Environmental Health - Pesticides

Human beings rely on a wide range of plants and animals for food. The majority of what people eat is grown or raised on the land, or from the waters, around the Earth. Plants or animals that interfere with or destroy human agricultural or livestock efforts are called pests. Animals, particularly insects and rodents, that can cause damage to human homes, lawns, food, and sanitation are also called pests. Pesticides are the products, usually chemically based, that are used to fight or kill these pests.

Common Types of Pesticides

Pesticides are used in agriculture on a large scale. Powerful chemical agents that deter a harmful weed or pest might be sprayed over large areas

of crops. On a smaller scale, individuals use pesticides to protect their homes and yards. Pesticide products can be bought in many forms including sprays, liquids, sticks, powders, crystals, balls, and foggers. Products that are commonly used to control pests around the house include insecticides (insects), termiticides (termites), rodenticides (rodents), fungicides (fungi, such as mold), and disinfectants (germs that can cause disease).

Pros and Cons of Pesticide Use

The use of pesticides is surrounded by controversy. Pesticides serve an invaluable function in protecting the crops and livestock that are vital to people's food supply. Pesticides can also help defend people's homes against germs and unsanitary and destructive pests. On the other hand, some pesticides contain and spread chemicals, which are toxic (poisonous), or even fatal, if they are consumed by human beings.

Each pesticide contains an active chemical ingredient that is targeted to kill a specific plant or animal pest. But these ingredients are surrounded, or carried, by chemical agents referred to as inerts. They are called inert (meaning lacking in active properties) because they do not have an active effect on the targeted pest. The problem is that inerts can be toxic to other animals or plants with which they come into contact. Some of these inerts are so toxic that, to insure public safety, the recommended usage of the pesticide is limited to mere ounces per acre of land.

Pesticide Risks in Agriculture

Although pesticides are a relatively cost-effective way to protect crops and livestock from damage or destruction, the potential health risks (and the costs that might be generated by them) also need to be considered. Aerial (air) or ground applications of pesticides are hard to control because herbicides (chemical agents used on damaging plants, such as weeds) can drift onto unintended areas.

Methods used to try to control this drift include applying pesticides closer to the ground; waiting for wind to be at a minimum when spraying; using spray nozzles that tightly focus the outgoing stream of pesticides; and adding thickeners to pesticides to help focus active ingredients toward the intended targets. Pesticide users also have to be careful to remove contamination from the sprayers before using them again. Tobacco, grapes, tomatoes, garden vegetables, and fruit trees are particularly vulnerable to certain pesticides used on other crops. The remains left in a sprayer from a previously used pesticide can harm these crops.

The federal government has set standards that the workers, equipment, and procedures involved with pesticide use in industrial agriculture have to meet. These standards help to protect workers, crops and livestock, and the public—the ultimate consumers of the food—from the health risks of pesticide contamination or exposure.

Organic (natural) farming methods do not involve the use of chemical-based pesticides. (Photograph by

Robert J. Huffman. Field Mark Publications

. Reproduced by permission.)

Protection from Pesticides

There are steps everyone can take to protect against the known (and potential) health risks of pesticide use or exposure.

• After pesticide is used on an area, it must be aired out.
• One can investigate and use non-chemical alternatives to pesticides.
• Pest control companies should be screened before being hired to work in the home.
• Pesticides must be stored carefully.
• Pesticides must be disposed of properly.
• Pesticides must not be applied or disposed of in streams or areas where wildlife drink and feed. (Waste can travel so it's important to be aware not only of the immediate location, but the areas and waterways it might be connected to, or drain into.)
• The Internet, science teachers, and the media can help to keep the public educated and updated on environmental issues.