Occurrence and Nationwide Risk Assessment of Typical Food Processing Contaminants in Human Milk in China

Typical environmental exposure and food processing contaminants, including acrylamide (AA) and monochloropropanediols (MCPDs), are widely present in the national Total Diet Survey. Nevertheless, the dietary exposure to and associated health risk of AA and MCPDs for breastfed infants remain unclear. Here, we assess the occurrence of AA, 3-monochloropropane-1,2-diol (3-MCPD), and 2-monochloropropane-1,2-diol (2-MCPD) in 3344 human milk samples collected from 24 provinces in China and further characterize their geographic distribution profiles and potential health risk to breastfed infants. At present, 100, 89, and 67% of the three typical contaminants are detected in human milk in this study, indicating widespread exposure risk at the nationwide level with higher exposure in urban areas. Risk assessment analyses demonstrate that 45.8 and 70.8% of provinces exhibit hazard quotients >1 for AA and 3-MCPD, respectively, signifying a potentially high health risk to breastfed infants in China. A worldwide comparison of occurrence and estimated daily intake in human milk and formula reveals that both AA and 3-MCPD show high levels in Chinese human milk. Our work demonstrates a potential risk of typical environmental and dietary sourced contaminants to breastfed infants and draws immediate attention to the health of the mother's diet during breast feeding.