Assessment and Characterization of Microplastic Contamination in the Tap Water Supply of the Three Barangays in Marikina City

Microplastics have emerged as a significant emerging pollutant in water, air, and soil. While numerous studies have assessed microplastics in the marine environment of the Philippines, there is a lack of locul research focusing on the contamination of microplastics in drinking water and tap water. Marikina\'s geophysical location makes it susceptible to flooding during heavy rainfall. Consequently, consistent flooding can damage the tap water supply, potentially introducing microplastics into the distribution system. The primary objective of this study is to assess and characterize the occurrence of microplastics in the tap water supply of the three barangays in Marikina City: Malanday, Nangka, and Tumana. Tap water samples were collected from households and subjected to density separation using sodium chloride (NaCl) and vacuum filtration. The resulting samples were then microscopically analyzed to determine the quantity, shape, size, and color of suspected microplastics. Subsequently, spectroscopy was employed to identify the polymer composition of the microplastics. The quantity of microplastics found in the nine sampling sites ranged from 14 to 135 particles per liter (ppl), predominantly consisting of blue fragment microplastics in terms of color and shape, and ranging in size from 20 to 500 micrometers. Spectroscopic analysis revealed that the majority of the microplastics were polyvinyl chloride (PVC). Blue fragment microplastics are highly associated with PVC pipes commonly used in household tap water supply systems. In conclusion, the presence of microplastics in the tap water supply may be correlated with the flooding conditions prevalent in the study area.