Neurobehavioral and neurochemical effects of nano-sized polypropylene accumulation in zebrafish (Danio rerio)

Plastic pollution, particularly nanoplastics (NPs), is a significant environmental contaminant that poses potential toxicological risks to organisms and ecosystems. Although extensive research has been conducted on the toxicity of NPs, our understanding remains limited, primarily because of the constraints of standardized toxicity studies using polymers of specific sizes and types. To address this gap, we conducted toxicity experiments using directly synthesized polypropylene nanoparticles (PP-NPs) in zebrafish (Danio rerio). The presence of PP-NPs in the zebrafish brain was confirmed using pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) and bio-transmission electron microscopy (bio-TEM). The accumulation of PP-NPs in the brain of D. rerio led to neurotoxicity, manifested as reduced motility and aggressiveness. Altered neurotransmitter levels and neural activity associated with behavior further supported these findings. This study suggests that environmental plastic pollutants may accumulate in the brain and cause neurotoxicity in organisms, emphasizing the need for appropriate management of these substances.