Analysis on advances and characteristics of microplastic pollution in China's lake ecosystems

China is the largest producer and consumer of plastics worldwide. Microplastic (MP) pollution has been a recent research hotspot in environmental science and ecology. This study collects and analyzes the statistical data for microplastics (MPs) 86 lakes in entire China's lake ecosystems in past five years (2016-2020), their range in area is 0.056-4543.000 km² (average: 566.045 km²), and the water storage varies from 0.162 × 10⁸ to 1050.000 × 10⁸ m³ (average: 77.884 ×10⁸ m³). The results showed (1) The MP abundance in lake surface water is significantly correlated with lake area (ρ = -0.562, p ＜0.01), provincial GDP (Gross Domestic Product, GDP) (ρ = 0.377, p = 0.002), GDP per capita (ρ = 0.346, p = 0.006), urban waste water discharge and ratio of agricultural land area (ρ = 0.369, p = 0.003). (2) The MP abundance in lake sediment is significantly correlated with per capita domestic volume of garbage disposal (ρ = -0.536, p ＜0.001), per capita urban waste water discharge (ρ = -0.544, p ＜0.001) and ratio of agricultural land area (ρ = 0.635, p ＜0.001). (3) Irrespective of whether the samples were from surface water or sediment, MPs were primarily transparent, and the dominant types were fragments, films, and fibers. In addition, the size of MPs samples was mostly less than 2 mm, and the major polymers were polyethylene (PE), polypropylene (PP), and polystyrene (PS). (4) The degree of MP pollution in organisms was related to the degree of environmental pollution. These findings could provide a theoretical basis for the control and management of MP pollution in China's lake ecosystems.