Investigating Multi-Mycotoxin Exposure in Occupational Settings: A Biomonitoring and Airborne Measurement Approach

Exploring the relationship between daily intake and urinary excretion of the mycotoxins T-2 and HT-2 toxin in humans

T-2 toxin (T-2) and HT-2 toxin (HT-2) are mycotoxins that can contaminate food, especially cereals. Exposure to T-2 and HT-2 has mainly been estimated using dietary exposure assessment, however, human biomonitoring presents another valuable approach. The relationship between daily intake and urinary excretion of T-2 and HT-2 over time in 40 Norwegian adults was modelled. T-2, HT-2 and T-2 triol were analysed in 24-h urine samples using LC-MS/MS. Dietary exposure of T-2 and HT-2 was calculated using 24-h weighed dietary records and concentration data in food derived from measured concentrations in raw food commodities. A statistical model was developed and fit to estimate the excreted fraction (fabs_excr) and residence time parameters. Without deconjugation prior to analysis, T-2, HT-2 or T-2 triol were not detected in the urine of the 40 adults. Applying a deconjugation step, total HT-2 (HT-2 and its glucuronides) was detected in almost all samples. Using the statistical model, the mean fabs_excr was estimated to be 0.184, equivalent to 18.4 %. The estimated time in which 97.5 % of the ingested T-2 and HT-2 was excreted as total HT-2 was 14.3 h, and the elimination half-life was 4.0 h. This study highlights the challenges involved in modelling the relationship between daily intake and urinary excretion of T-2 and HT-2 over time in humans. The findings indicate that approximately 20 % of the external exposure can be traced back in the urine within 24 h. However, additional research is required to support and strengthen these findings.

Unraveling the occupational exposure to mycotoxins in a waste management setting: results from a case study in Norway

Introduction

Waste management represents an occupational setting where fungi are significant contaminants. This study aimed to assess the exposure of waste workers to mycotoxins through a human biomonitoring study.

Methods

A total of 33 workers and 19 controls provided spot urine samples to determine 10 mycotoxins' urinary biomarkers using liquid chromatography coupled with mass spectrometry. Risk characterization was performed using hazard quotient and margin of exposure assessments.

Results

The results indicated that workers were exposed to six out of the 10 mycotoxins tested, with the following detection rates: deoxynivalenol (91%, 30/33), ochratoxin A (33%, 11/33), zearalenone (17%, 5/33), α-zearalenol (12%, 4/33), β-zearalenol (12%, 4/33), and HT-2 toxin (3%, 1/33). Within controls and outwith controls, were exposed to 5/10 and 2/10 mycotoxins, respectively. All participants exhibited hazard quotients for deoxynivalenol and zearalenone below one, indicating that the exposure is unlikely to pose a health risk. However, when considering the margin of exposure determined for ochratoxin A, 18% of the total participants presented results below 200 for non-neoplastic effects, and 100% of the total participants presented values below 10,000 for neoplastic effects, suggesting potential health concerns that require further assessment.

Discussion

This study highlights the need for future research on occupational exposure to mycotoxins in waste management settings.

Cross-sectional biomonitoring of urinary deoxynivalenol, T-2 and HT-2 toxins, and zearalenone in Japanese adults

BACKGROUND

Among the more than 300 mycotoxins that are known to have toxic effects on animals and humans, Fusarium toxins deoxynivalenol (DON), T-2 and HT-2 toxins (T2/HT2), and zearalenone (ZEN) are frequently detected in domestic agricultural products. This study aimed to assess DON, T2/HT2, and ZEN exposure in Japanese adults by measuring urinary mycotoxins, observing their distributions, and making comparisons with data from other countries.

METHODS

A total of 201 individuals participated in the study. Twenty-four-hour urine samples were collected from young adults (34 men and 35 women) in the Tokai region (urban area) and spot urine samples were collected from middle-aged and elderly adults (64 men and 68 women) in the Donan area of Hokkaido Prefecture (rural area). Urinary DON, T2/HT2, and ZEN levels were measured using a validated liquid chromatography-tandem mass spectrometry method.

