Seasonal variation of mycotoxin levels in poultry feeds and feed ingredients in Oyo State, Nigeria

Mycotoxins pose a major problem to poultry production as a result of feed contamination which has deleterious consequences such as production losses and human health risks. A total of 158 chicken feed samples were randomly collected from 46 consenting poultry farms in Oyo State throughout the wet season (April-October; 91 samples) and the dry season (November-March; 67 samples), including compounded feed (n = 129) and feed ingredients (n = 29). Samples were promptly transported to the laboratory in sterile plastic vials for lateral flow assay for mycotoxins using six different commercial mycotoxin test kits each for aflatoxin B1, zearalenone, deoxynivalenol, ochratoxin A, fumonisin, and T-2 toxin/HT-2 toxin. Summary values of mycotoxin levels (µg/kg) in the feedstuffs were represented as frequency or median (and range). Fisher exact or Mann-Whitney U tests were carried out where appropriate at α = 0.05. Every sample contained at least four mycotoxins. Aflatoxins and fumonisin co-occurred in 80% of the samples. Aflatoxin and fumonisin concentrations were above the permissible limits in 32.9% and 18.4% respectively in feedstuff sampled in the dry season while the values were 17.1% and 6.3% respectively during the wet season. Among feed ingredients, peanut cake and maize had the highest median concentration of aflatoxin and fumonisin, respectively. Median aflatoxin concentration in the feedstuff was significantly higher than the permissible limit irrespective of season. There is a need to frequently monitor mycotoxin levels of feed and feed ingredients and improve storage system for feed ingredients in order to reduce the risk associated with high mycotoxin intake in poultry.

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.

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.

Biomonitoring of Multiple Mycotoxins in Urine by GC-MS/MS: A Pilot Study on Patients with Esophageal Cancer in Golestan Province, Northeastern Iran

A pilot study to investigate the occurrence of 10 mycotoxins (deoxynivalenol, DON; 3-acetyldeoxynivalenol, 3-ADON; 15-acetyldeoxynivalenol, 15-ADON; fusarenon-X, FUS-X; diacetoxyscirpenol, DAS; nivalenol, NIV; neosolaniol, NEO; zearalenone, ZON; zearalanone, ZAN; T-2 toxin, T-2; and HT-2 toxin, HT-2) in esophageal cancer patients was performed with the urinary biomarkers approach in Golestan, Iran. Urine multimycotoxin analysis was performed by dispersive liquid–liquid microextraction and gas chromatography–tandem mass spectrometry (GC–MS/MS) analysis, and values were normalized with urinary creatinine (μg/g). Four mycotoxins, namely NEO (40%), HT-2 (17.6%), DON (10%), and HT-2 (5.8%), were detected in the analyzed urine samples. DON was only detected in the control group (5.09 μg/g creatinine), while T-2 (44.70 μg/g creatinine) was only present in the esophageal cancer group. NEO and HT-2 were quantified in both control and case groups, showing average of positive samples of 9.09 and 10.45 μg/g creatinine for NEO and 16.81 and 29.09 μg/g creatinine for HT-2, respectively. Mycotoxin co-occurrence was observed in three samples as binary (NEO/HT-2 and T-2/HT-2) and ternary (DON/NEO/HT-2) combinations, reaching total concentrations of 44.58, 79.13, and 30.04 µg/g creatinine, respectively. Further investigations are needed to explore a causal association between mycotoxin contamination and esophageal cancer. For this pilot study in Golestan, the low sample size was a very limiting factor.

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

Investigating workplace exposure to mycotoxins is of the utmost importance in supporting the implementation of preventive measures for workers. The aim of this study was to provide tools for measuring mycotoxins in urine and airborne samples. A multi-class mycotoxin method was developed in urine for the determination of aflatoxin B1, aflatoxin M1, ochratoxin A, ochratoxin α, deoxynivalenol, zearalenone, α-zearalenol, β-zearalenol, fumonisin B1, HT2-toxin and T2-toxin. Analysis was based on liquid chromatography-high resolution mass spectrometry. Sample pre-treatments included enzymatic digestion and an online or offline sample clean-up step. The method was validated according to the European Medicines Agency guidance procedures. In order to estimate external exposure, air samples collected with a CIP 10 (Capteur Individuel de Particules 10) personal dust sampler were analyzed for the quantification of up to ten mycotoxins, including aflatoxins, ochratoxin A, deoxynivalenol, zearalenone, fumonisin B1 and HT-2 toxin and T-2 toxin. The method was validated according to standards for workplace exposure to chemical and biological agents EN 482. Both methods, biomonitoring and airborne mycotoxin measurement, showed good analytical performances. They were successfully applied in a small pilot study to assess mycotoxin contamination in workers during cleaning of a grain elevator. We demonstrated that this approach was suitable for investigating occupational exposure to mycotoxins.

