Microplastics (MP) are omnipresent in ecosystems. Some studies focus on MP fates and their toxicology on biota for the last ten years in the world. In the present study, MP was identified in bivalve (Perna Viridis) collected in Vietnam for the first time using micro-Fourier transform infrared Microspectroscopy (µFTIR) technique. Organisms were digested by KOH 10% solution then separated using KI 50% solution. The average concentration evaluated at 2.60 MP/individual and 0.29 MP/gram of wet tissue. Six types of MP were found with a high proportion of polypropylene (PP) (31%) and polyester (23%). MP characterizations were also observed which bring to much important information such as the source of MP contamination in bivalve from Vietnam. Nevertheless, more work needs to be invested in the future such as on different species or environment compartments which permit to the global view of MP contamination in Vietnam.

Microplastics with particle size less than 5 mm are becoming a raising global environmental crisis. These pollutants were found from the poles to the equator, in continental shelves, coasts and in the oceans, moreover, they have also been identified in the water columns, sediments and even in a variety of organisms. The majority of microplastics that ended up in the oceans originate from the land. Due to their small size, they are easily accumulated in the food chain, causing harmful effects on organisms and human health. The bivalves especially caught the interest of scientific researchers because of their direct contact with microplastics through the filter-feeding habit. Therefore, it is essential to develop methods to determine the presence of microplastics in these organisms and identify their source. This study evaluated the efficiency of extracting microplastics from the tissues of green mussels (Perna viridis) using KOH 10% solution to digest and KI 50% as the separating solution. Mussel soft tissue samples were spiked five different types of microplastics: polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polypropylene (PP), high-density polyethylene (HDPE) and treated with KOH 10% solution and KI 50% solution. The presence of microplastics in some green mussel species was also investigated in some mussel farming areas in Giao Thuy, Nam Dinh province, Thi Nai, Quy Nhon, Binh Dinh province and Hue city, Thua Thien Hue province. The research results showed high efficiency of microplastic extraction and recovery with the range from 76% to 97%. Microplastic concentration obtained in all mussel samples variates from 1.0 ± 0.1 particles/g to 1.7 ± 0.6 particles/g, in which fiber microplastics predominated. Microplastics in mussel samples have small sizes of < 1,000 µm and 1,000–2,000 µm, make up 74.15–82.32% and 9.76–14.71%, respectively. Purple was dominant among all mussel samples. This study proved that using KOH 10% solution and KI 50% solution to isolate microplastics is a suitable approach and can be used in monitoring studies of microplastic pollution in bivalves.

Plastic materials are defined as including the whole of organic polymers owning plasticity. Their production increases rapidly due to their superior properties and applications in our life. Currently, the annual production of plastic is estimated at nearly 400 million tons. About 10% of the plastic produced is discharged into the seas and oceans. Microplastics (MP, less than 5 mm in size) are non-biodegradable and persistent in the environment and have the ability to accumulate in various environmental components, organisms and other human beings through the food chain. Therefore, assessing microplastic pollution becomes essential for the marine and ocean environment. This study aims to evaluate microplastic pollution in Nam Dinh seawater. Water samples were taken in summer 2020 and spring 2021 in Giao Thuy district, Nam Dinh province. Samples were treated with 30% H2O2 solution to remove organic matters and then microplastic buoyantly separated using saturated NaCl solution. MP was identified through observation under a stereo microscope (Olympus SZX2-TR300) and its nature was determined through infrared spectroscopy (µFTIR). Results show that a large level of pollution (average 6 to 8 particles/m3 and 10–14 million particles/km2) is associated with the predominant of colored fibers among MP characteristics. Most of the microplastics identified are Polypropylene in nature. Next, more research needs to be invested in this pollution problem, such as expanding the scope and research object.