Chemical pesticides come in various forms, such as herbicides, which kill plants; insecticides, which kill insects; and avicides, which kill birds. They might adversely affect air, water and soil, which in turn will affect human and animal life. Not only does pollution occur from application of these chemicals, it also might occur from improper storage, accidents during production and improper use.
The most common way that air is polluted by chemical pesticides is by the particles being carried by wind to other areas. This is especially common when an aerial spray is used. The particles attach to dust in the air and are then carried away by wind to other areas, perhaps contaminating wildlife and other plants. If chemical pesticides must be used, it is possible to take measures to help prevent the spread of the material by air. Keeping a boundary of trees around the sprayed area might keep a great deal of the chemical pesticides from spreading.
Chemical pesticides also might find their way into streams, rivers, wells and groundwater. This might happen from spillage because of improper storage, runoff of excess pesticides and the chemicals leaching from the soil to the groundwater. Areas that are located near water bodies are at even more of a risk. As with air pollution from chemical pesticides, measures might be taken to help prevent large quantities from polluting water, such as ensuring that a sufficient number of crops are planted at the time of application and trying to avoid spraying pesticides right before rainfall.
Many people feel that the use of chemical pesticides deteriorates the quality of soil in farmland. Materials in the pesticides might cause fewer natural inhabitants of the soil to be present, which might alter the soil's chemical makeup. In addition, if the pesticide remains in the soil, not only might it deteriorate soil quality, it also might leach through to groundwater or be carried away by wind.
All of these means of spreading pollution caused by chemical pesticides might affect humans and wildlife. It might get into their drinking water, into or on their food and on their skin, which might make them sick. Depending on the levels of pollution, lives also might be lost. For this reason, care should be taken whenever chemical pesticides are used or stored, in order to do the least amount of damage to surrounding organisms.