How many microplastics do we ingest when using disposable drink cups?

Abstract

Microplastics in food are receiving increasing attention because they are directly ingested by humans and pose a health threat. However, little attention has been paid to the microplastics resulting from the disposable drink cups. Here, we analyzed the microplastic contamination in beverages in three commonly used plastic cups (PP, PET, and PE cups). Effects of the cup materials, the residence time of the drink in the cup, shaking, and water temperatures on the microplastic release were systematically investigated. The results showed that the microplastic abundance in water reached 723–1,489 particles cup−1 after 5 min exposure and increased significantly with increasing residence time. The size of released microplastics was mainly in the range of < 50 µm. The shaking applied during transport promoted the release of microplastics from plastic cups. Besides, the results showed that cups released more microplastics when serving hot drinks than serving cold drinks. Based on the results, we estimated that people may unconsciously ingest 37,613–89,294 microplastics a year due to the use of one plastic cup every 4–5 days. Considering the potential harm of microplastics, the contamination of microplastics resulting from the use of plastic cups for drinks needs to be taken seriously.