A recent study from researchers at University of Montreal and Harvard found a link experts call "persuasive" between ADHD and exposure to common pesticides.
Since dysfunctional acetylcholine signaling is thought to be involved in ADHD, and organophosphates, the family of pesticides spawned by the creation of nerve gas agents in World War II, act by disrupting acetylcholine signaling, scientists decided to investigate a possible link between organophosphate exposure and ADHD.
The study examined more than 1,100 children, 150 of which were previously diagnosed as ADHD. The findings, published in Pediatrics, revealed that around 94% of children examined had detectable levels of organophosphate in their urine. Children with higher levels of residue had increased chances of ADHD.
Organophosphates kill agricultural pests by acting as neurotoxins in insects. Excessive exposure to organophosphates in humans are now known to have toxic effects.
Previous studies have shown that exposure to some organophosphate compounds cause hyperactivity and cognitive deficits in animals. This study found that exposure to organophosphates in developing children might have effects on neural systems and could contribute to ADHD behaviors, such as inattention, hyperactivity and impulsivity.
Children are thought to be most vulnerable because the developing brain is especially susceptible to neurotoxic substances. Organophosphate exposure during fetal development and the first 2-3 years of life has previously been linked to detrimental effects on neurodevelopment in young children, including behavioral problems and deficits in memory and motor skills. High levels of organophosphate metabolites have also been found in children with leukemia.
Where Are Most Organophosphates Found?
Organophosphate pesticides account for 38 percent of all pesticides in use throughout the world. According to the study, approximately 40 organophosphate pesticides are registered with the U.S. Environmental Protection Agency (EPA) for use in the United States, and based on 2001 estimates 73 million pounds of organophosphates are used per year.
The EPA considers food, drinking water, and residential pesticide use major sources of exposure. Residential pesticide use is common, but the important source of exposure to pesticides for infants and children would be from the diet, says the National Academy of Sciences.
Organophosphates are used mostly on berries, fruits and some vegetable crops. The U.S. Pesticide Residue Program Report for 2008 notes that measurable concentrations of the organophosphate malathion were found in 28 percent of blueberry samples, 25 percent of strawberry samples, and 19 percent of celery samples.
The Environmental Working group has found that commercial baby food is the predominant source of organophosphate exposure in infants 6-12 months of age. For young children, the most common culprits are apples, peaches, applesauce, popcorn, grapes, corn chips, and apple juice.
Other Health Concerns with Organophosphates
Each year organophosphates poison thousands of humans throughout the world, causing hundreds of deaths. Organophosphates have been linked to childhood cancers, mammary tumors, decreasing male fertility, paralysis, birth defects, depression, Restless Leg Syndrome, seizures, mental disorders and Parkinson's disease. Exposure to organophosphates have been shown to cause anxiety, irrability, runny nose, chest tightness, shortness of breath, sweating, vomiting, nausea, stomach cramps, tension, dizziness, insomnia, muscle twiching and confusion.
What Can You Do?
A study has shown that when children ate organic fruits, vegetables and juices, signs of pesticides were not found.
"The transformation is extremely rapid," said Chensheng Lu, the principal author of the study published online in the current issue of Environmental Health Perspectives.
"Once you switch from conventional food to organic, the pesticides that we can measure in the urine disappears. The level returns immediately when you go back to the conventional diets," said Lu, a professor at Emory University's School of Public Health and a leading authority on pesticides and children. Within eight to 36 hours of the children switching to organic food, the pesticides were no longer detected in the testing.
You can reduce you and your families exposure to organophosphates and other potentially harmful pesticides by buying organic produce, especially when buying foods that are most heavily laden with pesticides – celery, strawberries, blueberries, peaches, bell peppers, apples, raspberries and grapes rank among these high-pesticide crops.
ADHD AND PESTICIDES- VIDEO (senior author of the study speaks)
ABC NEWS ADHD AND PESTICIDES- VIDEO
ORGANOPHOSPHATES IMPLICATED IN MAD COW DISEASE- ARTICLE
ORGANOPHOSPHATES IN FLEA PET PRODUCTS- ARTICLE
ORGANOPHOSPHATES AND CHILD'S HEALTH- WEBSITE
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