Quantitative analysis of microplastic presence in commercially bottled drinking water brands and the associated human exposure

The presence of microplastic contaminants in bottled drinking water has raised growing concern due to their harmful effects on both human health and the environment. In this study, we investigate the occurrence of microplastics in 17 commercially available bottled water brands in Kota Kinabalu, Sabah, Malaysia. This study also quantifies the level of microplastics based on their sizes, shapes, colors, and polymer types. The associated risk through ingestion level of microplastics in drinking water was evaluated. The quantification analyses showed that the average abundance of MPs varied from 2 ± 1 particles/L to 42 ± 1.52 particles/L with the highest number of MPs found in brand D. The results showed that MPs were detected in four distinct forms (line, fragments, fibers, and pellet). MPs particle sizes ranged from 100 um – 5000 um with 38% of particles dominant in sizes 500 um to 1000 um. Microplastics were documented in five distinct colors, with black representing 48% of the total count. Infrared spectral analysis (FTIR) confirmed that the occurrence of high polypropylene (PP) polymers in bottled water primarily originate from the packaging materials and bottle caps. The estimated daily intake of microplastics (EDI) by children and adults was determined to be 0.53 and 0.19 particles/kg/day. These findings offer crucial data for a more in-depth assessment of the potential health risks linked to human exposure to microplastics.