Assessment of aflatoxin exposure among young children in Ethiopia using urinary biomarkers

Mycotoxins Exposure of Lactating Women and Its Relationship with Dietary and Pre/Post-Harvest Practices in Rural Ethiopia

Mycotoxins can be transferred to breast milk during lactation. Hence, the presence of multiple mycotoxins (aflatoxins B1, B2, G1, G2, and M1, alpha and beta zearalanol, deoxynivalenol, fumonisins B1, B2, B3, and hydrolyzed B1, nivalenol, ochratoxin A, ochratoxin alpha, and zearalenone) in breast milk samples was assessed in our study. Furthermore, the relationship between total fumonisins and pre/post-harvest and the women's dietary practices was examined. Liquid chromatography coupled with tandem mass spectrometry was used to analyze the 16 mycotoxins. An adjusted censored regression model was fitted to identify predictors of mycotoxins, i.e., total fumonisins. We detected only fumonisin B2 (15% of the samples) and fumonisin B3 (9% of the samples) while fumonisin B1 and nivalenol were detected only in a single breast milk sample. No association between total fumonisins and pre/post-harvest and dietary practices was found (p < 0.05). The overall exposure to mycotoxins was low in the studied women, although fumonisins contamination was not negligible. Moreover, the recorded total fumonisins was not associated with any of the pre/post-harvest and dietary practices. Therefore, to better identify predictors of fumonisin contamination in breast milk, longitudinal studies with food samples in addition to breast milk samples and with larger sample sizes are needed for the future.

Aflatoxins: Source, Detection, Clinical Features and Prevention

The most potent mycotoxin, aflatoxins are the secondary metabolite produced by fungi, especially Aspergillus, and have been found to be ubiquitous, contaminating cereals, crops, and even milk and causing major health and economic issues in some countries due to poor storage, substandard management, and lack of awareness. Different aspects of the toxin are reviewed here, including its structural biochemistry, occurrence, factors conducive to its contamination and intoxication and related clinical features, as well as suggested preventive and control strategies and detection methods.

Early-life chemical exposome and gut microbiome development: African research perspectives within a global environmental health context

The gut microbiome of neonates, infants, and toddlers (NITs) is very dynamic, and only begins to stabilize towards the third year of life. Within this period, exposure to xenobiotics may perturb the gut environment, thereby driving or contributing to microbial dysbiosis, which may negatively impact health into adulthood. Despite exposure of NITs globally, but especially in Africa, to copious amounts and types of xenobiotics - such as mycotoxins, pesticide residues, and heavy metals - little is known about their influence on the early-life microbiome or their effects on acute or long-term health. Within the African context, the influence of fermented foods, herbal mixtures, and the delivery environment on the early-life microbiome are often neglected, despite being potentially important factors that influence the microbiome. Consequently, data on in-depth understanding of the microbiome-exposome interactions is lacking in African cohorts. Collecting and evaluating such data is important because exposome-induced gut dysbiosis could potentially favor disease progression.

Urinary Aflatoxin M1 Concentration and Its Determinants in School-Age Children in Southern Ethiopia

Aflatoxins are mycotoxins that can contaminate grains, legumes, and oil seeds. These toxic compounds are an especially serious problem in tropical and sub-tropical climates. The objective of this study was to raise awareness of aflatoxin exposure among primary school children in Shebedino woreda, southern Ethiopia, by measuring urinary aflatoxin M1 (AFM1). The study employed a cross-sectional design and systematic random sampling of children from eight schools in the district. The mean ± SD age of the children was 9.0 ± 1.8 years. Most (84.6%) households were food insecure with 17.9% severely food insecure. Urinary AFM1 was detected in more than 93% of the children. The median [IQR] concentration of AFM1/Creat was 480 [203, 1085] pg/mg. Based on a multiple regression analysis: DDS, consumption of haricot bean or milk, source of drinking water, maternal education, and household food insecurity access scale scores were significantly associated with urinary AFM1/Creat. In conclusion, a high prevalence of urinary AFM1 was observed in this study. However, the relation between AFM1 and dietary intake was analyzed based on self-reported dietary data; hence, all of the staple foods as well as animal feeds in the study area should be assessed for aflatoxin contamination.

Aflatoxin exposure among children of age 12-59 Months in Butajira District, South-Central Ethiopia: a community based cross-sectional study

Background

The continued provision of safe food, free of aflatoxin remains a huge challenge in developing countries. Despite several favourable climatic conditions that facilitate aflatoxin contamination in Ethiopia, there is little information showing aflatoxin exposure in children. Therefore, this study assessed aflatoxin exposure among young children in Butajira district, South-Central Ethiopia.

