Health Impact of Pesticides on Residents and Horticultural Workers in the Lake Naivasha Region, Kenya

The horticultural sector has undergone tremendous growth in Kenya and is now the second largest foreign income earning sector in the country. Lake Naivasha is the hub of large scale horticultural farming in Kenya. This growth coupled with increased use of pesticides, may increase the possibility of pesticide exposure and its associated risks to workers and residents of the region. The purpose of this study was to assess the symptoms commonly experienced by residents of Naivasha town and their possible association to pesticide exposure. Purposive sampling of residents from Kamere, Kwa Muia, Kioto and Karagita was performed, as these residential areas have significant numbers of flower farm workers. By random selection, a total of 801 community members were recruited to participate in the study and data was collected by completing the prepared questionnaire and from clinical examinations. Results indicate that several residents exhibited respiratory; skin, joints and bones; and nervous system symptoms. We found a higher frequency of symptoms among planters, weeders, harvesters than in sprayers working in horticultural farms. We recommend training to planters, weeders, harvesters who are mainly women (61.6%) in this study concerning pesticide use as do sprayers; and second, longer reentry times between the last spraying of pesticide and entry of these workers is warranted, particularly in greenhouses. In this regard, reentry times for greenhouses and fields established for specific pesticides in Europe, North America, Japan or Australia should be adapted by Kenya, and these guidelines enforced by the Government of Kenya to reduce exposure to pesticides within this vulnerable work group. These workers should also use protective clothing including gloves and masks at all times while handling chemicals or recently sprayed plants or flowers. It would also be prudent for flower farm owners to introduce an integrated pest management regime to reduce pesticide use andworker exposures. Further research is required both to identify validated biomarkers that can reliably be used to identify pesticide exposure prior to the occurrence of acute toxicity; and to follow up individual cases of known exposures for chronic health effects.