TENDR Organophosphate Pesticides Profile
What are organophosphate pesticides?
Organophosphate pesticides (OPs) are a class of neurotoxic chemicals initially developed for use as warfare nerve agents in the 1930-40s. Many OPs, including malathion, dichlorvos, azinphos-methyl, and chlorpyrifos were licensed for insecticidal use during 1950-60 before there were requirements for evaluation of the potential human health or environmental impacts of pesticides. OPs are currently used on a wide variety of crops including fruit trees, vegetables, wheat, soy, corn, and cotton. While agriculture use of OPs has been declining in the United States, 33 million pounds were still applied in 2007 alone.
What are the main ways that OP pesticides get into people’s bodies, including pregnant women and children?
The widespread use can result in high exposures among agriculture workers. After working in pesticide-treated fields, farmworkers return home with OP residues on their clothing, boots, and skin and can inadvertently expose their families, including pregnant women and children. People living in homes or attending schools near treated farmland are also likely to be exposed to OPs, sometimes at or near occupational levels.
The general population can also be exposed to OPs, although at well-below occupational levels, by eating food or drinking water containing pesticide residues. OPs are also used for pest control within homes and public places such as hospitals, parks, schools, golf courses, and right-of-ways.
What are the effects of OP exposure on children’s brain development?
OPs are neurotoxins that inhibit the activity of acetylcholinesterase, an enzyme necessary for the proper functioning of nerves. During an acute poisoning incident, the enzyme is suppressed and nerve impulses fire uncontrollably, resulting in symptoms such as muscle spasms, confusion, dizziness, loss of consciousness, seizures, abdominal cramps, vomiting, diarrhea, cessation of breathing, paralysis, and death in extreme cases.
Long-term exposure to lower OP concentrations may not cause the same severe symptoms, but are still hazardous. The developing fetus and young child are particularly sensitive to OP exposure because the brain is growing and developing at an exceedingly rapid pace. Exposure during pregnancy is associated with developmental abnormalities, reduced motor function, and decreased IQ. Studies have also found associations between prenatal exposure and increased risk for neurobehavioral problems such as Attention Deficit Hyperactivity Disorder (ADHD)-like behaviors and autism spectrum disorder. Studies have found similar, serious neurodevelopmental effects from OP exposures in both rural and urban populations.