Aflatoxin M1 levels in urine and breast milk of lactating mothers in Kuala Lumpur, Malaysia.

Aflatoxins are carcinogens that can contaminate food and affect various body organs especially liver and kidney. When consumed, aflatoxin B₁ (AFB₁) is partially metabolised into aflatoxin M₁ (AFM₁), which is excreted in the urine. Breast milk may also contain AFM₁ due to maternal dietary intake from contaminated food. This cross-sectional study aimed to determine the levels of AFM₁ in both urine and breast milk among breastfeeding mothers (n = 256). The mother's demographic information was collected during recruitment. Mothers were then scheduled for an appointment to provide a morning urine sample along with five to ten mL samples of breast milk. AFM₁ levels in both samples were analysed using an enzyme-linked immunosorbent assay (ELISA). Spearman's rho and Chi-square were used to determine the associations between mean levels of AFM₁ in urine and breast milk. Findings show 68.0% of urine samples were contaminated with AFM1 (mean levels = 0.08 ± 0.04 ng/mL), while 14.8% of breast milk samples had AFM₁ (mean levels = 5.94 ± 1.81 ng/kg). Urine AFM₁ levels were not significantly associated with AFM₁ levels in breast milk (p > 0.05). This study can act as a baseline for future research examining long-term aflatoxin exposure among both mothers and infants.