Amount Of Aflatoxin Research Articles

Presence of mycotoxins in food: Can we use the data from the EU Rapid Alert System for quantitative risk assessment?

Mycotoxins are natural compounds that may cause various adverse toxicological manifestations in humans and animals. The nature, the severity and scope of their adverse activity are varied and in general, even in small amount they have potent carcinogenic, genotoxic effect and injure the immune system. In order to provide high level of health protection for consumers, the European Union has established strict regulatory limits, whose implementation is enforced.The EC (2001) Commission Regulation sets maximum levels for some mycotoxins in foodstuffs: for aflatoxins, ochratoxin A, patulin, deoxynivalenol, zearalenone, fumonisins, T-2 and HT-2 toxins. Particular product categories are regulated under specific decisions ordaining control of imported consignments at the point of entry. Due to the fact that only aflatoxins are addressed in the specific decisions, they are the mostly detected and notified mycotoxins in the EU Rapid Alert System for Food and Feed (RASFF). The second most frequent group, Ochratoxin A is typically detected during internal EU market controls. Most RASFF notifications concern product categories falling under specific EU decisions, especially the Aflatoxin content of nuts and nut products. Significant amount of aflatoxins can be found also in dried fruits, spices and herbs.The article reviews and analyses the data available in rapid alert system concerning mycotoxins notification, and evaluates the usefulness of this information for risk assessment. The value of RASFF system is unquestionable and it fulfils its intended function included in its name. The system is a significant source of valuable information, but for risk assessment purposes, other additional information is needed. It could be used most effectively for risk assessment, if it was to provide data on the ratio of all/tested/positive lots and if the authorities provided not only the positive results, but also the exact mycotoxins level of every analysed sample.

Aflatoxins and ochratoxins in serum samples of school children

Purpose. The analysis of urine samples of school children had indicated not only a high frequency of detection of aflatoxins during both seasons (rainy and dry), but also high concentration levels of these toxins. This created the impetus to test the sera of the same cohort of school children for the presence of these toxins, which would serve as a further indication of exposure to these carcinogens.Design. Analysis of the presence and quantity of aflatoxins and ochratoxins in serum samples of children from a single school.Results. The serum samples contained 57% aflatoxins and 19% ochratoxin A. Boys had a higher exposure rate than girls, as well as a higher concentration level of toxins, in some instances. However, these differences were not significant. The exposure rates and levels according to the age of these children were also not significant.Conclusions. Even though the exposure rates to aflatoxins and ochratoxin A were low compared with urine data from these children, the presence of these mycotoxins in sera is still a cause for concern.

Aspergillus Section Flavi and aflatoxins in dusts generated by agricultural processing facilities in the Philippines

AbstractRelatively few data exist regarding concentrations of aflatoxins and their causative organisms in dusts within occupational environments. Here, we examined Aspergillus Section Flavi populations and aflatoxin levels in 54 samples of dusts generated by agricultural processing facilities as possible indicators of aflatoxin exposure in the Philippines. The average incidence of Aspergillus Section Flavi expressed as a percentage of total mould populations in rice dust, corn dust, feed dust and copra dust were 8, 4, 31 and 10%, respectively. Predominant aflatoxigenic fungi isolated were Aspergillus flavus and A. parasiticus with ratios of 31:1, 40:5, 16:4 and 1:1 in rice dust, corn dust, feed dust and copra dust, respectively. Aflatoxins produced by selected isolates in in vitro rice culture ranged from 100 µg kg−1 to 100.5 mg kg−1. Toxigenicity of isolates based on the average aflatoxin concentrations produced by positive isolates were in the order of copra dust > corn dust > rice dust > feed dust. Average natural concentrations of aflatoxins in rice dust, corn dust, feed dust, and copra dust were 25, 6, 15 and 10 µg kg−1, respectively. Estimates of the amount of inhaled aflatoxins by workers in an 8‐h work shift ranged from 0.06 to 114 ng, the average of which is higher than the amount of aflatoxins ingested by Filipinos due to the consumption of polished rice. The presence of highly toxigenic Aspergillus Section Flavi and aflatoxins in agricultural dust is a critical health risk for workers, considering the frequency of exposure and the possibility of inhalation and subsequent absorption of aflatoxins in the respiratory tract. Copyright © 2006 Society of Chemical Industry

Spatial Relationships of Soil Texture and Crop Rotation to Aspergillus flavus Community Structure in South Texas

