Another study on human health and DDT: ADHD linked to DDT and other pesticides

Extravagant and way-too-enthusiastic claims that DDT is “harmless” to human health keep getting marginalized by new studies on the topic.

This week the Journal of the American Medical Association (JAMA) reported another study that links DDT to Attention Deficit Hyperactivity Disorder, “Increased Risk of ADHD Associated With Early Exposure to Pesticides, PCBs.”

I don’t have a full copy of the report yet.  Here is what is publicly available for free:

Individuals who are exposed early in life to organophosphates or organochlorine compounds, widely used as pesticides or for industrial applications, are at greater risk of developing attention-deficit/hyperactivity disorder (ADHD), according to recent studies. Previous studies had linked ADHD with very high levels of childhood exposure to organophosphate pesticides, such as levels experienced by children living in farming communities that used these chemicals. But a recent study using data from the National Health and Nutrition Examination Survey (NHANES) found that even children who experience more typical levels of pesticide exposure, such as from eating pesticide-treated fruits and vegetables, have a higher risk of developing the disorder.

JAMA. 2010;304(1):27-28.

Many of the chief junk science promoters will ignore this study, as they ignore almost all others — Steven Milloy, Roger Bate, Richard Tren, CEI, etc., etc.  How often does the junk science apple have to hit people before they figure out these people are malificent actors, when they claim DDT is harmless and we need more?

See also:

2 Responses to Another study on human health and DDT: ADHD linked to DDT and other pesticides

  1. Ed Darrell says:

    Lead, tobacco, and pesticides, are all poisons that work on the nervous system. See a pattern yet?

    Read the study: DDT wasn’t the last of the organophosphate pesticides.


  2. AM says:

    What else causes ADHD?

    OBJECTIVE: The study objective was to determine the independent and joint associations of prenatal tobacco and childhood lead exposures with attention-deficit/hyperactivity disorder (ADHD), as defined by current diagnostic criteria, in a national sample of US children. METHODS: Data are from the 2001-2004 National Health and Nutrition Examination Survey, a cross-sectional, nationally representative sample of the US population. Participants were 8 to 15 years of age (N = 2588). Prenatal tobacco exposure was measured by report of maternal cigarette use during pregnancy. Lead exposure was assessed by using current blood lead levels. The Diagnostic Interview Schedule for Children was used to ascertain the presence of ADHD in the past year, on the basis of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria. RESULTS: A total of 8.7% (95% confidence interval [CI]: 7.3%-10.1%) of children met criteria for ADHD. Prenatal tobacco exposure (adjusted odds ratio [aOR]: 2.4 [95% CI: 1.5-3.7]) and higher current blood lead concentrations (aOR for third versus first tertile: 2.3 [95% CI: 1.5-3.8]) were independently associated with ADHD. Compared with children with neither exposure, children with both exposures (prenatal tobacco exposure and third-tertile lead levels) had an even greater risk of ADHD (aOR: 8.1 [95% CI: 3.5-18.7]) than would be expected if the independent risks were multiplied (tobacco-lead exposure interaction term, P < .001). CONCLUSIONS: Prenatal tobacco and childhood lead exposures are associated with ADHD in US children, especially among those with both exposures.


    BACKGROUND: Previous research has suggested that television (TV) viewing may be associated with increased behavioral and emotional problems in children. However, there are few prospective studies targeted for its association with outcomes of children under 3 years old. The purpose of this study was to exam the association between children's early TV exposure at ages 18 and 30 months and the behavioral and emotional outcomes at age 30 months. METHODS: We analyzed data collected prospectively in the Japan Children's Study. TV exposure was assessed by mothers' report at infant ages of 18 and 30 months. The outcomes were assessed using the Strengths and Difficulties Questionnaire (SDQ). Analysis of Covariance was used to estimate the effect of TV exposure on behavioral and emotional outcomes. RESULTS: The percentage of children who watched TV 4 hours or more per day was 29.4% at age 18 months, 24.5% at age 30 months, and 21% at both ages. Hyperactivity-inattention at age 30 months was positively associated with TV exposure at age 18 months, whereas prosocial behavior was negatively associated with hours of exposure even after adjustment. However, there were no significant differences in SDQ subscales according to daily hours of TV viewing at age 30 months. CONCLUSIONS: Daily TV exposure at age 18 months was associated with hyperactivity-inattention and prosocial behavior at age 30 months. However, the directly casual relation was not proved in the present study. Additional research considering the TV program content and exposure timing are needed to investigate the causal relation between TV viewing and behavioral outcome.


    OBJECTIVES: We compared the frequency of behavioral problems in very preterm and term children at 5 years of age. We hypothesized that behavioral problems would be associated with cognitive impairment and environmental factors and that differences between the 2 groups would be reduced but persist after adjusting for cognitive performance and environmental factors. PATIENTS AND METHODS: The Etude Epidémiologique sur les Petits Ages Gestationnels (EPIPAGE) study was a prospective population-based cohort study that included all births occurring between 22 and 32 weeks' gestation and a control group of infants born at 39 to 40 weeks' gestation in 1997 in 9 French regions. Neonatal and obstetrics data were collected at birth. At 5 years of age, sociodemographic status and neurodevelopmental and cognitive development of the children, as well as maternal mental well-being, were assessed. The behavioral problems of 1102 very preterm and 375 term singletons without major impairments were studied by using the parent-completed Strengths and Difficulties Questionnaire. RESULTS: Parents of very preterm children reported significantly more behavioral problems, with a twofold higher prevalence compared with term children for hyperactivity/inattention, emotional symptoms, and peer problems. Behavioral problems were associated with low cognitive performance, developmental delay, hospitalizations of the child, young maternal age, and poor maternal mental well-being. Very preterm children were still at higher risk of behavioral problems compared with term children after adjustment for cognitive performance and all others factors. CONCLUSIONS: Behavioral problems were strongly related to cognitive impairment, but very preterm children were still at higher risk even after adjusting for cognitive performance. Early screening for behavioral problems should be encouraged for all very preterm children, and maternal well-being should also be the focus of special attention.


    I'm not saying that organochlorides DON'T cause ADHD (can't prove a negative), just that right now tobacco, lead, television, and premature birth have all been linked to ADHD. So your smug attitude that this is some sort of smoking gun is a bit premature.

    The questions to ask, if lead and tobacco were used so much more prevalently in the past, shouldn't we be seeing a decrease in ADHD children? If the peak years of DDT usage were prior to 1962, why are we still seeing a rise in ADHD? Is it a problem with diagnosis or definition?

    Remember that correlation is not causation until you can prove a mechanism of action.


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