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News Story
23 April 2019

Poisonous milk: How the lack of awareness can lead to a public health calamity

Photo: Dave Elsworth (ILRI) / Flickr.

Nutritious and versatile, milk is like white gold. This high-value product is especially popular in Kenya, where families on average spend 18% of their budget on dairy products. But recently it was reported that milk sold at local markets contains toxic chemicals. Contaminated milk isn’t only a major food safety issue, but also puts dairy farmers in a tight spot.

Chemical contamination of milk was reported in January 2019, with aflatoxin being the main contaminant.

Aflatoxins are highly toxic and linked to cancer, rates of which has recently gone up in Kenya.  An average Kenyan consumes more than a hundred litres of milk yearly, and there is possibility that high consumption of the “white gold” could be one of the causes.

Olivier Basole Kashongwe, lecturer and researcher at the department of animal sciences at Egerton University in Kenya, conducted extensive research on milk production systems, all the way from farm to fork. He found that the source of the problem is threefold: poor farm-level practices, transportation and access to market.

A matter of bad practices

Firstly, aflatoxin is produced by humidity loving moulds if the storage facilities are damp. And when the moulds grows on the livestock feed aflatoxins end up in the milk.

Secondly, while hygienic aluminum cans are the most preferable way to transport milk, the size of the cans exceeds the production capacity of a single smallholder. Therefore, farmers either use smaller plastic containers which don’t meet the hygiene requirements for milk delivery. Or the milk is pooled from several farms to fill up the aluminum cans, snowballing contamination and tangling the tracks.

Finally, the milk that reaches the market should be checked. But the authorities lack the capacity to reinforce quality control, and so contaminated milk reaches the markets without being noticed.

 “The market should reject milk with aflatoxins. But it is common that informal traders who want to bypass the law sell contaminated milk illegally in towns, especially when the regulators are not there or not able to find them,” says Olivier.

Plastic containers that don’t guarantee the necessary hygiene for milk delivery.

Photo: Olivier Basole Kashongwe (Egerton University, Kenya)

Lack of knowledge and awareness creates a perfect breeding condition for the aflatoxins: the farmers don’t know that their milk could contain aflatoxins, the traders can’t buffer the contamination because of their sparse ability to test the milk, and the consumers are not aware of the contamination, so they can’t influence from the demand side either. And so, the supply chain keeps going, despite the risks.

Peri-urban areas are affected the most. Olivier and his team found that 60% of milk sampled in Kenya’s peri-urban areas contained aflatoxins. Unlike the rural areas where cows mostly feed on natural pastures, farmers in peri-urban areas rely on feed concentrates, produced from cereals and their by-products. The raw materials used by the companies to produce the concentrates are often of poor-quality and often already contaminated with aflatoxins. The problem is then reinforced by overlooked storage infrastructure that rarely keeps the feed cool and dry.

“The general rule requires the processing companies to source raw material free of contaminants, but these regulations do not yet specify the imperative to check for toxins. And the repercussion in human health is huge,” says Olivier.

A matter of money and access

To overcome the issues of aflatoxins in milk, farmers need to learn to handle the feed safely. The time the forages should be harvested, for how long they should be dried before storage and how the feed should be preserved – all are important. Furthermore, feed storage facilities need to ensure dry conditions. Obviously, building such facilities and informing about the best practices requires investments, so the problem will remain until it receives adequate attention and effective support from public policy.

The Kenya Dairy Board tried to introduce the so called “mazzican” – a hygienic plastic container, smaller in size than the aluminium cans. The container easily fits on a motorbike and withstands bumpy roads better than large aluminium cans. This way smallholder farmers don’t need to mix their milk with that of other farms. The tracing is also easier because if contamination is discovered, regulators can find out which farm needs practice improvement. However, the attempt to implement maize can was not successful. The price of the container was too high and the availability too low.

Photo: Ben Lukuyu (ILRI) / Flickr.

What about antibiotics?

Sadly, aflatoxins are not the only contaminant found in milk. Olivier and his team have also seen that 6–7 % of the milk on the markets around Nairobi contains high levels of antibiotic residues. According to the Kenya Bureau of Standards, the amount of antibiotic residues in milk should be zero, but the levels reach above 100µg/L. Once consumed, the antibiotic residues make gut microbes resistant to treatment with antibiotics. Growing antimicrobial resistance is a creeping global public health catastrophe and needs urgent action.

Antibiotics are routinely used on many farms for disease control and prevention. Ideally, antibiotics should be phased out through higher animal welfare. However, during the implementation while the antibiotics are still in use, farmers have to respect withdrawal. The withdrawal time can range from one to 10 days, depending on the specie and the type of antibiotic. But the milk poured during the determined withdrawal time can’t be sold on the market, nor fed to other animals.

“Producers are aware of the issue with antibiotics. They know that they should respect the withdrawal period. But we find that some don’t want to lose the money by disposing of the milk with antimicrobials, and they deliver it to the market by means of informal channels.”

It’s not only the consumers who are exposed to antimicrobial resistance. The cows can develop resistance as well, becoming more vulnerable and prone to diseases. In the long run, this can cause their milk production to drop. So, making sure withdrawal periods are followed and respected ensures business sustainability for the farmers too.

How can these problems be solved? Olivier suggests stricter regulations on withdrawal periods. This way, veterinary practitioners responsible for the antibiotic treatment can follow up with farmers, check and enforce better practices. He also emphasizes the importance of researchers in practice development:

“As researchers we are there to show farmers that if a cow’s milk production is dropping, it’s probably because of excessive use of antibiotics or from ignoring the withdrawal periods, as well as due to high level of aflatoxins in their feed. Because for the cow, aflatoxin is a health risk too,” says Olivier.

If we are to overcome the issues of contaminated milk, we must increase awareness among producers too. In Kenya, many people farm according to traditional knowledge. These are not documented by science, and are not necessarily the best. Training the farmers on the most commercially and professionally effective procedures and methods is absolutely crucial for safe production of high quality milk.

But this cannot be done without effective policy. Researchers and policy-makers need to work together to develop the tools and the implementation capacity at farm and distribution levels as well as reinforce the best practices via the existing legal means. Because at the end of the day, health of millions is on the line.


Reporting by Linda Hansson, Communications Coordinator, SIANI and Focali. The interview with Olivier was done during the AgriFoSe2030 course: Translating science into policy and practice, held in Nairobi in January 2019. Read more about the course and AgriFoSe2030 here.