Pesticides the hidden killer in Kenyans’ food


A farmer sprays his maize farm with pesticide chemicals on June 25, 2021. PHOTO | JOHN NJOROGE | NMG


  • The thing with the environmental factors that cause cancer is that one has to be exposed to them consistently for prolonged periods.
  • Pesticides could just turn out to be one big category of substances that is seriously affecting our health. Not all of them, but many of them.

The annual incidence of cancer in Kenya rose from 37,000 to 47,884 new cases per year between 2012 and 2018, according to the Kenya Cancer Policy 2019-2030. In the same period, yearly cancer deaths rose from 28,500 in 2012 to 32,987 in 2018 — the four deaths per hour making cancer the third leading cause of death in Kenya after infectious and cardiovascular diseases.

The projections are not rosy either: these deaths could rise by up to 120 percent in the subsequent two decades.

As a medical doctor, I did not need these statistics to tell me that cancer cases are rising. I see it every day. We do know that cancer is multi-factorial. There is a genetic component, and there is an even bigger environmental component.

What has been baffling is that many of the cases are not in the patients we would expect. Young people — who are fit and do exercise, neither drink nor smoke, watch what they eat and take a fair amount of greens, have no family history of anything other than a common cold — are getting cancer. The question is why?

Recently, I quipped that had all 40 instances of clotting being investigated following Covid-19 vaccination happened in Kenya, nobody would have noticed the association. The thing is, our surveillance systems are yet to mature, if they are in place at all. Obvious linkages will be missed.

This is how we end up with media reports of potentially harmful substances being stocked in the food sections of supermarkets, or unmonitored poisons in the water in our taps, or the greens from the supermarket. The fact that we are just now strengthening our surveillance systems means that we are vulnerable to numerous risks.

The thing with the environmental factors that cause cancer is that one has to be exposed to them consistently for prolonged periods. This gives us an idea that these harmful agents are very much things we have in close proximity to us, things we would not even suspect to be harmful. We the Swahili say, kikulacho kinguoni mwako (what stings you is up close and personal).

Pesticides could just turn out to be one big category of substances that is seriously affecting our health. Not all of them, but many of them. Widespread use of very toxic, but inexpensive products, as well as small-scale farmers in Kenya not being able to mitigate risks, could have the impact of the statistics in my first paragraph.

Recently, I got the privilege of being invited to be part of a task force that was asked to review scientific evidence around a number of pesticide molecules that the Pest Control Products Board (PCPB) is considering removing from the Kenyan market due to possible harmful effects to health and to the environment. This is how I got insight into the secret world of pesticides. What I found was nothing short of astonishing.

Pesticides could be contributing in a big way to the rising incidence of cancers and many other non-communicable diseases. We eat every day. Farmers have understood that to get good yields, they must embrace some form of pest control measures. A good number of these chemical pest control measures leave residues on or in the farm produce that we consume.

While the quantities for each individual crop may be small, the fact that we eat every day means that over time, these quantities accumulate as do the harmful effects. As I looked at study after study, I could not understand why some of these molecules are allowed at all in Kenya, given that there are alternatives.

For example, the United States Environmental Protection Agency classifies Bifenthrin as a possible human carcinogen. It has been shown to cause a rise in the incidence of urinary bladder tumours, adenoma and adenocarcinoma of the liver, and bronchoalveolar adenomas and adenocarcinomas of the lung in mice.

It is very much on our shelves today. Some of the chemicals still in use here have been banned in Europe, yet in Kenya we are still using the same chemicals!

In ideal settings, there are clear guidelines on how pesticides should be applied. These are meant to protect farmers and consumers from unplanned exposures. However, competing interests, limitations in resources, and sometimes just inadequate information, means that shortcuts are taken and safety concerns relegated.

It is not clear that the recommended methods of application are adhered to. The staff that work on these farms are themselves not always fully protected: the flower farm workers in Naivasha and associated hospital visits should give an idea of what the actual situation on the ground is like.

The reason manufacturers are able to get away with deviations is that regulation and enforcement in this part of the world is still undergoing strengthening. Often we have to trust what the manufacturers say. This is not a fool-proof method.

Given the risks involved, noticing that we are still a few years away from being able to independently verify what goes into our food, we can and ought to adopt a higher standard for what we accept, especially when we have reasonable alternatives. By outlawing “notorious” molecules, it is less likely that farmers will have access to them and even less likely that they will legally find their way into our food.

Farmers should be supported to implement integrated pest management approaches, where synthetic pesticides — the least toxic of them— are the last step in a more holistic approach at farm agro-biodiversity, water recycling and soil health. Biopesticides are one of the tools in our toolbox that we have not adequately invested in despite Kenya’s available natural resources, such as neem and pyrethrum.

You may be interested to know that agrochemical producers have identified Africa as the next big market. The projected revenue from the sale of pesticides is projected to be as high as $6 billion per year in the early stages alone. Is Africa the next big frontier for the toxic pesticides?

We have to start being concerned about what we do. When all is said and done, we will find that the chemicals in the food we eat, the contaminants that find their way to farms, contribute to the many new health challenges, including cancers. It is my duty, and your duty, to keep ourselves and our people safe.

Dr Ng’ani is the Head of Critical Care at RFH Healthcare