Hazardous chemical additives within marine plastic debris and fishing gear: Occurrence and implications

Plastic products contain numerous additive chemicals, which are present in large amount, and can be transferred to the marine environment. In this study, we quantified chemical additives and persistent organic pollutants (POPs) in marine plastic debris, along with their corresponding new plastic products (e.g., fishing gear, packaging material, and cigarette butts). The levels of chemical additives were significantly higher than those of conventional POPs in plastic samples, which was indicative of the widespread utilization of additives in plastics. New plastic products contained significantly higher additive concentrations than plastic debris, implying potential leaching during use or after disposal in the marine environment. In fishing gear materials, buoys generally contained high concentrations of antioxidants (280-91,000 ng/g). Polyvinyl chloride (PVC) rope used in aquaculture had the highest phthalate and bisphenol A (BPA) concentrations, and the second-highest ultraviolet radiation stabilizers. Rubber bars from the tire recycling used in aquaculture contained the highest 6PPDquinone concentration, which is known to be responsible for salmon death. This is the first quantitative analysis of 6PPD-quinone in recycling tire, suggesting a need for chemical analysis of the tires itself, not only in environmental matrices. Compared to fishing gear materials, concentrations of the targeted chemical additives were relatively low in packaging material and cigarette butts, except for plastic bags. The concentration difference between new and debris was largest in PVC rope for aquaculture farm. It was estimated that 340-470 kg of phthalates and 140-194 kg of BPA are released into the sea from this PVC rope in Korean marine aquaculture. The study indicates that aquaculture fishing gear represents a significant source of chemical additives in the marine environment. It also suggests that exercising caution is crucial when considering the use of recycled plastics in aquaculture gear due to potential chemical contamination of the marine environment.