Cereal grains and their processed food products are frequently contaminated with mycotoxins. Among many, five major mycotoxins of aflatoxins, ochratoxins, fumonisins, deoxynivalenol, and zearalenone are of significant public health concern as they can cause adverse effects in humans. Being airborne or soilborne, the cosmopolitan nature of mycotoxigenic fungi contribute to the worldwide occurrence of mycotoxins. On the basis of the global occurrence data reported during the past 10 years, the incidences and maximum levels in raw cereal grains were 55% and 1642 μg/kg for aflatoxins, 29% and 1164 μg/kg for ochratoxin A, 61% and 71,121 μg/kg for fumonisins, 58% and 41,157 μg/kg, for deoxynivalenol, and 46% and 3049 μg/kg for zearalenone. The concentrations of mycotoxins tend to be lower in processed food products; the incidences varied depending on the individual mycotoxins, possibly due to the varying stability during processing and distribution of mycotoxins. It should be noted that more than one mycotoxin,...

Worldwide Occurrence of Mycotoxins in Cereals and Cereal-Derived Food Products: Public Health Perspectives of Their Co-occurrence.

Deoxynivalenol (DON) is a mycotoxin primarily produced by Fusarium fungi, occurring predominantly in cereal grains. Following the request of the European Commission, the CONTAM Panel assessed the risk to animal and human health related to DON, 3-acetyl-DON (3-Ac-DON), 15-acetyl-DON (15-Ac-DON) and DON-3-glucoside in food and feed. A total of 27,537, 13,892, 7,270 and 2,266 analytical data for DON, 3-Ac-DON, 15-Ac-DON and DON-3-glucoside, respectively, in food, feed and unprocessed grains collected from 2007 to 2014 were used. For human exposure, grains and grain-based products were main sources, whereas in farm and companion animals, cereal grains, cereal by-products and forage maize contributed most. DON is rapidly absorbed, distributed, and excreted. Since 3-Ac-DON and 15-Ac-DON are largely deacetylated and DON-3-glucoside cleaved in the intestines the same toxic effects as DON can be expected. The TDI of 1 μg/kg bw per day, that was established for DON based on reduced body weight gain in mice, was therefore used as a group-TDI for the sum of DON, 3-Ac-DON, 15-Ac-DON and DON-3-glucoside. In order to assess acute human health risk, epidemiological data from mycotoxicoses were assessed and a group-ARfD of 8 μg/kg bw per eating occasion was calculated. Estimates of acute dietary exposures were below this dose and did not raise a health concern in humans. The estimated mean chronic dietary exposure was above the group-TDI in infants, toddlers and other children, and at high exposure also in adolescents and adults, indicating a potential health concern. Based on estimated mean dietary concentrations in ruminants, poultry, rabbits, dogs and cats, most farmed fish species and horses, adverse effects are not expected. At the high dietary concentrations, there is a potential risk for chronic adverse effects in pigs and fish and for acute adverse effects in cats and farmed mink.

Risks to human and animal health related to the presence of deoxynivalenol and its acetylated and modified forms in food and feed

Since ochratoxin A (OTA) was discovered, it has been ubiquitous as a natural contaminant of moldy food and feed. The multiple toxic effects of OTA are a real threat for human beings and animal health. For example, OTA can cause porcine nephropathy but can also damage poultries. Humans exposed to OTA can develop (notably by inhalation in the development of acute renal failure within 24 h) a range of chronic disorders such as upper urothelial carcinoma. OTA plays the main role in the pathogenesis of some renal diseases including Balkan endemic nephropathy, kidney tumors occurring in certain endemic regions of the Balkan Peninsula, and chronic interstitial nephropathy occurring in Northern African countries and likely in other parts of the world. OTA leads to DNA adduct formation, which is known for its genotoxicity and carcinogenicity. The present article discusses how renal carcinogenicity and nephrotoxicity cause both oxidative stress and direct genotoxicity. Careful analyses of the data show that OTA carcinogenic effects are due to combined direct and indirect mechanisms (e.g., genotoxicity, oxidative stress, epigenetic factors). Altogether this provides strong evidence that OTA carcinogenicity can also occur in humans.

