Exploring microplastic distribution in Western North American snow

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Analytical Chemistry

Background:

• Atmospheric microplastic (MP) transport is poorly understood due to challenges in detecting small airborne particles.
• Snowfall offers a potential medium for inferring atmospheric MP presence and transport pathways.

Purpose of the Study:

• To develop and validate a streamlined method for quantifying microplastics in various snow types.
• To assess microplastic contamination in fresh snowfall, aged surface snow, and snowpack deposits across western coastal North America.

Main Methods:

• Sampling of fresh snowfall, summer surface snow, and snow pits at 11 sites.
• Microplastic detection and characterization using linear array µ-Fourier Transform Spectroscopy (µFTIR) and Open Specy.
• Analysis of recovery rates and blank samples to ensure data reliability.

Main Results:

• Microplastics were detected in all snow samples analyzed.
• MP concentrations varied significantly between remote and source-proximal sites, and across different snow types (fresh, aged, stratified).
• Negligible contamination was observed in blank samples, validating the methodology.

Conclusions:

• The developed method is effective for measuring MPs in pristine and remote environments.
• Snowfall serves as a valuable indicator for atmospheric microplastic deposition and transport.
• This study contributes crucial data to understanding the prevalence and distribution of airborne microplastics.