ABSTRACT Aspergillus flavus, the causal agent of aflatoxin contamination of cottonseed, is a natural inhabitant of soils. A. flavus can be divided into the S and L strains, of which the S-strain isolates, on average, produce greater quantities of aflatoxins than the L-strain isolates. Aflatoxin contamination can be severe in several crops in South Texas. The structure of A. flavus communities residing in soils of South Texas was determined from 326 soil samples collected from 152 fields located from the Rio Grande Valley in the south to Fort Bend County in the north from 2001 through 2003. Analysis of variance indicated significant differences in the incidence of A. flavus isolates belonging to the S strain (percent S) among regions. The Coastal Bend (30.7%) and Upper Coast (25.5%) regions had significantly higher percent S incidence than the Rio Grande Valley (4.8%). No significant differences in percent S among years were detected. The CFU per gram of soil were not significantly different among regions. Strain S incidence was positively correlated with clay content and negatively correlated with sand content. Fields cropped to cotton the previous year had a higher S-strain incidence, whereas fields cropped to corn had greater total quantities of A. flavus propagules. Maps of S-strain patterns show that the S strain constitutes >30% of the overall A. flavus community in the area extending from the central Coastal Bend region to the central Upper Coast region. The west Rio Grande Valley had the lowest S-strain incidence (<10%). Geographic variation in S-strain incidence may influence the distribution of aflatoxin contamination in South Texas.

Aflatoxins, patulin and ergosterol contents of dried figs in Turkey

Dried figs of three different categories, palatable, fluorescent, and cull, were investigated for their contents of aflatoxins (B1, B2, G1 and G2), patulin, and ergosterol. Samples were obtained from four fig processing plants located in a major fig producing area in the Aegean Region in Turkey. Affinity column clean-up methods were employed for aflatoxins. All aflatoxins, patulin, and ergosterol were determined using high performance liquid chromatography. Palatable figs contaminated with trace amounts of aflatoxins, patulin, and ergosterol, so they posed no risk for the consumer when national and/or international regulatory limits were considered. Fluorescent figs were contaminated with high (117.9–471.9 ppb) aflatoxin levels and cull figs with high patulin (39.3–151.6 ppb) and ergosterol (4.5–18 ppm) levels. The total aflatoxins content was significantly correlated with the patulin content (r 2 = 0.813, p < 0.002) and the ergosterol content (r 2 = 0.920, p < 0.002) only in fluorescent figs. However there was no significant correlation between patulin and ergosterol contents of fluorescent figs. Furthermore, there were no significant correlations between the contents of any two of the three substances in cull figs. This is the first report on the presence of patulin and its co-occurrence with aflatoxin in dried figs.

Aflatoxins and aflatoxigenic fungi in rice and its byproducts

This report gives a retrospective of studies done on aflatoxins and aflatoxigenic fungi in rice and its by-products. Previous studies on rice employed analytical methods with detection limits ranging from 0 .1 to 5μg/kg, which could mean that lower levels were overlooked, thus, underestimating the actual incidence of aflatoxins in the commodity. Aflatoxin production in rice is relatively minimal. However, high aflatoxin levels have been found in samples from some countries in Asia and Africa, which can be attributable to inadequate postharvest system. Incidence of aflatoxins in more than 2800 samples of rice and its products surveyed all over the world appears to have increased from 7% in the 70s to about 31% from 2000 onwards. Levels of AFB1 and total AF in samples analyzed were mostly beyond European Union regulatory limits; some even have levels above 20μg/kg, the amount of aflatoxins allowed in foods by Codex Alimentarius. Incidence of aflatoxigenic species, particularly A. flavus and A. parasiticus, in rice and its by-products appears to be concentrated in the tropical and subtropical regions, where prevailing environmental conditions are conducive to their growth. Due to increasing stringency of regulatory limits, there is a need to develop more sensitive methods that can detect the lower levels of aflatoxins found in rice and its by-products and ascertain the extent of contamination in these commodities. In order to regulate these commodities, continued monitoring is necessary to provide data that can serve as basis for exposure assessment studies. Other urgent areas for research are those of improved and integrated approaches to control aflatoxins and aflatoxigenic fungi at all stages of production and marketing.

