Detection of Microplastics in Bottled Water

Mismanagement of plastic waste has caused plastic leaking into nature and entering our food chain as microplastics, which may have negative impacts on wildlife and our health. However, data on microplastics in bottled water are still limited, especially in Sarawak, Malaysia. This study aims at investigating the presence of microplastics in the bottled water that manufactured locally. So that the F&B manufacturers and other key stakeholders can take necessary actions to prevent or minimize microplastics pollution in our drinking water. A total of 40 bottled MW and DW samples from 4 local products in Sarawak and Malaysia was investigated. A filtration and observation processes using the membrane filters (0.45 μm pore size) and digital microscope (Nikon Eclipse LV150N) were developed to identify and quantify the presence of microplastics based on their types, shapes, and sizes as criteria. A library database was also developed to ensure the consistency of this identification process. A total of 2022 microplastics with an average of 50.6 particles per bottle (500-mL packing) was detected in the samples. Bead, fibre, fragment and film were detected in all the samples, but fibre (48%) and fragment (36%) made up the majority (84%) of microplastics in the samples. However, microplastics in the MW samples were found 13% higher than the DW samples. This was also true across the products investigated in this study except between X (MW) and Z (DW). On the other hand, the results also indicated that the majority (66.7%) of microplastics smaller than 20 μm were consistently detected in all the samples. Nevertheless, other detection methods such as Raman, Fourier Transform Infrared (FTIR) Spectroscopy, etc. should be considered for a more thorough investigation. Lastly, it is important to revisit the sampling and testing procedures for similar studies like this to prevent or minimize any cross-contamination to the samples.