CAREER: Microplastics in snow-dominated environments - sources, transport, and fate

The accumulation of plastic debris is an increasing concern for the environment following decades of global plastic production. Microplastics (plastic particles less than 5 millimeters) have received increased scientific attention as they have been found around the globe, including recent studies which have shown microplastic contamination in remote locations.

However, questions remain about the sources, transport, and fate of microplastics deposited in the environment. The goal of this study is to measure the amount and type of microplastics deposited in snow and snow-fed water resources in the Sierra Nevada of California and Nevada. Measurements will be used to assess the sources of microplastics to the remote environment and the downstream fate of microplastics in important water resources.

The research findings will be integrated into a middle school mobile teaching kit. The mobile teaching kit will include a series of lessons surrounding the topics of hydrology, microplastics, anthropogenic pollution, and water quality, with the objective of enhancing an interest in science at the middle school level.

Microplastics have been observed throughout the environment, however, questions remain about the sources, transport, and fate of microplastics, particularly in remote environments. Through a combination of field and laboratory-based studies, the proposed research aims at assessing: (1) spatial variability of microplastics in snow from headwater basins; (2) deposition and subsequent vertical distribution of microplastics in the snowpack during accumulation and melt; and (3) fate of microplastics as they move downstream toward snow-fed water resources.

With a focus on snow and water resources in the Sierra Nevada of California and Nevada, the proposed work will develop methods for microplastic isolation and detection, conduct spatial and temporal sampling of snow, snowmelt, air and water, and apply infrared microscopy and Pyrolysis-GC/MS for characterization of type and amount of microplastics. The study will improve our understanding of sources to remote locations, microplastic transport in snow-dominated systems, and downstream contamination.

It will further generate data that can be used to better understand human impacts to freshwater resources beyond the Sierra Nevada, including other snow-dominated environments around the globe. The project will support training of two PhD and several undergraduate students and will develop a mobile teaching kit to provide educators with appropriate tools for exposing middle school students to microplastics, environmental science, and hydrology.

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.