Hesperian Health Guides

Long-term Health Effects of Pesticides

In this chapter:

Most pesticide poisoning comes from contact with pesticides over weeks, months, or years, not from using them only once. People may not get sick from pesticides until many years later. In adults, it can take 5, 10, 20, 30 years or more to get sick from regular exposure. How long it takes for illness to show up depends on many things. In children, it usually takes less time. Illness from pesticides can start in a baby before the baby is born, while the mother is pregnant and in contact with pesticides.

When a person is exposed to pesticides over a long period of time, it is hard to know if his health problems are caused by pesticides. Long-term exposure may cause long-term harm, such as cancer, and damage to the reproductive system, the liver, the brain, and other parts of the body.

Many long-term effects of pesticides are hard to see because people in farming areas are exposed to many different chemicals and because farm workers may move from place to place.

When people get cancer and other diseases, doctors and scientists may say the illness is due to chance, or to problems other than pesticides or contamination. They may tell us we cannot blame pesticides or other toxic chemicals. And sometimes people who sell pesticides or promote pesticide use will lie about it because they do not want to be responsible for other people’s health problems. They can say this because it is often impossible to prove without a doubt that an illness which takes a long time to develop was caused by a particular pesticide or other toxic chemical.

A man carries bananas through a plantation as an airplane sprays overhead.
A sick man in his bed wearing a breathing mask.
Juan worked in the banana plantations… …and 10 years later, he developed cancer.

Signs of long-term illness from pesticides

Pesticides and other toxics can cause many long-term (chronic) illnesses. Some signs of chronic illness are: weight loss, constant weakness, constant or bloody cough, wounds that do not heal, no feeling in the hands or feet, poor balance, loss of vision, very fast or very slow heartbeat, sudden mood changes, confusion, memory loss, and trouble concentrating.

If you have any of these signs, tell your doctor or health worker. Be sure to tell them all the ways you may have been in contact with pesticides and, if possible, which ones.

Some long-term health effects of pesticides

A thin man coughing.

Damage to the lungs: People exposed to pesticides may get a cough that never goes away, or have a tight feeling in the chest. These can be signs of bronchitis, asthma, or other lung diseases. Damage done over time to the lungs may lead to lung cancer. If you have any signs of lung damage, do not smoke cigarettes! Smoking makes lung disease worse.

Cancer: People exposed to pesticides have a higher chance of getting cancer than other people. This does not mean you will get cancer if you work with pesticides. But it means that working with pesticides gives you a higher risk of getting the disease.

Hundreds of pesticides and pesticide ingredients are known or believed to cause cancer. Many more have not yet been studied. The most common cancers caused by pesticides are blood cancer (leukemia), non-Hodgkins lymphoma, and brain cancer.

A man sitting next to a pesticide sprayer drinks from a bottle.
Because alcohol can damage the liver...
...drinking alcohol makes pesticide poisoning worse.

Damage to the liver: The liver helps clean the blood and get rid of poisons. Because pesticides are very strong poisons, the liver sometimes cannot get rid of them. Severe liver damage can happen after a serious poisoning or after working with pesticides for many months or years.

Toxic hepatitis: It is a liver disease people get from being exposed to pesticides. Toxic hepatitis can cause nausea, vomiting and fever, yellowing of the skin, and can destroy your liver.

Damage to the nervous system: Pesticides damage the brain and the nerves. Long-term exposure to pesticides can cause loss of memory, anxiety, mood changes, and trouble concentrating.

Damage to the immune system: Some pesticides weaken the immune system, which protects the body from disease. When the immune system is weak from poor nutrition, pesticides, or from illnesses like HIV, it is easier to get allergies and infections and it is harder to heal from ordinary illnesses.

Reproductive health effects of pesticides

A woman breastfeeding a baby.
Breast is best!

Pesticides have many of the same reproductive health effects as other toxic chemicals. They can harm people's ability to have babies, or for babies to grow up healthy.

Chemicals can enter a woman's body and appear in her breast milk later. There are so many pesticides in use all over the world that even mothers who have never used pesticides have some toxic chemicals in their breast milk.

Even if you think your breast milk may have pesticides in it, the benefits of breastfeeding are stronger than any possible harm from pesticides in breast milk. Breast milk is the best food to help a baby grow healthy and strong.

Some effects of pesticides on reproductive health are:

A pregnant woman standing next to a man.

Sterility: Many male farm workers around the world have become unable to have children after they worked with certain pesticides because they can no longer make sperm.

Birth defects: When a pregnant woman is exposed to pesticides, the baby inside her is also exposed and can be damaged. Being exposed to pesticides when pregnant does not always mean the baby will have birth defects. But the baby will have a higher risk of having birth defects, learning difficulties, allergies, and other health problems.

A farm worker standing beside his pesticide sprayer hands his clothes to a woman to wash.
Pesticides on clothing can affect anyone who comes into contact with them.

Damage to hormone-producing glands: Hormones control many of our body activities, such as growth and reproduction. When pesticides damage the glands that produce hormones, this can cause problems with childbirth and reproduction.

Even if a woman is exposed to pesticides before she is pregnant, she can have a miscarriage or the baby may be born dead because of the exposure.

This page was updated:05 Jan 2024