Critical gaps in nanoplastics research and their connection to risk assessment

Brittany E Cunningham; Emma E Sharpe; Susanne M Brander; Wayne G Landis; Stacey L Harper

doi:10.3389/ftox.2023.1154538

Critical gaps in nanoplastics research and their connection to risk assessment

Front Toxicol. 2023 Apr 24:5:1154538. doi: 10.3389/ftox.2023.1154538. eCollection 2023.

Authors

Brittany E Cunningham¹, Emma E Sharpe², Susanne M Brander^{1

3}, Wayne G Landis², Stacey L Harper^{1

4

5}

Affiliations

¹ Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, United States.
² Institute of Environmental Toxicology and Chemistry, Western Washington University, Bellingham, WA, United States.
³ Department of Fisheries and Wildlife, Coastal Oregon Experiment Station, Oregon State University, Corvallis, OR, United States.
⁴ School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, United States.
⁵ Oregon Nanoscience and Microtechnologies Institute, Corvallis, OR, United States.

Abstract

Reports of plastics, at higher levels than previously thought, in the water that we drink and the air that we breathe, are generating considerable interest and concern. Plastics have been recorded in almost every environment in the world with estimates on the order of trillions of microplastic pieces. Yet, this may very well be an underestimate of plastic pollution as a whole. Once microplastics (<5 mm) break down in the environment, they nominally enter the nanoscale (<1,000 nm), where they cannot be seen by the naked eye or even with the use of a typical laboratory microscope. Thus far, research has focused on plastics in the macro- (>25 mm) and micro-size ranges, which are easier to detect and identify, leaving large knowledge gaps in our understanding of nanoplastic debris. Our ability to ask and answer questions relating to the transport, fate, and potential toxicity of these particles is disadvantaged by the detection and identification limits of current technology. Furthermore, laboratory exposures have been substantially constrained to the study of commercially available nanoplastics; i.e., polystyrene spheres, which do not adequately reflect the composition of environmental plastic debris. While a great deal of plastic-focused research has been published in recent years, the pattern of the work does not answer a number of key factors vital to calculating risk that takes into account the smallest plastic particles; namely, sources, fate and transport, exposure measures, toxicity and effects. These data are critical to inform regulatory decision making and to implement adaptive management strategies that mitigate risk to human health and the environment. This paper reviews the current state-of-the-science on nanoplastic research, highlighting areas where data are needed to establish robust risk assessments that take into account plastics pollution. Where nanoplastic-specific data are not available, suggested substitutions are indicated.

Keywords: Bayesian network; microplastic; nanoplastic; risk assesment; toxicity.

Publication types

Review

Grants and funding

This work was funded by the National Science Foundation Growing Convergence Research Big Idea, 1935028 (to SH and SB) and 1935018 (to WL).