-1.75 times that of the control without MPs; and PBS MPs with the smallest particle size showed the greatest enhancement. The results of this study confirmed that polar MPs could strongly but reversibly sorb both polar and nonpolar OCs and hence promote the bioaccumulation of OCs to soil organisms.
Sign in to start a discussion.
More Papers Like This
Assessing the role of polyethylene microplastics as a vector for organic pollutants in soil: Ecotoxicological and molecular approaches
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.
Effects of nano- and microplastics on the bioaccumulation and distribution of phenanthrene in the soil feeding earthworm Metaphire guillelmi
Researchers investigated how nano- and microplastics affect the bioaccumulation of phenanthrene (a polycyclic aromatic hydrocarbon) in soil-feeding earthworms using C-radioactive labeling, finding that fine plastic particles decreased phenanthrene bioavailability in soil and reduced uptake by Metaphire guillelmi earthworms, with nanoplastics showing a stronger dilution effect than microplastics. Soil properties remained the dominant factor controlling bioaccumulation efficiency, and only limited vector effects of the plastic particles were observed.
Microplastics as a Vector for HOC Bioaccumulation in Earthworm Eisenia fetida in Soil: Importance of Chemical Diffusion and Particle Size
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.
Sorption to mulch film decreases bioavailability of two model pesticides for earthworms in soil
This study investigated how agricultural mulch film microplastics affect the bioavailability of pesticides to earthworms in soil. Sorption of two model pesticides onto mulch film microplastics significantly decreased their bioavailability, suggesting MPs may alter the ecological risk profile of pesticide-contaminated agricultural soils.
Size-dependent vector effects of microplastics on bioaccumulation of hydrophobic organic contaminants in earthworm: A dual-dosing study
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.