Assessment of microplastic contamination in clams and shrimp from estuarine environments of Goa: implications for environmental health and food safety

Microplastics (MPs) are emerging contaminants of global concern, particularly in estuarine ecosystems. This study aimed to quantify and compare the concentration of MPs in two economically important species: Meretrix casta collected from Siridao beach and Penaeus vannamei from a sluice gate harvest site in Siolim, in Goa, India. Water samples from both locations were also analyzed to evaluate environmental MP levels. MPs were present at both sites; however, water and shrimp from Siolim exhibited higher concentrations than the water and bivalves from Siridao. The MPs were predominantly fibres and fragments of polyamide, polyethylene, and polystyrene, most likely originating from anthropogenic activities such as fishing, tourism, and waste disposal. The coefficient of microplastic impact (CMPI) reveals the impact of fragments and fibres at both Siridao [fragments, 0.56 (maximum); fibres, 0.39 (average)] and Siolim sites [fibres, 0.87 (extreme)]. The bioaccumulation factor (BAF) was found to be highest at Siolim (> 1 for all MP types). The findings raise concerns about the potential health risks posed to local and tourist populations that consume seafood from coastal regions like Goa, as well as the broader ecological impacts of MP pollution.