Assessment of beach plastic waste and its heavy metal pollution in Shenzhen

Marine plastic waste has become a global environmental problem in recent years. In order to investigate the pollution of plastic waste and its heavy metal contamination on the coastline, plastic waste was collected from five typical beaches along the Shenzhen coastline. The compositions and sources of the beach plastic waste were analyzed. Its heavy metal content and leaching behavior were studied for the assessment of the potential health risk through ingestion. The results showed that plastics and foam plastics were the main compositions, accounting for up to 72% of the beach plastic waste. The main source of beach plastic waste included shoreline and recreational activities, accounting for up to 80.58%. In terms of heavy metal content, zinc (Zn), barium (Ba) and lead (Pb) had the higher contents than other heavy metals in plastic samples, and the average value of Zn was above 500 mg/kg. In the simulated gastric acid leaching test, Zn concentration was found to be the highest (0.7605~2.6283 mg/L), while manganese (Mn) showed the highest leaching ratio (16.22%~83.45%). Antinomy (Sb) showed the lowest concentration and leaching ratio. The results of health risk assessment through ingestion indicated that the heavy metals in plastic samples did not pose a health risk. This work would benefit the management of marine plastic waste by providing relevant fundamental information. © 2020, Editorial Board of China Environmental Science. All right reserved.