Organic micropollutants in plastic resin pellets from sand beaches of South Korea

Abstract

In order to assess the occurrence and distribution of microplastic debris in the coastal regions of South Korea, beach monitoring survey was conducted at four beaches in 2011 and 2012. Among the plastic samples collected in that survey, plastic resin pellet was selected and used for the chemical analysis of persistent organic pollutants (POPs). The FT-IR analysis showed that the primary synthetic polymers collected on the beaches were polypropylene (PP) and polyethylene (PE). According to their polymer type and the degree of weathering, the pellet samples were sorted into four groups: aged PP, fresh PP, aged PE, and fresh PE. All the beached pellets contained a wide range of toxic substances, indicating their widespread distribution in the Korean coastal environment. The overall concentrations (ng/g pellet) of organochlorines (OCs) in beached pellet were in the range of <0.15-50.8 for HCB, <0.1-4.09 for HCHs, <0.1-94.1 for CHLs, 0.24-75.8 for DDTs, and 0.21-1,350 for PCBs. PCBs and DDTs showed the highest median values (3.67 ng/g and 3.49 ng/g, respectively) and the highest detection frequencies (100%). In general, the concentration level of PCBs and DDTs accumulated in the pellet are between those reported from sediment and bivalves. The overall concentrations (ng/g pellet) of BFRs were in the range of <0.15-511 for PBDEs and 5.61-2,630 for HBCDs. Interestingly, the concentrations of emerging POPs such as brominated flame retardants were higher and (or) comparable to those of classical POPs such as PCBs and organochlorine pesticides. In general, PE accumulated larger amounts of POPs than PP. And aged pellet accumulated more contaminants than the fresh. The level of PCBs in aged PE pellet from South Korea is lower than those in Japan, Europe and USA, but is comparable to those in China and South America, and higher than those in Southeast Asia, Australia and Africa (http://www.pelletwatch.org). For DDTs, China and Vietnam shows the highest concentration and followed by USA, South America, Africa > Japan, South Korea, Europe, Australia.