Investigations into the presence of aflatoxins in human body fluids and tissues in relation to child health in the tropics

Research update on aflatoxins toxicity, metabolism, distribution, and detection: A concise overview

Serious health risks associated with the consumption of food products contaminated with aflatoxins (AFs) are worldwide recognized and depend predominantly on consumed AF concentration by diet. A low concentration of aflatoxins in cereals and related food commodities is unavoidable, especially in subtropic and tropic regions. Accordingly, risk assessment guidelines established by regulatory bodies in different countries help in the prevention of aflatoxin intoxication and the protection of public health. By assessing the maximal levels of aflatoxins in food products which are a potential risk to human health, it's possible to establish appropriate risk management strategies. Regarding, a few factors are crucial for making a rational risk management decision, such as toxicological profile, adequate information concerning the exposure duration, availability of routine and some novel analytical techniques, socioeconomic factors, food intake patterns, and maximal allowed levels of each aflatoxin in different food products which may be varied between countries.

Occurrence of Aflatoxin M1 in cow milk in El Salvador: Results from a two-year survey

Aflatoxin M₁ (AFM₁) is a metabolite of Aflatoxin B₁ (AFB₁) and is excreted through cow´s milk. AFM₁ contamination of milk is extended geographically and there might be seasons-related variations for both prevalence and contents, with higher than average values in regions with long periods of drought like El Salvador. Therefore, this project quantified AFM₁ levels in raw cow milk and AFs in cattle feedstuffs, during the transitional dry-rainy seasons of two consecutive years and it determined the variation of occurrence and contents associated to drought. Significant variations were shown from year to year in the prevalence of contamination (30% vs. 20%) and in the average levels of AFM₁ in milk (0.056 vs 0.039 μg/kg), associated with drought and increased temperature. The AFs median levels raised significantly with the drought period (from 22.5 to 10.3 μg/kg). A significant relationship was demonstrated between AFs levels and those of AFM₁, both in the year with drought and without that condition. AFM₁ positive cases and its levels in milk increase in drought and hot conditions, AFs levels in the cattle feed tend to be higher with the same, as well. Both relationship between AFs and AFM₁ levels and their association with drought were demonstrated. So that, heat and drought stress conditions can evoke raising effects on both Aflatoxins level and occurrence due to AFM₁ in milk is a carryover from AFs contaminated feedstuffs ingested by dairy cows.

Assessment of Aflatoxin M1 and M2 exposure risk through Oaxaca cheese consumption in southeastern Mexico

The present study evaluated the exposure of Southeast Mexican population to Aflatoxin M1 (AFM1) and M2 (AFM2) through the consumption of Oaxaca cheese. The intake of Oaxaca cheese was assessed via a food 7-day dairy questionnaire (N = 1100, 2014 and 2015). Thirty Oaxaca cheeses were randomly sampled, and the origin of the samples was also investigated. AFM1 and AFM2 were quantified by HPLC-FD. The exposure was assessed through the combination of the Probabilistic Density Functions (probabilistic approach). The percentage of the population at risk was calculated through the population exceeding the toxicological reference values (TDI). The risk assessment revealed that the population at higher risk to AFM1 and AFM2 was the children, followed by the adolescents and adult women. To our knowledge, the present study is the first to assess the exposure risk of different age groups of a population to AFM1 and AFM2 through the consumption of cheese.

Characterisation of aflatoxin and deoxynivalenol exposure among pregnant Egyptian women

Mycotoxins such as the aflatoxins and deoxynivalenol (DON) are frequent contaminants of food. Aflatoxin B1 (AFB1) and DON affect the immune system and restrict growth; additionally AFB1 is carcinogenic. To date there are limited descriptive biomarker data concerning maternal exposures during pregnancy, and none on co-exposures to these mycotoxins. This survey was a cross-sectional assessment providing descriptive data on the concentrations of serum aflatoxin-albumin (AF-alb), urinary aflatoxin M1 (AFM1), and urinary DON for 98 pregnant women from Egypt, in relation to diet and socioeconomic status, during the third trimester. AF-alb was detected in 34 of 98 (35%) samples, geometric mean (GM) of positives = 4.9 pg AF-lys mg(-1) albumin (95% confidence interval (CI) = 4.1-5.8 pg mg(-1)), and AFM1 in 44 of 93 (48%) samples, GM of positives = 19.7 pg mg(-1) creatinine (95%CI = 14.8-26.3 pg mg(-1)). AF-alb and AFM1 levels were positively correlated (R = 0.276, p = 0.007). DON was detected in 63 of 93 (68%), GM of positives = 2.8 ng mg(-1) (95%CI = 2.1-3.6 ng mg(-1)). Aflatoxin and DON biomarkers were observed in 41% of the subjects concurrently. The frequency and level of these biomarkers in Egyptian women were modest compared with known high-risk countries. However, this study represents the first biomarker survey to report on the occurrence of DON biomarkers in an African population, in addition to the co-occurrence of these two potent mycotoxins. This combined exposure may be of particular concern during pregnancy given the potential of toxin transfer to the foetus.

Mycotoxins and child health: the need for health risk assessment

The occurrences of mycotoxins as food contaminants in different localities particularly in developing countries and the inevitable exposure of populations and children to these toxins with probable adverse outcomes need be scientifically and systematically assessed. Health risk assessment developed in the 1980s is separate from risk management, both with risk communication form the risk analysis framework adopted by the World Health Organization. The process contributes increasingly to policy development, public health decision making, the establishment of mycotoxin regulations and research planning. However, the exercise of the risk assessment structured approach is not simple and is faced up to lack of data, capable infrastructure facilities and need for trained personnel and resources. Furthermore, adopted methodologies need be developed focusing on child characteristics and health concerns.