A preliminary assessment of microplastic occurrence and their potential risk as pollutant transport vectors: A case study in Phu Ly, Ha Nam, Vietnam

<title>Abstract</title> Nowadays, microplastics are a global concern due to their potential environmental risks. However, there is currently a scarcity of data on the presence and health risks of microplastics in Southeast Asia, especially in Vietnam. This study investigated the levels of microplastics (MPs) in surface waters and sediments in Phu Ly, Ha Nam, Vietnam. MP concentrations range from 0.17 to 6.2 µg L^{− 1} in surface water and 3.74 to 31.23 mg kg^{− 1} wet-weight of sediment, respectively. Nine trace metals (TMs), including Cd, Pb, Co, Ni, Mn, Cr, As, Cu, and Zn, were detected to associate with MPs in surface water in a concentration range of 0.0004–42.75 mg/g. We hypothesized that the TMs adsorbed on the surface of MPs were strongly correlated with environmental pollution levels and hydrodynamic conditions. MPs can be viewed as transport vehicles for TMs in the aquatic environment. The link between AMR bacteria/ genes and MPs is weak, but the role of MPs in the transportation of those risks cannot be dismissed. Although the HQs of TMs associated with MPs in this study were less than 1, indicating low health risks from the pollutants, regular monitoring of MPs and other environmental concerns such as TMs and AMR are needed due to the high mobility of MPs in the ecological system.