Home > Got Questions?, Science, Uncategorized > What do scientists mean when they talk about ‘environmental factors’ that cause autism?

What do scientists mean when they talk about ‘environmental factors’ that cause autism?

This week’s “Got Questions?” response comes from Alycia Halladay, PhD, Autism Speaks’ director of research for environmental science.

Research has taught us that there’s no simple explanation for what causes autism. We know that genes play a role, but they aren’t the whole picture. Environment also matters.

However “environment” can be a tricky term, as pediatrician Perri Klass recently noted in her New York Times column. In autism research, we use the word to refer to pretty much any influence beyond inherited genes—not just exposure to pollutants or other toxic chemicals.

In fact, the environmental factors that research most strongly links to autism are influences such as maternal infection during pregnancy (especially rubella), birth complications (especially those involving oxygen deprivation), and parental age at time of conception (dad as well as mom). Parents who wait less than one year between pregnancies may be at a slightly higher risk for having a child with autism. (Conversely, there is strong evidence that mothers who take prenatal vitamins before conceiving reduce the odds that their children will develop autism.)

Clearly, countless fetuses and babies are exposed to “environmental risk factors” such as these without ever developing autism. But if a child is genetically predisposed to autism, it appears that these influences further increase the risk. For this reason, we say that environmental factors increase the risk of autism rather than cause it.

Research has suggested that many other environmental, or nongenetic, factors may increase the risk for autism. But scientists can’t yet say whether these involve direct (versus coincidental) links. Such factors include a pregnant woman’s exposure to certain chemicals such as pesticides and phthalates (commonly found in plastics) or certain drugs such as terbutaline (used to stop premature labor), valproic acid (to control seizures), and some antipsychotics and mood stabilizers. Of course, in the case of medications, any possible increased risk of autism must be balanced against a woman’s medical needs—which can likewise affect the health of her pregnancy and children.

In addition, most environmental factors associated with autism appear to increase risk only slightly and only in combination with other factors such as genetic predisposition.  So it is difficult, in most cases, to pinpoint any one environmental influence. For these reasons, Autism Speaks continues to fund research on a wide range of environmental risk factors. Importantly, the more we learn about how these influences affect brain development, the better we can help the children, adults and families who are affected by autism.

Want to learn more about the research Autism Speaks is funding? On our Science Grant Search page, you can browse studies by topic and location. Finally, if you or your child is affected by autism, please consider participating in one of our clinical studies. Thanks, and please keep sending us your questions.

  1. Sarah
    September 30, 2011 at 7:38 am

    Somehow, get the word out to the twenty year olds… before conception.

    Thank you Autism Speaks.

  2. tracy colarusso
    September 30, 2011 at 9:35 am

    can they answer this? If environmental factors can influence it….why does only one of my twin boys have Autism?

  3. Jennifer
    September 30, 2011 at 9:39 am

    What about vaccines as potential causes?

  4. A mom!
    September 30, 2011 at 9:41 am

    We did the Chromosome test for my child and it came negative, I am still young and I had two other kids that are so healthy, my baby boy was so healthy as well, he was talking, walking, doing everything a child should do his age until the “MMR” vaccination, now everyone is telling me that doctors can’t prove that this is right, but I tell you that some countries don’t do MMR vaccine @ a young age any more, I read a lot and I hit my head over walls to know what is going on, I saw the videos of my baby over and over again not a clue on what happen, but I know that my previous doctor when she ask me about my child if he was sick and I told her YES he have runny nose and she made the MMR vaccine, I know she is the one to blame, parents should educate themselves from now on, some people knows that these vaccines should not be done before age of 2 and why is that because either a relative is a doctor or a nurse or they are doctors but others like me don’t know and we believe our doctors until this happen!!!
    My baby is gaining his stuff because of the love I give him, I am not making him feel he is different than his peers, he have mild Autism now and he is the love of my life but when I look back, it break my heart on what he went through for nothing! Just stop giving the MMR vaccination at a young age and start telling the truth to people!

  5. Ashley
    September 30, 2011 at 9:42 am

    So..this is almost word for word my senior thesis…only written 4 years later…interesting…

  6. Jennifer
    September 30, 2011 at 10:10 am

    My poor kids didn’t have a chance! My boys were 14 months apart, born to a mom in her 30’s, a dad in his 40’s. I took antidepressants, beta blockers, and injectable blood thinners, and have an auto-immune disease. Either way, they are a joy and a blessing to me, and all who know them.

