Lead Relative Bioavailability in Lip Products and Their Potential Health Risk to Women

Recent studies have investigated lead (Pb) concentrations in lip products but little is known about its oral bioavailability. In this study, 75 lipsticks and 18 lip glosses were assessed for Pb concentration, while 15 samples were assessed for Pb relative bioavailability (RBA, relative to Pb acetate absorption) using a mouse femur assay. Lead concentrations were 0.2–10 185 mg kg^–1, with 21 samples exceeding the Chinese limit of 40 mg kg^–1. Samples with orange and pink colors and/or low cost contained higher Pb concentrations. For samples with Pb > 7500 mg kg^–1, Pb was present due to the addition of lead chromate (PbCrO₄) as a colorant, which was confirmed by X-ray absorption near-edge structure analysis. Lead-RBA in 15 samples (87–10 185 mg kg^–1) ranged from 23% to 95%, being significantly higher in moderate Pb (56–95%; 87–300 mg kg^–1) than high Pb samples (23–48%; >300 mg kg^–1). The calculation of Pb intake based on Pb-RBA showed that lip product ingestion contributed 5.4–68% of the aggregate Pb exposure for women depending on Pb concentration. The high Pb concentration in some lip products together with their moderate Pb-RBA suggests that lip product ingestion is a potential health concern to women.