dc.description.abstract | Global concern regarding microplastic (MP) pollution increases. MPs may function as a novel
compartment for the partitioning of chemical pollutants, thereby altering their
bioavailability. 17α-ethinylestradiol (EE2), a potent endocrine disruptor compound, enters
soil via biosolid application. Limited literature about influenced partition of EE2 in soil due to
the presence of MPs is available. This research aims to assess the distribution of EE2 in soil in
the presence of MPs for the plastic types of polyethylene (PE), polyamide (PA) and
thermoplastic polyurethane (TPU) in different environmental compartments using mass
balance modelling, based on recent literature.
Generally, EE2 was found to be majorly bound to soil, except for low values of partitioning of
EE2 in soil, while high amounts PA MPs were present. Concluding, specific polymers in high
concentrations present, may influence the distribution of EE2 in soils co-contaminated with
MPs. The observed sorption order (PA> PE > TPU) differed from expectations based on
literature. Combined effects of differences in crystallinity and strength of hydrogen bonds of
PA possibly outweighs the difference in hydrophobic capacities between PA and PE. The
observed concentrations of EE2 distributed in various compartments are not expected to
show any adverse effects, based on the PNECwater. Also, less EE2 was taken up by biota in the
presence of a higher plastic mass, so the presence of MPs may reduce bioavailability of EE2.
However, this model does not adequately reflect real-life scenarios due to assumption made
and the nature of the parameters. Nevertheless, it provides a rough estimate of EE2
partitioning in soil in the presence of MPs and highlights the lack of knowledge about toxicity
of EE2 on soil organisms and the complexity of this matter. Follow-up research should focus
on identifying partition values for EE2, for the variety of MPs and their degree of weathering
found in soil. Additionally, trustworthy toxicity data is needed for accurate risk assessment. | |