The neglected potential source of microplastics from daily necessities: A study on protective mobile phone cases

Microplastics (MPs) pollution has become a serious global environment problem. It is therefore of practical significance to investigate the MP pollution caused by using plastic materials on a daily basis. In this study, different protective mobile phone cases (PMPCs) were selected as a representative plastic commodity that are in contact with the human body for long periods to explore the generation and transportation of MPs during 3 months of actual use. The average abundances were 1122 particles cm^-2 on the PMPC and 314 particles cm^-2 on the palm, respectively. There were four main kinds of MPs produced during the use of different PMPCs, which indicated that waste plastics may be recycled and used as raw materials, resulting in a complex PMPC composition. The median sizes of MPs on the surfaces of PMPCs and palms were 28 and 32 µm, respectively, which were smaller than the sizes reported in other studies. The combined effect of ultraviolet ageing and friction was the main reason for MP generation during daily PMPC use. Based on the results of a fitted regression equation and Monte Carlo simulation, the sharply generation of MPs may occur when PMPC was used for approximately 33 days.