Human exposure to microplastics via the consumption of nonalcoholic beverages in various packaging materials: The case of Hong Kong

Abstract

There is growing concern over microplastics in food and beverages, with potential implications for human health. However, little is known about microplastics in nonwater, nonalcoholic packaged beverages. This study addresses this research gap by implementing a dual-method approach that includes laboratory analysis to quantify microplastics in 50 packaged nonalcoholic beverages sold in Hong Kong, coupled with a beverage frequency questionnaire survey to provide a more accurate estimate of microplastic intake from these beverages. The beverages analysed spanned five categories–juice drinks, ready-to-drink teas, soda waters, soft drinks, and sports and energy drinks–and were packaged in four forms: aluminium cans, aseptic cartons, plastic bottles and glass bottles. The results showed that all beverage samples contained microplastics, with an average abundance of 42.1 ± 41.2 n/L (interquartile range [IQR]: 17.8–54.1 n/L), and these particles were predominantly smaller than 150 µm in size. Additionally, based on an annual beverage consumption rate of 157.3 ± 209.7 L/capita (IQR: 42.9–183.0 L/capita), it is estimated that Hong Kong adults ingest approximately 6200 microplastics per capita each year. The potential primary sources of these microplastics are atmospheric fallout and the packaging materials that endure mechanical stresses during the manufacturing and transportation of beverages. Compared to other known routes of exposure, including air, seafood, sugar, salt and honey, packaged nonalcoholic beverages present a comparable level of microplastic exposure, being lower than the first three but higher than the latter two. Nevertheless, the high prevalence of smaller microplastics in the samples is concerning. This study is considered to be important for food safety and human health, as it not only raises public awareness about microplastic contamination in packaged beverages but also serves as a call to action for the beverage industry to adopt more robust safety measures and for policymakers to revise packaging standards to reduce microplastic contamination and safeguard public health.