Microplastic Contamination in NYC Waterways: New Detection Methods

Objective

Quantify microplastic debris in NYC waterways and sediment using fluorescent imaging techniques, and develop particle-density calibrations under fluorescence, for potential use in the development of a remote sensing tool for detection of microplastic contamination in surface waters.

Background

Annual global plastic production presently exceeds 300 million tons. Given the vast amounts of plastic items that are produced, used, and discarded, it is not surprising that the UN Environment Program described the presence of plastic contaminants in the environment as one of the most critical environmental issues facing our species. While plastic bags, water bottles, straws, etc. are visible pollutants, environmental weathering breaks these products down into particles called microplastics.  Microplastics are increasingly abundant in marine environments, but because of their relatively small size (less than 5 mm in diameter), they have been difficult to detect—and thus are sometimes referred to as the “lost” particles. Environmentally, the lost fraction raises a number of concerns. Organic contaminants including petroleum products and pharmaceuticals are known to adsorb and concentrate on the surface of microplastics, which are often ingested by marine and freshwater organisms. This can lead to bioaccumulation of contaminants at higher trophic levels.

As part of the effort to understand the impact that microplastics can have on food webs and ecosystem stability, the scope of the microplastics contamination problem needs to be quantified. This capstone project will seek to quantify the abundance, size distribution, and chemical composition of microplastics in aquatic environments of New York City, employing both currently-established and new methods, in a laboratory setting, to samples collected from local waterways.

Suggested Approaches

1. Quantifying microplastics in NYC waterways: Collect surface water and sediment samples from designated waterways in the NYC metro area (e.g., Jamaica Bay) and use density separation and filtration to isolate microplastics from larger debris and organic material. Once separated, use published methods (fluorescent microscopy and imaging) to quantify microplastic abundance in the samples.
    
2. Particle density calibration curves: Use fluorescent dye techniques and UV-Vis/Fluorescent   spectroscopy to derive a calibration curve that can be used to quantify microplastic density from bulk aquatic samples.
    
3.  Particle identification using fluorescent emission: Employ UV-Vis spectroscopy to/ determine the peak emission wavelength associated with different polymers, e.g. polyolefin, polyester, polystyrene, nylon, etc.

iv.  Reporting: Draft a report that summarizes the experimental results, assesses the efficacy of the spectroscopic techniques, and considers their potential use in a tool for remote sensing of microplastic contamination in surface waters.