Autism Risk Linked To Distance From Power Plants

[n2doc]

ScienceDaily (Apr. 25, 2008) — How do mercury emissions affect pregnant mothers, the unborn and toddlers? Do the level of emissions impact autism rates? Does it matter whether a mercury-emitting source is 10 miles away from families versus 20 miles? Is the risk of autism greater for children who live closer to the pollution source?

A newly published study of Texas school district data and industrial mercury-release data, conducted by researchers at The University of Texas Health Science Center at San Antonio, indeed shows a statistically significant link between pounds of industrial release of mercury and increased autism rates. It also shows—for the first time in scientific literature—a statistically significant association between autism risk and distance from the mercury source.

“This is not a definitive study, but just one more that furthers the association between environmental mercury and autism,” said lead author Raymond F. Palmer, Ph.D., associate professor of family and community medicine at the UT Health Science Center San Antonio. The article is in the journal Health & Place.

Dr. Palmer, Stephen Blanchard, Ph.D., of Our Lady of the Lake University in San Antonio and Robert Wood of the UT Health Science Center found that community autism prevalence is reduced by 1 percent to 2 percent with each 10 miles of distance from the pollution source.

“This study was not designed to understand which individuals in the population are at risk due to mercury exposure,” Dr. Palmer said. “However, it does suggest generally that there is greater autism risk closer to the polluting source.”

more:

http://www.sciencedaily.com/releases/2008/04/080424120953.htm

[crimsonblue]

1. I hate to be the naysayer troll, but here goes..

looking at the limitations of the study, I'm not so sure this paper will hold up to scientific scrutiny. The prevalence rates were much lower than expected, and not all child age groups were included in the study. The study only included school age children and only represented central areas within the school districts. NEVERTHELESS, this study clearly highlights the need for further population health studies into pollutants. Bring on the flames....

[n2doc]

2. Your points are valid.

Also, there are obviously other things that will covary with distance from power plants. Still, anything that might provide a clue into this problem is worthwhile (as you note).

[moc]

4. The paper has already held up to scientific scrutiny.

Health & Place is peer-reviewed, and it's considered a good journal. I know because I review for them, and I have published there. Health & Place would be considered one of the top outlets for researchers who, like myself, study geographic/spatial determinants of health. (The other top outlet would be Social Science & Medicine, which is probably more prestigious, but H&P is nothing to sneeze at.) If it's been published in H&P, it's been reviewed by three experts in epidemiology, environmental health, and/or geospatial analysis plus the editor, and it passed muster (probably following revision and re-review).

I pulled the journal article down from my library and gave it a quick look. As a recommendation, I would never evaluate a study's methodological merit based on what you read in a newspaper. If you're really interested in evaluating its integrity, go to the original source. As someone whose research has shown up in the popular press, I can tell you that things get warped in the translation from academic journal to press release.

With that said, no study is perfect. All have their methodological weaknesses. The question is whether the value of the information contributed outweighs the limitations. Relying on school district identification of cases is probably the weakest link in this study, imo, because of all the vagaries associated with diagnosis. However, given the limitations of the data sources available, I'm not sure there's a better alternative for examining their study question. Another limitation that you didn't mention is the fact they did an ecological analysis - i.e., examining how variations in rates at the county (i.e., school district) level are related to distance from the exposure. There are limitations with which one can extrapolate from effects at the ecological level to effects at the individual level. You may have heard of the "ecological fallacy".

I'm not really sure I understand your point about the prevalence being lower than expected. I'm not sure what that has to do with the central point that proximity to power plants shifted rates.

Research like this is, by its nature, hypothesis generating, not hypothesis testing. The NIH is launching a huge cohort of 100,000 children from across the U.S., the National Children's Study, that will be examining the environmental correlates of a host of child health issues including autism using a longitudinal, prospective design. It will take such a study to tease apart the causal associations. Studies such as the one published in H&P reported here can provide guidance for hypothesis testing in studies like the NCS.

[Fire_Medic_Dave]

12. The author said, “This is not a definitive study"

It's actually in the post. We'll see what happens with a larger more comprehensive study.

David

[bluesmail]

3. Dibs: In Search of Self, was a bestseller decades ago

[4waterfalls]

5. More research is needed!!

I wouldnt doubt power plants may be "a" contributer,but something tells the real cause of autism is something else.The evidence shows autism runs in families,but can strike any family anywhere.Im glad that there is so much research into this crisis,I have two family members,from 2 different generations, who are severely autistic.It obviously genetic.What is at the bottom of it all..we must find out.Autism is hearbreaking...

[PADemD]

6. Has anyone looked at the amount of mercury in the mother's dental fillings?

[tavalon]

7. A few, but they don't get funding because it is in the interests of big pharma and dentistry,

that mercury and other heavy metals not be looked at as a possible contributor. They pay big money to squash any research that direction.

[trotsky]

9. Don't forget the lizard people and the Illuminati!

:tinfoilhat:

[tavalon]

10. Of course, it's easy to dismiss by such silliness, but I doubt you've

done the amount of looking into the autism issue that I have. As a matter of fact, I highly doubt it. So, feel free to take you tin foil hat smiley and shove it.

[trotsky]

11. I CAN USE TEH GOOGLE TOO!!!1!!1

Or did you get a real degree in immunology, physiology, or another medical science?

[Fire_Medic_Dave]

13. The silence is deafening.

[TZ]

14. I'm a biologist

There has been complete and total studies on that kind of mercury link by BOTH NIH AND WHO and they have concluded NO LINK.
My actual degree beats your doctorate in internet idiocy anyday. Of course you probably think Bush runs both NIH and WHO judging by your idiocy.

[TZ]

15. Total and complete bullshit

I have worked in both govt and private and money IS NOT SPENT TO SQUASH research.
However, big companies often won't finance risky new research but thats a whole nother story.
So tell me who do you work for that you *know* this? Pharma has no influence on private funding..although they do work to get alot of government grants to work on projects.

[Orrex]

8. I'm betting that it's the Thimerosal in the grandmother's polio vaccine in the 1930's

:eyes:

[varkam]

16. Not that I want to kick this, but there's some red flags here...

See Orac for a detailed explanation:

http://scienceblogs.com/insolence/2008/05/wait_its_not_mercury_in_vaccines_its_mer.php