EAR-PF: Microplastics and Nanoplastics as Vectors for Inorganic Pollution: Examining the Effect of Environmental Systems Conditions on Degradation Pathway and Sorption Potential

Dr. Lauren Pincus has been awarded an NSF EAR Postdoctoral Fellowship at Princeton University under the mentorship of Dr. Satish Myneni of Princeton University and Dr.

Peter Ryan of Middlebury College to investigate how microplastics and nanoplastics bind toxic contaminants as they degrade in the environment. Plastics are among the most widespread and persistent contaminants globally; however, large knowledge gaps remain in regards to our understanding of how plastics degrade in the environment and transport other pollutants that may be bound to their surface.

It is particularly important to understand the chemistry of microplastics (100 nm - 5 mm) and nanoplastics (< 100 nm) due to their small size increasing their ability to be ingested by organisms, resulting in biomagnification of any bound toxic contaminants up the food chain. Dr. Pincus will investigate how commonly used plastics degrade in the environment through both field and laboratory experiments.

She will then examine the ability of the aged microplastics/nanoplastics to attract contaminants of environmental and societal concern such as arsenic and lead. This study will focus on inorganic contaminants (e.g. toxic metals), as this is a less studied area than organic pollutants (e.g pesticides). The ultimate goal of this research is to develop a predictive understanding of how degraded microplastics/nanoplastics contribute to the spread of toxic pollutants like lead and arsenic.

Ultimately, this knowledge can inform the design of future plastics that can degrade more safely in the environment without transporting toxic metals. The results of this research will be shared with the general public through a lecture series at local businesses, non-profits, and community colleges on plastics in the environment. Opportunities will also be provided for both undergraduates and high school students to participate in this research project, with an emphasis on working with and mentoring students from underrepresented (female, minority, low-income) backgrounds.

The ultimate goal of this research is to develop a predictive understanding of how microplastic (MP) and nanoplastic (NP) degradation affects environmental fate of inorganic contaminants. Specifically, this project aims to: 1. Determine how environmental conditions affect the degradation pathway of MPs and NPs, 2.

Investigate differences in MP and NP sorption potential towards inorganic contaminants throughout the degradation process, 3. Identify key functional groups that control contaminant sorption by MPs and NPs, and 4. Elucidate the role of metal (hydr)oxide precipitates and biofilm formation on adsorption of inorganic contaminants by MPs and NPs.

A combination of field and laboratory studies will be used in order to isolate key environmental factors driving MP/NP weathering mechanisms that increase their sorption capacity towards inorganic contaminants. Ultimately this knowledge will enable design of plastics capable of safely degrading in the environment without the unintended hazard of serving as vectors for pollutant transport.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.