https://www.mdpi.com/2072-6651/8/7/191/pdf

Ochratoxin A: 50 Years of Research

EFSA was asked to deliver a scientific opinion on the risks to public health related to the presence of aflatoxins in food. The risk assessment was confined to aflatoxin B1 (AFB1), AFB2, AFG1, AFG2 and AFM1. More than 200,000 analytical results on the occurrence of aflatoxins were used in the evaluation. Grains and grain-based products made the largest contribution to the mean chronic dietary exposure to AFB1 in all age classes, while 'liquid milk' and 'fermented milk products' were the main contributors to the AFM1 mean exposure. Aflatoxins are genotoxic and AFB1 can cause hepatocellular carcinomas (HCCs) in humans. The CONTAM Panel selected a benchmark dose lower confidence limit (BMDL) for a benchmark response of 10% of 0.4 μg/kg body weight (bw) per day for the incidence of HCC in male rats following AFB1 exposure to be used in a margin of exposure (MOE) approach. The calculation of a BMDL from the human data was not appropriate; instead, the cancer potencies estimated by the Joint FAO/WHO Expert Committee on Food Additives in 2016 were used. For AFM1, a potency factor of 0.1 relative to AFB1 was used. For AFG1, AFB2 and AFG2, the in vivo data are not sufficient to derive potency factors and equal potency to AFB1 was assumed as in previous assessments. MOE values for AFB1 exposure ranged from 5,000 to 29 and for AFM1 from 100,000 to 508. The calculated MOEs are below 10,000 for AFB1 and also for AFM1 where some surveys, particularly for the younger age groups, have an MOE below 10,000. This raises a health concern. The estimated cancer risks in humans following exposure to AFB1 and AFM1 are in-line with the conclusion drawn from the MOEs. The conclusions also apply to the combined exposure to all five aflatoxins.

Risk assessment of aflatoxins in food

Mycotoxins are secondary fungal metabolites produced mainly by Aspergillus, Penicillium, and Fusarium. As evidenced by large-scale surveys, humans and animals are simultaneously exposed to several mycotoxins. Simultaneous exposure could result in synergistic, additive or antagonistic effects. However, most toxicity studies addressed the effects of mycotoxins separately. We present the experimental designs and we discuss the conclusions drawn from in vitro experiments exploring toxicological interactions of mycotoxins. We report more than 80 publications related to mycotoxin interactions. The studies explored combinations involving the regulated groups of mycotoxins, especially aflatoxins, ochratoxins, fumonisins, zearalenone and trichothecenes, but also the "emerging" mycotoxins beauvericin and enniatins. Over 50 publications are based on the arithmetic model of additivity. Few studies used the factorial designs or the theoretical biology-based models of additivity. The latter approaches are gaining increased attention. These analyses allow determination of the type of interaction and, optionally, its magnitude. The type of interaction reported for mycotoxin combinations depended on several factors, in particular cell models and the tested dose ranges. However, synergy among Fusarium toxins was highlighted in several studies. This review indicates that well-addressed in vitro studies remain valuable tools for the screening of interactive potential in mycotoxin mixtures.

https://hal-univ-tlse3.archives-ouvertes.fr/hal-03331138/document

Mycotoxins co-contamination: Methodological aspects and biological relevance of combined toxicity studies.

An improved "dilute and shoot" LC-MS/MS multibiomarker approach was used to monitor urinary excretion of 23 mycotoxins and their metabolites in hu- man populations from Asia (Bangladesh), Europe (Ger- many), and the Caribbean region (Haiti). Deoxynivalenol (DON), deoxynivalenol-3-glucuronide (DON-3-GlcA), T-2-toxin (T-2), HT-2-toxin (HT-2), HT-2-toxin-4- glucuronide (HT-2-4-GlcA), fumonisin B1 (FB1), afla- toxins (AFB1 ,A FB2 ,A FG1, AFG2 ,A FM1), zearalenone (ZEA), zearalanone (ZAN), their urinary metabolites α- zearalanol (α-ZEL) and β-zearalanol (β-ZEL), and cor- responding 14-O-glucuronic acid conjugates (ZEA-14- GlcA, ZAN-14-GlcA, β-ZEL, α/β-ZEL-14-GlcA), och- ratoxin A (OTA), and ochratoxin alpha (OTα )a s well as enniatin B (EnB) and dihydrocitrinone (DH-CIT) were among these compounds. Eight urinary mycotoxin biomarkers were detected (AFM1, DH-CIT, DON, DON-GLcA, EnB, FB1 ,O TA, andα-ZEL). DON and DON-GlcA were exclusively detected in urines from Germany and Haiti whereas urinary OTA and DH-CIT concentrations were significantly higher in Bangladeshi samples. AFM1 was present in samples from Bangladesh and Haiti only. Exposure was estimated by the calcula- tion of probable daily intakes (PDI), and estimates sug- gested occasional instances of toxin intakes that exceed established tolerable daily intakes (TDI). The detection of individual mycotoxin exposure by biomarker-based approaches is a meaningful addition to the classical mon- itoring of the mycotoxin content of the food supply.

A comparative study of the human urinary mycotoxin excretion patterns in Bangladesh, Germany, and Haiti using a rapid and sensitive LC-MS/MS approach.

Scope

In this study, the exposure of a German population (n = 101) to mycotoxins was assessed using an LC-MS/MS urinary multibiomarker approach. Food consumption of the participants was documented with a food frequency questionnaire to correlate mycotoxin exposure with individual nutritional habits.



