Pollution level of microplastics in sand beaches of four locations in the coast of El Salvador, Central America

In recent years, plastic debris has been reported on El Salvador beaches, including those located in rural areas and close to protected natural or Ramsar areas. However, there is still no scientific data able to neither the main microplastic sources nor their abundances. Therefore, the aim of this work was to assess the concentrations and spatial distributions, physical and chemical characteristics, and possible sources of microplastic in four of the main beaches along El Salvador coast: Barra de Santiago, El Majahual, El Espino, and Chiquiríin. The Nemerow pollution index (NPI) was employed to categorize the overall pollution levels of each beach. The results state that plastic debris negatively affects El Salvador coast and contributes to pollution of the Pacific coast of Central America. With abundances ranging from 4.5 to 18.5 item/kg d.w. or 48 to 300 item/m, the microplastic debris was mainly composed of fibers (85.9%) and fragments (8.4%). The Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) revealed that their main sources were colored synthetic organic materials and mainly composed of polypropylene (40%), polyethylene (20%), and polystyrene (20%). These materials are typically found in plastic bottles and their caps, single-use supermarket bags, food packaging, textiles, and drinking straws. Tourism and poor waste management practices are likely to be the main sources of microplastics, with rainwater and rivers as the primary transport mechanisms. Although the Nemerow pollution index (NPI) rated the pollution levels of the surveyed beaches as low, the ubiquitous presence of microplastics underscores an ongoing environmental problem that requires continuous monitoring and intervention.