Aflatoxins in stored maize and rice grains in Liaoning Province, China

Aflatoxin contamination and its relationship to storage length in stored maize and rice in Liaoning Province, northeastern China, was investigated. Aflatoxins in 110 samples collected from an area of 14.68 million km 2 covering storage length from 1 yr to over 10 yr were determined by high-performance liquid chromatography with fluorescence detection. The results showed that almost all samples collected contained aflatoxins. The average contents in maize, whole grain rice and brown rice were found to be 0.99, 3.87 and 0.88 μg kg −1, respectively. Three-fourths of the total aflatoxins in whole grain rice (3.87 μg kg −1) could be removed by dehusking to as low as 0.88 μg kg −1 in brown rice. No significant aflatoxin increase was observed in whole grain rice and brown rice over a 10-yr storage period. In maize, the amount of aflatoxins was significantly higher in 2-yr than 1-yr sample. Aflatoxin G 1 was detected as the major type of aflatoxin in over 40% of all stored grain samples tested and over 92% of rice samples examined. The aflatoxin content in maize and rice is much lower than the regulated maximum amount allowed in foodstuffs in China and other countries. We concluded that these grains are safe for human and livestock consumption and for trading.

Distribution of aflatoxins between extract and extraction residue of paprika using supercritical carbon dioxide

Paprika powder, naturally contaminated with aflatoxins, was extracted by supercritical carbon dioxide at standard conditions (300 bar and 50 degrees C). A lipophilic top phase and an aqueous base phase were obtained. These and the extraction residue were analysed by HPLC for aflatoxins. The main quantity of aflatoxins, about 60% of aflatoxin B1 and about 70% of aflatoxin B2 related to the original paprika powder, was found to be located in the extraction residue. This confirms the results of previous studies with other spices and demonstrates that the use for flavouring purposes of supercritical carbon dioxide extracts, rather than natural spice, offers potential application in reducing aflatoxin levels in spiced foods.

Liver Cancer and Aflatoxin: New Information from the Kenyan Outbreak

Millions of people are exposed to aflatoxins, toxic compounds produced by Aspergillus molds. These molds infest staple crops such as maize, peanuts, rice, and wheat throughout the world. Outbreaks of aflatoxicosis affecting up to several hundred people at a time have occurred sporadically, most recently in eastern Kenya in early 2004. An investigation of the Kenyan outbreak now yields new information on the risk factors associated with acute aflatoxin poisoning [EHP 113:1779–1783]. Chronic low-level exposure to aflatoxins, particularly aflatoxin B1, is associated with increased risk of developing liver cancer, impaired immune function, and malnutrition. Acute high-level exposure, which is less common, causes early symptoms of diminished appetite, malaise, and low fever. Later symptoms, including vomiting, abdominal pain, and hepatitis, signal potentially fatal liver failure. The Kenyan outbreak followed a poor harvest of maize that had been damaged and made susceptible to mold by drought. Furthermore, to guard against theft of the meager harvest, people stored the maize in their homes, which were warmer and moister than the granaries where it was usually stored. From January to June 2004, 317 people sought hospital treatment for symptoms of liver failure, and 125 died. Health officials ruled out viral liver diseases; suspecting acute aflatoxin poisoning, they examined maize samples and found aflatoxin B1 concentrations as high as 4,400 parts per billion (ppb), 220 times the Kenyan limit for food. Researchers conducted a case–control study using records for 40 patients (cases) who had been hospitalized with acute jaundice during late May and early June and 80 randomly selected controls. Jaundice is a nonspecific symptom of liver damage. Participants or family members completed questionnaires targeting maize quality, storage, preparation, and consumption. The researchers collected 1-kilogram samples of maize from households that still had grain left over from the time of the outbreak for measurement of aflatoxin concentrations. Blood samples from 29 patients and 62 controls were analyzed for concentrations of aflatoxin B1–lysine albumin adduct, a marker of aflatoxin exposure. The researchers also tested blood from 18 patients and 54 controls for hepatitis B surface antigen, an indicator of hepatitis B infection. In people with chronic low-level aflatoxin exposure, this virus enhances the risk of developing liver cancer. Maize from patients’ homes contained significantly higher amounts of aflatoxin (with a geometric mean of 354.5 ppb) compared to control households (with a geometric mean of 44.1 ppb). Patients’ serum aflatoxin adduct concentrations, which were comparable to those measured in previous outbreaks, were nearly 10 times higher than those of controls. Further, patients who died had higher blood levels of adducts than those who survived. Forty-four percent of the patients tested positive for hepatitis B, compared to 7% of controls. These analyses, with their greater level of detail, are the first to quantify the association between concentrations of aflatoxin in food, exposure history, concentrations of serum aflatoxin adducts, and acute aflatoxin poisoning. This study is also the first to quantify the independent association between hepatitis B infection and the effects of acute aflatoxin poisoning. The researchers suggest that monitoring both aflatoxin concentrations in crops and the incidence of acute jaundice could permit earlier recognition of food contamination and help prevent an outbreak from becoming widespread. Further, they suggest that future use of blood tests for aflatoxin B1–lysine albumin adducts could serve to diagnose aflatoxin poisoning and to gauge the success of measures for reducing aflatoxin exposure.

