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    There Is No Pandemic Of Chemicals Causing Brain Disorders In Children
    By Laura Plunkett | February 18th 2014 04:30 AM | 9 comments | Print | E-mail | Track Comments
    About Laura

    Laura Plunkett, Ph.D. in Pharmacology from The University of Georgia. Currently owner and principal of Integrative Biostrategies LLC, a scientific...

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    Last week, an article appeared in The Lancet Neurology (doi:10.1016/S1474-4422(13)70278-3) which reviewed studies and asserted that there is a "pandemic" of developmental toxicity. This led to a press release and a variety of stories in the media linking things like pesticides to brain disorders in children.

    The new article is an update of the authors’ 2006 paper on the same topic. Unfortunately, the authors continue to forget or ignore the fundamental principle of toxicology that underpins the effects that chemicals can have on living organisms, dose-response. As a result, this 2014 review suffers from the same use of faulty logic applied in 2006 in Grandjean and Landrigan’s apparent desire to promote their opinions without considering the basis in reason or scientific method.

    As before, Grandjean and Landrigan compile a list of chemicals that they claim is expanding in terms of having been identified as causing developmental neurotoxicity in humans, again relying on epidemiological studies where there was no clear measure of exposure. They mention ethanol as an example of a human developmental neurotoxin, which exemplifies their faulty logic. Abuse during pregnancy causes fetal alcohol syndrome, which is a highly variable group of birth defects that includes mental retardation, low birth weight, and malformations of the skull and face that tend to occur in babies born to mothers that repeatedly ingested high doses of alcohol during pregnancy.


    Pesticides were implicated in ADD, autism and cognitive delays in a new paper. But does the science show that? Image link: Harvard School of Public Health

    However, there are no data to show that maternal exposure to low, environmentally relevant levels of ethanol (i.e., concentrations that are known to be present in foods we eat every day) places the fetus at any risk of developmental toxicity. It is the dose of the chemical, and the pattern of exposure, that determines whether a chemical produces an adverse effect on an organism, not simply the presence of a chemical, even for developmental neurotoxicity.

    Just as a critical concentration at the site of action is needed before a drug can produce its beneficial effects in humans, the same principle applies to toxicity produced by a chemical. Effects that might be reported at high doses will not occur at lower doses if the concentration at the site of action falls below the threshold for toxicity.

    As I pointed out in 2006, if Grandjean and Landrigan’s logic is applied to drugs, an “outbreak of cures” would be predicted to be triggered by any dose of any drug. Evidence-based medical practice has proven that this is not the case.

    As a result, evidence-based toxicology and epidemiology dictates that the dose of chemical is the critical factor when examining the risk posed by a chemical and argue against a “pandemic” of developmental neurotoxicity associated with chemical exposure.

    Although the issues of autism, preterm birth rates, pediatric bipolar disorder, and other neurological conditions mentioned by the authors clearly are issues of concern in medicine today, improvements in diagnostic methods and criteria for such diseases may account for much of the purported increase in developmental neurotoxicity that is discussed by Grandjjean and Landrigan.

    As a result, Grandjean and Landrigan’s conclusions are flawed and lack a sound basis in toxicology and the science of risk assessment.

    Reference:

    Philippe Grandjean MD, Philip J Landrigan MD, 'Neurobehavioural effects of developmental toxicity', The Lancet Neurology, Volume 13, Issue 3, Pages 330 - 338, March 2014  doi:10.1016/S1474-4422(13)70278-3

    Comments

    Not chemicals? Perhaps the author, and we here in the US as a whole, should consider this: http://informahealthcare.com/doi/abs/10.3109/13550281003685839 And while we are considering what is at the link, also consider the fact that the ten states with the highest cancer incidence, and the states with the highest infant mortality are also states where SV40 contaminated polio vaccines were given.

    Hank
    Yeah, chemicals will be the death of us all. Look at what an organic egg label would look like, if dangerous organic eggs were required to have ingredient labels.

    Luckily, you eat food and eat products that contain no chemicals of any kind. And you have never been sick. Must be nice!
    "...a study of mothers living in the California Central Valley showed that children born to mothers who had been exposed to organochlorine (OC) insecticides that were agriculturally applied within 500 m of the home between gestational days (GD) 26 and 81 (during neural tube closure) were 7.6 times more likely to be diagnosed with ASD than the children of mothers who lived in the lowest exposure quartile. "

    Nothing to see here. Move along.

