The European Commission has banned three of the most widely applied insecticides due to the risk to bees and other pollinators.
The April ban on thiamethoxam, imidacloprid and clothianidin, expected to come into force this year, covers all outdoor uses in Europe. The chemical use will, however, be permitted in permanent greenhouses where exposure to bees is unlikely.
The commission considered scientific evidence that neonicotinoids not only cause disorientation and fertility reduction and weaken the immune system of many species of these insects but also affect birds and aquatic life such as fish and macroinvertebrates.
However, despite the African honey bee being more sensitive to these neonicotinoids than the European one, the pesticides are still heavily and widely used in Kenya. Imidacloprid and thiamethoxam, for example, are approved for use in controlling insect pests in coffee trees, French beans, maize, cotton, wheat, forestry nurseries, roses, tobacco and vegetables.
PEST CONTROL PRODUCTS
The Pest Control Products Board (PCPB) has registered 718 products, of which 28 per cent are not approved in Europe because of their potential human or environmental health effects. There are 41 products in the local market which contain these two active ingredients.
Considering that many crops grown in the country, especially those important to small-scale farmers, depend on insect pollination for good yields and quality and that these farmers are the majority in the sector, the welfare of bees is highly dependent on them. However, farmers are often not aware of the potential toxicity of pesticides available in local agro-vets towards pollinators.
A 2013 survey showed that farmers in various parts of the country do not follow pesticide usage advice — like avoiding application in the morning, when pollinators are active.
This exacerbates the decline in production of crops that are wholly dependent on pollinators, such as passion fruit, pumpkin, watermelon, okra and strawberries.
The yields and quality of other crops, such as coffee, avocado, mango and runner beans, are also affected negatively.
Risk to humans
Scientific findings show neonicotinoids pose a health risk to the human nervous system and contaminate waterways and food. Studies show nearly 75 per cent of honey produced in the world contains at least one toxic neonicotinoid pesticide.
In Kenya, the highest level of thiamethoxam measured in pollen was 0.05 milligrammes per kilogramme, five times higher than the maximum residue limits (MRL) of 0.01mg/kg.
Given all these risks and the fact that Kenya is food-insecure, a ban on neonicotinoids in the country would be an important step. That would allow for further detailed studies to determine the extent of the damage that the pesticides have on the environment, pollinators and human beings.
These risk assessments would, however, depend on several factors — including how the regulatory authority, PCPB, views the risks to pollinators and other insects, the forthcoming studies on local pollinator populations and also how they are affected by the neonicotinoids that are in use.
Strict measures should be enforced by regulators such as Nema, Kephis, PCPB and the Ministry of Agriculture so that pesticides proven to be toxic are banned and not made available locally.
Farmers should be advised on environmentally safe methods of applying pesticides and safe frequencies and beekeepers to locate apiaries away from cultivated areas of intensive conventional cropping to minimise honey bee exposure by foraging on contaminated pollen and nectar and carrying pesticides into the food chain.
Kenya should, however, prioritise a shift towards more natural and sustainable farming practices that minimise the use of fertilisers and pesticides and promote and preserve healthy and diverse soil ecosystems.
Dr Bollmohr is an environmental scientist and managing director of EcoTrac Consulting. [email protected]