A Preliminary Analysis of Heavy Metals Consentration on Existing Mesoplastic in a Tropical River: Study Cases in Deli RiverNovrida Harpah, Dhea Syafira, Zaid Perdana, Hafizhul Khair, Isra Suryati and Meutia NurfahasdiE3S Web Conf., 519 (2024) 03019DOI: https://doi.org/10.1051/e3sconf/202451903019