Aloo, T. C.2015-06-162015-06-162004International workshop on ‘Environmental Health Education in the East African Region’ 24th - 26th March 20040001-0001-1http://ir-library.ku.ac.ke/handle/123456789/12954This paper was presented at the International workshop on ‘Environmental Health Education in the East African Region’ 24th - 26th March 2004 held at Kenyatta University Nairobi, KenyaAbstract Trees and forests have beneficial effects on the environment. They conserve biodiversity, protect soils and watersheds and act as a carbon sink. Deforestation on the other hand results in deleterious effects on the environment. The bestknowneffects of deforestation are those attributed to the green house gases and climate change. Deforestationalso results in habitat changes, which affect disease vectors and parasites resulting in a change in disease incidences. Thispaper explores the effects of trees, forests and deforestation on human health. It is based on a survey of available literature and a three-week market survey conducted in Nairobi. The paper starts by discussing the role of herbal medicines andforest foods on human health. The thrust of thepaper is on the effect of deforestation on a few nameddiseases. Deforestation is the most important factor in some disease incidences due to the resultant alteration of the vector habitat. Human populations venturing into and opening up new forest areas for settlement are exposed to diseases such as yellow fever and malaria. Deforestation or bush clearance has been used to control tsetse flies, vectors of sleeping sickness and has also been shownto result in lower incidents of river blindness (Taylor 1997). Only one incidence of afforestation resulting in increasedmalaria is reported in Trinidad (Taylor 1997). In. view of the importance of forestry and trees in human life, the paper recommends the inclusionof relevant forestry topics in the material taught to students of Environmental HealthenArticle