    Hank
    If we are just going to match curves, I can implicate the price of steel in the rioting of Kiev.  If you really want to see autism rates spike upward, look for wealthy neighborhoods in California where there happen to be a lot of pediatricians. Lots and lots of kids move there and then get diagnosed with autism. Los Angeles must be some sort of nexus for autism that it just turns kids that way within 6 months of moving there.

    You are like a baseball player bragging that they led the team in ninth inning doubles in the month of August; you are usually really obscure statistics and attributing causation. That is not how science works.
    Just because there is such a thing as statistical error does not mean that every study you disagree with committed that same statistical error. In fact, you are pointing out a statistical problem from a different study.

    That is not how science works either.

    More than just those two studies have demonstrated the need to further research the statistical relationship between pesticides and developmental problems. But to hear you tell it, the thousands of kids with autism is just an obscure statistic that can't really be linked to anything. So obviously there is no need to even research.

    Hank
    And yet if you shine that Awesome Light of Truth on your sweeping proclamation that pesticides must cause autism because a tiny epidemiological study found autism and then looked for correlations to it - and, what a shock, found something - you would see why it fails. Do you understand irony any more than you understand cause and effect versus correlation and causation false equivalence?
    I did not say that pesticides caused autism, I said that the statistical relationship justified the need for more research. And it was not one study, it was all of them. As far as I know, there have not been any studies of AChE inhibiting pesticides that found them to be safe for human consumption. Two of the most frequently used pesticides worldwide are the OPs chlorpyrifos and diazinon, but we really should include monomethyl carbamates (CBs) in the group too.

    You keep getting upset at me for finding correlations, but I am not a voice in the wilderness here. Pretty much every government body that regulates pesticides has found the same correlation to be suspicious, and has adjusted the warning labels accordingly.

    If you are going to keep repeating your claim that pesticides are unrelated to neurological development, then you are going to need to provide some proof. Your egg analogy is getting old, and your other arguments are baseless repetition. You keep mis-stating my position, which I assume means that you don't have any response to the research, or to the things that I actually did say.

    In a study comparing physiological effects of 11 pyrethroid compounds in rats, the type 2 pyrethroids strongly induced increased Ca2+ channel influx into the cell, whereas the type 1 pyrethroids did not (Breckenridge et al. 2009). It should be noted that these three exposure types induced calcium perturbations at levels below those described as having a toxic effect on the basis of primary mechanisms of action.

    That is not my opinion, that is a scientific fact. If your argument follows true to form, you are going to repeat your statement that the increased diagnosis was due to better detection methods. If not, then you will find some other fact that is even more unrelated.

    But heaven forbid that we should talk about Ca2 channel influx and the relationship to autism.

    Hank
    Now you are moving the goalposts. That is the second of the 5 Reasons People Stop Replying To Your Comments you have used . You have zero interest in actual research, your goal is to promote unsubstantiated conspiracy theory. Go comment on Mercola.com and you are likely to have an easier time.
    The original article was a broad assertion that pesticides do not cause autism. The article came to this conclusion based on a simple refutation of a narrow study. The broad picture is that there is plenty of good evidence that the chemicals in pesticides are linked to brain development disorders in general, and autism in particular.

    And the evidence is getting stronger. Each new study that is published chips away at the manufacturer's claim that pesticides are unrelated to human development. The only studies that support the company line are the ones that assume laboratory conditions and micro-exposure. These are not real world studies, but pesticide manufacturers are allowed to use them to claim their products are safe. This is not good science and you know it.

    This is hardly moving the goalpost, this is the original goalpost. I am not making that up, I am quoting well-known research, including http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3404662/ which refutes many of the assertions in the original article.

    While the research paper came to the ultimate conclusion that more research is needed, that is still a vastly different conclusion than you came to. Your conclusion is that everyone who disagrees with you is a quoting from a "conspiracy theory" website.

    This is one of the dozens of personal insults you have included in your responses to me over the years, and yet you still continue claiming that I am the one who ignores the rules of polite discussion.

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