Postnatal exposure to toxic metals for infants residing in proximity to municipal waste incinerators in China.

Municipal waste incineration (MWI) has become a critical waste management strategy in urban China, yet concerns remain over emissions of toxic metals and their potential health effects. This study evaluated postnatal exposure to mercury (Hg), lead (Pb), arsenic (As), cadmium (Cd), chromium (Cr), and thallium (Tl) via breast milk among mothers living near MWIs in Shenzhen. Breast milk samples from 199 lactating mothers (101 exposed within 5 km of MWIs; 98 non-exposed) were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). After adjusting for residential and lifestyle variables, Pb levels were significantly higher in the exposed group (p = 0.03). Risk characterization indicated low concern for infant intake of Cd, Pb, and Hg, while exposure to As, Cr, and Tl, particularly Cr, could not be excluded. Several demographic and dietary factors, including seafood consumption, maternal BMI, and education level, were associated with metal concentrations. These findings suggest proximity to MWIs may elevate Pb exposure in infants via breast milk and highlight the need for environmental monitoring and protective policies to reduce early-life toxic metal exposures.