Occurrence and characterization of microplastics in bottled drinking water

Microplastics (MPs) have been identified in diverse settings, including drinking water, freshwater, food, air, and marine environments. This study employed stereomicroscopic and µ-Raman techniques to analyze water samples from ten widely consumed bottled water brands, aiming to detect and characterize MPs. Additionally, the oral consumption of MPs per capita was estimated. The average abundance of MPs ranged from 9 ± 1.00 MPs/L to 3 ± 1.73 MPs/L across all brands. Various MPs shapes were observed, including fibers, fragments, films, and pellets, with fibers being predominant (58.928%). MPs were categorized by color into five groups (red, blue, black, yellow, and transparent), with red comprising approximately 35.714% of the total count. All identified MPs were less than 500 µm in size. µ-Raman analysis validated the presence of eight different polymer types in the samples, namely Polypropylene (PP) (37.5%), Polymethyl methacrylate (PMMA) (3.571%), polystyrene (PS) (33.928%), polycarbonate (PC) (3.571%), polybutylene1 (PB1) (14.2%), Isotactic polypropylene (iPP) (7.142), Nylone 6-α polymorph (αNY6) (5.357%), and polyvinyl alcohol (PVOH) (1.785%). The estimated daily intake of MPs per person was determined to be 0.42 MPs, translating to an annual intake of 153.3 MPs per person. The origin of MPs in bottled water was likely attributed to both raw water sources and packaging materials, underscoring the need for further investigation. Given the potential health implications of human exposure to drinking water MPs, careful consideration should be given to the use of plastic packaging for potable water.