Aflatoxin in milk raises safety concerns


Of the over 6,400 samples collected from 1,100 towns/cities in India, 93% were found to be safe. But 5.7% had aflatoxin M1 residues beyond the permissible limit. The highest levels of aflatoxin M1 residue in milk were seen in three States — Tamil Nadu, Delhi and Kerala. International Agency for Research on Cancer (IARC) has classified aflatoxin M1 as “possibly carcinogenic to humans”.

The most comprehensive and representative milk safety and quality survey undertaken on 6,432 samples collected between May and October last year has demolished the common perception of large-scale adulteration of milk in India. The samples were picked from over 1,100 town/cities with over 50,000 population.

The survey carried out by an independent agency at the behest of the Food Safety and Standards Authority of India (FSSAI) found 93% of the samples were absolutely safe for consumption. The samples were tested for the presence of 13 common adulterants and three contaminants — pesticides, aflatoxin M1 and antibiotics.

In all, only 12 adulterated samples were found to be unsafe for human consumption. The adulterated samples were subjected to confirmatory tests to be doubly sure of the true status of the samples. The adulterated samples were from just three States — Telangana (nine), Madhya Pradesh (two) and Kerala (one).

Aflatoxin M1 present in 368 samples

The survey claims that quantitative analysis of all adulterated samples carried out showed that the amount of adulterants and contaminants in the dozen milk samples was not high and hence “unlikely to pose serious threat” to human health. However, the survey did find 368 samples (5.7%) had aflatoxin M1 residues beyond the permissible limit of 0.5 microgram per kilogram. Compared with aflatoxin M1, antibiotics was seen above the permissible level in only 77 samples, and these were in samples taken from Madhya Pradesh, Maharashtra and Uttar Pradesh.

Aflatoxin M1 health concerns

At 227, aflatoxin M1 was more widely present in processed milk samples than in raw milk (141). This is the first time that presence of aflatoxin M1 in milk has been assessed. According to the FSSAI, the presence of aflatoxin M1 in milk is from feed and fodder, which is not regulated. The highest levels of aflatoxin M1 residue in milk were seen in three States — Tamil Nadu (88 out of 551 samples), Delhi (38 out of 262 samples) and Kerala (37 out of 187 samples).

According to the International Agency for Research on Cancer (IARC) aflatoxin M1 has been classified as “possibly carcinogenic to humans”. Its carcinogenic potency is estimated to be about one-tenth of aflatoxin B1. Since the current survey has limited itself to milk, it is not clear how widespread aflatoxin M1 contamination is in milk products such as cheese and hence the total exposure to it. Aflatoxin M1 in milk and milk products is a public health concern especially in the case of infants and young children.

According to the World Health Organisation, human exposure to aflatoxin M1 in milk and milk products is especially high in areas where the quality of grains used as animal feed is poor. Hence all attempts need to taken both before and after food crop harvest to reduce the amount of this toxin. Improper storage of food harvest in warm and humid conditions leads to aflatoxin contamination much higher than what is seen in the field. Equally important is the need to have in place facilities to regularly test for aflatoxin M1.

Published in The Hindu on October 21, 2019