Contamination of microplastics in mangrove sediment cores from Lach Huyen area, Hai Phong city, Vietnam

Abstract Microplastics have been found in coastal ecosystems since the 1970s, causing many negative impacts on the environment and aquatic organisms. In the present study, we examined the microplastic concentration and sediment grain size in mangrove sediment cores near Lach Huyen Port, Hai Phong city, Vietnam. The microplastic concentration in mangrove sediments varied from 0-3150 particles/kg with an average value of 1309.1±124.8 particles/kg, much higher than in similar regions worldwide. They are mainly secondary microplastics with various colors and sizes. The microplastic types include 80% of microfibers and the rest is a mixture of microfoam, microfragment, and microfilm. Research results showed that the concentration of microplastics tends to decrease from top to bottom of the sediment cores. However, the present study did not find any relationship between sediment grain size and microplastic abundance. Future studies should assess the pollution sources, factors influencing microplastic distribution, and the effects of microplastic contamination on coastal ecosystems in this area.