Microplastic Contamination in Urban Groundwater: A Case Study From Jakarta Megacity, Indonesia

Abstract

Microplastics, classified as emerging contaminants, are recognized for their pollution of various environments, including groundwater. This study focuses on Jakarta, a major city in Asia where some communities still rely on groundwater as their source of clean water. We analyzed 121 groundwater samples from West Jakarta and South Jakarta to assess microplastic abundance and characteristics including color, shape, size, and material. The study also explored the correlation between microplastic abundance and influencing factors such as distance to septic tanks, distance to temporary waste disposal sites, Escherichia coli concentrations, and total coliform concentrations. The results indicate microplastic concentrations ranging from 28 to 236 particles/L with averages of 104 particles/L in West Jakarta and 78 particles/L in South Jakarta. Fragments were the most common shapes (85.68%), followed by fibers (12.86%), films (0.8%), and microbeads (0.66%). Black (85.93%) was the dominant color of microplastics, followed by red (8.2%), transparent (3.13%), blue (1.76%), yellow (0.75%), and green (0.23%). Microplastic size ranged from 20 μm to 3.76 mm, with the dominant polymer materials being Tencel, cellophane, and polyethylene (PE). Further analysis showed a significant correlation between microplastic abundance and distance to temporary waste disposal sites, with closer proximity resulting in higher concentrations. Trends in correlations between microplastic abundance and distance to septic tanks, E. coli concentration, and total coliform concentration were observable but not significant.