Assessing microplastic pollution vulnerability in a protected coastal lagoon in the Mediterranean Coast of Egypt using GIS modeling

Lake Burullus is a coastal wetland and protected area on the Mediterranean coast of Egypt. Despite the importance of this lake to the livelihood of millions of Egyptians, intensive anthropogenic activities and drainage water input have impacted its water quality. The current work aimed to evaluate the distribution and composition of microplastics (MPs) in Lake Burullus and analyze the impact of non-point pollution sources on their distribution and fate. The results showed that the average concentration of MPs in the open water was significantly lower (165.0 MPs/m³) than that near the drains (835.6 MPs/m³). The thermal analysis indicated the presence of eight thermoplastic polymers, originating from diffuse sources mainly via land-based activities. Moreover, a model was generated using ArcGIS 10.5 to assess the vulnerability of surface water to pollution from non-point sources. This model incorporated factors such as proximity to roads, waterways, land use, and urban areas, in addition to salinity and total suspended solids (TSS). Comprehensive maps were generated to visually illustrate the areas expected to be affected by MPs pollution. The results showed that waterways played an important role in in the transport of MPs to Lake Burullus. In addition, urban areas were identified as pollution hotspots, indicating the impact of land-use changes in urban areas. Salinity and TSS were also identified as important factors affecting the fate of MPs. Implementing strong measures to control land pollution in urban areas and managing wastewater inputs is highly recommended to effectively mitigate the impact of MPs on the ecosystem of Lake Burullus.