Effect-Directed Analysis of Ah Receptor-Mediated Potencies in Microplastics Deployed in a Remote Tropical Marine Environment

Abstract

To facilitate the study of potential harmful compounds sorbed to microplastics, an effect-directed analysis using the DR CALUX ® assay as screening tool for Aryl hydrocarbon receptor (AhR)-active compounds in extracts of marine deployed microplastics and chemical analysis of hydrophobic organic compounds (HOCs) was conducted. Pellets of three plastic polymers [low-density polyethylene (LDPE), high-density polyethylene (HDPE) and high-impact polystyrene (HIPS)] were deployed at Heron Island in the Great Barrier Reef, Australia, for up to 8 months. Detected AhR-mediated potencies (bio-TEQs) of extracted plastic pellets ranged from 15 to 100 pg/g. Contributions of target HOCs to the overall bioactivities were negligible. To identify the major contributors, remaining plastic pellets were used for fractionation with a gas chromatography (GC) fractionation platform featuring parallel mass spectrometric (MS) detection. The bioassay analysis showed two bioactive fractions of each polymer with bio-TEQs ranging from 5.7 to 14 pg/g. High resolution MS was used in order to identify bioactive compounds in the fractions. No AhR agonists could be identified in fractions of HDPE or LDPE. Via a multivariate statistical approach the polystyrene (PS) trimer 1e-Phenyl-4e-(1-phenylethyl)-tetralin was identified in fractions of HIPS and in fractions of the blank polymer of HIPS.

Effects of leachates from UV-weathered microplastic on the microalgae Scenedesmus vacuolatus

“…Our findings highlight that degrading and largely additive-free pre-production polymers have the potential to induce adverse effects on whole organisms, particularly PE; however, stronger adverse effects were observed if the polymers contained additives or other chemicals. As a future step, advanced chemical analytical tools, e.g., effect-directed analysis combined with non-target screening, would be necessary to resolve the chemicals causing these effects [44,45]. Therefore, the application of effect-based tools provides a reliable strategy to assess potential environmental risks from potentially hazardous materials like plastics.…”

Plastics as a carrier of chemical additives to the Arctic: possibilities for strategic monitoring across the circumpolar North

“…In step-wise approaches, the complexity of the sample is reduced and candidates for an observed toxic effect are attempted to be identified. These approaches have been applied to plastics to a limited extent (Schönlau et al 2019) and offer possibilities of addressing toxicity and chemical identification in a complex setting. Additionally, new effects monitoring tools can be used to determine contaminant burdens across species.…”

Freshwater systems in the Anthropocene: why we need to evaluate microplastics in the context of multiple stressors

“…Microplastics are a contaminant of emerging concern in freshwater ecosystems (Lambert and Wagner 2018;Rochman and Hoellein 2020). They can cause a range of adverse effects in freshwater biota at multiple levels of biological organization, due in part to their inherent complexity (e.g., size, polymer, morphology) (Rochman et al 2019;Bucci et al 2020).…”

“…Microplastics are a contaminant of emerging concern in freshwater ecosystems (Lambert and Wagner 2018;Rochman and Hoellein 2020). They can cause a range of adverse effects in freshwater biota at multiple levels of biological organization, due in part to their inherent complexity (e.g., size, polymer, morphology) (Rochman et al 2019;Bucci et al 2020). Studies that investigate microplastics as a single stressor (e.g., Li et al 2024;Malinowski et al 2023;Schür et al 2023) have demonstrated that microplastics are impacting freshwater ecosystems.…”

“…Microplastics as a physical and chemical stressor Microplastics (<5 mm; Arthur et al 2009) are inherently complex, varying in toxicity across physical and chemical characteristics (Rochman et al 2019), whose nature and interactions remain misunderstood. While it has become clear that certain morphologies, sizes, polymer types, and additives may lead to varying effects (Zimmermann et al 2020;Strungaru et al 2019;Bucci et al 2020;da Costa et al 2023), most studies do not design experiments to evaluate these characteristics in combination; thus, failing to consider the inherent complexity of microplastics.…”