    My neighbor had a son between my two boys. My boys have Asperger’s, hers is Autistic. There are a number of kids in my neighborhood who are on the spectrum. My neighbor and I have several similar personality traits – both dominant people and both very intelligent and driven toward success. Our husbands are both pilots – both airline pilots and military pilots. They are both very considerate and tender hearted men, both honorable and intelligent.

    But without my “struggles” I would miss out on the blessing.

  7. September 30, 2011 at 10:25 am

    This rings so true in the case of our daughter who is autistic. I am especially convinced that the oxygen deprivation and the medication to assist in premature delivery is a factor in our case. Thank you for sharing these comments.

  8. Iris Reeves
    September 30, 2011 at 10:25 am

    I look at pictures of my grandson before the MMR shot and look at the pictures taken after and the difference is there…..no questions, except WHY. Please do not get this shot until your child is at least 3 years old and if your child is sick, resch. the appt. Also have them separate the shots not all of it on the same day!!!!

  9. Elmer Wurts
    September 30, 2011 at 10:28 am

    There’s a very good book by Dr. Andrew J. Wakefield with a foreword by Jenny McCarthy that goes over the controversy regarding Autism and Vaccines. I highly recommend “Callous Disregard” by Andrew Wakefield it sheds light on the facts and medical studies conducted. It may be late for some of our children but we can help future generations and their families.

    • ES
      September 30, 2011 at 9:30 pm

      If those two were giving away a free car, I wouldn’t take it. Neither one is an expert on anything but self-promotion. Meanwhile, measles and whooping cough and HiB infections, complications and deaths are going up due to their callous disregard for actual science. There is no link between vaccines and autism. Read the following book excerpt to find out the terrible consequences one family went through because they decided not to vaccinate their kids. http://www.npr.org/2011/01/09/132735944/as-the-facts-win-out-vaccinations-may-too

      • Sarah
        October 3, 2011 at 11:32 am

        Thank you Thank you Thank you ES!!!! I am so sick of this Vaccine debate!!! Here they are telling you it’s Environment and they don’t believe it. And that women who “highly recommends” Wakefield and McCarthy WHAT!!!!! Wakefield should be be put on trail for murder and McCarthy who cares what that air head blond has to say, she turned her back on the Autism community when she found out her son didn’t have Autism after all. She is a idiot , like me and many other mother’s of Autistic children think she just needs to go away we never asked her to speak for us !!!!!! Stop putting public health at risk Vaccinate your children!!!!!!!!!!!

  10. alicia
    September 30, 2011 at 10:35 am

    Intersting. Although I am still not sure about the environmental influence especially those around the time of birth. I have three children, two sons both have Autism (ages 12 and 3, two different fathers) and a daughter with perfect development (age 20 Months). The funny that gets me is my sons are also far apart in age with different fathers, both developed the same way (i.e. same speech, social, and behavioral issues), although my younger son is a bit worse behaviorally. My oldest son was born with beathing issues, my younger son was born with pneumonia, which I also had while 8 months pregnant. But the kicker of it all is my little girl, who was born not breathing for 40 minutes, she only had a heart beat. She seems to be prefectly normal, talking like crazy and social as can be. I guess you never know how it will turn out until it done.

  11. ailyn delgado
    September 30, 2011 at 10:37 am

    I will expouse to radiaction while was pregnant and my son has autism.

  12. mandi
    September 30, 2011 at 10:41 am

    Why are they not looking into the possibilities that maybe drugs used during labor like the epidural and potocin could be contributing???

    • MB
      September 30, 2011 at 7:46 pm

      i agree w/ mandi that there could be a correlation there-c sections, epidurals and inducing labor has increased dramatically over the past 10 years!

  13. aunt tara
    September 30, 2011 at 11:02 am

    Thank you! My godson had a very similar experience. I believe fully this article is lacking in information. I’m not sure why “they” won’t tell the truth about the vaccines and the heavy metals they contain, but the more we raise awareness the more people may be able to avoid the tragedy of watching their children regress. Once again thank you.

  14. Eddie Cabbage
    September 30, 2011 at 11:22 am

    They know environmental factors make a difference but they don’t know how?

    so they don’t really know at all.