Methods

Community based cross-sectional study stratified by agro-ecology was employed in Health and Demographic Surveillance Site (HDSS) of Butajira. The study included 332 children aged 12–59 months and were selected by simple random sampling technique using the HDSS registration number as a sampling frame. We collected data on dietary practice and aflatoxin exposure. Aflatoxin M1 concentration in urine was measured by Enzyme-Linked Immunosorbent assay (ELISA). The data analysis was carried out using STATA.

Results

Detectable urinary Aflatoxin M1 was found in 62.4% (95% CI: 56.9 – 67.5%) of the children at a level ranging from 0.15 to 0.4 ng/ml. Children living in lowland agro-ecological zone had [AOR = 2.11 (95% CI; 1.15, 3.88] odds of being exposed to aflatoxin as compared to children living in highland agro-ecological zone. Children at lower socio-economic status [AOR = 0.27 (95% CI; 0.14, 0.50] and medium socio-economic status [AOR = 0.47 (95% CI; 0.25, 0.87] had 73% and 53% lower odds of being exposed to aflatoxin as compared to children in the higher socio-economic status, respectively.

Conclusions

Aflatoxin exposure among young children was very high in South-Central Ethiopia. This high aflatoxin exposure might emphasize the need for aflatoxin exposure mitigation strategies in Ethiopia. Especially, raising awareness of the community towards aflatoxin exposure is very crucial. In addition, further research is required to assess long-term aflatoxin exposure and its association with child growth and development.

Multiple mycotoxin exposure during pregnancy and risks of adverse birth outcomes: a prospective cohort study in rural Ethiopia

INTRODUCTION

Mycotoxin exposure during pregnancy has been associated with adverse birth outcomes in low- and middle-income countries. The evidence, however, is inconsistent and mainly limited to the assessment of a single mycotoxin. We assessed biomarkers of exposure to multiple mycotoxins during pregnancy and their associations with adverse birth outcomes in rural Ethiopia.

METHODS

We analyzed data from 579 pregnant women between 8 and 24 weeks of completed gestation enrolled in a prospective cohort study. Serum mycotoxin concentrations were determined using liquid chromatography coupled with tandem mass spectrometry. Multivariable linear probability models, adjusted for potential confounding factors and multiple comparisons, were fitted to assess the associations between mycotoxin exposure and small for gestational age and preterm birth. We applied principal component analysis to reduce the dimensionality of biomarker data from several taxonomic mycotoxin groups.

RESULTS

All pregnant women were co-exposed to at least five mycotoxins, and one pregnant woman was co-exposed to 27 mycotoxins. Fumonisins (FB), i.e., FB₂, FB₃, FB₁, and tenuazonic acid were the most frequently identified mycotoxins in 98.8, 95.3, 93.3, and 81.4% of the samples respectively. Deoxynivalenol was detected in 38.7%, nivalenol in 50.1%, ochratoxin α in 67.9%, and zearalenone in 50.9% of the serum samples. After adjustment, we found no statistically significant (all P ≥ 0.05) associations between mycotoxin exposures and birth outcomes.

CONCLUSIONS

Despite our study providing no evidence for relationships between mycotoxin biomarkers and adverse birth outcomes, our findings do indicate an extensive presence of multiple mycotoxin exposure among pregnant women. Public health policies and nutrition-sensitive interventions must ensure exposure to mycotoxins is reduced in rural Ethiopia.

Mycotoxin exposure biomonitoring in breastfed and non-exclusively breastfed Nigerian children

