Toxins 2021, 13, 795. https://doi.org/10.3390/toxins13110795 www.mdpi.com/journal/toxins Article Assessment of Dietary Exposure to Ochratoxin A in Lebanese Students and Its Urinary Biomarker Analysis Manar Al Ayoubi 1 , Mohammad Salman 2 , Lucia Gambacorta 3 , Nada El Darra 1 and Michele Solfrizzo 3, * 1 Department of Nutrition and Dietetics, Faculty of Health Sciences, Beirut Arab University, Tarik El Jedidah – Beirut, P.O.Box: 115020 Riad EL Solh, Beirut 1107 2809, Lebanon; mga249@student.bau.edu.lb (M.A.A.); n.aldarra@bau.edu.lb (N.E.D.) 2 Mycotoxins Department, Lebanese Agricultural Research Institute, Fanar P.O. Box 2611, Beirut 1107 2809, Lebanon; Relhage@lari.gov.lb 3 Institute of Sciences of Food Production (ISPA), National Research Council of Italy, V. Amendola 122/o, 70126 Bari, Italy; lucia.gambacorta@ispa.cnr.it * Correspondence: michele.solfrizzo@ispa.cnr.it Abstract: The present study investigated the dietary and urinary OTA occurrence among 44 Leba- nese children. Relying on HPLC-FLD analysis, OTA was found in all the urine samples and in 46.5% and 25% of the 24 h duplicate diet and dinner samples, respectively. The means of OTA levels in positive samples were 0.32 ± 0.1 ng/g in 24 h diet, 0.32 ± 0.18 ng/g in dinner and 0.022 ± 0.012 ng/mL in urines. These values corresponded to margin of exposure (MOE) means of 7907 ± 5922 (neo- plastic) and 2579 ± 1932 (non-neoplastic) calculated from positive 24 h diet, while 961 ± 599 (neo- plastic) and 313 ± 195 (non-neoplastic) calculated from the urine. Since the MOE levels for the neo- plastic effect were below the limit (10,000), a major health threat was detected and must be ad- dressed as a health institutions’ priority. Besides, the wide difference between PDIs and MOEs cal- culated from food and urine suggests conducting further OTA’s toxicokinetics studies before using urine to measure OTA exposure. Keywords: Ochratoxin A; biomarker; risk assessment; urine; duplicate diets; exposure Key Contribution: The exposure to OTA was measured through diet and urine analysis of 44 chil- dren in Lebanon. OTA was found in all the urine samples and in 46.5% of the 24 h duplicate diet. OTA mean levels in positive samples were 0.32 ± 0.1 ng/g in 24 h diet and 0.022 ± 0.012 ng/mL in urines. The risk characterization of the children’ exposure to OTA highlighted a critical threat to their health. No correlation was found between the urinary and dietary OTA concentrations. 1. Introduction Ochratoxin A (OTA) has been recognized as one of the major mycotoxins contami- nating a variety of food products. Cacao and its products, cereals and cereal-based prod- ucts, dried fruits, nuts, pulses, spices, beans, grapefruit juice, beer, wine, herbal infusion, in addition to several products derived from animals, are the most susceptible goods to be contaminated by OTA, based on the European Food Safety Authority (EFSA) opinion [1,2]. Penicillium verrucosum and P. nordicum are two species from the Penicillium family that produce OTA, mainly known for its nephrotoxicity, while Aspergillus ochraceus and A. carbonarius are two of more than twenty OTA producing species of Aspergillus family that occur mostly in tropical, subtropical, and Mediterranean areas [3,4]. Research studies have concluded that frequent urinary tract neoplasm and the famed lethal disease that targets kidneys of south-eastern areas in Europe known as Balkan en- demic nephropathy (BEN) could be consequences of the OTA presence in food [5,6]. This Citation: Al Ayoubi, M.; Salman, M.; Gambacorta, L.; El Darra, N.; Solfrizzo, M. Assessment of Dietary Exposure to Ochratoxin A in Lebanese Students and Its Urinary Biomarker Analysis. Toxins 2021, 13, 795. https://doi.org/ 10.3390/toxins13110795 Received: 5 August 2021 Accepted: 7 November 2021 Published: 10 November 2021 Publisher’s Note: MDPI stays neu- tral with regard to jurisdictional claims in published maps and institu- tional affiliations. Copyright: © 2021 by the authors. Li- censee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and con- ditions of the Creative Commons At- tribution (CC BY) license (http://crea- tivecommons.org/licenses/by/4.0/).