Assessing microplastic contamination in soda beverages: A Multi-city, Multi-container laser Direct infrared spectroscopy study

Microplastics are tiny plastic particles, typically smaller than 5 mm in diameter, that result from the degradation of larger plastic products. Minuscule pollutants are increasingly being found in our food supply, especially in beverages, raising substantial health concerns. Ingested microplastics can release hazardous chemicals and act as carriers of pathogens, leading to adverse health effects upon chronic exposure. Despite the numerous studies on microplastic contamination, few have assessed the influence of geographic location and container type on the presence of microplastics in beverages. Our comprehensive study bridges this research gap by collecting a particular soda beverage from Atlanta, Chicago, Los Angeles, and Washington D.C. and examining three different types of beverage containers: aluminum, glass, and plastic. Using direct laser infrared spectroscopy, we identified the types and quantified the numbers of microplastics. Our statistical analysis, which incorporated principal component analysis, investigated the distribution of microplastics in beverage samples, focusing on the impacts of geographic location and container material. Notably, our analysis revealed that the microplastic profiles were distinguishable in some cities, although not all. Conversely, no distinguishability was revealed between the different container types. This study sheds light on the complex patterns of microplastic contamination according to geographical location and packaging. Our findings contribute to a broader effort to understand and address the widespread challenges of microplastics, with implications for public health and ecosystem preservation.