Microplastics release from infant feeding bottles and milk storage bags

The health impairment of microplastics (MPs) in infants has received considerable attention, with oral ingestion being an important exposure route. However, research remains limited on MPs released in feeding bottles (FBs) and breastmilk storage bottles (BSBs) during daily use. To address this gap, our study investigated the MPs released from polyphenylene sulfone resins (PPSU)-FBs, silicone-FBs, polyethylene (PE)-BSBs, and low-density polyethylene (LDPE)-BSBs under typical usage conditions. Our findings revealed that the four materials of FBs and BSBs can release 1465–5893 particles/L MPs (median concentration). The predominant MPs released from all FBs and PE-BSBs were identified as PE, while LDPE-BSBs predominantly released polyethylene terephthalate (PET) and acrylates (ACR). Approximately 70% of MPs were found within the 20–50 μm particle size range. Higher temperatures led to a two-fold increase in the total MPs. Notably, infants would additionally intake 2080–5910 MPs per day through FBs and BSBs. Months with higher nutritional requirements, and when using silicone FBs and LDPE BSBs, increased the ingestion of MPs in infants. In conclusion, our study highlighted that those FBs and BSBs can precipitate varying numbers, types, and particle sizes of MPs. To protect infants from MPs ingestion, it is recommended to choose non-plastic FBs and non-plastic breastmilk storage containers.