    Don’t believe it, autism is 100% genetic

    • A mom!
      September 30, 2011 at 12:14 pm

      It is not genetic! We don’t have anyone in my family with Autism, we did the chromosome test and it came negative…
      My heart is crying but I believe and I am totally sure it is the MMR vaccine, well, doctors tell people they know about its dangerous effect but not us! shame! Truly shame on them!

  15. proudmama
    September 30, 2011 at 1:13 pm

    I don’t know what to believe anymore. I took topamax before I found out I was pregnant and I always thought that is what caused my sons autism. I don’t think it’s the vaccines that caused my sons autism because I noticed things before he received his mmr. But none the less, he is mine and he has autism and I can’t change that. I can only help him overcome it. I love my son so very much! He is perfect in every way.

  16. Katie Wright
    September 30, 2011 at 2:41 pm

    You cannot be serious. AS cannot have this conversation and hide from the vaccine issue. Naturally for many vaccines were not a trigger but for so many they were.

    Over stimulation of the immune system resulting in regression, chronic illness and autism is such a common trajectory into autism. Please stop hiding from this. Children like mine, ironically, need to be represented by AS science in these discussions.

  17. MB
    September 30, 2011 at 7:42 pm

    My son was 2 weeks overdue, never had a shot until he was 6 months old, and even then it was one at a time. He’s never had the MMR. He is our first child. The only medication I took was a prenatal. My husband and I were both in our early 30’s, and I was never sick a day in my pregnancy, not even a cold. I thought I did everything right, as autism was my #1 fear. My son still has PDD-NOS. Sure, I ate out of phalate bowls. But that alone can’t be it. I used to obsess over what caused his autism, as he doesn’t meet any of the risk factors. But he’s wonderful and bright and I wouldn’t change a thing about him. But, I have come to believe there are no real answers to this epidemic.

  18. lupinssupins
    September 30, 2011 at 8:51 pm

    My older son is on the spectrum, while his younger brother is not. Both were vaccinated on the same schedule, except that, by the time my “NT” son was born, there were actually even MORE vaccines available. Not only did all these shots not “give” him autism, they saved him from, for ex., the haemophilis influenzae which had gravely sickened my older son, husband & mother-in-law years before. I also have family members who were crippled by polio before that vaccine’s availability; my 2 older brothers nearly died of whooping cough as toddlers and we were all nearly orphaned by the meningitis that sent our mother into a coma when I was a baby. I am GRATEFUL that vaccines have saved so many others from so much suffering & death.

    I am saddened & appalled at the influence Andrew Wakefield & his slapdash, amateurish “study” continue to have on the discussion of the causes of autism! British medical authorities have taken away that charlatan’s medical license for a reason, and no, that reason is NOT some imagined Big Pharm “conspiracy”! As a pediatrician friend of mine, the smartest & kindest doctor I have ever known, has lamented, the cult-like anti-vaccine movement has cost LIVES! I am no fan of the drug companies & their greed, but the discredited vaccine scare has actually killed real children. @A Mom, I am sorry for your grief and for what your son went through. But what is this “chromosome test” you keep mentioning? There IS no chromosome test for autism! Whatever prenatal tests you had, they were not for autism.

  19. Bharbara Gudmundson
    September 30, 2011 at 8:59 pm

    I have been doing work on an environmental issue that for 70 years has been affecting every living thing on the North American Continent. In 1991 I began working on the issue of the release of garbage leachate on to streets and lanes in North American cities and towns. In 1938 compactor garbage trucks began to be used in North American cities while at the same time during the 1930’s, 1940’s and 1950’s there was a large increase in the types of chemicals being created and thrown into the garbage. These compactor trucks contain many combinations of chemicals that are the results of what kinds of garbage is picked up in various districts. We line our landfills with geomembrane linings (that are as thick as 60 garbage bags laid out one on top of the other) in an attempt to contain the garbage leachate that is created because of the dangers presented to the area the landfill is built on. Before the trucks ever get to the landfill a great deal of the garbage leachate in the garbage has been released while the truck driver travels his/her route. These are compactor trucks and during the compacting the solids are separated from the fluid similar to what happens when you squeeze an orange to separate the juice.
    My environmental work has been the investigation of the release of garbage leachate on to streets and lanes of North American communities. For twenty years my work has been to photograph and film the release of garbage leachate and inform all levels of government and organizations of what is occurring. When I hear, during the investigation and discussions about the causes of Autism, and that there is an environmental factor it always leads me to believe there is a co-relation with my environmental work. This question keeps coming to the forefront whenever I hear about the environmental factors being put forward where Autism is concerned. Many times I have attempted to ensure the researchers in Autism organizations understand there may be a co-relation.

