REFLECTIVE SPECTRA OF PLASTIC OBJECTS AND COMMON GEOLOGIC SUBSTRATES: A FEASIBLY STUDY FOR THE DEVELOPMENT OF A HYPERSPECTRAL LIBRARY FOR STUDYING PLASTIC POLLUTION

Plastic pollution has been an increasingly dire issue in modern times, presenting innumerable environmental risks on a global scale. In the century following the first production of synthetic plastics, the oceans have become a labyrinth of debris. Plastics in the modern day are completely ubiquitous- being used in everything from medical supplies to car parts to shipping containers and single-use food packaging. While plastics are commonly recyclable, the bulk of what is no longer needed is most often discarded. Generally intended to be taken to landfills, plastic waste is often lost in transport or disposed of indiscriminately. Once plastic debris has reached a waterway, it begins its exodus to the ocean. In determining the extent of plastic pollution and the primary contributors of plastic waste, a novel solution lies in the use of hyperspectral remote sensing and the building of detailed spectral libraries. Whether or not plastics have rich reflective spectra useful for hyperspectral imaging and are distinct from common geomaterial substrates is not known. As a preliminary evaluation, spectra were collected on numerous plastic objects in the 350-2500 nm range using an ASD spectroradiometer. Several well characterized substrates were also analyzed. The majority of plastics have spectral features in the short wave infrared that are distinct and useful for hyperspectral imaging. Many of these features do not overlap with geological substrate features. This project suggests that developing an effective hyperspectral library for plastic pollution is feasible but will require an extremely large sample size of plastic material, numerous relevant substrates and several environmental conditions. Key in developing such a library is acquiring aged plastics as UV damage, biological growth and mechanical degradation will modify spectra of a given plastic object over time. This project is a first step toward global monitoring of plastic pollution.