Can the colors of beach-stranded plastic pellets in beaches provide additional information for the environmental monitoring? A case study around the Santos Port, Brazil

Plastic pellets are granules of different polymers used in the manufacture of various plastic products. Plastic pellets can reach the environment due to losses after their manufacturing process, especially the transportation. Loading in harbour areas and transport by ships are the main sources of plastic pellets to the ocean and coastal areas. After pellets reach the environment, they may adsorb and concentrate chemicals contaminants from different sources. Moreover, the weathering of plastic pellets may result in color changes, from white to brownish. This study aimed to analyse the color pattern of pellets collected on beaches of the central coast of São Paulo, Brazil, as an indicator of weathering and ageing processes. Plastic pellets were collected in four sampling surveys conducted between April 2012 and September 2015, and then separated in five color groups: white, yellowish, orange, brown, and pigmented. All sampled beaches had a consistent pattern of light-toned pellets (white and yellowish). This pattern was also found over time, suggesting a constant supply of plastic pellets to the beaches, coming from the harbour area. We also recommend the use of the color pattern of plastic pellets in citizen science monitoring programs.