Nanoplastics in the Environment
There has been an increasing awareness of the potential ecotoxicological consequences of the growing presence of plastic materials in the environment. Among these, due to their inherent physical and chemical characteristics, microplastics have received special attention, though smaller particles, defined as nanoplastics, could have more pervasive effects. However, their presence is difficult to be accurately determined, due to the technical difficulties in isolating and quantifying these small particles. There is, nonetheless, an ample consensus that nanoplastics are not only present, but that they also pose a significant threat to the environment, organisms and, ultimately, human health, not only due to their reduced size (<1 μm), but also due to their characteristic high surface area, which may have ecotoxicological implications, as other contaminants, including organic pollutants, may be adsorbed. In spite of these potential harmful effects, currently available data should be examined carefully, as most studies have been based on the use of nanoplastics and/or organic pollutants whose concentrations far exceed those expected in the natural environment. Herein, based on the currently available literature, the most relevant sources and fates of nanoplastics are discussed, as well as their potential – if any – effects and the key challenges scientists currently face in this field of research.