The Effects of Herbicides & Pesticides on Humans

Pesticides and herbicides are pervasive chemicals in the environment. Pesticide, according to, is an umbrella term that encompasses herbicides and insecticides 2. Herbicides are believed to present a bigger threat because they are highly concentrated in the water supply, due to runoff from agricultural use. The prevalent exposure of the world's populations to these substances has caused concern over their potential health consequences. These consequences are especially alarming as their effects are believed to induce devastating and life-long diseases, and deformities in children and unborn fetuses.

Endocrine Disruptors

The endocrine system is a messaging system that uses hormones and the bloodstream to convey responses throughout the body. A 1999 Pesticides News article classifies pesticides as endocrine disruptors. The action of these chemicals has been described as able to mimic the effects of human estrogen or testosterone; additionally, they are disruptive to the synthesis and breakdown of both estrogen and testosterone. The major endocrine glands include the pituitary gland, thyroid, adrenals, ovaries and testes. Adults can be affected by these chemicals. The article suggests however, that the effects that accumulate over the years in a developing person or during the intricate in-utero developmental process are far more dangerous. It has been found that animals and humans exposed to these chemicals in the womb are at a high risk of developing deformed reproductive anatomies, defects or alterations in sexual behavior, sperm counts, metabolism and brain development.

Autism and ADHD

Many pesticides, and thus herbicides, are petroleum-based. Petroleum, as a fat-soluble substance, has long-term effects in the body because:

  • it remains in fat-laden tissues
  • like the brain
  • adipose cells
  • for a long period of time

Children are noted by the Pesticide Action Network to be at a higher risk for brain development and functional issues associated with pesticides, due to a higher consumption by children of such chemicals 1. The article notes that, when comparing food and air consumption on a pound to pound basis in children versus adults, children are more greatly exposed to environmental pesticides and herbicides. As such, the article lists that neurological developmental issues, such as autism and attention-deficit/hyperactivity disorder, are more prevalent when exposure to pesticides during critical periods of brain development has occurred. Moreover, a 2010 Pediatrics journal article theorized that organophosphates, a class of pesticide, may contribute to the prevalence of ADHD; exposure to this pesticide is most common in American children in the 8- to 15-year-old age group. However, additional research is needed to confirm a causal relationship.


Many studies of pesticides and herbicides have been performed on the workers and handlers of these chemicals, such as farmers and their families. However, a 2010 Organic Consumers Association article by Dan Sharpley notes that a specialized type of cancer known as acute lymphoblastic leukemia is assumed to be directly linked to pesticide exposure in a normal, non-agriculture setting 3. They add that pesticides are not directly causative and that genetic susceptibility also plays a role.

Other Effects

The diversity of pesticides and the way that each person metabolizes them may shed light on their diverse actions and detrimental effects in the body. The website lists alachlor, atrazine, endothall, lindane and methoxychlor as commonly used herbicides and insecticides 2. Outside of their major effects on the endocrine system and their role in inducing neurological issues and childhood cancers, the site lists other non-specific effects of ingestion as eye, liver, kidney or spleen problems. They additionally describe anemia, cardiovascular, stomach and intestinal problems as related to pesticide exposure.