Ship paint as a new input source of floating microplastics in surface microlayer

Abstract

Small size and low specific gravity of microplastics are expected to be accumulated within the surface microlayer (SML) along with SML’s high surficial tension. In this study, plastic-like particles was identified by FT-IR microscope in SML from ten stations of southern coast of South Korea in May and July, 2012, respectively. Abundances of microplastics are in the ranged of 68-473 particles/L in May and 60-253 particles/L in July. Results from FT-IR identification showed that microplastics in the SML contains at least two polymer types in fragment 1) polyester (soybean oil modified phthalic alkyd) and 2) poly(acrylate:styrene) copolymer. Two co-polymer types accounted for over 90% of total microplastics abundances. Two major types of co-polymers are known to be used in ship paint, coating, pharmaceutical, oil industry, textile finishing and etc. Ship paint were suspected as origin of the co-polymer fragments, considering their distinct green or blue color as well as thousands of fishing boats registered in the study area. The FT-IR spectrums of the major microplastic co-polymer fragments in the SML and the ship paint chips collected from several boat hulls in the study area matched identically. It indicates that two co-polymer particles are mainly originated from ship paints applied to ship hulls. It is unclear, however, yet that the co-polymer fragments were introduced to surface water directly from during ship mL from ten stations of southern coast of South Korea in May and July, 2012, respectively. Abundances of microplastics are in the ranged of 68-473 particles/L in May and 60-253 particles/L in July. Results from FT-IR identification showed that microplastics in the SML contains at least two polymer types in fragment 1) polyester (soybean oil modified phthalic alkyd) and 2) poly(acrylate:styrene) copolymer. Two co-polymer types accounted for over 90% of total microplastics abundances. Two major types of co-polymers are known to be used in ship paint, coating, pharmaceutical, oil industry, textile finishing and etc. Ship paint were suspected as origin of the co-polymer fragments, considering their distinct green or blue color as well as thousands of fishing boats registered in the study area. The FT-IR spectrums of the major microplastic co-polymer fragments in the SML and the ship paint chips collected from several boat hulls in the study area matched identically. It indicates that two co-polymer particles are mainly originated from ship paints applied to ship hulls. It is unclear, however, yet that the co-polymer fragments were introduced to surface water directly from during ship m