Once inside an organism, a pesticide can metabolize via internal enzyme systems. Recent studies have revealed that multiple organisms often are involved in the degradation phenomenon. Previous notions that single species are solely responsible for microbial degradation of a pesticide probably are not correct. Different species have different capabilities, and together they can form a 'pool of talent' resulting in degradation of the pesticide. The likelihood that the chemical will be completely degraded is decreased if any of the microbes are missing from the pool.
Abiotic degradation results in less transformation of a molecule than does biological degradation.
Reaction with water breaks apart the molecule, and the extent of breakdown is pH dependent. In either case, pesticides absorb energy from sunlight, become unstable or reactive, and degrade. Photolysis can occur in water, in air, or on surfaces such as soil or a plant leaf. Volatilization Volatilization is the process whereby a solid or liquid evaporates into the atmosphere as a gas. The process provides a significant pathway of transfer for some pesticides.