The Plastic Age: River Pollution in China from Crop Production and Urbanization

Many rivers are pollutedwith macro (>5 mm)- and microplastics(<5 mm). We assess plastic pollution in rivers from crop productionand urbanization in 395 Chinese sub-basins. We develop and evaluatean integrated model (MARINA-Plastics model, China-1.0) that considersplastics in crop production (plastic films from mulching and greenhouses,diffuse sources), sewage systems (point sources), and mismanaged solidwaste (diffuse source). Model results indicated that 716 kton of plasticsentered Chinese rivers in 2015. Macroplastics in rivers account for85% of the total amount of plastics (in mass). Around 71% of thistotal plastic is from about one-fifth of the basin area. These sub-basinsare located in central and eastern China, and they are densely populatedwith intensive agricultural activities. Agricultural plastic filmscontribute 20% to plastics in Chinese rivers. Moreover, 65% of plasticsare from mismanaged waste in urban and rural areas. Sewage is responsiblefor the majority of microplastics in rivers. Our study could supportthe design of plastic pollution control policies and thus contributeto green development in China and elsewhere. Plastic pollution in rivers is modeledfor nearly 400 Chinesesub-basins, and the importance of agriculture and urbanization ishighlighted for pollution control.