Identification and quantification of additive-derived chemicals in beached micro–mesoplastics and macroplastics

Although marine plastic debris are expected to retain various chemical additives, little is known about the additives that are retained. We conducted a screening analysis of additives in 261 macroplastic and micro–mesoplastic debris from two beaches. We detected 52 chemicals—antioxidants, phthalates, ultraviolet stabilizers, hindered amine light stabilizers, and flame retardants—and quantified the concentrations of 15 of them. Comparison of the concentrations of Irgafos 168, an antioxidant stabilizer, among sample categories indicated that leaching had occurred from micro–mesoplastics. Differences in diffusion rates between polymer types may explain faster leaching from polyethylene than polypropylene. The significant amounts of Irgafos 168 retained in even micro–mesoplastics indicated the importance of plastics as a vector of additives. This study provides fundamental data needed to assess the risks to organisms from exposure to plastic additives and to understand the effect of stabilizers on the aging behavior of marine plastics.