Aflatoxin levels in maize and maize products during the 2004 food poisoning outbreak in eastern province of Kenya

On 10th May, 2004 food samples suspected to have caused acute poisoning in Makueni district were received at the National Public Health Laboratory Services (NPHLS). On analysis, they were found to be highly contaminated with aflatoxin B1. More cases of poisoning were reported in the district and in neighbouring districts of Kitui, Machakos and Thika. As at 20th July, 2004 the Ministry of Health was aware of 317 cases of which 125 resulted in deaths. To assess the magnitude of aflatoxin contamination of maize and maize products in the affected areas. Random environmental sampling of maize and maize products and case/control samples of the same in the affected regions and subsequent determination of aflatoxin levels using immunoaffinity coupled with solution fluorometry. National Public Health Laboratory Services, Ministry of Health, Kenya, from May to August, 2004. A total of 480 samples comprising 362 random environmental samples, 26 cases and 92 controls were collected and analysed. The foods analysed included maize grains, maize flour and dehulled dry maize, traditionally known as muthokoi. Forty six point four per cent of the environmental samples, 15% of cases and 29.3% of controls were within the maximum permissible limit of 20 microg implying that over 50% (54.4) of the total did not comply and would be regarded as unfit for human consumption. 6.9% of the environmental samples, 57.7% of cases and 21.7 of controls had levels beyond 1000 microg/Kg. The amount of aflatoxin observed in the food samples had a range of 0-58,000 microg/Kg. The population in the affected region was exposed to high levels of aflatoxin. There is need to address the issue of pre and post harvest handling of grain and establishing monitoring and surveillance for early detection and intervention.

The determination of aflatoxins in spices by immunoaffinity column extraction using HPLC

SummarySeventy‐five samples of different spices marketed in Turkey were purchased from bazaars, herbal shops and supermarkets. Equal amounts of paprika, chilli, black peppers and cumin were purchased and used to test and compare the amount of aflatoxin contamination. Two different analytical methods were examined for their efficacy by adding a known amount of aflatoxin to the blank samples of paprika. Twenty‐seven paprika, all the chilli powder and four ground black pepper samples were contaminated with aflatoxin B1 in the range of 0.5–116.4, 1.6–80.4 and 0.3–1.2 μg kg−1 respectively. Twenty‐three (30%) paprika and chilli powder samples were above the regulatory limits used in the European Union. No aflatoxin contamination was detected in the cumin samples at a detection limit of 0.2 μg kg−1.

The aflatoxin contamination of some pepper types sold in Turkey

In the present study, 44 red-scaled pepper and 26 red powder pepper samples obtained from various spice retailers in Erzurum, and 20 isot (red pepper produced in Sanliurfa) were investigated for aflatoxin contamination using thin layer chromatography. Aflatoxin (B + G) was found in 8 red pepper samples (18.2%), and 3 red powder peppers (10.7%), and 1 isot sample (5%). The aflatoxin amount ranged from 1.1 to 97.5 ppb in all samples investigated. The highest amount of aflatoxin was found in red-scaled pepper. Species of Aspergillus, Penicillium and Rhizopus were generally contaminants of all samples.

Substrate suitability of different genotypes of sorghum in relation to Aspergillus infection and aflatoxin production.

Grain sorghum is often damaged by rain in the field and severely infected by grain mold, which includes Aspergillus infection and aflatoxin production. The objective of the study is to investigate the extent of aflatoxin production with Aspergillus infection in vitro in different sorghum genotypes with different pericarps, red, yellow, and white, the physical and chemical characteristics of grain during infection, and the changes in grain polyphenols and phytic acid in comparison to maize and groundnut. The physical characters and biochemical composition of sorghum grain contribute to make it less susceptible to Aspergillus infection and aflatoxin contamination compared to maize and groundnut. The lowest amounts of aflatoxin and ergosterol were observed in genotypes with red pericarp, whereas higher amounts of aflatoxin and ergosterol were found in white genotypes followed by maize and groundnut. All of the red genotypes differ in polyphenol composition and aflatoxin produced, showing resistance to mold damage. Another indication of resistance in red genotypes was the delayed peaking of aflatoxin production (9 days after infection). In red sorghum genotypes there was a significant, positive correlation existing between polyphenol content and aflatoxin produced at 3 and 6 days after infection, the r values being 0.589 and 0.513, respectively. The starch content decreased whereas the protein content in all sorghum genotypes increased during infection. Maximum phytic acid was observed in white sorghum genotypes. Phytic acid in yellow genotypes was found to have a significant negative correlation (r = -0.569) with aflatoxin produced.

