Preliminary determination of microplastics in bivalves collected from Phu Yen, Central Viet Nam

Abstract

In this study, four common bivalves including Meretrix lusoria (clam), Anadara subcrenata (ark clam), Crassostrea gigas (oyster), and Perna viridi (green mussels) which are popularly consumed were collected from a seafood market in Phu Yen, Central Viet Nam to investigate the occurrence of microplastics (MPs) in their tissues. Samples were treated with a 10 % (w/v) KOH solution for 48 hours and incubated at 40 ∘C. The base-sample ratio was 10:1 v/w (i.e 10 mL of 10 % KOH solution per 1.0 gram of a tissue sample). Sodium iodide was used to extract MPs from tissue samples. The number of MP items determined in clam, ark clam, oyster, and green mussels registered by weight and individual were 0.2-0.5, 0.1-0.8, 0.1-0.5, and 0.1-1.0 (item/g-ww), and 1-3, 1-3, 1-9, and 1-5 (items/individual), respectively. Fiber has the common shape (69-92 % of total items), followed by fragment. Furthermore, polyethylene terephthalate was the most common fiber, which was often confirmed when micro-fiber was analyzed by the FTIR technique. As the first investigation on MPs in bivalve tissue from Phu Yen, Central Viet Nam, this study indicated that relatively high levels of MPs were found in commercial bivalves collected from a seafood market in Central Viet Nam, warning of a potentially high risk to humans when consuming bivalves as daily food.