Urinary multi-mycotoxin exposure in the Portuguese population and associated sociodemographic determinants.

European human biomonitoring (HBM) studies have increasingly adopted multi-mycotoxin approaches to capture complex exposure scenarios encountered in real-life diets. This nation-wide study provides the characterization, for the first time, of the mycotoxin profile of 295 urine samples collected from the Portuguese population in the continent and islands (archipelagos of Madeira and Azores), using an optimized and validated LC-MS/MS method for the characterization of 39 mycotoxins/metabolites. Nearly all study participants (99.3%) were exposed to at least one mycotoxin, with around half (54.2%) being co-exposed to only 2 detectable mycotoxins. Free-deoxynivalenol (free-DON, 84.7%) and tenuazonic acid (TeA, 95.6%) were the most prevalent mycotoxins. Citrinin (CIT, 11.5%), α-zearalenone (α-ZEL, 10.5%) and ochratoxin A (OTA, 9.5%) showed detection rates near 10%. Median concentrations (P50) for the two predominant mycotoxins were 0.79 μg/L (0.72 μg/g creatinine) for free-DON and 2.45 μg/L (2.08 μg/g creatinine) for TeA, with maximum values of 11.77 μg/L (10.06 μg/g creatinine) and 90.91 μg/L (114.15 μg/g creatinine), respectively. Sociodemographic patterns showed lower exposure in the Centre region and higher free-DON exposure in southern Portugal and the archipelagos. TeA exposure differed significantly by region and was lowest in the Lisbon Metropolitan Area and Algarve compared to the Center reference region. Low educational levels and spring sampling correlated with higher exposure for both toxins, but only education levels showed statistical significance in the linear regression analyses. For both TeA and free-DON, no differences in exposure were observed by sex, occupational status, or degree of urbanization. Overall, these findings underscore the importance of continuous surveillance, particularly under the current climate change scenario, and highlight the relevance of integrating human biomonitoring into national food safety and public health strategies.