Hepatotoxicity of aflatoxin B1 and its oxidative effects in wood dust Egyptian exposed workers

The goal of the present study is to estimate the oxidative effects of AFB1 induced hepatotoxicity in furniture wood dust exposed workers. A cross-sectional comparative study was designed for comparing AFB1/albumin (AFB1/alb) levels and liver functions [alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP)], malondialdehyde (MDA), glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) in 88 furniture workers and 78 controls not occupationally exposed to wood dust. The AFB1/Alb, AST, ALT, MDA, and GPx were significantly higher; while, CAT significantly reduced in workers compared with controls. There was a significant correlation between AFB1/Alb and MDA level with the liver enzymes among both groups. CAT was inversely correlated with AFB1/Alb and the liver enzymes, and GPx was inversely correlated with AST in the workers. It was concluded that wood dust exposure is associated with raised serum levels of AFB1 and oxidative stress.

Occupational Exposure to Mycotoxins-Different Sampling Strategies Telling a Common Story Regarding Occupational Studies Performed in Portugal (2012-2020)

In occupational settings where exposure to organic dust occurs (e.g., intensive animal production, waste management, farming and many others) workers can also be exposed to mycotoxins. However, recognizing exposure to mycotoxins in workplace environments does not happen commonly and, consequently, remains as a not identified occupational risk factor. In the last decade, work developed in different occupational settings, using different sampling approaches reported that occupational exposure to mycotoxins occurs and it's of upmost importance to be seen as an occupational concern that needs to be tackled. This paper intends to discuss the several possibilities available for assessing and characterizing the occupational exposure to mycotoxins through the description of the advantages and limitations of the different sampling strategies. Overviewing the approaches and the main achievements used in several field campaigns developed in Portugal, the knowledge obtained will be used to support the identification of the main aspects to consider when designing new occupational studies. The need for additional research work will also be discussed where new directions to follow will be debated.

The effects of waste sorting in environmental microbiome, THP-1 cell viability and inflammatory responses

Workers in the waste sorting industry are exposed to diverse bioaerosols. Characterization of these bioaerosols is necessary to more accurately assess the health risks of exposure. The use of high-throughput DNA sequencing for improved analysis of microbial composition of bioaerosols, in combination with their in vitro study in relevant cell cultures, represents an important opportunity to find answers on the biological effects of bioaerosols. This study aimed to characterize by high-throughput sequencing the biodiversity present in complex aerosol mixtures retained in forklift air conditioning filters of a waste-sorting industry and its effects on cytotoxicity and secretion of proinflammatory cytokines in vitro using human macrophages derived from monocytic THP-1 cells. Seventeen filters from the filtration system from forklifts operating in one waste sorting facility and one control filter (similar filter without prior use) were analyzed using high-throughput sequencing and toxicological tests in vitro. A trend of positive correlation was seen between the number of bacterial and fungal OTUs (r = 0.47, p = 0.06). Seven filters (39%) exhibited low or moderate cytotoxicity (p < 0.05). The highest cytotoxic responses had a reduction in cell viability between 17 and 22%. Filter samples evoked proinflammatory responses, especially the production of TNFα. No significant correlation was found between fungal richness and inflammatory responses in vitro. The data obtained stress the need of thorough exposure assessment in waste-sorting industry and to take immunomodulatory properties into consideration for bioaerosols hazard characterization. The broad spectrum of microbial contamination detected in this study demonstrates that adequate monitoring of bioaerosol exposure is necessary to evaluate and minimize risks. The combined techniques can support the implementation of effective environmental monitoring programs of public and occupational health importance.

Occupational Exposure to Mycotoxins: Current Knowledge and Prospects

Occupational exposure to mycotoxins is supposedly very frequent, but it is rarely reported in the scientific literature. Several recent studies described occupational exposure to the aflatoxin B1 (AFB1) mycotoxin in different occupational settings. Previously, exposure to other mycotoxins was shown in the animal husbandry and food processing sectors, confirming that occupational exposure cannot be negligible. However, no guidelines or standard methodologies are available for helping occupational hygienists to consider mycotoxin exposure in their interventions. This article reviews the literature on this problem and recommends some actions for the better management of this risk factor in occupational settings, especially where environmental conditions are favorable to fungal presence.

