It is important to understand the degradation and persistence of pesticides in soil and water in order to maximize pesticide efficacy while minimizing any detrimental effects they may have on the ecosystem.
Understanding mobility of pesticides is an important part of environmental toxicology and chemistry. Pesticides need to be mobile enough to allow them to be transported to the site of action. On the other hand, pesticides that are too mobile will rapidly dissipate once applied to the target area and contaminate water and sediment. Many factors can affect the mobility of pesticides in soil and water including soil characteristics, pesticide properties, and timing of application.
In recent years, transgenic crops have increased significantly in their usage in agriculture. Many of these crops produce insecticidal Bt proteins that target specific insect pests. As with conventional chemicals, it is important to know the fate of these insecticidal Bt proteins in the environment. The fate data is used in the risk assessment process to determine potential exposure of the insecticidal Bt proteins to non-target organisms.
Extensive pesticide use over several decades has resulted in the contamination of soils and water bodies. Pesticides can either these ecosystems either by intentional application, or incidentally by spray drift, surface water runoff, or spills. These pesticides may have a variety of detrimental effects on aquatic and terrestrial organisms, and could lead to disruption of the ecosystem. Cleaning up contaminated sites by conventional methods, such as excavation and storage off-site, can be expensive and not practical for areas with only minor contamination issues.
Veterinary pharmaceuticals have emerged in recent years as a contaminant of concern in the environment. While not applied to soil and water bodies directly, veterinary pharmaceuticals enter the ecosystem after being excreted by grazing livestock or by the spreading of manue on agricultural fields as fertilizer. As with other chemicals, veterinary pharmaceuticals may have detrimental effects on aquatic and terrestrial organisms, particularly on bacteria where they may contribute to the development of antibiotic resistance.
