Investigation on microplastics in some bivalves at Binh Dien Market in Hochiminh City, Vietnam

Abstract

Microplastics (MPs) and their risk to living things and human health have been attained a lot of attention worldwide. Reports on the MPs in mollusks used as seafood are being increased in all continents. However, the information is limited in Vietnam. This study aimed to identify the quantitative presence of MPs in three bivalves (Anadara granosa, Meretrix lyrata, and Ensidens sp.) in Hochiminh City which are popularly used as daily seafood by local residents. Samples of the bivalves were bought biweekly from the wholesale market Binh Dien, Hochiminh City, from February to April 2022. All three bivalve species were found with fiber MPs in their tissues. The concentrations of MPs (mean ± standard deviation) were 8.9 ± 5.4 items/individual (idv), and 4.2 ± 3.2 items/gram wet weight (g ww) in the A. granosa; 6.4 ± 2.6 items/idv, and 1.1 ± 0.4 items/g ww in the M. lyrata; and 5.9 ± 2.8 items/idv, and 0.7 ± 0.3 items/g ww in the Ensidens sp. The shorter length the fiber MPs were, the higher concentration they were, in the samples. Eight different colors of MPs in the bivalves were observed including blue, black, red, yellow, green, white, pink and grey in which the blue color was dominant in the samples. Chemical analysis with the fourier transform infrared microspectroscope revealed that 50% of fibers were polyethylene terephthalate (PET), polyethylene (PE) and rayon. This study firstly reported the MPs in the Ensidens sp. and the A. granosa (as items/ g ww). The total fiber intake from the three bivalve consumption was approximately 3,992 items per person per year. The presence of MPs in the bivalves used as food in Hochiminh City possesses a health risk to local people who commonly consume them as daily food. Further insight studies on the effects of MPs from food on human health in Hochiminh City are suggested.