(Beyond Pesticides, March 21, 2014) Banned pesticides and flame retardants may be the cause of higher autistic behaviors for children who were exposed in utero, according to new research published last week in the journal Environmental Health Perspectives. Previous research has demonstrated that organochlorine chemicals are linked to learning problems, such as attention-deficit hyperactivity disorder (ADHD), especially in boys. This research is one of the first studies to evaluate their contribution to autistic behaviors.
According to the study, Gestational Exposure to Endocrine-Disrupting Chemicals and Reciprocal Social, Repetitive, and Stereotypic Behaviors in 4- and 5-Year Old Children, children who were exposed to higher levels of brominated flame retardant PBDE-28 and trans-nonachlor, a component of the banned pesticide chlordane, scored higher in terms of autistic behavioral patterns as ranked by their mothers.
In the study, researchers conducted a case-cohort study recruiting 175 pregnant women from seven prenatal clinics within the greater Cincinnati, Ohio region who provided urine and blood samples during pregnancy to measure the concentration of endocrine disrupting chemicals. On average, pregnant women had 44 suspected hormone disrupting chemicals.
Five years later, when children had turned four or five, mothers were asked to rank their children’s behavior based on a series of factors including how well they played with other children or how frequently they made eye contact when spoken to. Those with higher scores had more autistic behaviors. Although a high score does not necessarily mean the child is autistic, the Social Responsiveness Scale, as it’s called, is often used by teachers and parents to determine the severity of behaviors.
Researchers found that children with the highest exposure to trans-nonachlor in utero scored an average of 4.1 points higher on the scale than those with less exposure, while those exposed to the brominated flame retardant PBDE-28 scored an average of 2.5 points higher. Although the increase in autism-like behaviors to the two chemicals were slight, it does demonstrate a pattern consistent with other behavioral disorders such as ADHD.
While most organochlorine pesticides are banned or restricted ””chlordane was banned in the 1980s”” their residues still continue to cause problems decades after their widespread use has ended. This study reinforces the need for a more precautionary approach to regulating pesticides and industrial chemicals. Once released into the environment, many chemicals can affect health for generations, either through persistence in the environment or long-term changes to the genetic code of humans and other animals.
Autism is a developmental disorder which has dramatically risen over the last decade: between 2002 and 2012 autism rates in the United State climbed to 78 percent. It affects the brain’s normal development impairing social interaction and communication skills. With boys four times more likely to develop autism than girls, it’s clear that hormones are directly linked to its development, and conversely that hormone disrupting chemicals like chlordane would disrupt that development.
Organochlorine pesticides have previously been linked to a number of other adverse effects to human health, including birth defects and diabetes. This study illustrates how the health impacts of pesticides can be often delayed, and pesticides once considered to pose “acceptable” risks are continuing to affect public health. In response to the growing evidence linking pesticide exposures to numerous human health effects, Beyond Pesticides launched the Pesticide-Induced Diseases Database to capture the range of diseases linked to pesticides through epidemiologic studies. The database, which currently contains hundreds of entries of epidemiologic and laboratory exposure studies, is continually updated to track the emerging findings and trends.
Join us and continue the conversation with James Roberts, MD at Beyond Pesticides’ 32nd National Pesticide Forum, Advancing Sustainable Communities: People, Pollinators and Practices, April 11-12, 2013, Portland State University, Portland, OR to discussthe impact of pesticide exposure on children and organic solutions for the future. This years’ forum will focus on solutions to the decline of pollinators and other beneficials; strengthening the organic food production system; regulating and right-to-know genetically engineered food; improving farmworker protection and agricultural justice; and creating healthy buildings, schools and homes.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.