Preliminary study of microplastic in bottled drinking water

Abstract

Microplastic is widely discussed and has become growing attention because of its negative impact on the environment and the well-being of living organisms. Some international studies have found microplastics in some foods and beverages, such as honey, beer, table salt, and drinking water. However, there are few accurate analytical techniques for identifying and analysing microplastics, especially in beverages and foods. This preliminary study investigates microplastics that might contaminate bottled drinking water, their physical properties, and their types of material. Five local brands of 120 ml bottled drinking water were used for this research, collected from a traditional market in South Tangerang. The samples were observed visually for microplastic's presence, sizes, and shapes using a digital microscope. Furthermore, material identification using a Microscope - Fourier transform infra-red (μ-FTIR) was conducted to analyse the types of material present in the samples. The results show that all examined samples were contaminated, and the major pollutants were fibres with lengths between 0.042 and 3.668 mm. According to the material identification result using μ-FTIR, materials found in most samples are cellulose-based polymers, which are used widely for natural textiles (e.g., cotton) and synthetic fibres. In the five brands of the analysed bottled drinking water, neither the packaging material polypropylene nor the bottle caps made of polyethylene were detected. These findings indicate that the analysed bottled drinking water was not contaminated by microplastic, but by micro debris of natural cellulose-based polymers.