Researchers worldwide are confronting the challenge of microplastic and toxic chemical pollution in ecosystems. Microplastics act as vectors, transporting toxic chemicals. This study examines the presence and distribution of microplastics and polychlorinated biphenyls (PCBs) in the surface waters of the Langat River, Malaysia, across six sites from the open sea to riverine areas. Microplastic surfaces showed cracks, pitholes, particle adherence, and diatoms, with aluminum (Al) and potassium (K) identified through Scanning Electron Microscopy/Energy Dispersive X-ray spectroscopy. Gas Chromatography-Mass Spectrometry revealed various PCB types on these microplastics. Temperature, pH, and salinity significantly influenced PCB diffusion and sorption efficiency, with open sea conditions enhancing diffusion and potentially stabilizing persistent organic pollutants (POPs), while estuarine conditions affected microplastic surface charges. These findings underscore the role of microplastics as substrates for co-pollutant attachment and highlight the need for regular monitoring in Malaysia and Southeast Asia's riverine and estuary ecosystems.

Microplastic,Southeast Asia,PCBs,Estuary,Seawater,surface water