Dry and wet deposition of microplastics in a semi-arid region (Shiraz, Iran)

Microplastics (MP) have been retrieved from settled dusts and rainfall collected monthly over a period of year daily an additional ten days in the city Shiraz at elevated remote site (Mount Derak) Iran. Total deposition ranged about 1000 to 3500 MP m?2 200 600 Mount Derak, with greater taking place during dry months (June November) than when precipitation events occurred. Overall, was dominated by deposition, appearing washout inhibit local resuspension material dampening ground. The majority dust (>99%) fibrous nature, finest particles measured (<100 ?m length) comprising ~20–40% ~70–80% Derak analysis selected samples (n = 34) revealing most abundant polymers be polypropylene, polyethylene polystyrene terephthalate. While Shiraz, sources are likely significant, occurrence back trajectories computed HYSPLIT suggest that distal sources, mainly carried air masses north west, also important. observations here add growing evidence global ubiquity long-range transport atmosphere reinforce calls for more research into potential impacts this environmental compartment.