RESULTS

For DON, T2/HT2, and ZEN, the detection frequencies above the limit of detection (LOD) level (0.15, 0.13, and 0.01 µg/L, respectively) in all the samples were 53%, 26%, and 71%, respectively. The median concentrations (95th percentile) of urinary DON, HT2, and ZEN were 0.19 (3.93),

CONCLUSIONS

This study represents the first comprehensive exposure assessment for DON, T2/HT2, and ZEN in Japanese adults using human biomonitoring methods. These data provide valuable information for a better understanding of mycotoxin exposure in Japan.

Collapse

Key Words

• Human biomonitoring
• Japanese adults
• Liquid chromatography–tandem mass spectrometry
• Mycotoxin
• Urine

Collapse

MESH Headings

• Humans
• Zearalenone/urine
• Japan
• Male
• Female
• Trichothecenes/urine
• T-2 Toxin/analogs & derivatives
• T-2 Toxin/urine
• Biological Monitoring
• Adult
• Middle Aged
• Aged
• Cross-Sectional Studies
• Young Adult
• Mycotoxins/urine
• Environmental Exposure/analysis
• East Asian People

Collapse

Grants Collapse

Affiliation(s)

Toshiki Tajima Department of Biomolecular Sciences, Field of Omics Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-minami, Higashi-ku, Nagoya 461-8673, Japan
Tomohiko Isobe Health and Environmental Risk Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
Isao Saito Department of Biomolecular Sciences, Field of Omics Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-minami, Higashi-ku, Nagoya 461-8673, Japan
Takaaki Kondo Department of Biomolecular Sciences, Field of Omics Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-minami, Higashi-ku, Nagoya 461-8673, Japan
Koji Suzuki Department of Preventive Medical Sciences, Fujita Health University School of Medical Sciences, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake 470-1192, Japan
Ryosuke Fujii Department of Preventive Medical Sciences, Fujita Health University School of Medical Sciences, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake 470-1192, Japan
Yoshiki Tsuboi Department of Preventive Medical Sciences, Fujita Health University School of Medical Sciences, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake 470-1192, Japan
Yoshiko Sugita-Konishi Faculty of Applied Biosciences, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
Jun Ueyama Department of Biomolecular Sciences, Field of Omics Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-minami, Higashi-ku, Nagoya 461-8673, Japan

Collapse

Occurrence of the two major regulated mycotoxins, ochratoxin A and fumonisin B1, in cereal and cereal-based products in Europe and toxicological effects: A review

Among cereal contaminants, mycotoxins are of concern due to their importance in terms of food and feed safety. The difficulty in establishing a diagnosis for mycotoxicosis relies on the fact that the effects are most often subclinical for chronic exposure and the most common scenario is multi-contamination by various toxins. Mycotoxin co-occurrence is a major food safety concern as additive or even synergic toxic impacts may occur, but also regarding current regulations as they mainly concern individual mycotoxin levels in specific foods and feed in the food chain. However, due to the large number of possible mycotoxin combinations, there is still limited knowledge on co-exposure toxicity data, which depends on several parameters. In this context, this systematic review aims to provide an overview of the toxic effects of two regulated mycotoxins, namely ochratoxin A and fumonisin B1. This review focused on the 2012-2022 period and analysed the occurrence in Europe of the selected mycotoxins in different food matrices (cereals and cereal-derived products), and their toxic impact, alone or in combination, on in vitro intestinal and hepatic human cells. To better understand and evaluate the associated risks, further research is needed using new approach methodologies (NAM), such as in vitro 3D models. KEY CONTRIBUTION: Cereals and their derived products are the most important food source for humans and feed for animals worldwide. This manuscript is a state of the art review of the literature over the last ten years on ochratoxin A and fumonisin B1 mycotoxins in these products in Europe as well as their toxicological effects, alone and in combination, on human cells. Future perspectives and some challenges regarding the assessment of toxicological effects of mycotoxins are also discussed.

