Food scientists warn of rising contamination as adulterated milk, unconventional meats spread
From left: Syprine Otieno, Ansimiirwe Mackay, Valerie Lucy Njeri, Mercy Chelangat and Telly Tubby Wanjiru during a one-month International Youth Talent Exchange programme at the School of Life Sciences, Tianjin Normal University in China. During the programme, they tested meat samples from buffalo, pork, and shrimp using modern DNA extraction techniques.
What you need to know:
- The concerns come amid scientific studies pointing to microbial contamination in vegetables and fresh produce as well as heavy metal contamination in some animal products mainly due to biomagnification (the process where toxic substances (like pesticides or heavy metals) become more concentrated in the bodies of animals as they move up the food chain).
Food scientists have raised alarm over persistent food contamination across the country, which is driven by a combination of environmental, behavioural, and regulatory factors. Their concerns come amid scientific studies pointing to microbial contamination in vegetables and fresh produce as well as heavy metal contamination in some animal products mainly due to biomagnification (the process where toxic substances (like pesticides or heavy metals) become more concentrated in the bodies of animals as they move up the food chain).
The scientists are now warning people against consuming milk that has had water added to increase its volume before being sold. According to the chairman of the Department of Food Science, Nutrition and Technology in the Faculty of Agriculture at the University of Nairobi, Dr Dasel Kaindi, the availability of adulterated milk in the market highlights existing food safety gaps in the country.
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“Food safety is becoming a very critical area for us now because cases of chronic diseases are on the rise as people are being exposed to hazardous biological agents,” Dr Kaindi told Healthy Nation.
Apart from milk, Dr Kaindi also raised concerns over alarming cases where unconventional animal meats such as donkey, dog, or cat find their way onto people’s plates. He also cautioned people against eating animals that have died of unknown causes as well as consuming expired packaged foods.
“Other issues relate to integrity such as when a farmer sprays crops with pesticides and instead of waiting for the required period for residues to reduce before taking the product to market, they sell the produce while it still contains pesticide residues, which become chemical hazards.”
According to food safety researchers, contamination can occur at any point along the food value chain; from production, harvesting, storage, and transportation, to sale and food preparation. Additionally, they note that chemicals used in food production such as pesticides and veterinary drugs pose major problems due to poor application and post-application management practices, as well as the use of highly hazardous pesticides.
Speaking recently during an experience-sharing event with five outstanding university students who participated in a one-month International Youth Talent Exchange Programme in China, Dr Kaindi advocated for a joint, specialised food safety laboratory as part of a Kenya-China exchange programme to address weaknesses in the country’s food safety testing techniques.
“Our universities and some research institutions have food safety testing equipment, but what is lacking is the sequencing capacity. We currently have to send samples outside the country, which makes sequencing very expensive for Kenya.”
During the one-month International Youth Talent Exchange Programme in China, five students from the University of Nairobi and Embu University received hands-on training in key laboratory techniques such as Polymerase Chain Reaction (PCR), engaged in experimental design and real sample testing, and completed data analysis and report writing.
“At the School of Life Sciences, Tianjin Normal University in China, we tested meat samples from buffalo, pork, and shrimp using modern DNA extraction techniques. It exposed us to molecular technologies for identifying meat types and authenticating the kind of meat people are consuming,” said Syprine Otieno, a Biochemistry major at the University of Nairobi.
Other student participants in the exchange programme included Ansimiirwe Mackay (Food Science, UoN), Mercy Chelangat (Horticulture, Embu), Telly Tubby Wanjiru (Microbiology, UoN), and Valerie Lucy Njeri (Crop Science, Embu).
Mackay noted that each student prepared their own food sample and used PCR to amplify DNA, then compared results.
Aaron Kecha, technical advisor at CEJAD (a chemicals and waste NGO), said unsafe food is rampant in Kenya. “Spot studies show chemical preservatives in butcheries, salmonella on vegetables, dioxins in eggs, pesticide residues, and contaminated fish. This points to overstretched enforcement in a largely informal sector.”
He added that post-harvest issues such as poor processing (aflatoxins), packaging, lack of sanitation in informal markets, and low hygiene knowledge also contaminate food.
He explained that domestic surveillance is under-resourced, with weak coordination and poorly harmonised standards, making monitoring difficult. Export markets, however, have stringent standards. “The country has invested in quality control to access global markets,” he explained.
Kenya has food safety policies, including the National Food Safety Policy (2021), which serves as the primary instrument for a farm-to-fork integrated safety system. While this policy acknowledges that national food control agencies possess inspection and registration services capable of conducting periodic inspections, taking samples, certifying food for local consumption, assuring compliance with national standards, and facilitating surveillance, Kecha noted that inspection services remain largely reactive, triggered only by problems that are presented or perceived.
“The policy focuses on harmonising inter-agency efforts and improving trade compliance with international standards.”
The Food, Drugs and Chemical Substances Act (Cap 254) requires routine medical exams for food handlers, including stool and urine tests for specific pathogens. The Kenya Bureau of Standards certifies processed foods for export and domestic markets under the Standards Act (Cap 496). The Public Health Act (Cap 242) regulates hygiene, meat inspection, and milk safety.
A 2023 CEJAD report found free-range chicken eggs near dumpsites and e-waste recycling yards contained extremely high levels of persistent organic pollutants (POPs); dangerous, non-biodegradable compounds. “Chickens scavenge in dumpsite, and people living nearby are exposed,” Kecha said.
Eggs sampled from Dandora, Nairobi’s largest dumpsite, had POPs concentrations up to 111 times EU limits. “An adult eating one egg could exceed the EU daily safety limit for more than 250 days,” the report states.
The five university students funded by the China Exchange Programme show how bilateral training can bridge food safety gaps. Prof Wang Shangxue, director of the Confucius Institute at UoN, said the project “develops skilled professionals through a Chinese language plus food safety testing model.”