Urinary aflatoxin exposure monitoring in rural and semi-urban populations in Ogun state, Nigeria

Aflatoxins are a major class of fungal toxins that have food safety importance due to their economic and health impacts. This pilot aflatoxin exposure biomonitoring study on 84 individuals was conducted in a rural (Ilumafon) and a semi-urban community (Ilishan Remo) of Ogun state, Nigeria, to compare aflatoxin exposures among the two population cohorts. First morning urine samples were obtained from the participants, and the urinary aflatoxin M₁ (AFM₁) levels were measured by a quantitative Helica Biosystems Inc. ELISA kit assay. About 99% (83 out of 84) of the urine samples had detectable AFM₁ levels in the range of 0.06 to 0.51 ng mL^-1 (median: 0.27 ng mL^-1). The mean urinary AFM₁ levels were significantly (p = 0.001) higher in the semi-urban population (0.31 ± 0.09 ng mL^-1) compared to the rural population (0.24 ± 0.07 ng mL^-1). There were, however, no significant differences in mean urinary AFM₁ levels of males and females, and among children, adolescents and adults. This study indicates high aflatoxin exposure to the extent of public health concerns in the studied populations. Thus, more efforts are required for aflatoxin exposure monitoring and control in high-risk regions.

Aflatoxin M1 in milk and milk products: a short review

Aflatoxin M1 (AFM1) is associated with carcinogenicity, genotoxicity, mutagenicity, and teratogenicity and as a result, represents a human health problem worldwide. This review will detail the toxicity, analytical methodology, occurrence, and prevention and control of AFM1 in milk and milk products. The probable daily intakes (PDI) per bodyweight (bw) worldwide ranged from 0.002 to 0.26 ng/kg bw/day for AFM1. Nevertheless, the high occurrence of AFM1 demonstrated in this review establishes the need for monitoring to reduce the risk of toxicity to humans. The recommended extraction method of AFM1 from milk is liquid-liquid with acetonitrile because of the acceptable recoveries (85-97%), compatibility with the environment, and cleanest extracts. The recommended analytical technique for the determination of AFM1 in milk is the high performance-liquid chromatography-fluorescence detector (HPLC-FLD), achieving a 0.001 µg/kg detection limit. The HPLC-FLD is the most common internationally recognised official method for the analysis of AFM1 in milk. The suggested extraction and analytical method for cheese is dichloromethane (81-108% recoveries) and ELISA, respectively. This review reports the projected worldwide occurrence of AFM1 in milk of 2010-2015. Of the 7,841 samples, 5,873 (75%) were positive for AFM1, 26% (2,042) exceeded the maximum residue levels (MRL) of 0.05 µg/kg defined by the European Union and 1.53% (120) exceeded the MRL of 0.5 µg/kg defined by the US Food and Drug Administration. The most effective way of preventing AFM1 occurrences is to reduce contamination of AFB1 in animal feed using biological control with atoxigenic strains of Aspergillus flavus, proper storage of crops, and the addition of binders to AFB1-contaminated feed. Controllable measures include the addition of binders and use of biological transforming agents such as lactic acid bacteria applied directly to milk. Though the one accepted method for the control of AFM1 in milk and milk products is the enforcement of governmental MRL.

Biomonitoring of Mycotoxins in Urine: Pilot Study in Mill Workers

Contamination of grains with mycotoxins results in a dietary background exposure of the general population. In occupational settings such as during processing of raw materials as in milling, an additional mycotoxin exposure by inhalation is possible. Biomonitoring is an integrative approach to assess human exposure from various sources and by all routes. To investigate possible workplace exposure to mycotoxins, a pilot study was conducted that compared levels of urinary biomarkers in mill workers to those in a control group with dietary mycotoxin intake alone. Workers (n = 17) from three grain mills in North Rhine Westphalia, Germany, provided spot urines during shift; volunteers (n = 13, IfADo staff) with matched age structure served as control group. The mycotoxins selected for biomarker analysis were citrinin (CIT) deoxynivalenol (DON), ochratoxin A (OTA), and zearalenone (ZEN). Immunoaffinity columns (CIT, DON, ZEN) or liquid-liquid extraction (OTA) was employed for urine sample cleanup prior to targeted analysis by liquid chromatography with tandem mass spectrometry (LC-MS/MS) or by high-performance liquid chromatography (HPLC). In addition, mycotoxin metabolites that may be formed in the organism were analyzed, including deepoxy-deoxynivalenol (DOM-1), ochratoxin alpha (OTα), dihydrocitrinone (DH-CIT), and α- and β-zearalenol (α- and β-ZEL), as well as phase II metabolites that were hydrolyzed with β-glucuronidase/arylsulfatase prior to sample cleanup. All analyte concentrations were adjusted for creatinine (crea) content in the spot urine samples. Citrinin, DON, OTA, and ZEN were detected in nearly all urine samples from mill workers and controls. Interestingly, DH-CIT was found at higher mean levels than the parent compound (~0.14 and 0.045 µg/g crea, respectively), suggesting an effective metabolism of CIT in humans. Other metabolites DOM-1, OTα, and α- and β-ZEL were detected less frequently in urine. Deoxynivalenol was detected at the highest concentrations (mean ~6 µg/g crea), followed by OTA (mean ~0.08 µg/g crea); ZEN (mean ~0.03 µg/g crea) and its metabolites appeared in urine at lower levels. Mycotoxin biomarker levels in urine from mill workers and controls were not significantly different. From these results it is concluded that biomarker levels measured in urine samples from the two cohorts reflect mainly dietary mycotoxin exposure. An additional occupational (inhalational) exposure of mill workers, if any, is apparently low at the investigated workplaces.