Human Biomonitoring Guidance Values for Deoxynivalenol Derived under the European Human Biomonitoring Initiative (HBM4EU)

The mycotoxin deoxynivalenol (DON) was one of the priority substances in the European Joint Human Biomonitoring Initiative (HBM4EU) project. In this study, to better interpret the actual internal exposure of DON in the general population and safeguard public health, human biomonitoring guidance values of DON for the general population (HBM-GVGenPop) were derived. The HBM-GVGenPop of DON was based on either the total DON (DON and its glucuronides) or DON's main metabolite (DON-15-GlcA) levels in 24-h urine samples, resulting in a HBM-GVGenPop of 0.023 µg/mL for the total DON or a HBM-GVGenPop of 0.020 µg/mL for DON-15-GlcA. The use of 24-h urine samples is recommended based on the fact that DON and its metabolites have a short elimination half-life (T1/2), and 95% of the cumulative amount was excreted within 12 h after DON intake. The T1/2 for DON, DON-15-GlcA, and total DON were estimated to be 2.55 h, 2.95 h, and 2.95 h, respectively. Therefore, a 24-h urine sample reflects almost all of the DON exposure from the previous day, and this type of sample was considered for the derivation of a HBM-GVGenPop for DON.

Aflatoxin M1 Analysis in Urine of Mill Workers in Bangladesh: A Pilot Study

Presence of aflatoxin B1 (AFB1) in food and feed is a serious problem, especially in developing countries. Human exposure to this carcinogenic mycotoxin can occur through dietary intake, but also through inhalation or dermal contact when handling and processing AFB1-contaminated crops. A suitable biomarker of AFB1 exposure by all routes is the occurrence of its hydroxylated metabolite aflatoxin M1 (AFM1) in urine. To assess mycotoxin exposure in mill workers in Bangladesh, we analyzed AFM1 levels in urine samples of this population group who may encounter both dietary and occupational AFB1 exposure. In this pilot study, a total of 76 participants (51 mill workers and 25 controls) were enrolled from the Sylhet region of Bangladesh. Urine samples were collected from people who worked in rice, wheat, maize and spice mills and from controls with no occupational contact to these materials. A questionnaire was used to collect information on basic characteristics and normal food habits of all participants. Levels of AFM1 in the urine samples were determined by a competitive enzyme linked immunosorbent assay. AFM1 was detected in 96.1% of mill workers' urine samples with a range of LOD (40) of 217.7 pg/mL and also in 92% of control subject's urine samples with a range of LOD of 307.0 pg/mL). The mean level of AFM1 in mill workers' urine (106.5 ± 35.0 pg/mL) was slightly lower than that of the control group (123.3 ± 52.4 pg/mL), whilst the mean AFM1 urinary level adjusted for creatinine was higher in mill workers (142.1 ± 126.1 pg/mg crea) than in the control group (98.5 ± 71.2 pg/mg crea). Yet, these differences in biomarker levels were not statistically significant. Slightly different mean urinary AFM1 levels were observed between maize mill, spice mill, rice mill, and wheat mill workers, yet biomarker values are based on a small number of individuals in these subgroups. No significant correlations were found between the study subjects' urine AFM1 levels and their consumption of some staple food items, except for a significant correlation observed between urinary biomarker levels and consumption of groundnuts. In conclusion, this pilot study revealed the frequent presence of AFM1 in the urine of mill workers in Bangladesh and those of concurrent controls with dietary AFB1 exposure only. The absence of a statistical difference in mean biomarker levels for workers and controls suggests that in the specific setting, no extra occupational exposure occurred. Yet, the high prevalence of non-negligible AFM1 levels in the collected urines encourage further studies in Bangladesh regarding aflatoxin exposure.

