Aflatoxin M1 in raw, pasteurized and UHT milk marketed in Iran

Review, meta-analysis and carcinogenic risk assessment of aflatoxin M1 in different types of milks in Iran

REVIEWS

Despite in recent decades, several studies on the concentration of aflatoxins M1(AFM1) in various milks have been studied, as we know, no systematic review, meta-analysis and carcinogenic risk assessment study was conducted in Iran till now.

OBJECTIVES

In this study, a systematic review was conducted to collect, meta-analysis and carcinogenic risk assessment of the quantitative data regarding the prevalence and concentration of AFM1 in several types of milk produced in Iran.

CONTENT

In our study, the concentration and prevalence of AFM1 in different types of milk (Raw, pasteurized, and UHT) from 113 original articles in Iran using searching the Web of Science, PubMed, Scopus, Science Direct and Google Scholar (in Persian and English) databases from 2002 to august 2021 were collected. The concentration of AFM1 was meta-analyzed using the random effect model (REM) based on type of milk (raw, pasteurized and UHT) subgroups and Monte Carlo simulation (MCS) approach was used to assess safety risks and investigate carcinogenic effects of AFM1 using Crystal-Ball software (Version 11.1.3, Oracle, Inc., USA).

SUMMARY AND OUTLOOK

The 113 original article (In English and Persian) were included in this review. Meta-analysis indicated lower and upper of AFM1 in subgroups of raw, pasteurized and UHT milk in Iran was 9, 720, 2.7, 230.2, 19.23, and 221.6 ng/kg respectively. The Point estimate for carcinogenic risk of AFM1 showed as result of age increasing, the carcinogenic risk of Aflatoxin M 1 decreases and concentration of Aflatoxin M1 (ng/liter), plays the most effective role in carcinogenic risk of AFM1.

CONCLUSION

The presence of AFM1 in milk and its products due to its high toxicity and carcinogenic properties is a public health concern that the results show that the risk of carcinogenesis is higher at younger ages (less than 20 years). As a result, there is a strong association between consumption of raw milk, pasteurized milk and UHT and the risk of cancer in children and adults in Iran.

The occurrence of aflatoxin M1 in milk samples of Iran: a systematic review and meta-analysis

In this study, the average level of aflatoxin M1 in various types of milk from 107 articles (297 studies with 16,274 milk samples) were meta-analyzed using random-effect model based on the milk varieties (animal species and heating processes), geographical regions, seasons, detection techniques and dairy farming subgroups. Studies on milk contamination with aflatoxin M1 in Iran were collected using universal and Persian databanks from January 1974 to the end of November 2021. The overall aflatoxin M1 mean concentration and prevalence in milk samples of Iran were 39.65 ng/l (95% CI: 36.00-43.30) and 80% (95% CI: 76-85%), respectively. The rank order of importance of various variables in mean levels of aflatoxin M1 in milk samples included milk type (animal species) > geographical regions > detection techniques > dairy farming types > milk types (heating processes) > seasons. Findings revealed that the overall content of aflatoxin M1 in milk samples of Iran was lower than that allowed by the European Union, Institute of Standards and Industrial Research of Iran, and the USA, possibly due to the milk monitoring by the Iranian regulatory systems.

Occurrence of Aflatoxin M1 in Cow, Goat, Buffalo, Camel, and Yak Milk in China in 2016

In this present study, 195 cow milk, 100 goat milk, 50 buffalo milk, 50 camel milk, and 50 yak milk samples were collected in China in May and October 2016. The presence of aflatoxin M1 (AFM1) was determined using enzyme-linked immunosorbent assay method. For all cow milk samples, 128 samples (65.7%) contained AFM1 in concentrations ranging from 0.005 to 0.191 µg/L, and 6 samples (3.1%) from Sichuan province in October were contaminated with AFM1 above 0.05 µg/L (EU limit). For all goat milk samples, 76.0% of samples contained AFM1 in concentrations ranging from 0.005 to 0.135 µg/L, and 9 samples (9.0%) from Shanxi province in October were contaminated with AFM1 above 0.05 µg/L. For all buffalo milk samples, 24 samples (48.0%) contained AFM1 in concentrations ranging from 0.005 to 0.089 µg/L, and 2 samples collected in October were contaminated with AFM1 above 0.05 µg/L. Furthermore, 28.0% of samples contained AFM1 in concentrations ranging from 0.005 to 0.007 µg/L in camel milk samples, and 18.0% of samples contained AFM1 in concentrations ranging from 0.005 to 0.007 µg/L in yak milk samples. Our survey study has expanded the current knowledge of the occurrence of AFM1 in milk from five dairy species in China, in particular the minor dairy species.

Health risk assessment of aflatoxin M1 in infant formula milk in IR Iran

In this study, two accurate, precise, selective and sensitive methods were developed for determining aflatoxin M1 (AFM1) in infant formula milk using immunoaffinity column clean-up followed by high performance liquid chromatography (HPLC) with fluorescence detection. The validated methods were used for determination of AFM1 in 29 samples of 6 different infant formula milk brands and the risk of AFM1 in infants aged zero to 6 months old was assessed using cancer risk, Margin of Exposure (MOE) and Hazard Index (HI). Only one sample (3.4%) was contaminated with AFM1. Although the results showed that MOE values for the mean and median exposure to AFM1 was <10,000 in infants, the additional cancer risk due to mean and median exposure to AFM1 in infant <6 months were 0.00010 and 0.00012 additional cases per year per 10⁵ individuals, respectively, which indicates no health concern. In addition, HI values for the mean and median exposure to AFM1 for infants were quite below one which indicates no health concern. To the best of our knowledge, this is the first report on risk assessment of AFM1 in infant formula milk consumed by Iranian infants <6 months old, presenting a low risk for the evaluated groups.