Sorption is the attraction of a pesticide to inorganic and organic soil surfaces. When pesticides are sorbed to soils, they are less likely to leach. Water Solubility expresses the amount of pesticide that will dissolve in a given amount of water. Pesticides with large water solubility generally have lower sorption. This makes them more mobile in the environment and more readily available for leaching to ground water or to running off with surface water.
Persistence refers to the amount of time a pesticide remains in the environment.
It is measured by half-life. More persistent pesticides that have longer half-lives can pose a greater threat to the environment since they remain there longer. Pesticides are degraded into harmless compounds by sunlight, soil microorganisms and a variety of chemical and physical reactions. The rate of degradation is affected by the physical, chemical and biological characteristics of the pesticide and the associated environment. To maximize pesticide effectiveness and minimize potential environmental concerns, the properties of the pesticide must be compatible with the physical, chemical and biological conditions of the application site.