Environmental Chemicals and Autism

A Scoping Review of the Human and Animal Research, 2019

The Endocrine Disruption Exchange newest scoping review finds that 152 environmental chemicals have been investigated in humans or animals for their association with autism. TEDX highlight the need for systematic review of lead, PCBs, and chlorpyrifos.

Abstract

Background
Estimates of autism prevalence have increased dramatically over the past two decades. Evidence suggests environmental factors may contribute to the etiology of the disorder.

Objectives
This scoping review aimed to identify and categorize primary research and reviews on the association between prenatal and early postnatal exposure to environmental chemicals and the development of autism in epidemiological studies and rodent models of autism.

Methods
PubMed was searched through 8 February 2018. Included studies assessed exposure to environmental chemicals prior to 2 months of age in humans or 14 d in rodents. Rodent studies were considered relevant if they included at least one measurement of reciprocal social communicative behavior or repetitive and stereotyped behavior. Study details are presented in interactive displays using Tableau Public.

Results
The search returned 21,603 unique studies, of which 54 epidemiological studies, 46 experimental rodent studies, and 50 reviews were deemed relevant, covering 152 chemical exposures. The most frequently studied exposures in humans were particulate matter (n=14), mercury (n=14), nonspecific air pollution (n=10), and lead (n=10). In rodent studies, the most frequently studied exposures were chlorpyrifos (n=9), mercury (n=6), and lead (n=4).

Discussion
Although research is growing rapidly, wide variability exists in study design and conduct, exposures investigated, and outcomes assessed. Conclusions focus on recommendations to guide development of best practices in epidemiology and toxicology, including greater harmonization across these fields of research to more quickly and efficiently identify chemicals of concern. In particular, we recommend chlorpyrifos, lead, and polychlorinated biphenyls (PCBs) be systematically reviewed in order to assess their relationship with the development of autism. There is a pressing need to move forward quickly and efficiently to understand environmental influences on autism in order to answer current regulatory questions and inform treatment and prevention efforts.

Time Bomb: a Journey into Old Exposures, Gametic Glitches, and the Autism Explosion

Slides from Society for Neuroscience Wonder, February 2017

This presentation to a student-run chapter of SFN explained the history and science behind the “Time Bomb” hypothesis of autism.

DES DiEthylStilbestrol Resources

Seven famous ecologists discover their contamination from endocrine disruptors

100% of the personalities have traces of Bisphenols, PCBs, pesticides and phthalates

Générations Futures EXPPERT survey number 9 provides the results of tests for the presence of suspected or known endocrine disruptors in hair samples of some leading environmentalists in France. The worrying and conclusive results are the basis for a further call to the European Commission to improve its proposal on criteria for identifying endocrine disrupting chemicals ahead of a possible vote by EU Member States on 28 February 2017.

Paris, Brussels, 24 February 2017 – Seven environmentalists in France have their hair analysed for traces of endocrine disrupting chemicals. Generations Futures, with the support of HEAL and other members of the EDC-Free Europe coalition, published a new report yesterday, the 9th survey of the EXPPERT series on population exposure to chemicals that are suspected or known to disrupt the endocrine system. The results are unchallengeable!

Who?
In this new survey, Générations Futures asked personalities from the environmental movement to entrust to us a lock of their hair, which we had analysed by a competent laboratory. The participants were Yann Arthus-Bertrand, Isabelle Autissier, Delphine Batho, José Bové, Nicolas Hulot, Yannick Jadot and Marie-Monique Robin.

What?
Approximately 200 pesticides (products used in agriculture and in the home to get rid of “harmful” or “undesirable” flora and fauna) and pesticide metabolites (resulting from metabolism), three bisphenols (plasticiser used in the composition of the polycarbonate – hard plastic), 13 phthalates and metabolites of phthalates (plasticisers used to soften plastics) and 32 PCB congeners (PCBs have been banned since 1987 but were used massively in electric transformers and as heat transfer fluid.).

Results?
100% of the personalities has traces of each of the families of compounds analysed in their bodies!

- – We discover between 36 (D. Batho) and 68 (I. Autissier) endocrine disrupters per personality. The quantities varied from 9 031 μg/mg of endocrine disrupting chemical (D. Batho) to 158 643 μg/mg (I. Autism) – a discrepancy factor of 17.5 times between the least contaminated person (D. Batho) and the most contaminated person (I. Autissier). This clearly shows that individual’s exposure is not uniform but rather varies considerably according to the environment in which they circulate and/or in which they have developed and lived.

- Bisphenols:
All the personalities tested had at least one of the three bisphenols in their hair. Three out of the seven people tested had the renowned Bisphenol A in their hair: M-M. Robin, Y. Arthus-Bertrand and I. Autissier. All 7 had Bisphenol S but none had signs of Bisphenol F.

- Phthalates:
11 of the 13 phthalates or metabolites of phthalates tested for were found at least in one person. Neither MMP or DPP were found in any sample. The number of phthalates and metabolites of phthalates found ranged from eight to 11 depending on the individual. Between six and 10 of these molecules could be quantified in each person.

- PCBs:
All samples that could be analysed contained PCBs: between 14 and 30 PCBs were found in participants’ samples.

- Pesticides:
32 molecules suspected of being endocrine disruptors or endocrine disrupting metabolites were found in at least one person. Between nine and 25 of these pesticides were found in each hair sample tested.

“The hair of the personalities tested all contain an important cocktail of many endocrine disruptors (between 36 and 68 per person) although tests were only carried out on four families of chemicals. And these cocktails pose a problem – what is the health impact of this mixture?”

says Francois Veillerette, Director of Générations Futures.

“This report points out more than ever the need to remove endocrine disrupting substances from our environment. Only a truly protective definition within the European framework will ensure that endocrine disruptors are excluded from the market and protect populations from these hazardous compounds. That is why the vote on the Standing Committee on Plants, Animals, Food and Feed (SCOPAFF) on 28 February is so important! We urge all national governments to reject the European Commission’s proposal on the criteria for endocrine disrupting chemicals in its current form and insist on major changes to ensure that proven, probable or suspected endocrine disruptors to which we are exposed are identified as such. Only in this way will these chemicals be prohibited from use as required in the European legislation voted in 2009, to protect our health.”

he concluded.

Contacts
EXPPERT Surveys
  1. EXPPERT Survey 1: Which endocrine disrupting insecticides are children exposed to everyday? Press release, Brussels, 25 March 2013.
  2. EXPPERT Survey 2: Endocrine Disrupting Chemicals and banned Pesticides in strawberries. Press release, 25 March 2013.
  3. EXPPERT Survey 3: How are children exposed to Endocrine Disrupting Chemicals? Press release, 9 July 2014.
  4. EXPPERT Survey 4: Nineteen endocrine disrupting pesticides found in samples of women’s hair. Press release, 12 March 2015. Our blog.
  5. EXPPERT Survey 5: Pesticides that are banned or suspected to be EDCs are found in green salads. Press release, 22 September 2015. Our blog.
  6. EXPPERT Survey 6: Homes close to pesticide spraying show all year exposure. Press release, 1 March 2016. Our blog.
  7. EXPPERT Survey 7: Exposure to endocrine-disrupting pesticides. What are the exposures in daily life? Press release, 11 October 2016. Our blog.
  8. EXPPERT Survey 8: Exposure to endocrine-disrupting pesticides in water. Press release, 8 January 2017. Our blog.
  9. EXPPERT Survey 9: Seven French celebrities discover their contamination from endocrine disruptors. Press release, 24 February 2017. Our blog.