Characterization of petroleum-based plastics and their absorbed trace metals from the sediments of the Marina Beach in Chennai, India

Background: Pollution by marine plastic debris becomes an increasing global concern. Characteristics of petroleum-based plastics pollution and its absorbed metals in Marina Beach, Chennai, in India are not reported yet. In this study, we first characterized the petroleum-based plastic debris and quantified the concentration of arsenic (As), chromium (Cr), copper (Cu), and lead (Pb) in plastics from the Marina Beach. Results: A total of 2275 samples of the sediments were collected from three different locations across the Marina Beach. Our results showed that plastics debris mainly were three shapes as fiber, sphere, and fragment. The plastic fragments were mechanically eroded and chemically weathered observed by the scanning electron microscope (SEM). Five types of polymers were identified, including low-density polyethylene (LDPE), polyethylene terephthalate (PET), polypropylene (PP), polyamide (PA), and polycarbonate (PC). Their absorbed trace metals, such as Cr, As, Pb, and Cu, were determined by the inductively coupled plasma mass spectrometry (ICP-MS). The level of As was high in most plastics. However, the highest levels of Pb, Cu, and Cr were in the PA, PP, and PA, respectively, implying the adsorption preference of plastics from different sources. Conclusion: Taken together, this study first characterized petroleum-based plastics and their absorbed trace metals in the sediments of the Marina Beach, indicating that petroleum-based plastics acted as the vectors for the transportation of metal elements in the marine biome.