Development of a Generic PBK Model for Human Biomonitoring with an Application to Deoxynivalenol

Toxicokinetic modelling provides a powerful tool in relating internal human exposure (i.e., assessed through urinary biomarker levels) to external exposure. Chemical specific toxicokinetic models are available; however, this specificity prevents their application to similar contaminants or to other routes of exposure. For this reason, we investigated whether a generic physiological-based kinetic (PBK) model might be a suitable alternative for a biokinetic model of deoxynivalenol (DON). IndusChemFate (ICF) was selected as a generic PBK model, which could be fit for purpose. Being suited for simulating multiple routes of exposure, ICF has particularly been used to relate the inhalation and dermal exposure of industrial chemicals to their urinary excretion. For the first time, the ICF model was adapted as a generic model for the human biomonitoring of mycotoxins, thereby extending its applicability domain. For this purpose, chemical-specific data for DON and its metabolites were collected directly from the literature (distribution and metabolism) or indirectly (absorption and excretion) by fitting the ICF model to previously described urinary excretion data. The obtained results indicate that this generic model can be used to model the urinary excretion of DON and its glucuronidated metabolites following dietary exposure to DON. Additionally, the present study establishes the basis for further development of the model to include an inhalation exposure route alongside the oral exposure route.

Literature review and evaluation of biomarkers, matrices and analytical methods for chemicals selected in the research program Human Biomonitoring for the European Union (HBM4EU)

Humans are potentially exposed to a large amount of chemicals present in the environment and in the workplace. In the European Human Biomonitoring initiative (Human Biomonitoring for the European Union = HBM4EU), acrylamide, mycotoxins (aflatoxin B1, deoxynivalenol, fumonisin B1), diisocyanates (4,4'-methylenediphenyl diisocyanate, 2,4- and 2,6-toluene diisocyanate), and pyrethroids were included among the prioritized chemicals of concern for human health. For the present literature review, the analytical methods used in worldwide biomonitoring studies for these compounds were collected and presented in comprehensive tables, including the following parameter: determined biomarker, matrix, sample amount, work-up procedure, available laboratory quality assurance and quality assessment information, analytical techniques, and limit of detection. Based on the data presented in these tables, the most suitable methods were recommended. According to the paradigm of biomonitoring, the information about two different biomarkers of exposure was evaluated: a) internal dose = parent compounds and metabolites in urine and blood; and b) the biologically effective = dose measured as blood protein adducts. Urine was the preferred matrix used for deoxynivalenol, fumonisin B1, and pyrethroids (biomarkers of internal dose). Markers of the biological effective dose were determined as hemoglobin adducts for diisocyanates and acrylamide, and as serum-albumin-adducts of aflatoxin B1 and diisocyanates. The analyses and quantitation of the protein adducts in blood or the metabolites in urine were mostly performed with LC-MS/MS or GC-MS in the presence of isotope-labeled internal standards. This review also addresses the critical aspects of the application, use and selection of biomarkers. For future biomonitoring studies, a more comprehensive approach is discussed to broaden the selection of compounds.

Assessment of occupational and dietary exposures of feed handling workers to mycotoxins in rural areas from São Paulo, Brazil

In the current study, the occupational and dietary exposures of feed handling workers (N = 28) to aflatoxins (AFs), fumonisins (FBs), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEN), toxins T-2 and HT-2 were assessed for the first time in animal-producing farms and feed factories from São Paulo, Brazil. Mycotoxins in food (n = 244) and airborne dust (n = 27), as well as biomarkers in urine (n = 97) samples were determined by liquid chromatography coupled with tandem mass spectrometry. FBs were detected in all airborne dust samples, with concentrations ranging from 7.85 to 16,839 ng/m³. The mean probable daily intake (PDI) based on food data were 0.005, 0.769, 0.673 and 0.012 μg/kg of body weight (bw)/day for AFs, FBs, DON and ZEN, respectively. Mean PDI values obtained through urinary biomarkers were 0.29, 0.10, 0.50, 9.72 and 0.10 μg/kg body weight/day for AFB₁, DON, OTA, FB₁ and ZEN, respectively. The analyses based on urinary biomarkers revealed a potential health concern for OTA and FBs, although no potential health concern was observed with PDI calculated through food data. Results of this trial stress the need for preventive measures to avoid health risks of workers in Brazilian animal-producing farms and feed industries.