    Research from October 2008 to April 2009
    http://www.flickr.com/photos/bharbara/collections/72157622539601206/

  20. mother of 3
    September 30, 2011 at 11:42 pm

    My son was not vaccinated at all and he still has Autism. What a load of crap it is genetic but nobody wants to believe it, they all want something or someone else to blame, a reason why it isnt their fault. My son has my genes and his dads genes, those combined gave him austim. At the end of the day it doesnt really matter. We all need to spend our time working with our childrent o help them be the bast the possibly can be, not trying to blame all our lifes problems on other people or the ellusive “THEY” who wont tell you all whats going on

  21. Katie Wright
    October 1, 2011 at 10:08 am

    MB, you were so much smarter than me! I thought separating vaccines was nonsense. However, I did try to do everything “right” within my ability; no meds, no alcohol, no caffeine….and yet here we both are. I can completely understand why vaccines are not an issue that interests you, it wasn’t a factor for your child.
    I had a typically developing, happy, chatty boy and post a half dozen vaccines he was essentially gone- no PDD – I am talking a month or 2- then straight to severe, severe autism.
    There are different answers for different ASD kids, so some, like me, the answer to my son’s ASD is obvious, for you it isn’t the same. I get that.

  22. Sarah
    October 1, 2011 at 5:17 pm

    My son had a chromosomal DNA microarray analysis done and the results came back “normal” per the lab report. Autism was listed as one of the conditions tested for which may mean that the lab was looking for a deletion or a mutation which they did not find. My son is genetically “normal” and we have no history of autism in my family yet he regressed and was dxed at age 3. I think some autism is genetic but there is a large subpopulation of children with autism that had an environmental exposure early in life that impacted their neurodevelopment. I believe a neurotoxin(s) is involved which is why the autism numbers are so high.

    Perhaps we need tighter controls on products (toys, food, medicine) imported from overseas that may be contaminated or contain harmful toxins that are dangerous to our kids.

    • SuLu
      October 5, 2011 at 4:51 am

      Sarah, chromosomal microarray analysis is NOT even remotely a definitive test for autism or any specific ASD. It can merely identify a tiny percentage of chromosomal abnormalities that are SOMETIMES thought to be related to [NOT diagnostic of] a very small percentage [nor more than 15%, and that's being generious] of ASDs, or in some cases only to conditions that have some occasional co-morbidity with autism, such as Fragile X. No one who “passes” their CMA can be said to be free of autism, not even at that one moment in time! We now know that autism does not merely have an ONSET of approx. age 2-3 years, but merely starts to MANIFEST at that age. Except in the rarest of cases [& even those "exceptions" are still only conjecture], it is present in the baby all along.
      As for having no family history of autism, that’s what I thought, too, but you’d be surprised. Often, there are autism traits scattered all thru a family that have never amounted to a diagnosis– after all, did you know that Asperger’s Syndrome did not make the DSM until 1994? After my son’s dx as a young adult, I mentioned that the doctor wondered about there being no AS in our family. My brother exclaimed, “Are you KIDDING?! Hellooo– our father!” My ex-husband [the one who had refused to pursue our son's being "different" b/c he didn't want him "labeled"] said, “Wait, I thought it was probably from MY father!” And years after my son was born, 2 of my Maternal cousins had children with far more profound autism than my son. One of those is the twin of a “neuro-typical”– same genes, same diet, same vaccination schedule, same environment, same toys– it just HAPPENS! What’s more, he’s the only one of EIGHT children [again, same parents, upbringing, vaccination schedule] to have autism! Averages are just that– averages.

      As much as we love and care for all our children, “just the way they are,” as dear,sweet Fred Rogers [who, in retrospect, had quite a lot of Aspie traits] used to say, autism takes a terrible toll on a family. It can be exhausting, frustrating, and heartbreaking to long for the communication and affection that we find missing in our parent-child relationship. So we struggle to find someone, something, to blame– Sometimes it’s ourselves, as we wonder guiltily if that one dose of [random med, sushi, alcohol, coffee] we took before we knew we were pregnant was the cause. Sometimes it’s our doctors– why didn’t they tell me x, y, z? Or our family— why didn’t mom/dad tell me about their Cousin Johnny in an institution? And, thanks to that charlatan, ex-doctor Andrew Wakefield, tens of thousands of grieving or ranting parents blame vaccines, leading to hundreds of needless deaths from diseases which actually ARE preventable, in a vain effort to prevent a non-lethal spectrum of disorders that so fare, are, sadly, NOT preventable.

