Acute and chronic ingestion of polyethylene (PE) microplastics has mild effects on honey bee health and cognition. (15th July 2022)

• Record Type: Journal Article
• Authors: Balzani, Paride; Galeotti, Giorgia; Scheggi, Sara; Masoni, Alberto; Santini, Giacomo; Baracchi, David
• Is Part Of: Environmental pollution. Volume 305(2022)
• Publication Date: 2022-07-15
• Subjects: Apis mellifera -- Learning and memory -- Microplastics -- Pollinators -- Pollution -- Stressors; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2022.119318
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The massive use of plastic has contributed to huge quantities of hazardous refuse at a global scale and represents one of the most prominent issues of the Anthropocene. Microplastics (MPs) have been detected in almost all environments and pose a potential threat to a variety of plant and animal species. Many studies have reported a variety of effects, from negligible to detrimental, of MPs to aquatic organisms. Conversely, much less is known about their effect on terrestrial biota, and particularly on animal behavior and cognition. We assessed the oral toxicity of polyethylene (PE) MPs at three different concentrations (0.5, 5, and 50 mg L −1 ), and at different timescales (1 day and 7 days of exposure) and tested for their effects on survival, food intake, sucrose responsiveness, habituation to sucrose and appetitive olfactory learning and memory in the honey bee Apis mellifera . We found that workers were not completely unaffected by acute and prolonged ingestion of this polymer. A significant effect of PE on bee mortality was found for the highest concentration but not for lower ones. PE affected feeding behavior in a concentration-dependent manner, with bees consuming more food than controls when exposed to low concentration PE. Regarding our behavioral and cognitive experiments, the high concentration PE was found to affect only bees' ability to respond consistently to sucrose but not sucrose sensitivity, habituation to sucrose or learning and memory abilities, even for prolonged exposure to PE. While these last results may look somewhat encouraging, we discussed why caution is warranted before ruling out the possibility that PE particles at environmental concentrations are harmful to honey bees. Graphical abstract: Image 1 Highlights: Microplastics (MPs) are one of the most prominent issues of the Anthropocene. Very little is known about the impact of PE exposure on terrestrial biota. Polyethylene microparticle toxicity was assessed in the pollinator Apis mellifera . Polyethylene affects bee survival and feeding in a dose dependent manner. Polyethylene impairs neither associative and non-associative learning nor memory.