Brain damage and behavioural disorders in fish induced by plastic nanoparticles delivered through the food chain

Karin Mattsson,Elyse V Johnson,Anders Malmendal,Lars-Anders Hansson,Sara Linse,Tommy Cedervall

doi:10.1038/s41598-017-10813-0

Abstract

The tremendous increases in production of plastic materials has led to an accumulation of plastic pollution worldwide. Many studies have addressed the physical effects of large-sized plastics on organisms, whereas few have focused on plastic nanoparticles, despite their distinct chemical, physical and mechanical properties. Hence our understanding of their effects on ecosystem function, behaviour and metabolism of organisms remains elusive. Here we demonstrate that plastic nanoparticles reduce survival of aquatic zooplankton and penetrate the blood-to-brain barrier in fish and cause behavioural disorders. Hence, for the first time, we uncover direct interactions between plastic nanoparticles and brain tissue, which is the likely mechanism behind the observed behavioural disorders in the top consumer. In a broader perspective, our findings demonstrate that plastic nanoparticles are transferred up through a food chain, enter the brain of the top consumer and affect its behaviour, thereby severely disrupting the function of natural ecosystems.

Highlights

The production of plastic material has increased tremendously during the last decades[1, 2], and about 10% of the plastics produced annually end up in the oceans[3] through sewage treatment plants, waste handling or aerial deposition[4], constituting 60–80% of the total marine debris[5]
We report novel findings on how plastic nanoparticles strongly affect an aquatic food chain from the zooplankter Daphnia magna to the top consumer, the freshwater fish, Crucian carp (Carassius carassius), which is common in anthropogenically affected waters
Those behavioural disorders depended on the size of the nanoparticles and analyses by hyperspectral microscopy showed that the plastic nanoparticles were present in the fish brains

Summary

Introduction

The production of plastic material has increased tremendously during the last decades[1, 2], and about 10% of the plastics produced annually end up in the oceans[3] through sewage treatment plants, waste handling or aerial deposition[4], constituting 60–80% of the total marine debris[5]. Plastic material is broken down to nanoparticles[9,10,11,12], which may be an even more potent threat since plastic nanoparticles are able to pass through biological barriers[13], penetrate tissues[14] and accumulate in organs[15] and affect behaviour and metabolism of organisms[16, 17]. Those effects are generally not due to the toxicity of the material per se, but rather a result of the physical features of the nanoparticles. On a broader scale such effects are likely to considerably affect natural ecosystems, since top predators have a crucial impact on lower trophic levels and ecosystem functions[33]

Methods

Results

Conclusion