Hesperian Health Guides

Environmental Problems from GE Crops

In this chapter:

When large corporations make and sell only a few kinds of seed, and then convince farmers worldwide to use only these seeds, many different types of plants may be lost and food security is harmed. But the most harmful effect of GE crops on the environment is the loss of biodiversity essential for a healthy environment.

Loss of natural pest controls. Some GE crops are made with pesticides inside them. When pesticides are used without careful controls, the pests they are meant to kill can become resistant to them.

Harm to wildlife and soil. Pesticides in GE crops kill helpful insects and bacteria that live in the soil. They may also harm birds, bats, and other animals that help pollinate plants and control pests.

Effects on nearby plants. Pollen from GE crops blows in the wind and spreads to other plants that are similar to them. But because GE plants are new, nobody knows for sure what long-term effects this may have.

In a field with dead birds on the ground, a farmer wielding a hoe fights off big bugs labelled,"Loss of traditional crops," "Pesticide poisoned soil," and "Harm to wildlife."
Farmers suffer when GE crops harm the environment.

Better safe than sorry

An African proverb says, “If you have to test the depth of a river, put one leg in the water first. This way you do not risk drowning.” This is another way to say it is wise to act with precaution, and to follow the precautionary principle. When we are thinking about using new inventions and substances, it is best to know they are safe, rather than risk being harmed unnecessarily.

But corporations and governments are testing GE foods on us every day by having us plant and eat them without knowing what harm they may cause. They are forcing us to “test the depth of the river” with 2 legs, instead of one!

People speaking.
Try these improved seeds.
Will the crop be safe to eat?
What will the long-term health effects be?
I'm not sure that's the best choice for us.

How do you know if seeds and food are genetically engineered?

Most genetically engineered seeds do not look, feel, smell, or taste any different than ordinary seeds, so they may be planted by farmers who do not know what they are. Monsanto, the company that makes most GE products, has refused to label them as GE foods, so the people who eat them cannot know if they are GE foods. The only way to know if seeds and food are GE is to test their genetic structure. Testing kits are available, but expensive, in the United States and Europe.

Mother Seeds of Resistance

In Chiapas, Mexico, farmers are concerned that pollen from GE crops may affect their maize crops. With the help of international supporters, they found a way to test their crops to know if they are affected in any way. The project is called “Mother Seeds of Resistance.”


Seeds are tested with testing kits bought from companies in Europe or the United States. By finding out if their crops have been contaminated by GE maize, they can tell their communities and their government about the problem, and work to prevent it from spreading further. Because they are testing the seeds themselves, farmers gain control over the process — a kind of control that is lost by not knowing what is in the crops they are growing.

By taking back control of their crops, farmers in Chiapas are protecting their food security while practicing long-term food sovereignty.

This page was updated:05 Jan 2024