Providing Biological Plausibility for Exposure-Health Relationships for the Mycotoxins Deoxynivalenol (DON) and Fumonisin B1 (FB1) in Humans Using the AOP Framework

Humans are chronically exposed to the mycotoxins deoxynivalenol (DON) and fumonisin B1 (FB1), as indicated by their widespread presence in foods and occasional exposure in the workplace. This exposure is confirmed by human biomonitoring (HBM) studies on (metabolites of) these mycotoxins in human matrices. We evaluated the exposure-health relationship of the mycotoxins in humans by reviewing the available literature. Since human studies did not allow the identification of unequivocal chronic health effects upon exposure to DON and FB1, the adverse outcome pathway (AOP) framework was used to structure additional mechanistic evidence from in vitro and animal studies on the identified adverse effects. In addition to a preliminary AOP for DON resulting in the adverse outcome (AO) 'reduced body weight gain', we developed a more elaborated AOP for FB1, from the molecular initiating event (MIE) 'inhibition of ceramide synthases' leading to the AO 'neural tube defects'. The mechanistic evidence from AOPs can be used to support the limited evidence from human studies, to focus FB1- and DON-related research in humans to identify related early biomarkers of effect. In order to establish additional human exposure-health relationships in the future, recommendations are given to maximize the information that can be obtained from HBM.

Developments in mycotoxin analysis: an update for 2020-2021

This review summarises developments published in the period from mid-2020 to mid-2021 on the analysis of a number of diverse matrices for mycotoxins. Notable developments in all aspects of mycotoxin analysis, from sampling and quality assurance/quality control of analytical results, to the various detection and quantitation technologies ranging from single mycotoxin biosensors to comprehensive instrumental methods are presented and discussed. The summary and discussion of this past year’s developments in detection and quantitation technology covers chromatography with targeted or non-targeted high resolution mass spectrometry, tandem mass spectrometry, detection other than mass spectrometry, biosensors, as well as assays using alternatives to antibodies. This critical review aims to briefly present the most important recent developments and trends in mycotoxin determination, as well as to address limitations of the presented methodologies.

Comparison of analytical approaches for identifying airborne microorganisms in a livestock facility

An intensive study, applied to a site characterized by multiple sources of microorganisms, was aimed at understanding the best approach to study bioaerosol. Culture-based, molecular biological, and chemical methods were applied to Particulate Matter (PM) samples collected in a livestock facility, during spring and autumn seasons, in two different outdoor areas. The first one was close to a place where feed was stored and handled and the second next to an open cowshed. Qualitative analysis of bacteria was performed by sequencing techniques applied to DNA extracted from both isolated culturable bacteria and particulate matter samples. Quantification of microorganisms was achieved through three distinct approaches. Microorganism colonies were counted, after incubation at 28 °C, and expressed as colony-forming units (CFU) per m³. Chemical method consisted in the identification of individual biomarkers, and their conversion to number of microorganisms per m³, using proper conversion factors. Finally, qPCR was applied to DNA extracted from PM samples, and the results were expressed as total amount of bacteria present in the bioaerosol (UG/m³). The presence of airborne sterols was also studied to broaden the knowledge of bioaerosol components in atmosphere. Small seasonal differences and major sampling site differences occurred. Obviously, culture-dependent method identified less and different bacteria, than culture-independent approach. The chemical approach and the culture independent metagenomic method were in good agreement. As expected, CFU/m³ accounted for not more than 0.3% of bacteria calculated as the average of chemical and culture independent metagenomic methods. The complexity of the obtained results shows that the different approaches are complementary to obtain an exhaustive description of bioaresol in terms of concentration, speciation, viability, pathogenicity.

