James Hrynyshyn is a freelance science journalist based in western North Carolina, where he tries to put degrees in marine biology and journalism to good use.
This is not good. A report from the Arctic Monitoring and Assessment Programme says toxic pollutants, presumably estrogen mimics and other organochlorines, are skewing the sex ratio in Greenland.
Twice as many girls as boys are being born in some Arctic villages because of high levels of man-made chemicals in the blood of pregnant women, according to scientists from the Arctic Monitoring and Assessment Programme (Amap).This story has received moderate attention in England, but nothing over on this of the pond. Why is that?The scientists, who say the findings could explain the recent excess of girl babies across much of the northern hemisphere, are widening their investigation across the most acutely affected communities in Russia, Greenland and Canada to try to discover the size of the imbalance in Inuit communities of the far north.
In the communities of Greenland and eastern Russia monitored so far, the ratio was found to be two girls to one boy. In one village in Greenland only girls have been born.
Comments
Color me skeptical. The article states the (supposedly) observed imbalance is "because of high levels of man-made chemicals in the blood of pregnant women" (my emphasis). That's certainly an unsubstantiated claim, even if there truly is a statistically significant sex bias.
The article goes on to claim:
That, frankly, is BS. I don't believe for one second that any chemicals are turning genetically male (XY) fetuses into biologically female infants.
Maybe there's something worth investigating here, but the level of BS in the article makes me highly suspicious.
Posted by: qetzal | September 13, 2007 2:23 PM
Just to clarify, I don't dispute the possibility that certain chemicals could alter apparent sex at some small rate. I do reject the claim that approximately 1/3 of all XY fetuses are developing into biologically female infants. That's what would be required to get a 2:1 bias in female births, assuming approximatley 1:1 XY:XX fetuses.
Posted by: qetzal | September 13, 2007 2:31 PM
Yeah, determining the sex of a baby is a man's job! And he should do it within around the time of fertilization.
Posted by: Tegumai Bopsulai, FCD | September 13, 2007 3:13 PM
Maybe this might balance out the side-effects of China's one-child policy?
Ok, that might be a bit TOO cynical for a Thursday....
Posted by: G Barnett | September 13, 2007 3:13 PM
Here's a PDF file that talks goes over the type of pollutants found in arctic populations. What's remarkable is that there are certain populations that have pretty huge concentrations of mercury and PCBs.
There's also some evidence to link PCBs with sexual abnormalities.
The other possibility is that the various pollutants are causing selective sperm damage (XY sperm tends to be fragile), or otherwise killing off male embryos.
Posted by: Adam | September 13, 2007 3:54 PM
I share qetzal's concerns. One could make up some barely credible mechanisms, such as destruction of male embryo's, but they don't sound pretty convincing.
Posted by: bigTom | September 13, 2007 3:58 PM
G Barnett beat me to it. I was going to suggest that this might be great opportunity for some entrepreneur to set up an online dating service, or more to the point, a marriage arrangement service between parents in Greenland and China/India. Considering the relative difference in populations, the money in such a business plan will come entirely from membership fees, not from actual match-ups.
Posted by: John McKay | September 13, 2007 5:56 PM
The sex ratio has also been changing towards more females in Aamjiwnaang First Nation, a community near the petro-chemical complexes in Sarnia, Ontario. The suggestion here has also been that it is a result of pollution.
Posted by: Richard Simons | September 13, 2007 6:16 PM
I do reject the claim that approximately 1/3 of all XY fetuses are developing into biologically female infants.
On what basis? Personal incredulity? While I would agree that we need to be very careful when it comes to press releases based on as-yet-unpublished research, I'm not sure you can just dismiss it out of hand.
And it doesn't necessarily require that 1/3 of XY fetuses developing into biologically female infants - you could also produce the claimed effect if 1/2 of XY fetuses don't survive to term. Or some combination of the two.
Posted by: Dunc | September 14, 2007 5:10 AM
Dunc wrote:
Yes, it does. "It" being the conclusion that the chemicals were "triggering changes in the sex of unborn children in the first three weeks of gestation." That's what the article claims in the passage I quoted in my first comment.
I reject that as a reasonable explanation for the reported 2:1 sex ratio, based on basic knowledge of mammalian reproduction. I also reject that anyone could scientifically conclude that fetal sex was changing in utero, based on a biased sex ratio and chemicals in the blood.
