Microplastic Abundance and Variation in the Blind Brook Stream

Plastic usage has increased significantly in the 20th and 21st centuries due to advancements in chemical engineering, coupled with extreme demand due to increased plastic usage. Microplastics have entered the environment with consequences to the landscape, wildlife, and human health. Microplastics can have significant effects on energy reserves, hormone production, and digestion, among other health issues. This study aims to determine where the greatest distribution of microplastics occurs throughout the Blind Brook stream and identify the most common microplastic shapes. Sediment samples were collected along the stream for microplastic observation using 100 mL containers. Density separation was conducted using a sea salt solution to separate the microplastics from the sediment. The microplastic-containing supernatant was vacuumed into another beaker and poured through p4 fiberglass filters to filter the microplastics from the supernatant. The filters were viewed under the microscope and photographed. Microplastic abundance was the greatest on the western branch of the stream, with a total of 132 microplastics observed, and filaments were the most common microplastic type found across all sites. Microplastic abundance (µplastics g-1) was not significantly different between sites. Microplastic type had a greater influence on microplastic abundance than site, largely due to the significant differences between types. This study will serve as a baseline for future microplastic studies done at Purchase College.