Oral Session 6 | Wednesday, October 5, 09:40–10:00 | Abstract 678
Measurements of the inherent optical properties of microplastic assemblages
Since the advent of industrial manufacturing of petroleum-based plastics, their use in everyday products has become ubiquitous due to their durability, moldability, low weight, and affordability. As a consequence, plastics have quickly become one of the largest sources of solid waste pollution on the planet, and can now be found in marine sediment, coastal waters, surface waters of oceanic gyres, and within marine organisms. However, the extent of this problem has yet to be fully realized partly due to the challenges associated with discrete water sampling in the vast global oceans. Optical detection of microplastics is one promising approach with the potential to circumnavigate temporal and spatial limitations of discrete water sampling, though methodological techniques are still in their infancy and libraries of inherent optical properties (IOPs) of microplastics are sparse. In the current study we describe our results and technique for measurement of the IOPs of aqueous suspensions of microplastic assemblages generated with commonly utilized plastics. The measurements included angle-resolved polarized light scattering and spectral absorption and beam attenuation. We also performed ancillary characterization of assemblages in terms of particle properties, including size distribution, orientation, shape, and mass concentrations of suspended matter and carbon. Important distinctions with respect to typical marine particle assemblages are examined. These results are expected to be particularly useful for radiative transfer simulations as well as the development of novel plastic detection techniques from remote or in situ optical measurements.
Daniel Koestner, University of Bergen, 0000-0002-2252-4847
Robert Foster, US Naval Research Laboratory, 0000-0002-4186-2147
Ahmed El-Habashi, US Naval Research Laboratory