Determination of Aflatoxin B 1 in Highly Contaminated Peanut Samples Using HPLC and ELISA

The precision, accuracy, detection limit and peanut matrix influence of an ELISA were analysed in the determination of aflatoxin B 1 . The assay was performed on two different reference samples: peanut extract and peanut paste, that were spiked with known amounts of aflatoxins. The lower detectable level was 0.5 w g kg -1 . The average intra-assay precision expressed as coefficient of variation (CV) was 11.7% for concentrations between 2.54 and 901 w g kg -1 and the average inter-assay precision was 29.7% for the same range of concentrations. The average accuracy measured by a recovery assay in samples that contained only aflatoxin B 1 was 107%. The correlation between the ELISA and high-performance liquid chromatography (HPLC) applied to 28 peanut samples artificially contaminated with Aspergillus flavus and A. parasiticus spores showed a high correlation ( r = 0.977, P < 0.0001). The detection limits and matrix influence associated with our ELISA procedure were more sensitive than those reported for other ELISA procedures due to specific antiserum treatment.

Aspergillus flavus and Aflatoxin Contamination of Leguminous Trees of the Sonoran Desert in Arizona

ABSTRACT Aspergillus spp. in section Flavi were frequently associated with desert tree legumes in uncultivated areas of the Sonoran Desert. Of 270 samples of debris and fruits of mesquite (Prosopis spp.), ironwood (Olneya tesota), acacia (Acacia spp.), and palo verde (Cercidium and Parkinsonia spp.), 87% were positive for A. flavus (S and L strains) and A. tamarii. A. flavus was the most common species (87%) among the 3,763 isolates examined. Mesquite pods were both the substrate from which A. flavus was recovered most frequently and the substrate from native habitats with the greatest aflatoxin content. In vitro, most desert legumes supported significant growth, reproduction, and aflatoxin production by A. flavus, with mesquite pods yielding 1 x 10(10) propagules/g and 5,000 mug/kg of aflatoxin B(1). Twenty percent of legume pods collected in the desert contained measurable quantities of aflatoxin, ranging from 1 to >2,500 mug/kg. Insect-damaged mesquite pods had significantly higher aflatoxin than intact pods. Legumes are apparently important reservoirs of aflatoxin-producing fungi and significant sources of aflatoxin contamination in the native Sonoran Desert habitats of Arizona.

Surface binding of aflatoxin B(1) by lactic acid bacteria.

Specific lactic acid bacterial strains remove toxins from liquid media by physical binding. The stability of the aflatoxin B(1) complexes formed with 12 bacterial strains in both viable and nonviable (heat- or acid-treated) forms was assessed by repetitive aqueous extraction. By the fifth extraction, up to 71% of the total aflatoxin B(1) remained bound. Nonviable bacteria retained the highest amount of aflatoxin B(1). Lactobacillus rhamnosus strain GG (ATCC 53103) and L. rhamnosus strain LC-705 (DSM 7061) removed aflatoxin B(1) from solution most efficiently and were selected for further study. The accessibility of bound aflatoxin B(1) to an antibody in an indirect competitive inhibition enzyme-linked immunosorbent assay suggests that surface components of these bacteria are involved in binding. Further evidence is the recovery of around 90% of the bound aflatoxin from the bacteria by solvent extraction. Autoclaving and sonication did not release any detectable aflatoxin B(1). Variation in temperature (4 to 37 degrees C) and pH (2 to 10) did not have any significant effect on the amount of aflatoxin B(1) released. Binding of aflatoxin B(1) appears to be predominantly extracellular for viable and heat-treated bacteria. Acid treatment may permit intracellular binding. In all cases, binding is of a reversible nature, but the stability of the complexes formed depends on strain, treatment, and environmental conditions.