A multi-specimen, multi-mycotoxin approach involving ultra-sensitive LC-MS/MS analysis of breast milk, complementary food and urine was applied to examine mycotoxin co-exposure in 65 infants, aged 1-18 months, in Ogun state, Nigeria. Aflatoxin M₁ was detected in breast milk (4/22 (18%)), while six other classes of mycotoxins were quantified; including dihydrocitrinone (6/22 (27%); range: 14.0-59.7 ng/L) and sterigmatocystin (1/22 (5%); 1.2 ng/L) detected for the first time. Seven distinct classes of mycotoxins including aflatoxins (9/42 (21%); range: 1.0-16.2 µg/kg) and fumonisins (12/42 (29%); range: 7.9-194 µg/kg) contaminated complementary food. Mycotoxins covering seven distinct classes with diverse structures and modes of action were detected in 64/65 (99%) of the urine samples, demonstrating ubiquitous exposure. Two aflatoxin metabolites (AFM₁ and AFQ₁) and FB₁ were detected in 6/65 (9%), 44/65 (68%) and 17/65 (26%) of urine samples, respectively. Mixtures of mycotoxin classes were common, including 22/22 (100%), 14/42 (33%) and 56/65 (86%) samples having 2-6, 2-4, or 2-6 mycotoxins present, for breast milk, complementary food and urine, respectively. Aflatoxin and/or fumonisin was detected in 4/22 (18%), 12/42 (29%) and 46/65 (71%) for breast milk, complimentary foods and urine, respectively. Furthermore, the detection frequency, median concentrations and occurrence of mixtures were typically greater in urine of non-exclusively breastfed compared to exclusively breastfed infants. The study provides novel insights into mycotoxin co-exposures in early-life. Albeit a small sample set, it highlights transition to higher levels of infant mycotoxin exposure as complementary foods are introduced, providing impetus to mitigate during this critical early-life period and encourage breastfeeding.

Mycotoxin-mixture assessment in mother-infant pairs in Nigeria: From mothers' meal to infants' urine

Exposure to food and environmental contaminants is a global environmental health issue. In this study, innovative LC-MS/MS approaches were applied to investigate mycotoxin co-exposure in mother-infant pairs (n = 23) by analyzing matched plate-ready food, breast milk and urine samples of mothers and their exclusively breastfed infants. The study revealed frequent co-occurrence of two to five mycotoxins. Regulated (e.g. aflatoxins, deoxynivalenol and ochratoxin A) and emerging mycotoxins (e.g. alternariol monomethyl ether and beauvericin) were frequently detected (3 %-89 % and 45 %-100 %), in at least one specimen. In addition, a moderate association of ochratoxin A in milk to urine of mothers (r = 0.47; p = 0.003) and infants (r = 0.52; p = 0.019) but no other significant correlations were found. Average concentration levels in food mostly did not exceed European maximum residue limits, and intake estimates demonstrated exposure below tolerable daily intake values. Infants were exposed to significantly lower toxin levels compared to their mothers, indicating the protective effect of breastfeeding. However, the transfer into milk and urine and the resulting chronic low-dose exposure warrant further monitoring. In the future, occurrence of mycotoxin-mixtures, and their combined toxicological effects need to be comprehensively considered and implemented in risk management strategies. These should aim to minimize early-life exposure in critical developmental stages.

Aflatoxin Biosynthesis, Genetic Regulation, Toxicity, and Control Strategies: A Review

Aflatoxins (AFs) are highly toxic and cancer-causing compounds, predominantly synthesized by the Aspergillus species. AFs biosynthesis is a lengthy process that requires as minimum as 30 genes grouped inside 75 kilobytes (kB) of gene clusters, which are regulated by specific transcription factors, including aflR, aflS, and some general transcription factors. This paper summarizes the status of research on characterizing structural and regulatory genes associated with AF production and their roles in aflatoxigenic fungi, particularly Aspergillus flavus and A. parasiticus, and enhances the current understanding of AFs that adversely affect humans and animals with a great emphasis on toxicity and preventive methods.

The aflatoxin situation in Africa: Systematic literature review

Contamination of African staple foods is a major issue for human and animal health, nutrition, and trade. This review aimed to collect and synthesize the available evidence on geographical spread, scale of contamination, disease burden, economic impact, and mitigation measures for aflatoxins in Africa by way of a systematic literature review. This knowledge can enhance management strategies for the major challenges to combat aflatoxins. The search was conducted by applying a predefined search strategy, using bibliographic databases and websites, covering the period 2010 to 2018. Results showed that maize, peanuts, and animal feeds were the most studied commodities. For maize, all studies indicated mean AFB₁ to exceed the European Union legal limit. From studies on contamination levels and biomarkers, it is clear that overall exposure is high, leading to a substantial increase in long-term disease burden. In addition, concentrations in food occasionally can reach very high levels, causing acute aflatoxicoses. The trade-related impact of aflatoxin contamination was mainly evaluated from the standpoint of aflatoxin regulation affecting products imported from Africa. There was a limited number of studies on health-related economic impacts, pointing out a gap in peer-reviewed literature. A number of mitigation measures have been developed, but proof of cost-effectiveness or even costs alone of the practices is often lacking. We recommend more emphasis to be put in peer-reviewed studies on evidence-based cost-effective mitigation strategies for aflatoxins, on the scale and spread of the problem and its impacts on public health and economics for use in evidence-based policies.

