The fields will give your child autism!

[simonmaal]

This week's conspiracy theory courtesy of our friends at WDDTY involves a supposed link between pesticides and autism. Here is a summary of the claim (sent to me in an e-mail):

Children who are exposed to agricultural pesticides while developing in the womb are six times more likely to develop autism. The first eight weeks after conception seem to be the most vulnerable time, and the risk increases dramatically if, during that time, their mothers were living close to farms that had used pesticides, and especially dicifol and endosulfan.source: http://www.wddty.com/03363800369655039095/autism-pesticides-on-farms-may-be-a-trigger.html

I really have no idea what to make of this claim. Does anybody have any thoughts?

[Safe-Keeper]

Don't take pesticides while pregnant.

Seriously, though, it's possible, but doesn't seem likely to me. But then again, I've got no knowledge in the field at all, so I'll leave it to the professionals to answer.

[jon]

Paper's discussed here, if that helps http://autismdiva.blogspot.com/2007/07/autism-blame-bug-killers.html

[Professor Yaffle]

The relevant journal is free and online, but I couldn't find the paper. I found on on pesticides and neuro developmental delay, and another one on airbourne pollution and autism. I'm not sure if it is either of these, or if it is in the next issue which isn't online yet.

[simonmaal]

The biggest problem I have with this so far is the term "exposure to the insecticides in the womb". Of all the sources I have looked at (including the blog that Jon linked to), I can't see beyond this rather nebulous term to get at the core of the argument.

The only thing I can seem to find is that endosulfan is...a neurotoxic organochlorine insecticide of the cyclodiene (http://en.wikipedia.org/wiki/Cyclodiene) family of pesticides. It is highly toxic (http://en.wikipedia.org/wiki/Toxic) and an endocrine disruptor (http://en.wikipedia.org/wiki/Endocrine_disruptor), and it is banned in several countries (wikipedia (http://forums.randi.org/showthread.php?t=91190) reference).

I know to take wikipedia with a pinch of salt, but the most relevant part seems to be this: Doses as low as 35mg/kg have been documented to cause death in humans This article (http://www.epa.gov/oppsrrd1/REDs/endosulfan_red.pdf) by the EPA lists the acute reference dose (http://en.wikipedia.org/wiki/Reference_dose) for dietary exposure to endosulfan as 0.015 mg/kg for adults and 0.0015 mg/kg for children. For chronic dietary expsoure, the EPA references doses are 0.006 mg/kg-day and 0.0006 mg/kg-day for adults and children, respectively.

The kind of questions I would like answering are: How much of these insecticides can get into the womb and how? Does the pesticide have the same effects in utero as it does when ingested, breathed or touched? And how can a causal link be established between the insecticides and autism? Have their been any alleged cases of autism resulting from exposure to the insecticides in infancy/childhood rather than in the womb?

There seems to be a lot of detail missing from this claim, and my own thoughts are that this is another media scare (seized upon by the anti-establishment alternative lobby), but there is a chance it is not. So it would be useful if anybody could shed any light on this.