
Study: Association of Maternal Insecticide Levels with Autism in Offspring - OKWhatNow
https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.2018.17101129
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gcthomas
Interesting, but from the abstract it looks too underpowered to allow firm
conclusions.

Of the two stated primary measures, one was not associated with autism and the
other was only very marginally significant (at p=0.05), so it is rather
vulnerable to a reversal if the research is replicated.

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psychometry
I also wonder why they did simple case-control matching rather than propensity
scores. The number of unobserved confounders you could imagine is high in an
analysis like this.

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cultus
It looks like this is too underpowered to get anything out of this. The 95% CI
is 1.02-1.7. Considering that the great majority of statistical tests in
studies like this have null results (but usually aren't reported), there is a
very good, possibly more than 50% chance, that this is bogus.

I've basically stopped paying attention to studies like this. In replication
studies in medicine and psychology, these kind of fishing expeditions have a
very low chance of being successfully replicated.

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bhouston
Interesting, but given that DDT (of which DDE is a metabolite) was banned
except for a few specific use cases, can we really do much about this now? Is
this DDT/DDE from the few specific use cases were DDT is still legal (disease
control of malaria) or is this from previous accumulations from the
environment from when DDT was widely utilized?

Reference:
[https://en.wikipedia.org/wiki/DDT#United_States_ban](https://en.wikipedia.org/wiki/DDT#United_States_ban)

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tremon
It's probably the latter. From the first paragraph of the wikipedia page on
DDE [1]:

 _Due to DDT’s massive prevalence in society and agriculture during the mid
20th century, DDT and DDE are still widely seen in animal tissue samples. DDE
is [..] rarely excreted from the body, and concentrations tend to increase
throughout life. The major exception is the excretion of DDE in breast milk,
which transfers a substantial portion of the mother 's DDE burden to the young
animal or child_

[1]
[https://en.wikipedia.org/wiki/Dichlorodiphenyldichloroethyle...](https://en.wikipedia.org/wiki/Dichlorodiphenyldichloroethylene)

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jamesrcole
The breast milk thing makes me think: If a substantial portion of the DDT is
removed from the mother through breast milk, what difference does it make for
subsequent children? And could it be somehow exploited to help remove more of
the risk?

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Herodotus38
Or, you should see a big difference in breast fed children vs those that had
formula. I'm pretty sure that variable has been heavily researched without any
significant difference.

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jamesrcole
I'm saying something different: does it remove enough DDT from the mothers
body to affect womb development of _subsequent_ children?

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Herodotus38
I see your logic and it makes sense. My point was more that if we posit DDT in
breast milk caused autism, we'd expect to see a difference in rates of breast
vs bottle fed kids, which we don't. So I'm skeptical of it being a big player,
but I'll admit I haven't looked into this area deeply.

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alexandercrohde
I wonder what other pesticides are associated with autism?

You'd of course hope the FDA/EPA would research this [autism risk] before
making a pesticide legal, but how could they? In actuality, they give a very
high dose to rats/dags/rabbits for a short term and use that as their best
approximation of safety[1].

[1] [https://www.epa.gov/risk/human-health-risk-
assessment](https://www.epa.gov/risk/human-health-risk-assessment)