Incidence of mycoflora and mycotoxins in some edible fruits and seeds of forest origin

Twelve fungi namelyAlternaria alternata, Aspergillus flavus, A niger, A ochraceus, Actinomucor repens, Capnodoium spp., Curvularia lunata, Fusarium pallidoroseum, F solani, F verticillioides, Penicillium citrinum and Rhizopus stolonifer were recorded from samples ofAegle marmelos, Aesculus indica, Buchanania lanzan andPinus gerardiana. In case ofPrunus amygdalus only Rstolonifer was recorded. A significant variation in pattern of mycoflora incidence was observed in terms of source and season. Fungal infestation in most of the substrates was found to be highest during monsoon. Aflatoxins were the most common mycotoxins elaborated by different isolates ofA flavus obtained fromA marmelos, B lanzan andP gerardiana. The amount of aflatoxins produced by the toxigenic isolates ofA flavus was in the range of traces to 0.9-26.0 μg/ml inA marmelos, 0.8-17.5 μg/ml inP gerardiana and 0.65-13.2 μg/ml inB lanzan. The percentage toxigenicity was comparatively lower in the isolates of other mycotoxigenic fungi. Aflatoxins were detected almost in all the samples analyzed for mycotoxin contamination. However, traces of zearalenone were detected inA marmelos. The concentration of aflatoxin B1 was in the range of 0.13-0.75 μg/g inA marmelos, 0.09-0.60 μg/g inP gerardiana and 0.01-0.20 ug/g inB lanzan. Mycotoxins were not detected inAesculus indica andPrunus amygdalus.

Growth and aflatoxin production ofaspergillus flavus on some spices marketed in Turkey.

Growth and aflatoxin production byAspergillus flavus (MAM-268 C17, TNS=98) on autoclaved coconut, black pepper, crushed red pepper, red pepper powder were studied. Coconut were found to be a better substrate for fungal growth, as well as aflatoxin production. Red pepper powder could be considered as a poor substrate for fungal growth. The amount of aflatoxin found in crushed red pepper under laboratory conditions is much less compared with coconut, black pepper and red pepper powder.

A survey of ethnic foods for microbial quality and content aflatoxin

A range of ethnic foods was examined for their microbiological content in relation to total viable counts (TVC) of aerobic bacteria, counts of presumptive coliforms, yeast and mould counts; presence of Salmonella spp., Listeria monocytogenes, Escherichia coli 0157:H7 and Campylobacter spp.; total enumeration of Clostridium perfringens, Staphylococcus aureus and Bacillus spp.; identification of moulds and the presence of total aflatoxins. Samples, which included cereals, nuts, dried fruits, herbs and spices, were obtained from local retail outlets and distributors. It was established that three samples of pistachio nuts contained significant levels of aflatoxins. The concentration of total aflatoxins in these three nut samples ranged from 15 to 259 µg/kg of sample. Only two other samples contained trace amounts of aflatoxins, all other samples analysed were found to be free of any detectable level of aflatoxins. TVCs, coliform counts and yeast and mould counts varied widely depending on the matrix tested. Generally, rice, wheat and peanuts produced low counts whereas other nuts, gram flour and spices produced much higher counts. Cl. perfringens, Staph. aureus, and Bacillus spp. were common in spices, nuts and gram flour, however, Listeria monocytogenes was only detected in four samples and in no sample could Salmonella spp, E. coli 0157:H7 or Campylobacter spp. be detected.

Seasonal variation in exposure frequency and concentration levels of aflatoxins and ochratoxins in urine samples of boys and girls.

Urine samples from children in Sierra Leone (134 boys and 110 girls), were collected during the dry season. During the rainy season samples were collected from 97 boys and 93 girls. Analysis of the dry season samples, revealed that, with the exception of one boy, all children had detectable amounts of aflatoxins and/or ochratoxins in their urine. Similarly, with the exception of four children (two from each sex), rainy season urine samples also contained these two mycotoxins. There were significant differences in the frequency of exposure to some mycotoxins: ochratoxin A (OTA), p < 0.01; 4-hydroxyochratoxin A (4R-OTA), p < 0.002; aflatoxin M1 (AFM 1), p < 0.04; aflatoxicol (AFL), p < 0.03; aflatoxin B2 (AFB2), p < 0.04. There were also significant differences in the levels of aflatoxin B1 (AFB1), (p < 0.05) and AFB2, (p < 0.02) detected in dry season samples. Stratification of these results according to season and sex, has indicated significant differences with respect to 4R-OTA (p < 0.04) and AFB1 (p < 0.02). The results of this study show that in Sierra Leone, children are frequently and constantly exposed to both aflatoxins and ochratoxins.