  23. October 2, 2011 at 12:53 am

    It`s an absolute crime that an article like this doesn`t cover the mercury, vaccination, acetone overloads our systems go through and the probable generational vaccination damage done. Try to explain why there are almost no autistic kids over 32 years. I went to school in the 60`s and early 70`s and I am positive there wasn`t the presence of autistic kids like there is now. The simple fact is someone is trying to cover their own butt because it is impossible that we don`t know the cause. In the 60`s most everyone thought it was possible that tobacco caused cancer but because of the tobacco companies comections and money it wasnt until the 70`s that they started agreeing it was the main cause. Right now with Autism most everyone are pointing to the secondary factors rather than the primary. WHY. Because the vaccin manufactureres have so much control and power in this country. It is clouding every ones ability to see the truth. People We Must fight this. Talk Talk Talk. Don`t give in to the insanity like the sixties.

    • lupinssupins
      October 5, 2011 at 5:21 am

      Sorry, Randy. I, too, went to school in the 1960s and early 70s, and if you’re “positive there wasn’t the ‘presence’ of autistic kids like there is now”… don’t you have any idea what was done with such children in those days? Of COURSE we didn’t see them at OUR schools! They would never have been allowed in! .. Except for those “Aspies” who were blessed with a broader range of “savant” interests, who would have just been thought of nerdish Brainiac types, or “excessively shy” or “quirky,” which would have included several members of my and my husband’s families, whose various genes came together to lead to my beautiful, sweet, Aspie son. The rest would have been routinely institutionalized, usually at the “well meaning advice” or even insistence of their doctors, with such blessed exceptions as Temple Grandin’s mother. [Temple would be about our contemporary, I think, and SHE was certainly "present" back in our day.] “Inclusion” and “mainstreaming” wouldn’t come along for decades. In my city, a major school exclusively for autism was founded in 1971 and had no shortage of applicants. As more is learned about autism, for example that it is not one, clear-cut disease, but an entire spectrum of disorders, of course there will be more cases diagnosed. To say it’s “impossible that we don`t know the cause” of something you claim barely existed 30 years ago is absurd. We don’t know the “cause” of all kinds of diseases, disorders & syndromes! And to blame ASDs on everything that has changed in our environment during the same time period as its apparent incidence has increased is just irresponsible conspiracy-mongering.

  24. JulieK
    October 2, 2011 at 10:40 pm

    Seriously, you people are not recommended a book by Dr. Wakefield? I have fraternal twins. One is on the spectrum; the other is perfect and the brightest of all my children. It’s just plain old dumb luck – the luck of the draw, the cards we’re dealt…. It’s the chemical make-up of some people and some who may be sensitive to this or that. I don’t sneeze near ragweed, but my step son’s nose practically runs off his head. Must be his MMR vaccine.

    It wasn’t the shot. It was there all the time. I knew he was different by the time he was 6 months old. I had a lot to compare him to, so in that regard I was lucky. I didn’t cause. A shot didn’t cause it. That’s just the way he is.

  25. Jessica E
    October 3, 2011 at 4:53 pm

    Has this really turned into a Vaccine issue? Wow mom’s against Vaccines will grasp at anything now wouldn’t you? You do know that Vaccines causing Autism has been dis proven over and over again? You do know that in many cases signs of Autism will not show up in Children until ages 2-4 right and not because of the MMR’s. You do understand that if the child was fine before a fever and isn’t after that the Autism was always there,a fever can happen with a cold , the flu , chicken pox and god forbid measles. By not getting your child vaccinated is harming your child , my child and other children. There are many factors in the rise of Autism….. just because it’s there , genetics , age of the parents , and most likely food additives , air pollution , and pesticides. Could be all of the above but vaccines……No diffidently NOT!

