How dirt, drugs and toxins end up in the milk you drink

Both packed and dispensed milk failed the safety test in a study that found toxic levels of contamination. Are dairy farmers and milk retailers sacrificing health standards in the chase for money?

In Summary

• Packaged milk and that sold in ATM machines is highly contaminated, according to lab results.

• The milk contains a substantive number of E. coli, which indicates faecal contamination, hence not fit for human consumption.

Milk on display at a supermarket
Milk on display at a supermarket
Image: FILE

Kenyans have become cautious of the food they consume due to numerous cases of food poisoning, linkage with cancer-causing organisms and general safety of food.

This concern led us to investigate the safety of a product that has proliferated with the advent of new distribution channels: milk. We scrutinised milk sold in ATMs and the packaged milk.

Our findings gave no reprieve to worried consumers. They established that most of the milk being sold in supermarkets and ATM machines is contaminated.


We bought milk from different supermarkets within Nairobi CBD, Kangemi, Rongai and Buruburu, which are highly populated.

The process started by collecting sterilised carrier bottles from the National Public Health laboratory next to Kenyatta National Hospital. These were used to store samples of milk bought from the ATM machines, while samples of the packaged milk were taken as bought. The samples were delivered to the labs within two hours of collection.

Gerald Githinji, a lab technician from the government lab, says any sample of food should be taken to the lab within 24 hours from the time of collection, or stored in a cooler box in containers that the lab provides.

The test results, which we received after five working days, showed that the milk is unsatisfactory for human consumption as it contains high levels of coliforms.


Githinji explained that coliform refers to a variety of bacteria found in water, soil, vegetation and on human body and skin.

The results from the ATM milk machines showed that the count of coliforms was more than 2,400 colony-forming units per millilitre (CFU/ml) of food, which is higher than the recommended level of 10 CFU/ml.

What is more shocking is that the most probable count of pathogens like Escherichia coli was at 4 in 1ml of the raw milk bought from the ATM machines. This means it has faecal contamination, which could be human or from the cows.


For the packaged milk, the coliform was between 210 to 15 CFU/ml, while the E. coli was at a safe level of zero.

The cleanliness of those milk ATMs is questionable. You cannot tell the hygiene and how they are cleaned
Agriculture CAS Andrew Tuimur


Githinji pointed an accusing finger at farmers during the milking process.

“This contamination could have happened if the farmers used cow dung while milking instead of the recommended milking jelly,” he said.

Kelvin Momanyi, a veterinary officer from the International Livestock Research Institute, says the allowed limits by the Kenya Dairy Board for UHT milk should be 0 CFU/ml, while pasteurised milk should be less or equal to 10 CFU/ml.

Pasteurised milk is cooled to certain temperatures or boiled to reduce the bacteria load.

In raw milk, as per KDB and the East African Community standards, the coliform counts for very good milk should be between 0-1000 CFU/ml and 1, 000- 50, 000 CGU/ml in good milk.

He says pasteurisation destroys all coliforms. “Therefore, their presence in pasteurised products indicates lack of hygiene and sanitation in post-pasteurisation operations, handling and packaging,” he says.

Agriculture CAS Andrew Tuimur said the milk being sold in ATM machines should be pasteurised. “But we are not sure of what is being sold there. The risk of contamination is very high and then, of course, the cleanliness of those ATM machines is questionable. You cannot tell the hygiene and how they are cleaned,” he said.

Kenya Dairy Board managing director Margaret Kibogy reiterated that the milk in ATM machines should be pasteurised. He said the dispenser must show evidence that the milk is from a processor who has pasteurised the milk.

“There must also be the sell and expiry date. This is a requirement they must have, and we cancel any ATM machine operator who does not meet the requirements,” she said.

Kibogy said there are about 15,000 ATM machine operators countywide, and that one must be registered and licensed by KDB.

“KDA trains them on milk handling and there is even a book specifically for milk ATMs. Some of these requirements are also included in the new dairy regulation,” she said.

Because the payment is also based on the quantity or volumes, farmers will also tend to add water into the milk. When you add water, the safety of the water will also affect the safety of the milk
ILRI veterinary officer Kelvin Momanyi


Adulteration is another challenge facing the industry. Kibogy said there are cases of people using preservatives, though this is not common.

“We also have antibiotics because of the withdrawal periods. Some of it is lack of knowledge, while some of it is intentional. There are also cases of aflatoxin coming from feeds that farmers may not have control over, but the prevalence is not high,” the MD said.

Momanyi adds that payment of milk is based on butterfat in milk, so farmers tend to add things like Blue Band to fetch more.

“Secondly, because the payment is also based on the quantity or volumes, farmers will also tend to add water into the milk. When you add water, the safety of the water will also affect the safety of the milk,” he said.

This water may be contaminated maybe with pathogens like E. coli and salmonela. These are pathogens that could be transferred from any environment or when farmers use dirty equipment, or when they don't wash their hands. This will lead to the contamination of milk.

“When looking at milk safety, we are also looking at how that animal is treated. If a farmer does self-treatment to the animal, he or she will not be able to observe the withdrawal period,” Momanyi said.

"When a farmer does this, those residues of the drugs will end up within the milk. That is why it is important for a farmer to always get advice from a registered animal health provider."

The withdrawal period for antibiotics is three days or 36 hours for milk, and seven to 21 days for meat.

Aflatoxin is another common problem. When a farmer feeds animals with maize that is contaminated with aflatoxin, this will end up as residue in the milk.

“This means the consumer of the milk, too, will be taking in those aflatoxins in small doses. Aflatoxin has been associated with cancer, and these are some of the impacts that are not seen immediately,” Momanyi said.

A study released by Egerton University last month showed that 60 per cent of milk sold by milk vendors and kiosks in urban centers in Kenya is contaminated with aflatoxin.

Researchers from Egerton's Animal Sciences department attributed this to the use of contaminated raw materials for processing animal feeds and unhygienic transportation and storage of milk from the farm level to the consumer level.

The report also indicated that mismanagement of animal disease with antibiotics also led to milk contamination.

Another study was carried out by ILRI this year on the occurrence of aflatoxin M1 in raw milk traded informally in peri-urban Nairobi. All the 96 samples collected had AFMI levels above the limit of detection 5 ng/kg.

“Two-thirds of the samples had AFM1 levels above 50 ng/kg and 7.5 per cent of the samples exceeded 500 ng/kg. Most of the traders had little knowledge,” the report read.

The study concluded that the prevalence of raw milk with AFM1 is high, while knowledge is low. Fermentation reduced the AFM1 levels.


MD Kibogy said following complaints from the public, KDB has now looked at the proposed milk regulations and incorporated feedback.

The Milk Bill 2019, described as discriminating by some industry players, would have criminalised farmers for selling milk to neighbours and consumers and unless the milk is pasteurised before leaving the farm gate.

“We are forming a technical working group to relook at the document and look at the feedback we received from the industry, and then will do public participation in various counties,” Kibogy said.

"This is going to take some time before we can be able to have a regulation, but we want to consult all stakeholders."

She said the regulation is trying to address the issue of milk safety, how to handle and the normal standards of milk.

“We have been doing awareness from the whole value chain, including farmers, processors, transporters and the consumers. The industry is beginning to respond positively towards achieving the issues of basic hygiene, using aluminium containers to transport milk instead of plastics,” Kibogy said.

She said KDB is establishing its own laboratories to test the safety of milk in a more effective way. “But the board has a mobile lab, which we use to do own monitoring and surveillance,” she said.

Edited by T Jalio