Polycyclic aromatic hydrocarbons (PAHs) in plastic pellets: variability in the concentration and composition at different sediment depths in a sandy beach.

Plastic pellets have the ability to adsorb organic pollutants such as PAHs. This study analyzed the variability in the concentration and composition of PAHs on plastic pellets sampled up to 1m deep in the sediment of a sandy beach. The toxic potential of PAHs was analyzed, and the possible sources of contamination are discussed. The total PAHs varied, with the highest concentrations in the surface layer; the priority PAHs showed a different pattern. PAHs at greater depths did not reach toxicity levels above the PEL. The composition of PAHs differed between pellets from the shallower and from deeper sediment layers, and was suggested a mixture of sources. These results provided the first information on the depth distribution of PAHs in sandy beaches, associated with plastic pellets; and evidenced the potential environmental risk. Similarly to the abundance of pellets, the toxic potential is underestimated in surface samples.