Accelerated Weathering Increases the Release of Toxic Leachates from Microplastic Particles as Demonstrated through Altered Toxicity to the Green Algae Raphidocelis subcapitata

Abstract

Studies that evaluate the impact of microplastic particles (MPs) often apply particles of pristine material. However, MPs are affected by various abiotic and biotic processes in the environment that possibly modify their physical and chemical characteristics, which might then result in their altered toxic effect. This study evaluated the consequence of weathering on the release of toxic leachates from microplastics. MPs derived from six marine antifouling paints, end-of-life tires, and unplasticised PVC were exposed to UV-C radiation to simulate weathering. Non-weathered and weathered MPs were leached in algae growth medium for 72 h to demonstrate additive release under freshwater conditions. The model organism, green algae Raphidocelis subcapitata, was exposed to the resulting leachates of both non-weathered and weathered MPs. The results of the growth inhibition tests showed that the leachates of weathered microparticles were more toxic than of the non-weathered material, which was reflected in their lower median effect concentration (EC50) values. Chemical analysis of the leachates revealed that the concentration of heavy metals was several times higher in the leachates of the weathered MPs compared to the non-weathered ones, which likely contributed to the increased toxicity. Our findings suggest including weathered microplastic particles in exposure studies due to their probably differing impact on biota from MPs of pristine materials.

Chemical effects of different types of rubber-based products on early life stages of Pacific oyster, Crassostrea gigas

“…(i) new products induce stronger deleterious effects owing to a higher amount of additives in their leachates compared with their used counterparts that have already released these additives during their lifetime; (ii) adsorption of environmental contaminants (e.g., metals, PAHs) and/or product transformation occurring throughout the item's lifetime increase the toxicity of used products compared with new ones; and (iii) weathering alters the surface layers of plastic products, exacerbating the release of additives (e.g., Simon et al, 2021;Gardon et al, 2020;Tian et al, 2020;Nobre et al, 2015).…”

Plastic Leachate Exposure Drives Antibiotic Resistance and Virulence in Marine Bacterial Communities

“…have been reported as coral and algal pathogens (Brown et al, 2013; Peng and Li, 2013; Vairappan et al, 2001), and associated with disease in marine arthropods (Alfiansah et al, 2020). Plastic pollution has been shown to have toxic effects on both algae and marine invertebrates (Haegerbaeumer et al, 2019; Pisani et al, 2022; Simon et al, 2021; Zhu et al, 2022), and entanglement by plastic particles may significantly increase the risk of disease in scleractinian corals (Lamb et al, 2018). Here, we show that an additional consequence of plastic pollution for these organisms might be greater disease susceptibility due to the enrichment of pathogenic bacteria and their associated virulence traits.…”

“…The ability to tolerate exposure to common inorganic and/or organic components of plastic leachate has been shown to be highly variable across different marine microbes. Exposure to chemicals leaching from plastics is detrimental to some marine organisms, such as zooplankton (Gewert et al, 2021; Lithner et al, 2009), green algae (Simon et al, 2021), bacterial picocyanobacteria (Sarker et al, 2020; Tetu et al, 2019), and other keystone marine microbes, including SAR11 (Focardi et al, 2022). However, some marine heterotrophic bacteria appear to benefit from plastic leach exposure, likely from the increase in available dissolved organic carbon (Birnstiel et al, 2022; Focardi et al, 2022; Romera-Castillo et al, 2018).…”

Effect of land use on microplastic pollution in a major boundary waterway: The Arvand River

“…The toxic leachates from weathered MPs cause potential adverse effects on organisms (Campanale et al, 2020;Simon et al, 2021). Using SEM/EDX, Fries et al (2013) showed that the presence of Al and Zn could be related to the ability of MP particles to attract these elements while titanium-dioxide nanoparticles (TiO 2 -NPs) could leach from polymer from its use as additive.…”