    I had to read a above comment again and again to believe that someone wrote it and meant it….. Recommended Wakefeild? Really ? You are going to recommend a book written by a man who has be discredited by every research lab from the United States to England? A man who fudged findings and was hired by attorneys that represented parents who were suing the MMR companies? A man who has lost his license because he had lied to millions of people and helped cause 100’s for deaths due to his lies ? Did you really do that ? Then you made matters worse by topping it off by recommending a book written by Jenny McCarthy , a women who’s claim to fame is to show every thing to everyone? A women who’s claim to fame is to play a stupid women over and over again. A women who has closed her schools for Autistic children once she found out her son DIDN”T have Autism? I liked how someone put it “she turned her back on the Autistic community” and ” none of asked her to speak for us ” . Yet you want people to give these two people more money to lie to us and make us look like fools?

    Lets do right by our kids once one thing ( Like Vaccines ) has been dis proven lets move on to the next. Stop hanging onto Vaccines they aren’t to blame!

  26. Sarah
    October 5, 2011 at 9:57 am

    Sulu,

    The CMA was recommended by my sons neurologist. “Autism” was listed among the conditions tested for as I said I assume they were looking for a deletion or a mutation. Family traits existed in the past perhaps but not full blown manifestation of this disorder that require therapeutic interventions as we are seeing today. There has to be an environmental trigger. Genes may play a supporting role but the environment or environmental exposure is a primary factor.

    Last year, experts from the US EPA, UC Davis and NIEHS testified before a US Senate subcommittee on childrens health that environmental factors play a significant role in the autism increase.

    Dr. Isaac Pessah from UC Davis Center for Children’s Environmental Health and Disease Prevention Professor of Toxicology said:

    “Yet genetics alone cannot account for the majority of autism cases currently being diagnosed. There is lack of full concordance between monozygotic twins, with some estimate ranging as low as 60%, and the prevalence of ASD among siblings has been reported as high as 14%. Interactions among multiple genes are likely to contribute to various types of autism, and heritable epigenetic factors and/or non-heritable environmental exposures are likely to significantly contribute to susceptibility and variable expression of autism and autism-related traits.”

    Listen to testimony below.

    Subcommittee on Children’s Health hearing entitled, “State of Research on Potential Environmental Health Factors with Autism and Related Neurodevelopment Disorders.”
    Tuesday, August 3, 2010

    http://epw.senate.gov/public/index.cfm?FuseAction=Hearings.Hearing&Hearing_ID=1ab3cf42-802a-23ad-4a3a-686da83bf6d0

    Regarding Wakefield, he is NO charlatan. He his highly educated a a well respected gastroenteroligists before being embroiled in a very controversial issue fed by the media and Mr. Brian Deer. A man with NO medical training who somehow has the ear of the British Medical establishment.

    I’ve heard Wakefield speak. The man is brilliant. Recent findings of gastrointestinal inflammation by a team of respected researchers including Dr. Tim Buie, are consistent with his research that many children with autism have chronic GI inflammation.

  27. Sarah
    October 5, 2011 at 2:45 pm

    Here’s an excerpt for a letter written by from Isaac Pessah, Director, UC Davis Center for Children’s Environmental Health and Disease Prevention Professor of Toxicology to the U.S. Senate Committee on Environment and Public Works

    “The vast majority of public and private resources has, and continues, to support work on identifying genetic impairments associated with autism risk. From these studies we have learned that genetics alone cannot predict the majority of autism cases, the patterns of impairments, severity, nor can they predict success for current treatment modalities. Moreover, we have learned that many of the molecular and cellular systems that are associated with autism are the very same ones that are the target of environmental chemicals currently of concern to human health because of their widespread use.”

    and

    “We know that autism prevalence continues to increase dramatically clearly implicating environmental factors in autism risk. We must identify which environmental exposures and combination of exposures are contributing to increased overall risk in the population and identify the most susceptible groups. Only by bringing together the concerted effort of multidisciplinary teams of scientists can we identify which of the >80,000 commercially important chemicals currently in production promote developmental neurotoxicity consistent with the immunological and neurological impairments identified in individuals with idiopathic autism. It is clear that their is a critical need to identify which chemicals in the environment that influence the same biological pathways known to be affected in autism. Limiting exposure to these chemicals is the only way to mitigate or prevent autism in susceptible individuals”

    Source:
    http://epw.senate.gov/public/index.cfm?FuseAction=Files.View&FileStore_id=d155fff0-c84d-41ee-959d-afe443436781

  1. September 30, 2011 at 2:31 pm

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