In vitro characterization of cadmium transport across the gastro-intestinal membrane of the fathead minnow (Pimephales promelas) in the presence and absence of microplastics

• Published in: Environmental toxicology and pharmacology 2023-08, Vol.101, p.104195-104195, Article 104195
• Main Authors: Zink, Lauren, Simonis, Carolyn, Wiseman, Steve, Pyle, Gregory G.
• Format: Article
• Language: English
• Subjects: Cadmium translocation; Dietary metals; Luminal transport; Mucosal epithelium
• ISSN: 1382-6689; 1872-7077
• DOI: 10.1016/j.etap.2023.104195

There is concern that microplastics can act as a vector for cadmium through adsorption and desorption of free-ionic cadmium. Little is known about the uptake of cadmium following ingestion of cadmium-microplastic complexes. This study used an in vitro gut sac technique to investigate the translocation of cadmium across the gut barrier of fathead minnows following the simulated ingestion of cadmium, microplastics, or their complexed mixture. Microplastics did not cross the gut membrane, nor did microplastics alter the rate of cadmium translocation, which was estimated to be 1.2 ± 0.04 ng Cd / hour. Less cadmium translocated when cadmium-microplastic complexes were injected than the equivalent dose of only cadmium, indicating that the presence of microplastics was protective of dietary cadmium uptake. This work highlights the importance of considering dietary uptake and the role of microplastics acting as a vector for cadmium in aquatic environments and stresses the need to understand how environmental (digestive or ambient) characteristics govern cadmium-microplastic interactions. •Polyethylene microplastics (5 −7 µm) did not cross the gut membrane.•Cadmium partially dissociated from microplastics and crossed the gut membrane.•Microplastics were protective against cadmium internalization.•Builds knowledge of cadmium-microplastic associations in the digestive environment.