MICROPLASTIC TRANSPORT IN THE HUDSON VALLEY WATERSHED

A new environmental threat known as microplastics is contaminating the Hudson River Watershed. Microplastics are entering the environment through a number of different means: drainage of personal care products containing microbeads, fragmentation and run off from larger plastic, and fibers released from washing of nylon or acrylic fabrics. Recent studies have shown a growing presence of microplastics in the Hudson River. Due to their high resistance to degradation, accumulation of microplastics may result in harmful impact on humans and the environment. This study investigates the contribution of Hudson River tributaries and their role in transport of microplastics throughout surrounding watershed, directly to the Hudson River. The tributaries in the study were chosen based upon their use, pre-assessed water quality and their locations. The four sampled tributaries were located in the State of New York. Sampling was performed using a flow through technique with a drift net collecting all particulate matter larger than 333 µm. In each water sample the following water quality parameters were measured; pH, dissolved oxygen, temperature, conductivity and E. coli colonies. Particulate debris was sorted and seperated into microplastic and organic contaminants using a light microscope. The samples were analyzed using wet peroxide oxidation (WPO) method to decompose any organic material. Esri ArcGIS was applied to find correlation between land use, population density, and wastewater treatment outfalls and microplastic content. Our resuts showed the largest amount of microplastic throughout all streams, were in the form of fibers and the lowest in the form of beads. Microplastics structural makeup was verified using infrared spectroscopy. E. coli was tested using an enzyme plating technique (ColiPlate™). All four sampled stream had unsafe levels of E. coli colonies for drinking water (>1MPNs) with an average of 124.5 MPNs/100 ml, and three out of the four having unsafe levels of E. Coli for recreational water (>100MPNs) with an average of the three being 158 MPNs/100 ml. Microplastics were detected in all samples collected from all tributaries. The content ranged from ~4% to ~20% plastic debris. There was statistical differences in microplastic content between all tributaries. The study rasises concerns that tributaries, and related communities, play significant roles in tranpsort of microplastics through the Hudson River watershed.