Determinants of Potentially Toxic Element Concentrations in Human Colostrum: A Cross- Sectional Study in Curitiba, Southern Brazil

Background: Human milk, particularly colostrum, is a valuable matrix for human biomonitoring because it reflects early-life exposure to potentially toxic elements during a critical period of neonatal development. Objectives: To identify biological, socioeconomic, behavioral, and environmental factors associated with aluminum, arsenic, cadmium, and lead concentrations in colostrum from lactating women living in Southern Brazil. Methods: This cross-sectional study included 61 lactating women recruited at a public maternity hospital. Colostrum samples were collected, lyophilized, digested, and analyzed using graphite furnace atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry. Element-specific statistical strategies were applied to account for left-censored data. Logistic regression models were used to evaluate factors associated with detectable concentrations (≥ limit of quantification), and multiple linear regression models were applied for continuous outcomes when all samples were quantifiable. Results: Arsenic concentrations were below detection limits in all samples. Cadmium showed extreme left-censoring, with only three samples above the limit of quantification. Lead concentrations were quantifiable in 45.9% of samples and tap water consumption showed a borderline association with detectable lead ( OR = 3.01, p = .066). Aluminum was detected in 100% of samples and was inversely associated with maternal age (β = −0.038, p = .021). Conclusions: Potentially toxic elements showed distinct detection patterns and determinants in colostrum. These findings support the use of colostrum as a valuable matrix for assessing early-life chemical exposure and may inform maternal–infant environmental biomonitoring strategies while reinforcing breastfeeding promotion and protection.