The transfer and resulting negative effects of nano- and micro-plastics through the aquatic trophic web—A discreet threat to human health

Abstract

The ubiquitous occurrence of plastic nano- and micro-particle contamination has raised concerns about its potential risks and impacts on the global environment, especially in aquatic ecosystems. Hundreds of aquatic species, from different trophic levels, have been affected by this “new” contaminant, which has been reported mainly in their digestive tracts. Consequently, current knowledge about plastic nano- and micro-particle spread and the potential impact on aquatic biota is growing rapidly. However, there is a significant lack of understanding of the trophic spread of microplastic contamination and integration of knowledge derived from laboratory assays with that from field research is difficult. Field experiments are unable to deal with differentiating between directly and indirectly ingested plastic microparticles. On the other hand, laboratory assays evaluating the influence of plastic microparticles and of their adhered or constitutive toxins on representative species cannot satisfactorily simulate the real environment. As a result, little is known about the effective transfer of plastic particles through the trophic net and the resulting human health risks. The present review seeks to gather information that can give a more accurate idea of the current situation and future challenges to be faced in mitigating the environmental and human effects of plastic particle pollution in aquatic, particularly estuarine, ecosystems.