Pathways of pesticide

Pesticide spread in the environment

What happens to pesticides (crop protection products) that are sprayed on arable land? In chemical control of a weed, fungus or pest insect, an entire area of land is often sprayed. The pesticides remain in the environment for a shorter or longer period and in some cases can even make their way far from the place where they were used. They are often found in rivers or streams but also in the groundwater. Residues from pesticides have even been found in rain. The risk of unwanted spread of pesticides to the environment is mainly related to cropping and spraying techniques and also to natural conditions and processes (climate, soil properties, etc.).

Some of the pesticides sprayed on fields can be transported to the surrounding land and water. Pesticides can be transported away in the air through wind drift and evaporation and then carried back to soil or water by rainfall. Surface run-off and percolation of water to the drainage system can carry pesticides out into rivers and lakes. Leaching of water through the soil can carry pesticides down to the groundwater. Various spillages during handling can also lead to pesticides going astray into the environment. Figure: Modified after Lennart Torstensson, SLU