Seasonal variation characteristics of microplastics in water environment of lakes with different functions

<title>Abstract</title> Human activities and urbanization may have accelerated the enrichment and dissemination of microplastics in lakes. In this study, three typical functional lakes (HRR: the lake with a hospital and restaurant region; PER: the lake with a play and entertainment region; SMY: the lake in a primitive arboretum) were selected to compare the occurrence characteristics and seasonal changes of microplastics, which were sampled on January 23, April 23, July 23, and October 23, 2021. The results showed that the abundance of microplastics in the HRR was (5.73±0.81)-(13.57±7.95) items/L, in the PER was (8.2±1.06)- (19.73±3.73) items/L, and in the SMY lake was (2.93±1.3)-(11.4±1.8) items/L. Additionally, the microplastics were mainly fibers, some were fragments and films, and a small amount were pellets; the color was mainly blue, and the particle size was mainly 0-1mm. The average abundance of microplastics exhibits significant seasonal specificity in three functional lakes, the HRR reached its peak value in July, the PER reached its peak value in January, and the SMY was in April. Meanwhile, the abundance and color richness of microplastics in the HRR and the PER were significantly higher than those of microplastics in the SMY. This indicated that the enrichment of microplastics is highly correlated with human activities.