Continuum from microplastics to nanoplastics: effects of size and source on the estuarine bivalve Scrobicularia plana

Abstract

Plastic has been largely detected in estuarine environments and represent major concern towards aquatic living organisms. Whereas the majority of previous studies analyze the effects of standard particles, mainly polystyrene (PS), not representative to what is found in natural environments, the present study evaluates the impact of microplastics (MPs) and nanoplastics (NPs) under realistic exposure conditions. Scrobicularia plana individuals were exposed to low concentrations (0.008, 10 and 100 µg L − 1 ) of environmental MPs and NPs as well as to standard PS NPs, as a comparison condition. The aim of this study was to understand the ecotoxicological effects of environmental plastic particles on S. plana gills and digestive glands but also to compare the effects of plastic polymers size in order to highlight if the size could induce different toxicity pro les within this model organism, at different levels of biological organization. Results showed a differential induction of detoxi cation enzymes (CAT, GST), immunity (AcP), DNA damage processes as well as differential effect on behavior and condition index of animals depending upon the type of plastic, the size, the concentration tested and the type of organ. This study underlines the necessity of testing i) plastics collected from the environment as compared to standard ones and ii) the effect of size using plastics coming from the same batch of macrosized plastics. This study concludes on the future need directions that plastic-based studies must take in order to be able to generate large quantity of relevant data that could be used for future regulatory needs on the use of plastic.

Toxicity assessment of environmental MPs and NPs and polystyrene NPs on the bivalve Corbicula fluminea using a multi-marker approach

“…No alteration of the CI was demonstrated for the different plastic particles tested. Our results agree with previous studies that have shown no effect of plastic particles on the body condition index of different bivalves (Bour et al, 2018;Joyce and Falkenberg, 2022;Métais et al, 2023;Ribeiro et al, 2017;Von Moos et al, 2012).…”

“…In their study, these authors also reported higher growth inhibition of microalgae S. subspicatus exposed to environmental NPs than standard ones (Baudrimont et al, 2019). In addition, two studies using the same plastic particles as in our study demonstrated that PS NPs did not present the same toxicity as compared to ENV MPs and NPs in the mussel Mytilus edulis and clam Scrobicularia plana (Métais et al, 2023;Roman et al, 2023). However, there is a knowledge gap on the mechanisms of toxicity of environmental MPs and NPs, and further investigations are needed to explore their potential joint toxicity with chemicals.…”

“…Indeed, the properties of standard MPs and NPs differ from those identified in the environment in terms of shape, composition, surface charge, adsorbed contaminants, or biofilms covering their surface (Gigault et al, 2016(Gigault et al, , 2018Phuong et al, 2016). To date, very few studies have been carried out to compare the toxicity of pristine plastic particles with those derived from the environment (Arini et al, 2022a(Arini et al, , 2022bBaudrimont et al, 2019;Lebordais et al, 2021bLebordais et al, , 2021aMétais et al, 2023). Pioneering studies revealed that the toxic effects of plastic particles could be underestimated using standard particles compared to those derived from the environment on the algae S. subspicatus (Baudrimont et al, 2019) and the oyster I. alatus (Arini et al, 2022a).…”

Environmental and Sublethal Concentrations of Polystyrene Nanoplastics Induced Antioxidant System, Transcriptomic Responses, and Disturbed Gut Microbiota in Oyster Magallana Hongkongensis

“…The selection of PS-NPs exposure concentrations was informed by the NPs concentration in their natural habitat and toxicological research findings from other research. 4,23 A seven-day toxicological experiment was conducted under semistatic conditions to assess the effects of the exposure solution on the test subjects. Fluorescence intensity measurements were obtained each time the exposure solution was prepared and replaced to ensure the accurate concentration of the exposure solution throughout the study.…”

“…3 Exposure to NPs at concentrations of 10 μg/L and 100 μg/L was observed to alter the catalytic activities of catalase (CAT) and glutathione s-transferase (GST) within the gill and gonad tissues in Scrobicularia plana. 4 Besides, when exposed to 100 mg/L NPs, a large number of oyster sperm and eggs became deformed. 5 The intestine serves as the primary organ for nutrient absorption and digestion in oysters, and it is the initial site for the entry and accumulation of toxins.…”