The degradation of bulk plastics in the environment leads to the release of microplastics that can contaminate water supplies, agricultural fields, and foods we consume. Weathering of a single microplastic particle can yield up to billions of nanoplastics and nanoplastic pollution is expected to be ubiquitous in the environment. Nanoplastics are potentially more hazardous than microplastics because they can cross biological membranes; yet, there is little data on the occurrence, fate and impacts of nanoplastics. A key challenge in understanding the environmental burden of nanoplastics is the detection of such small, carbon-based particles in complex natural matrices such as soils.
Environmental nanoplastics are often thought of as an extension of microplastics with a distinction based on an arbitrary size cut-off, typically 100 nm or 1000 nm. In our view, in terms of environmental implications and analytical challenges, a size cut-off distinction provides little guidance. While a consensus on the precise definition of “nanoplastic” has yet to be reached, we advocate for a characteristic-based distinction between nanoplastics and microplastics. Based on existing literature and analytical methods, we present a set of characteristics, distinct from microplastics and other contaminants, that define environmental nanoplastics.
This lecture will present an overview of our work aimed at overcoming challenges to better understand the fate and impacts of nanoplastics in terrestrial and aquatic environments. I will discuss new approaches for detection of nanoplastics in complex matrices and recent advances in our understanding of the toxicity of nanoplastics.