Methods and results

The presence of 23 urinary biomarkers including trichothecenes (deoxynivalenol (DON), DON-3-glucuronide (DON-3-GlcA), T-2 toxin, HT-2 toxin (HT-2, HT-2-toxin-4-glucuronide (HT-2-GlcA), fumonisins (fumonisin B1, fumonisin B2), aflatoxins (aflatoxin B1, aflatoxin G2, aflatoxin B2, aflatoxin M1), zearalenone and derivatives (zearalanone, α-zearalenol, β-zearalenol, zearalenone-14-O-glucuronide, zearalanone-14-O-glucuronide, α-zearalenol-14-O-glucuronide/β-zearalenol-14-O-glucuronide), ochratoxin A, ochratoxin alpha, enniatin B and dihydrocitrinone was evaluated using a validated, sensitive “dilute and shoot”-LC-MS/MS method applying Scheduled MRMTM technology. Six mycotoxins and urinary metabolites were detected (DON, DON-3-GlcA, zearalenone-14-O-glucuronide, T-2 toxin, enniatin B, and dihydrocitrinone) in 87% of the samples in single- or co-occurence. Only DON and DON-3-GlcA were detectable in quantifiable amounts. A provisional mean daily intake of 0.52 μg DON/kg body weight was calculated. No statistical evidence for the correlation of staple food intake and urinary biomarker concentration could be determined.



Conclusion

The results of this study suggest a low everyday exposure of the investigated German population to mycotoxins, but reveal peak exposures above the widely accepted tolerable daily intake to DON in parts of the population.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/mnfr.201400406

Determination of mycotoxin exposure in Germany using an LC‐MS/MS multibiomarker approach

Using micro high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) a simple and fast method for the quantitative determination of 26 mycotoxins was developed. Sample preparation consists of a single extraction step and a dilute-and-shoot approach without further cleanup. With a total run time of 9 min and solvent consumption below 0.3 mL per chromatographic run, the presented method is cost-effective. All toxins regulated by the European Commission with maximum or guidance levels in grain products (fumonisins B1 and B2 (FB1 and FB2)); deoxynivalenol (DON); aflatoxins B1, G1, B2, and G2 (AFB1, AFG1, AFB2, and AFG2); ochratoxin A (OTA); T-2 and HT-2 toxins; and zearalenone (ZEN) can be quantified with this method. Furthermore, the enniatins B, B1, A, and A1 (EnB, EnB1, EnA, and EnA1); beauvericin (BEA); 3-acetyl-deoxynivalenol (3-AcDON); fusarin C (FusC); sterigmatocystin (STC); gliotoxin (GT); and the Alternaria toxins alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), tentoxin (TEN), and altertoxin I (ATX I) can also be quantified. For all regulated compounds, recoveries ranged between 76 and 120 %. For all other toxins, the recovery was at least 51 %. The method was applied for the analysis of 42 maize samples from field trials in South Africa.

A new approach using micro HPLC-MS/MS for multi-mycotoxin analysis in maize samples

Several drugs for human use possess genotoxic properties as a necessary consequence of their intended therapeutic effect (e.g. antineoplastics). Health workers may be exposed to these chemicals in various occupational settings such as dose preparation and administration. To date, there are no quantitative risk assessment models to estimate the cancer risk of health workers due to the handling of genotoxic drugs. We therefore developed a quantitative risk assessment model to assess the cancer risk of occupational exposure to genotoxic drugs in healthcare settings based on the threshold of toxicological concern (TTC) concept. This model was used to evaluate the cancer risk of health workers due to the handling of genotoxic drugs in modern health care facilities.We modified the threshold of toxicological concern (TTC) concept to fit the purpose of occupational cancer risk assessment. The risk model underlying ICH guideline M7 (R1): "assessment and control of DNA reactive (mutagenic) impurities in pharmaceuticals to limit potential carcinogenic risk" was used as a starting point for our model. We conducted a short review of studies on the occupational exposure of health workers to genotoxic drugs. These occupational exposure data were compared to the acceptable exposure levels resulting from our TTC based risk model.Based on the threshold of toxicological concern (TTC) concept, we defined an acceptable daily intake (ADI) of 4 μg/day as threshold of no concern for the exposure of health workers to genotoxic drugs. Regarding the dermal exposure of health workers to genotoxic drugs, we derived a corresponding acceptable surface contamination level (ASCL) of 20 ng/cm2. Both ADI and ASCL are usually not exceeded in modern healthcare settings. Current safety precautions provide sufficient protection to health workers.The application of our model indicates that workers in modern healthcare facilities are not at risk of developing work related cancer above widely accepted cancer risk levels due to the occupational exposure to genotoxic drugs. Hence, the present study may assist employers and public authorities to make informed decisions concerning the need for (further) protective measures and during risk communication to health workers. 

/pdf/a-simple-approach-to-assess-the-cancer-risk-of-occupational-13gjm7w3.pdf

Johannes Gerding

Papers

A comparative study of the human urinary mycotoxin excretion patterns in Bangladesh, Germany, and Haiti using a rapid and sensitive LC-MS/MS approach.

Determination of mycotoxin exposure in Germany using an LC‐MS/MS multibiomarker approach

A new approach using micro HPLC-MS/MS for multi-mycotoxin analysis in maize samples

A simple approach to assess the cancer risk of occupational exposure to genotoxic drugs in healthcare settings