How Herbicides Affect People

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Herbicides are poisonous chemicals that are used to kill unwanted plants, and are considered to be a type of pesticide. They are frequently used around the home and farm and represent a serious health hazard to adults, but they are especially hazardous to children and pets. Texas A&M University notes that exposure to herbicides can produce mild symptoms, such as rashes, nausea and headaches; more dangerous symptoms, such as seizures and convulsions; and even death.


Herbicides are commonly found as liquids or powders, and are sometimes premixed into fertilizer products. Herbicides are classified according to the types of plants that they affect. Broad-spectrum herbicides will kill any plant on which they are applied, while selective herbicides are designed to target only certain types of plants. Contact herbicides affect only the part of a plant that the chemical touches, while systemic herbicides are designed to be drawn up into the plant through its roots or absorbed through its leaves and stems. Systemic herbicides kill the entire plant. Although many modern herbicides are less toxic than their predecessors, they are still poisons and should always be handled with caution.

Skin Irritations and Allergic Reactions

According to the University of Missouri, herbicides are designed to be toxic to plants but in general are not highly toxic to mammals. Skin irritations are some of the most common effects when a person comes into contact with herbicides, and are most likely to happen on exposed areas, such as the hands and forearms. Some chemicals may burn the skin and should be washed off immediately with cold water. The Department of Veterans Affairs confirms that chloracne, a form of acne, is associated with exposure to Agent Orange. It can be mild or severe, and last up to several years. In severe cases, the skin may thicken and flake off. During the Vietnam War, the U.S. military sprayed millions of gallons of the herbicide Agent Orange between 1961 and 1971, in an attempt to defoliate trees in the jungle and deprive the enemy of food and cover.


The Department of Veterans Affairs acknowledges that the herbicide Agent Orange is responsible for a wide range of health problems in Vietnam veterans, including several types of cancer. The National Academy of Sciences concluded that there was a positive correlation between the incidence of Hodgkin’s disease, a cancer of the lymph system, and exposure to the herbicide Agent Orange. The VA also notes that non-Hodgkin’s lymphoma is also associated with exposure to the defoliant. Herbicides are also suspected as causes of prostate cancer, cancers of the lungs and bronchial tubes, and cancers of the larynx and trachea.

Nervous System Disorders

Some herbicides can cause nervous system disorders, such as peripheral neuropathy. The early symptoms of this disease include numbness and tingling in the toes and fingers, gradually spreading to include the hands and feet. Pain may be present, as well as muscle weakness and sensitivity to touch. Acute peripheral neuropathy occurs within a few weeks of being exposed. The VA cites peripheral neuropathy as another symptom of exposure to Agent Orange.

Effects on Children

Children and infants are at a higher risk for illnesses from herbicides than adults. According to the EPA, because children are still developing, their immune systems are less able to protect them from damage from herbicides. Children are also more likely to play in areas that expose them to chemicals, such as rolling on the floor or lawn. Mild exposure can result in complaints of dizziness and nausea, but herbicides may also cause neurological and developmental damage to children.


Pets can be poisoned by herbicides by coming into contact with the chemicals when they are outside, but herbicides kept in the home may also be a problem if they are stored where pets can get to them. Pets can ingest herbicides by chewing on plants or toys that have been contaminated, or when they lick themselves after coming into contact with the chemical. Animals that bring herbicides into the house may spread the chemicals around the home and leave residue on furniture and carpets.