Agriculture/Pesticides
Introduction
A pesticide is any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest (epa.gov). Pests can be defined as any organism that causes plant diseases. Agricultural pesticides are then those chemicals that are used by farmers to prevent the effectivity of the pests on the growth and productivity of agricultural crops.
Pesticides are either restricted or unclassified.
- Restricted means it can cause harm to humans or the environment.
- Unclassified refers to all other pesticides.
Pesticides are made up of active and inert ingredients. There are certain labeling requirements for the commercial distribution of products that used agricultural pesticides. The active ones are those which do the damage to the pest, federal law mandates that these ingredients be clearly labeled on the packaging. Inert ingredients are not required to be labeled as they do not cause harm, they are usually present as a solvent in the solution. (inert ingredients are not necessarily non-toxic). All pesticides must be registered with the EPA before they can be sold or distributed. There are many tests and requirements concerning the potential effects of the pesticides in order to be approved.
- Sources of Agricultural Pesticides
Pesticides became common after the second World War as part of the war effort was scientific research into a way to end hunger, i.e. pesticides and the increasing productivity and availability of food production with their help. Currently an estimated 3.2 million tons of pesticides are used each year.
Pesticides are wasted in environments where the farmer has little knowledge or care for the detrimental effects of the pesticides. Without regulations and enforcements these pesticides can easily be spread farther than their intended area. This is especially common in developing countries. With misuse the pesticides can easily be picked up by the rainwater and washed into the streams as runoff.
- Transport of Agricultural Pesticides
Pesticides can be transported to humans or other organisms in a variety of ways. It is near to impossible for the pesticide to only affect its targeted crop.
-Wind is one transportation method. The wind picks up the pesticides and can blow them onto other farms or into rivers.
-It can be absorbed into the soil and then taken up by other organisms or can contaminate the surface and groundwater that run over/through it.
- Pesticides are then absorbed by the plants which is detrimental to the growth of the plants.
- That which is not absorbed usually remains on the surface and flows into streams as surface runoff. It is dissolved into the water and then can be taken in by plants and animals. The streams would then be considered a reservoir of pesticides with a relatively high abundance level.