CHARACTERIZATION AND QUANTIFICATION OF THE INTERACTION BETWEEN HEAVY METALS AND MICRO-BEADS IN PERSONAL CARE PRODUCTS: POTENTIAL IMPACTS OF PLASTIC PRODUCTS AT THE BALTIMORE HARBOR, MD
Iron and Manganese, two of the most common metals found in the sedimentary environment, are used as metals mimicking potential contaminants to be in contact with micro-beads. The purpose is to determine the quantity of contaminants adsorbed on the micro-beads’ surfaces. Experiments are being done by exposing micro-beads to a set of distinct concentrations of Fe and Mn that reflect concentrations found in costal ecosystems. Aqueous solutions prepared under circum-neutral pH and room temperature conditions will be monitored and preserved at predetermined time intervals for quantification using inductively coupled plasma mass spectrometry (ICP-MS) and Scanning Electron Microscope (SEM) on selected samples.
Preliminary experiments performed so far are interactions of Fe with two of the isolated micro-beads, namely Dove and Neutrogena Personal Care Products, which are known to exist to in coastal environments. Two different concentrations of Fe were used and they clearly show the influence of the amount of iron adsorbed onto the surfaces of the micro-beads. The micro-beads used were characterized previously in this research and were observed to have various shapes, sizes, colors, hardness, and surface morphologies. These variant properties (such as the roughness or surface area of these micro-beads) may be significant factors in the quantities of contaminants adsorbed by the micro-beads when interacting with metals in the aqueous environment.
More experimental work is underway and results will be analyzed and presented. The overall objective is continuing this study on sediments and water from the Baltimore Harbor water and sediments. The anticipated results may provide a better understanding of the fate and transport of micro-plastic pollution and their impacts on the cycling of metals in costal environments and in the lives of marine organisms.