Aflatoxin M1 in Africa: Exposure Assessment, Regulations, and Prevention Strategies - A Review

Aflatoxins are the most harmful mycotoxins causing health problems to human and animal. Many acute aflatoxin outbreaks have been reported in Africa, especially in Kenya and Tanzania. When ingested, aflatoxin B1 is converted by hydroxylation in the liver into aflatoxin M1, which is excreted in milk of dairy females and in urine of exposed populations. This review aims to highlight the AFM1 studies carried out in African regions (North Africa, East Africa, West Africa, Central Africa, and Southern Africa), particularly AFM1 occurrence in milk and dairy products, and in human biological fluids (breast milk, serum, and urine) of the populations exposed. Strategies for AFM1 detoxification will be considered, as well as AFM1 regulations as compared to the legislation adopted worldwide and the assessment of AFM1 exposure of some African populations. Egypt, Kenya, and Nigeria have the highest number of investigations on AFM1 in the continent. Indeed, some reports showed that 100% of the samples analyzed exceeded the EU regulations (50 ng/kg), especially in Zimbabwe, Nigeria, Sudan, and Egypt. Furthermore, AFM1 levels up to 8,000, 6,999, 6,900, and 2040 ng/kg have been reported in milk from Egypt, Kenya, Sudan, and Nigeria, respectively. Data on AFM1 occurrence in human biological fluids have also shown that exposure of African populations is mainly due to milk intake and breastfeeding, with 85-100% of children being exposed to high levels. Food fermentation in Africa has been tried for AFM1 detoxification strategies. Few African countries have set regulations for AFM1 in milk and derivatives, generally similar to those of the Codex alimentarius, the US or the EU standards.

Determination of aflatoxin M1 and deoxynivalenol biomarkers in infants and children urines from Bangladesh

The mycotoxins aflatoxin B1 (AFB1) and deoxynivalenol (DON) are found worldwide in crops and dietary staples. The prevalence and levels of these contaminants can vary greatly, and data in Bangladeshi food commodities are scarce. To characterize human exposure, we have conducted biomonitoring, analyzing AFM1 (a metabolite of AFB1) and DON levels in urines of adult cohorts in Bangladesh. Yet, AFM1 and DON occurrence has not been studied in the very young population of this country. Thus, the same methods, HPLC-FD for AFM1 and LC-MS/MS for DON analysis, were now applied to determine these biomarkers in urines of infants (n = 49) and young children (n = 105) in Rajshahi and Dhaka district. Overall, AFM1 and DON detection frequency was 43.5% and 33.4%, with 34.7% and 11.5% in infant and 47.6% and 39.4% in children urines, respectively. The mean AFM1 levels in all infants (9.1 ± 14.3, max 55.6 pg/mL) and children (8.8 ± 12.9, max 75.3 pg/mL) were not significantly different. The AFM1 mean level was slightly higher in Dhaka (9.4 ± 12.4) compared to Rajshahi (8.5 ± 13.9 pg/mL) district. The average DON level was about 2-fold higher in infant (3.8 ± 2.9, max 6.8 ng/mL) than children urines (1.6 ± 1.8, max 8.6 ng/mL), and higher in Rajshahi (2.1 ± 2.3 ng/mL) than Dhaka (1.4 ± 1.6 ng/mL) district. The biomarker-based estimated average daily DON intake (29.6 ± 108.3 ng/kg bw in infants and 36.4 ± 81.8 ng/kg bw in children) or the maximum exposure (560 ng/kg bw) do not exceed the current maximum provisional tolerable daily intake value of 1 µg/kg bw for DON, although DON exposure in infants and children is higher than that of Bangladeshi adults. The AFM1 urine levels in young children are somewhat lower than those found previously in adult cohorts in Bangladesh, but the frequent detection of this biomarker for AFB1 exposure raises further concerns, also for this vulnerable part of the population. Therefore, continuous surveillance for aflatoxins in Bangladeshi food commodities is clearly required, first to identify major sources of intake and then to reduce exposure.