Assessment of workers' exposure to aflatoxin B1 in a Portuguese waste industry

Aflatoxin B1 (AFB1) is considered by different International Agencies as a genotoxic and potent hepatocarcinogen. However, despite the fact that the fungi producing this compound are detected in some work environments, AFB1 is rarely monitored in occupational settings. The aim of the present investigation was to assess exposure to AFB1 of workers from one Portuguese waste company located in the outskirt of Lisbon. Occupational exposure assessment to AFB1 was done with a biomarker of internal dose that measures AFB1 in the serum by enzyme-linked immunosorbent assay. Forty-one workers from the waste company were enrolled in this study (26 from sorting; 9 from composting; 6 from incineration). A control group (n = 30) was also considered in order to know the AFB1 background levels for the Portuguese population. All the workers showed detectable levels of AFB1 with values ranging from 2.5ng ml(-1) to 25.9ng ml(-1) with a median value of 9.9±5.4ng ml(-1). All of the controls showed values below the method's detection limit. Results obtained showed much higher (8-fold higher) values when compared with other Portuguese settings already studied, such as poultry and swine production. Besides this mycotoxin, other mycotoxins are probably present in this occupational setting and this aspect should be taken into consideration for the risk assessment process due to possible synergistic reactions. The data obtained suggests that exposure to AFB1 occurs in a waste management setting and claims attention for the need of appliance of preventive and protective safety measures.

Mycotoxin exposure in rural residents in northern Nigeria: a pilot study using multi-urinary biomarkers

A pilot, cross-sectional, correlational study was conducted in eight rural communities in northern Nigeria to investigate mycotoxin exposures in 120 volunteers (19 children, 20 adolescents and 81 adults) using a modern LC-MS/MS based multi-biomarker approach. First morning urine samples were analyzed and urinary biomarker levels correlated with mycotoxin levels in foods consumed the day before urine collection. A total of eight analytes were detected in 61/120 (50.8%) of studied urine samples, with ochratoxin A, aflatoxin M1 and fumonisin B1 being the most frequently occurring biomarkers of exposure. These mycotoxin biomarkers were present in samples from all age categories, suggestive of chronic (lifetime) exposures. Rough estimates of mycotoxin intake suggested some exposures were higher than the tolerable daily intake. Overall, rural consumer populations from Nasarawa were more exposed to several mixtures of mycotoxins in their diets relative to those from Kaduna as shown by food and urine biomarker data. This study has shown that mycotoxin co-exposure may be a major public health challenge in rural Nigeria; this calls for urgent intervention.

Estimation of fungal contamination and mycotoxin production at workplaces in composting plants, tanneries, archives and libraries

The aim of this research was to estimate fungal contamination at workplaces in composting plants, tanneries, libraries and archives. The influence of raw material processed or stored at these workplaces (compost, leather, cellulose) on the toxigenicity and cytotoxicity of fungi was also investigated. Qualitative and quantitative mycological analysis confirmed a high contamination in composting plants and tanneries, while materials in archives and libraries were less contaminated. Among the 74 fungal species present in the studied work environments, 15 species were identified as useful indicators of microbial contamination based on their presence at the workplace, frequency of occurrence and harmfulness to health. For nine Aspergillus and Penicillium isolates, identification was confirmed on the basis of molecular techniques, i.e. internal transcribed spacer region and β-tubulin gene sequencing, and the obtained nucleotide sequences were deposited into the NCBI GenBank Database. Five strains were cytotoxic to swine kidney cells. Strains of Aspergillus fumigatus originating from a composting plant produced large quantities of fumitremorgin C, fumiquinazoline F, fumagillin, fumigaclavine, helvolic acid, methylsulochrin, pyripyropene A, brevianamid F, verruculogen and others, as analysed by high performance liquid chromatography-tandem mass spectrometry. In the case of Penicillium chrysogenum originating from a tannery, meleagrin, secalonic acid D, roquefortine C, emodin and other metabolites were detected. These findings confirmed the hypothesis that these species may be a health risk factor to workers. Interestingly, the presence of compost extract, leather or cellulose in the culture medium apparently affected the ability of the selected fungi to produce (cytotoxic) mycotoxins.