Children's exposure to mycotoxins and risk characterization using urinary biomarkers in São Paulo, Brazil

Abstract

This study assessed mycotoxin exposure of preschoolers (3-6 years, n = 26), schoolers (7-10 years, n = 29), and adolescents (11-17 years, n = 49) from São Paulo, Brazil, by analyzing mycotoxin biomarkers in urine samples. Analyses were performed using ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS), for determination of aflatoxin M₁ (AFM₁), ochratoxin A (OTA), fumonisins B₁ (FB₁) and B₂ (FB₂), deoxynivalenol (DON), T-2 and HT-2 toxins, zearalenone (ZEN) and its metabolites α- and β-zearalenol (ZEL). Urinary ZEN and its metabolites (α- and β-ZEL) were the most frequently detected biomarkers, followed by FBs (FB₁+FB₂), DON, and OTA. Co-exposure to 2-6 mycotoxins was observed in 63 % of samples, most prominently among schoolers (69 %), followed by adolescents (63 %) and preschoolers (61 %). Estimated daily intake (EDI) values were calculated under lower (LB), middle (MB), and upper bound (UB) scenarios. Several 95th percentile UB-EDI values exceeded maximum level (ML) or tolerable daily intake (TDI) limits, particularly for preschoolers regarding exposure to AFM₁ (EDI: 0.786 μg/kg body weight (bw)/day), FBs (EDI: 5.22 μg/kg bw/day), OTA (EDI: 0.683 μg/kg bw/day) and the sum of ZEN, α- and β-ZEL (ZENeq) (0.92 μg/kg bw/day). Under the UB scenario, hazard quotient (HQ) values > 1 were found for OTA in 100 % of preschoolers (median: 1.71) and schoolers (1.4), and ZENeq in about 77 % of preschoolers (median: 1.14). Margin of exposure (MoE) values for AFM₁ were <10,000 across all age groups, indicating potential carcinogenic concern. These results underscore substantial real-life co-exposure to multiple mycotoxins in children in Brazil, reinforcing the need for age-specific surveillance and risk management strategies. The detection of multiple toxins above safety thresholds highlights the vulnerability of this population and the importance of strengthened food safety policies.

Keywords: Biomarkers; Children; Exposure; Mycotoxins; Risk; UPLC-MS/MS; Urine.