A review of microplastic pollution characteristics in global urban freshwater catchments

Microplastics are the newly identified pollutant of this century, yet they are already detected everywhere worldwide. Microplastic pollution in global marine environments has been intensively reported. Evidence of microplastic pollution is emerging in other environments, including land, freshwater, atmosphere, and organisms. Public concerns were also raised about microplastic pollution around them. From terrestrial environments, through freshwater environments, finally to marine environments, is a major transportation route of microplastic pollution. Human activities are the fundamental source of microplastic pollution. Cities, with the highest population density on this planet, are important sources of microplastic pollutants. This chapter focuses on urban freshwater environments, the first receptor, and major transporter of urban microplastics. By reviewing microplastic pollution in global urban freshwater catchments, urban microplastic pollution characteristics were clarified, and the key information to prevent urban microplastic discharge was sought.