Determination of Urinary Mycotoxin Biomarkers Using a Sensitive Online Solid Phase Extraction-UHPLC-MS/MS Method

In the course of assessing the human exposure to mycotoxins, biomarker-based approaches have proven to be important tools. Low concentration levels, complex matrix compositions, structurally diverse analytes, and the large size of sample cohorts are the main challenges of analytical procedures. For that reason, an online solid phase extraction-ultra high-performance liquid chromatography-tandem mass spectrometry (online SPE-UHPLC-MS/MS) method was developed, allowing for the sensitive, robust, and rapid analysis of 11 relevant mycotoxins and mycotoxin metabolites in human urine. The included spectrum of analytes comprises aflatoxin M₁ (AFM₁), altenuene (ALT), alternariol monomethyl ether (AME), alternariol (AOH), citrinin (CIT) and its metabolite dihydrocitrinone (DH-CIT), fumonisin B₁ (FB₁), ochratoxin A (OTA), and zearalenone (ZEN) as well as α- and β-zearalenol (α- and β-ZEL). Reliable quantitation was achieved by means of stable isotope dilution, except for ALT, AME and AOH using matrix calibrations. The evaluation of method performance displayed low limits of detection in the range of pg/mL urine, satisfactory apparent recovery rates as well as high accuracy and precision during intra- and interday repeatability. Within the analysis of Zimbabwean urine samples (n = 50), the applicability of the newly developed method was shown. In addition to FB₁ being quantifiable in all analyzed samples, six other mycotoxin biomarkers were detected. Compared to the occurrence rates obtained after analyzing the same sample set using an established dilute and shoot (DaS) approach, a considerably higher number of positive samples was observed when applying the online SPE method. Owing to the increased sensitivity, less need of sample handling, and low time effort, the herein presented online SPE approach provides a valuable contribution to human biomonitoring of mycotoxin exposure.

Mycotoxins Exposure of French Grain Elevator Workers: Biomonitoring and Airborne Measurements

It is now recognized that additional exposure to mycotoxins may occur through inhalation of contaminated dust at a workplace. The aim of this study was to characterize the multi-mycotoxin exposure of French grain elevator workers using biomonitoring and airborne measurements. Eighteen workers participated in the study. Personal airborne dust samples were analyzed for their mycotoxin concentrations. Workers provided multiple urine samples including pre-shift, post-shift and first morning urine samples or 24 h urine samples. Mycotoxin urinary biomarkers (aflatoxin B1, aflatoxin M1, ochratoxin A, ochratoxin α, deoxynivalenol, zearalenone, α-zearalenol, β-zearalenol, fumonisin B1, HT-2 toxin and T-2 toxin) were measured using a liquid chromatography–high-resolution mass spectrometry method. Grain elevator workers were highly exposed to organic airborne dust (median 4.92 mg.m⁻³). DON, ZEN and FB1 were frequent contaminants in 54, 76 and 72% of air samples, respectively. The mycotoxin biomarkers quantified were DON (98%), ZEN (99%), α-ZEL (52%), β-ZEL (33%), OTA (76%), T-2 (4%) and HT-2 (4%). DON elimination profiles showed highest concentrations in samples collected after the end of the work shift and the urinary DON concentrations were significantly higher in post-shift than in pre-shift-samples (9.9 and 22.1 µg/L, respectively). ZEN and its metabolites concentrations did not vary according to the sampling time. However, the levels of α-/β-ZEL were consistent with an additional occupational exposure. These data provide valuable information on grain worker exposure to mycotoxins. They also highlight the usefulness of multi-mycotoxin methods in assessing external and internal exposures, which shed light on the extent and pathways of exposure occurring in occupational settings.