Pesticides are used to prevent, control harmful organisms or to reduce their damage in agriculture. The use of pesticides is still indispensable in order to prevent the negative effects of the agricultural diseases and pests.3,2 million tons in the world, almost 40 thousand tons of pesticide consumption in Turkey is the most important indicator of this. Pesticides get mixed and transform through air, water and soil then other living things in these environments. The movement of a pesticide is affected by its chemical structure, physical properties, formulation and application type, climatic and agricultural conditions. During the pesticide spraying an amount gets lost due to evaporation and dispersion, whereas the other part remains on the plant and the soil surface. Mixed up to air, pesticides can return to the world via wind movements, rain, snow or fog. Pesticides reaching plants and other non-target organisms in this way, can cause residual toxicity. Pesticides in soil get destructed biologically an photochemically by the action of solar radiation, soil microorganisms and other organisms; move to surface through capillary water and mix up with air. Precautions For Reducing Effects of Pesticides on Human and Environmental Health Harvest spraying intervals should be long enough and producers must adhere to intervals. Reducing pesticide applications should be made in food treatment process. LD50 must be known and written for each pesticide. Pesticides less toxic to human and the environment should be preferred. Persistent organic pollutant pesticides (DDT, Dieldrin, Endrin, Heptachlor) should be banned. Practitioners must be educated, children should not be operated in practice, special protective equipments should be used. Nourishment shouldn’t be taken during preparation and application. Overdose and unnecessary repeated applications should be avoided. During aerial spraying meteorological conditions should be considered, honey producers should be warned. Equipment used in application should be destroyed     Keywords: pesticide, environmental health, biocide