Please note that I didn't dismiss the research out of hand. I said I was skeptical and suspicious. More specifically, I'm skeptical of making judgments ("This is not good") based on what the article reports.
Posted by: qetzal | September 14, 2007 10:18 AM
I think we can safely say "this is not good" regardless of the causes, can't we?
Posted by: James Hrynyshyn | September 14, 2007 10:34 AM
James,
Only if we can safely conclude that the reported imbalance in sex ratios is real and persistent.
Is that a safe conclusion? Not based on the Guardian article, at least. Here's another quote:
If this quote is accurate, Reierson is making an extraordinary claim. At minimum, he'd need data showing that a significant fraction of female infants are genetically XY. If he had such data, I'd expect him to make a big point of it.
Unless he was misquoted, it sounds like Reierson is drawing an entirely unwarranted conclusion from whatever data he has. IF that's the case, then it makes me wonder about the scientific validity of the whole study.
Once again, I'm not saying the study IS invalid. I'm saying the available information warrants caution and skepticism. Note that I tried to find additional info on AMAP's web site, without success.
Posted by: qetzal | September 14, 2007 12:28 PM
qetzal: you're not getting my point, which is, WHATEVER the cause, whatever the mechanism, it's not good news. SOMETHING is skewing the sex ratio, and in what universe could that be a good thing?
Posted by: James Hrynyshyn | September 14, 2007 1:00 PM
James,
I do get your point, and I agree, with one caveat. It's a bad thing if it's true.
My point is this: how do you know the sex ratio really is skewed? Given the available evidence (to whit, the Guardian article), I don't think that's a safe assumption!
We don't have any actual data. We don't know how many births went into that analysis. We don't know the statistical significance and how it was calculated. We don't know how the researchers controlled for errors and bias.
We do know that the Guardian article contains statements that are suspect. We know that one of the researchers is either quoted or misquoted making what I contend is a very unwarranted conclusion.
In light of all that, my point is that we should NOT assume the sex ratio is really skewed. Absent better information, we cannot adequately exclude poor methodology, small sample size effects, selection bias, or a host of other reasonable explanations that might completely obviate the claimed skewing.
If that's the case, 'this' is not a bad thing because 'this' doesn't exist.
Posted by: qetzal | September 14, 2007 2:52 PM
I just wrote a post addressing some of the skepticism expressed in the comments here. Let me just say that there is a good bit of research published on endocrine disruptors, there are known mechanisms for genotypically XY individuals to be phenotypically female, and there is also a correlation between PCBs in the Great Lakes region, and a preponderance of female births (6:4 to 6.5:3.5). Please do be skeptical, but please also get the background info.
Posted by: Joseph j7uy5 | September 14, 2007 5:41 PM
I think it's wise to be skeptical about any scientific matter reported in a British newspaper. The sensationalism and general 'sky-is-falling' tone of the British press is legendary.
Posted by: Gerard Harbison | September 14, 2007 6:37 PM
Agreed. Here's an excerpt from another reporter's take:
(http://www.thenews.com.pk/print1.asp?id=72051)
He said full results for the widening of the survey would not be published until next year but preliminary results for Greenland showed the same 2:1 ratio in the north.
Posted by: James Hrynyshyn | September 14, 2007 6:54 PM
Why, exactly, is this such a bad thing?
I guess it could be caused by something that will have worse effects than this, but why is this effect in itself so bad? What social consequences are predicted? More lesbianism in 15 or 20 years' time? More covert or overt polygyny? More social acceptance of embryonic sex selection? More emigration of young women from Greenland to other places? More immigration of young men to Greenland from elsewhere (from China, perhaps?)? Are any of these necessarily disastrous?
If sex ratios were being skewed the other way, we could, perhaps, predict a more violent society down the track - though who really knows? This way, that's not a plausible prediction at all. Maybe Greenland will end up as a more peaceful place if it has a society and an electorate dominated by women.
I mean, it's one thing to have an intuitive response that it's bad. It's another to say exactly what the effects will be, and whether, on balance, they will turn out to be bad or not. It's all speculative. For all we know at this point, it's possible that Greenland's culture and mores will adapt nicely, and the Greenlanders will take this in their stride.
Posted by: Russell Blackford | September 16, 2007 8:01 AM