Mycotoxin Occurrence, Exposure and Health Implications in Infants and Young Children in Sub-Saharan Africa: A Review

Infants and young children (IYC) remain the most vulnerable population group to environmental hazards worldwide, especially in economically developing regions such as sub-Saharan Africa (SSA). As a result, several governmental and non-governmental institutions including health, environmental and food safety networks and researchers have been proactive toward protecting this group. Mycotoxins, toxic secondary fungal metabolites, contribute largely to the health risks of this young population. In SSA, the scenario is worsened by socioeconomic status, poor agricultural and storage practices, and low level of awareness, as well as the non-establishment and lack of enforcement of regulatory limits in the region. Studies have revealed mycotoxin occurrence in breast milk and other weaning foods. Of concern is the early exposure of infants to mycotoxins through transplacental transfer and breast milk as a consequence of maternal exposure, which may result in adverse health effects. The current paper presents an overview of mycotoxin occurrence in foods intended for IYC in SSA. It discusses the imperative evidence of mycotoxin exposure of this population group in SSA, taking into account consumption data and the occurrence of mycotoxins in food, as well as biomonitoring approaches. Additionally, it discusses the health implications associated with IYC exposure to mycotoxins in SSA.

Mycotoxins in Ethiopia: A Review on Prevalence, Economic and Health Impacts

Mycotoxigenic fungi and their toxins are a global concern, causing huge economic and health impacts in developing countries such as Ethiopia, where the mycotoxin control system is inadequate. This work aimed to review the occurrences of agriculturally essential fungi such as Aspergillus, Fusarium, and Penicillium and their major mycotoxins in Ethiopian food/feedstuffs. The incidents of crucial toxins, including aflatoxins (B1, B2, G1, G2, M1), fumonisins (B1, B2), zearalenone, deoxynivalenol, and ochratoxin A, were studied. The impacts of chronic aflatoxin exposure on liver cancer risks, synergy with chronic hepatitis B infection, and possible links with Ethiopian childhood malnutrition were thoroughly examined. In addition, health risks of other potential mycotoxin exposure are also discussed, and the impacts of unsafe level of mycotoxin contaminations on economically essential export products and livestock productions were assessed. Feasible mycotoxin mitigation strategies such as biocontrol methods and binding agents (bentonite) were recommended because they are relatively cheap for low-income farmers and widely available in Ethiopia, respectively. Moreover, Ethiopian mycotoxin regulations, storage practice, adulteration practice, mycotoxin tests, and knowledge gaps among value chain actors were highlighted. Finally, sustained public awareness was suggested, along with technical and human capacity developments in the food control sector.

Biomonitoring of Aflatoxin B1 and Deoxynivalenol in a Rural Pakistan Population Using Ultra-Sensitive LC-MS/MS Method

There are limited data on exposure to mycotoxins in Pakistan. Here, we measured exposure to deoxynivalenol (DON), a common contaminant of wheat, and aflatoxin B1 (AFB1), a known contaminant of rice, using biomarkers of exposure. Wheat (n = 195) and rice (n = 62) samples were analyzed for AFB1 and DON levels, and the corresponding urinary biomarkers were analyzed in urine samples from a rural population (n = 264, aged 4-80 years, male 58%) using ultra-sensitive liquid chromatography-tandem mass spectrometry. AFB1 was detected in 66% of rice (5.04 ± 11.94 µg/kg) and 3% of wheat samples. AFM1 (hydroxylated form of AFB1)was detected in 69% of urine samples, mean 0.023 ± 0.048 ng/mL and DON was detected in 20% of urine samples, mean 0.170 ± 0.129 ng/mL. The maximum probable daily intake for DON derived from the urinary biomarker was 59.8 ng/kg b.w./day, which is below the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives' tolerable daily intake (1000 ng/kg b.w./day). However, for aflatoxin, the derived margin of exposure (MoE) of (13.2) was well below the safe MoE (10,000) suggested by the European Food Safety Authority. The calculated aflatoxin-associated cancer risk of 0.514/105 individuals/year suggests that measures should be taken to reduce the AFB1 contamination in food, particularly rice, in Pakistan.

Mycotoxin exposure and human cancer risk: A systematic review of epidemiological studies

