Not so long ago, Nairobi County Executive Committee Member for Agriculture, Livestock Development and Fisheries Anne Lokidor expressed concern over the heavy pollution of the city’s rivers and implications for urban farming.
“The reason why Nairobi River is polluted,” she told Seeds of Gold, “is that most industries discharge their waste into it. Even if it’s sewage that is discharged, it should pass through a central point where it is cleaned completely before it is channelled to the river.”
This is not being done, she added, prompting discussions with her environment counterpart, former Nairobi Town Clerk John Gakuo, whom, she said, was in talks with National Environment Management Authority to address the issue alongside the city’s Department of Public Health.
Not mentioned by Lokidor, are the industrialists, given that there are laws in place to prevent pollution of river courses.
They also have corporate social responsibility that ought to take into account the many poor urban farmers and downstream communities, for whom the city’s rivers are a means of livelihood.
So, what is urban farming? It the cultivation and distribution of food in or around a village, town or city. Hampwaye G., Neil E and Ingombe L. in their book, The role of urban agriculture in addressing household poverty and food security: The case of Zambia, bring its various practices into the equation — animal husbandry, aquaculture, agroforestry, urban beekeeping and horticulture. Its cross-cutting nature means that it cannot be left to one county.
It is in this regard that Lokidor says: “We cannot allow the farmers to grow their crops there until the river is cleaned.” And yet, hers is more as an aspiration than a practicability, as she hastened to point out that before they put a stop to riverside vegetable-growing, they have to take farmers’ interests into account.
“When you take something from someone,” she said, “You should be able to give them something back.”
From July, she said, urban farmers in the heavily-polluted areas such as Kibera, would be given moist gardens. “We are still in the process of identifying other beneficiaries so that they can begin growing vegetables in moist and hanging gardens and flowerpots.” That way, you don’t just deny the urban farmers their source of livelihood — the riverbeds — but you give them back something which is safer and clean,” the officer said.
She added that the cleaning of Nairobi River is at the procurement stage.
Lokidor is not the only one concerned about crop pollution in urban farming. In a recent interview, Agriculture Principal Secretary Sicily Kariuki told Seeds of Gold that the ministry has been developing a national urban farming policy since 2009.
The objective of the Urban Agriculture, Livestock and Fisheries Policy is to promote and regulate environmentally sustainable methods of improving incomes, food security, creating employment, enhancing living standards and reducing poverty.
Public health concerns that Lokidor expresses are captured in the draft policy, which will also address issues of land use and environmental management. In this regard, a specific aim of the policy is to promote conservation of the environment by management of waste and other pollutants, the PS said.
University of Nairobi soil scientist Nancy Karanja, who has done extensive work in Kibera, told Seeds of Gold that riverside farming has great potential among poor urban dwellers. She alluded to a farmer in one of her research who had made a fortune as a small-time urban farmer in Kenya’s most expansive slum to buy land in Kakamega, western Kenya.
However, she brought a new twist to the debate on pollution of crops grown along Nairobi riverbeds. She pointed out that the danger of chemical pollution of crops grown along Nairobi River is real, but that toxic contamination is less pronounced upstream than downstream below the city’s Industrial Area and beyond.
The don referred to a 2008 study she conducted with 14 other researchers, namely M. Njenga, P. Munyao, E. Kang’ethe, G. Kironchi, C. Kabiru, K. Kathuru, C. Muneri, P. Kinyari, C. Githuku, W. Kaluli, J. Gathenya, P. Home, S. Githiga and L. Bebora.
The professor acknowledged that there was heavy metal pollution, notably chromium, at the Kibera study site, and in Ruai, which is below Industrial Area. Vegetables grown along the river were found to have high levels of cadmium and lead.
On the other hand, vegetables sold in open-air city markets such as Gikomba, Kangemi, Githurai and Kawangware had heavy bacterial loads, which were higher than those produced along the Nairobi River, notably E. Coli, a bacterium found in human faeces, and which, according to the Dictionary of Contemporary English, “can make you very ill if it is in any food that you eat.”
The implication is that while the heavy pathogen load in vegetables sold in the city’s open-air markets can be neutralised through cooking, those that are used in salads, notably tomatoes, lettuce and cucumber require thorough cleaning to make them safe to eat raw.
Another twist she brought into the debate is that, contrary to fears that vegetables grown along Nairobi’s riverbeds posed a hazard to their urban consumers, the fears were far-fetched for two reasons: First, the farmers irrigate their vegetables at the roots largely avoiding the edible leaves, and, second, urban slum farmers had such a huge and ready clientele that their produce was virtually mopped up in the farms and was hardly part of the urban market chain.
The don said: “Farmers know how to manage this waste water. It never touches the vegetable. They use the furrow system such that the water is in furrows. It never touches the vegetables. And when they are harvesting, they don’t run any water.”
So, what is the way forward?
The study came up with a raft of recommendations that include the need to install and maintain sewer infrastructure.
Where it is not applicable, “construct small wastewater treatment plants within the Nairobi River basin to reduce the heavy metal loading in the sewer line.”
The Nairobi Water and Sewerage Company was also called upon to establish water quality monitoring along Nairobi’s rivers.
The recommendations also take on board Lokidor’s environmental concerns — that pre-treatment of effluent by industries should be enforced to conform to Nema’s standards and guidelines.
The recommendations further take cognisance of the fact that “while farmers have a sense of what they can do at the household level and what governments need to avail, they have shown lack of measures to deal with heavy metal long-term exposure.
It is imperative that all involved are aware of the risks posed by utilisation of wastewater in irrigated agriculture as each study site is unique in the quality of water it uses.”
And while the study noted that infection of vegetables like kale (sukuma wiki) by faecal bacteria can be dealt with through cooking, “There is need for further research to find out the biological contaminations in vegetables such as lettuce, tomatoes and cauliflower among others that are eaten raw.”
Baffled by the fact that vegetables sold in urban open-air markets had loads of bacteria, the researchers recommended that a study on handling of vegetables from farm to market should be carried out to establish sources of biological contamination along the market chain.
The researchers also called for further studies “to ascertain risk pathways of the heavy metals to humans and livestock and consequently on population in the neighbourhoods.”