Pesticides, what are they?
We've all heard the term pesticides before, but do we really know what they are?
Pesticides are chemicals that we use to kill undesireable organisms.
When we say undesireable organisms, we are referring to organisms (plants, animals, insects, etc.) that are harmful to us. Some of these organisms, or "pests," eat our crops, while others spread diseases. And it doesn't always have to be this serious. Weeds can be considered a pest for just growing in the wrong places (our yards). The point is, if we are using some type of chemical to control these pests, that chemical would be considered a pesticide.
The Need for Pesticides
Many of the pesticides that we use make our lives easier. For instance, (using some of our earlier examples) the pesticides in wool and our wood makes our clothes and furniture last longer. You wouldn't want to have to buy a new wool sweater every year, would you?
The fact that pesticides are in our food is probably what makes people the most uncomfortable. Do we really need that? Why can't all the farmers just grow food organically?
The answer, unfortunately, is that with current agricultural methods and technologies it is not possible to provide the quantities currently needed for the number of people living in the earth. Pesticides allow us to increase our harvests and feed more people.
In addition to applications in agriculture, pesticides have many other important uses. Many pests transmit diseases which are very dangerous to us.
For example, In the past, malaria was once a serious disease that killed millions of people globally. (The photo to the right shows the red blood cells of someone with malaria.) To fight this problem, we used the pesticide DDT, to kill the mosquitoes which transmitted the disease. It was successful, and the number of people who died from malaria shrank drastically. (More on this later.)
Here's another example that many of us can relate to: Millions of people in the US. have allergic reactions to the cockroaches in our homes. The pesticides in insect sprays and baits help reduce this problem.
Dangers of Pesticides
Presently, we are using more pesticides than ever. Here in the US, we use almost 4 pounds of it annually per person! Although most modern pesticides are much safer than their predecessors, a few of our commonly used pesticides are considered toxic.
In lab tests where high doses of pesticides were given, researchers have observed some significant health effects. Genetic damage, reproductive problems, and possible links to cancer are just some of the risks associated with pesticides.
As you can see, the pesticide issue is very complex. There is definitely a need for certain pesticides in such areas as agriculture and disease prevention, and yet there are also some obvious health risks from some of these chemicals.
To illustrate the constant debate over pesticide usage and to help you develop your own opinion about pesticides, we'll now talk about DDT, one of the most powerful and controversial pesticides in the 20th century.
This completes our Introduction to Pesticides.
Return to the beginning of the Pesticides unit