Understanding Microplastic Aerosols: Clouds, Precipitation, and Beyond

ALEXANDRIA JOHNSON, Gouri Prabhakar, Purdue University

     Abstract Number: 254
     Working Group: Chemicals of Emerging Concern in Aerosol: Sources, Transformations, and Impacts

Abstract
Plastic has become a ubiquitous material in modern day life. The plastics we use, and discard, can take upwards of 500 years to decompose. Even then, the material itself never actually disappears; it just breaks down in to smaller and smaller pieces. In recent years these small pieces, known as microplastics and nanoplastics, have been found almost everywhere, from the guts and gills of fish in the great lakes, to remote locations like Antarctica and the world's highest peaks. Identifying the role these tiny bits of plastic play in our environment now is key to understanding our changing world and assessing how the role of plastics will change with time.

In this research we are working towards understanding the presence of microplastics and nanoplastics in two ways. The first is the identification and quantification of microplastics from rain and snow collected in the Greater Lafayette, Indiana region. Samples collected at the ground from the summer of 2023 onward are being analyzed to identify plastics through microscope and SEM images. Additional data collected on site allows for us to link the presence of plastics with the overall meteorological (wind speed, temperature, time since last rainfall, etc.) and microphysical (drop size distribution, cumulative precipitation, etc.) conditions of rain and snow events. Second is investigating how these plastics become integrated into clouds and precipitation and the effects they have on cloud microphysical processes through laboratory studies. In particular, we are working towards isolating microplastics and nanoplastics from events in such a way that mechanical and chemical aging is preserved, allowing for their nucleation and chemical properties to be analyzed through controlled experiments.