SAPEA: A scientific perspective on microplastics in nature and society

The report comprehensively examines the best available evidence from the natural sciences and computer modelling, as well as social, political and behavioural sciences. Its key conlusions are: 

• Microplastics -- tiny particles under 5mm in length -- are already present across air, soil and sediment, freshwaters, seas and oceans, plants and animals, and in several components of the human diet.
• These particles come from a variety of sources, including plastic products, textiles, fisheries, agriculture, industry and general waste.
• In controlled experiments, high concentrations of these particles have been shown to cause physical harm to the environment and living creatures, including inducing inflammation and stress.
• However, the concentration levels measured in many real-world locations are well below this threshold -- though there are also limitations in the measurement methods currently available.
• Meanwhile, in other parts of the environment, there is no reliable evidence about the levels or effects of these particles. This is true especially of nanoplastics, which are very difficult to measure and evaluate.