Nano-sized particles of plastic can be more damaging to marine species than larger sized microplastics, a new study shows.
Lab tests revealed that nanoplastics can damage cell membranes in tiny marine creatures called rotifers (Rotifera), disrupting their natural defences against toxicants.
The researchers found that rotifers that had been exposed to nanoparticles of polystyrene were significantly more susceptible to the lethal effects of persistent organic pollutants (POPs). Reference.
Among the various materials found inside microplastic pollution, nanosized microplastics are of particular concern due to difficulties in quantification and detection; moreover, they are predicted to be abundant in aquatic environments with stronger toxicity than microsized microplastics. Here, we demonstrated a stronger accumulation of nanosized microbeads in the marine rotifer Brachionus koreanus compared to microsized ones, which was associated with oxidative stress-induced damages on lipid membranes. In addition, multixenobiotic resistance conferred by P-glycoproteins and multidrug resistance proteins, as a first line of membrane defense, was inhibited by nanoplastic pre-exposure, leading to enhanced toxicity of 2,2′,4,4′-tetrabromodiphenyl ether and triclosan in B. koreanus. Our study provides a molecular mechanistic insight into the toxicity of nanosized microplastics toward aquatic invertebrates and further implies the significance of synergetic effects of microplastics with other environmental persistent organic pollutants.