First documented evidence of mesoplastic pollution in the Philippines: The case of the sandy beaches in Iligan City

The problem of marine plastic pollution is multifaceted and a substantial threat to the environment and human well-being. Despite being a leading marine plastic contributor in the world, the prevalence of mesoplastics in the Philippines is yet to be ascertained. The study aimed to quantify and characterize the mesoplastics on the 10 sandy beaches (inside and outside the city center) of Iligan City, Philippines. Samples were extracted, quantified, and characterized based on their morphology and chemical composition. A total of 166 mesoplastics were collected from the ten sampling sites. Fragment mesoplastics accounted for 66.9% of the plastic debris found across all sites, with sizes in the range of 21 to 25mm (31.3%), and white/transparent (31.1%) being predominant. Attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy identified polyethylene, polyethylene terephthalate, and polypropylene as the dominant mesoplastic polymer. We also found that mesoplastics were significantly more abundant on beaches within the city center (39.67 ± 3.11 items/m2) than on beaches away from the city center (13.02 ± 1.80 items/m2). This study provides a useful baseline of information on mesoplastic distributions in densely populated urban areas. Our results suggest that there is a pressing need to strengthen existing policies on solid waste management and develop new strategies to mitigate plastic pollution. Addressing this issue is of utmost importance considering the potentially harmful effects of mesoplastics on marine organisms and ecosystems. To the best of our knowledge, this is the first report on mesoplastic pollution in the Philippines.