In recent years, there has been an increasing interest in investigating the carcinogenicity of mycotoxins in humans. This systematic review aims to provide an overview of data linking exposure to different mycotoxins with human cancer risk. Publications (2019 and earlier) of case-control or longitudinal cohort studies were identified in PubMed and EMBASE. These articles were then screened by independent reviewers and their quality was assessed according to the Newcastle-Ottawa scale. Animal, cross-sectional, and molecular studies satisfied criteria for exclusion. In total, 14 articles were included: 13 case-control studies and 1 longitudinal cohort study. Included articles focused on associations of mycotoxin exposure with primary liver, breast, and cervical cancer. Overall, a positive association between the consumption of aflatoxin-contaminated foods and primary liver cancer risk was verified. Two case-control studies in Africa investigated the relationship between zearalenone and its metabolites and breast cancer risk, though conflicting results were reported. Two case-control studies investigated the association between hepatocellular carcinoma and fumonisin B1 exposure, but no significant associations were observed. This systematic review incorporates several clear observations of dose-dependent associations between aflatoxins and liver cancer risk, in keeping with IARC Monograph conclusions. Only few human epidemiological studies investigated the associations between mycotoxin exposures and cancer risk. To close this gap, more in-depth research is needed to unravel evidence for other common mycotoxins, such as deoxynivalenol and ochratoxin A. The link between mycotoxin exposures and cancer risk has mainly been established in experimental studies, and needs to be confirmed in human epidemiological studies to support the evidence-based public health strategies.

Dietary mycotoxins exposure and child growth, immune system, morbidity, and mortality: a systematic literature review

The aim of this study was to systematically review associations between dietary mycotoxins exposure and child growth and morbidity of children aged 5 years or younger. Peer-reviewed literature was searched in MEDLINE, EMBASE, COCHRANE, CINAHL, Web of Science, and PsycINFO. Experimental and observational studies were considered. The exposures were dietary mycotoxins during pregnancy, lactation and childhood, and mycotoxins concentrations in the diet, breast milk, urine, and blood. From a total of 4869 references, 86 full-text papers were extracted of which 50 were included in this review. The methodological quality and risk of bias were evaluated and quality of the collective evidence was assessed using GRADE. Uncertainty remains whether mycotoxins exposure affects child growth, immunity and mortality and the overall quality of the evidence is very low. Overall however, we cannot rule out a possible association between dietary mycotoxins, in particular, AF and FUM and child malnutrition. Our analyses were limited by the reporting quality, difference in findings, heterogeneity of outcomes, mycotoxins detection methods, and the observational nature of most studies. Robust study designs with adequate sample size, use of validated biomarkers of exposure and assessment of co-occurrence of mycotoxins and their synergistic effects are required to provide the further evidence regarding a potential effect of dietary mycotoxins exposure on child growth and immunity.

High-performance liquid chromatography and Enzyme-Linked Immunosorbent Assay techniques for detection and quantification of aflatoxin B1 in feed samples: a comparative study

OBJECTIVE

Comparison was done between high-performance liquid chromatography (HPLC) and a competitive enzyme-linked immunosorbent assay (ELISA) for detection and quantification of aflatoxin B₁ (AFB₁) in feed samples. The two procedures were standardized and validated before the actual experiment. Five concentrations (0, 5, 10, 20 and 30 ppb) of feed samples were used for both methods. For the HPLC technique, the samples were extracted in acetonitrile/water (90/10) solution, cleaned-up using solid phase extraction (SPE) column, and derivatized by water/trifluoroacetic acid/glacial acetic acid (35/10/5) solution before instrument analysis. The samples were extracted in 70% methanol for the ELISA technique.

RESULTS

The two tests showed very strong linearity with correlation coefficient value of > 0.99 using standard solutions. The mean recovery rate was 92.42% (with relative standard deviation (RSD) of 5.97) and 75.64% (RSD = 34.88) for HPLC and ELISA, respectively. There was no statistically significant difference in recovery rate between the two methods. There was a positive correlation (r = 0.84) between them which indicated that the two techniques can be used to detect and quantify aflatoxin B₁ in feed samples. However, there were variations among replicates for the ELISA method, which shows that this method is more applicable for screening purposes.

Frequency and levels of aflatoxin M1 in urine of children in Bogota, Colombia

A study was conducted to investigate the frequency and levels of AFM₁ and AFM₂ in urine from children who attended the emergency service of a pediatric referral hospital in Bogota, Colombia. A survey on the consumption of foods likely to be a source of aflatoxins and on sociodemographic variables was conducted as well. The frequency of AFM₁ in urine was found to be 41.7% with an average concentration in positive samples of 16 pg mL^-1 ± 10.7 pg mL^-1 (range > LOD-48.5 pg mL^-1). The presence of AFM₁ in the urine was related to the consumption of cereals likely to be contaminated with AFB₁, especially corn and rice. No detectable levels of AFM₂ were found in any sample. The results show that children's exposure to aflatoxins in Colombia is indeed a problem and should be one of the priorities of the health authorities. Continuous monitoring of aflatoxins in foods should be carried out, in compliance with Colombian regulations, using analytical methods that allow determination and quantification of aflatoxins in different biological and non-biological matrices at trace levels.

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.