As I get labeled “most controversial” (thank you, whoever), let me mention a perfect yet extraordinary example showing how any claim, however far-fetched and based on little or no science at all, can be dressed as the latest scientific warning about impending doom caused by humanity’s excesses, without of course anybody involved showing any sign of critical thinking.
I am talking about the “Guardian news” (from Sep 12, 2007) that “man-made chemicals [should be] blamed as many more girls than boys are born in Arctic” (that is, twice as many girls as boys). This is specific to the Guardian as every other link I have found about it, can be traced back to a Paul Brown reporting from Nuuk, Greenland, that
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)
[…] The scientists measured the man-made chemicals in women’s blood that mimic human hormones and concluded that they were capable of triggering changes in the sex of unborn children in the first three weeks of gestation. The chemicals are carried in the mother’s bloodstream through the placenta to the foetus, switching hormones to create girl children.
This would have been an incredible finding, shattering a lot of established ideas on the roles of chromosomes in humans. And it was picked up as such by treehugger.com (no comment) and a scienceblogs site called (the irony!) “Island of Doubt“. Its author James Hrynyshyn wrote on Sep 13, 2007, that the news was “not good“, proceeding then to equivocate when pointed out how outerwordly it all sounded.
What makes this all exemplary is that it would have taken just a few minutes to figure out the holes in the story. First of all, the “findings” were:
“disclosed at a symposium of religious, scientific and environmental leaders in Greenland’s capital, Nuuk,…organised by the Patriarch of the Orthodox Church, Bartholomew I, which is looking at the effects of environmental pollution on the Arctic.“
More importantly, there was very little about the “findings” in the AMAP communications at the time (and even less, today). The 2006 State of the Arctic Environment Report (SOAER) says nothing at all about skewed sex ratios. An AMAP report from 2001 titled “Human Health” mentions two works by Mocarelli and others showing a change in the boys/girls ratio due to exposure to dioxin by the fathers (and so it would have nothing to do with the Guardian’s claim)
Mocarelli P, Brambilla P et al. Change in sex ratio with exposure to dioxin. Lancet 1996; 348: 409.
Mocarelli, P., P.M. Gerthoux, E. Ferrari, D.G. Petterson, S.M. Kieszak, P. Brambilla, N. Vincoli, S. Signorini, P. Tramacere, V. Carreri, E.J. Sampson, W.E. Turner and L.L. Needham, 2000. Paternal con- centrations of dioxin and sex ratio of offspring. The Lancet 355:1858-1863
There is also an AMAP report from 2000 (mentioning the excess girls as per the Mocarelli’s studies, but also the absence of such an excess in a similar situation in Taiwan). An AMAP poster from 2002 mentioning a decrease in the number of male newborns in whales (from 56% to 44%, far far less than what claimed about humans).
What would explain the enthusiasm leading to the…unorthodox announcement at the Orthodox Church symposium rather than through the usual scientific channels (or even, an official press release), is the AMAP report from 2006 saying that “Two new special projects have been initiated: one investigating contaminants in relation to sex ratio (based on the results from the PTS report)“. Hoever, in the Conclusions and Recommendations of the PTS report one reads something extremely vague:
Statistically significant associations have been found between blood concentrations of total PCBs (Arochlor 1260), lead and a number of non-specific reproductive and developmental health effects such as the prevalence of low birth weight, premature births, stillbirths and major structural malformations. Serum concentrations of total PCBs in maternal blood also appear to be associated with impacts on newborn sex ratios.
Anybody with a half-curious mind would have also read the literature mentioned by AMAP, for example this article from 2006, “Pathways of endocrine disruption during male sexual differentiation and masculinization“, where the abstract ends:
There is currently no definitive evidence that exposure of humans to environmental chemicals can induce testicular dysgenesis and/or impair masculinization, though pathways via which this could potentially occur are established.
It should have gone without saying that even if AMAP had found that “definitive evidence“, of course they wouldn’t just have seen two girls for every boy, but an enormous number of boys with various degrees of “endocrine disruption“.
There’s more, thanks to our hindsight of 2011. Of course the Guardian article has never been followed by any update (you know there’s something particularly fishy when all mainstream media but one refuse to report a story). How about AMAP? Here’s from their 2009 report, with some added emphasis:
POPs exposures have been suggested as the reason for observed alterations in birth sex ratios in animal populations and occasionally in human studies. New research results with pigs, which have a similar reproductive system to humans, indicate that exposure of sperm to environmentally pertinent organochlorine mixtures in vitro adversely affects oocyte development, polyspermy, sperm fertility and embryonic development. However, a comparison of existing population studies, one including Arctic countries, did not reveal any definitive or consistent relationship between POPs, sperm X:Y ratios or male:female birth ratios. Emerging data from a larger cohort in the Russian Arctic indicate that increasing maternal PCB concentrations may be associated with an initial effect of increasing the male:female newborn ratio; however, causality has not been determined and the increase in the ratio appears to disappear in the highest concentration group. The possible effects of other contaminants have not been determined. Systematic epidemiological studies, including all possible confounders and other relevant contaminants, must be performed before any conclusive statements can be made about contaminants and sex ratios in Arctic populations
[…] Results from the INUENDO study…This study indicates that POP exposure might be involved in changing the proportion of ejaculated Y-bearing spermatozoa in human populations. Inter- country differences, with different exposure situations and doses, may contribute to varying Y:X chromosome ratios. However, the higher proportion of Y sperm did not support the observed increase in the female:male ratio reported previously
[…] In general, no definitive conclusion could be drawn from these studies. Emerging data from a larger cohort in the Russian Arctic indicate that increasing maternal PCB concentrations may be associated with an initial effect of increasing the ratio of male:female newborns. The Russian results appear to confirm the trend reported in the previous AMAP Human Health assessment (AMAP, 2003); however, causality has not been determined and the increase in the ratio appears to disappear in the highest concentration group
Good luck with finding any of that in the Guardian. In the meanwhile, the initial rubbish gets repeated verbatim, for example in a highly-praised book by Sara Wheeler, titled “The Magnetic North” and reviewed with the brains fully shut by Holly Morris for the New York Times:
One boggling case in point: “Endocrine-disrupting chemicals handed up the food chain have triggered changes in the sex of unborn children in the first three weeks of gestations, resulting in the birth of twice as many girls as boys in some villages in Greenland and among the Inuit nations of eastern Russia.”
No prize if you notice the full certainty of Wheeler (and Morris): HAVE TRIGGERED CHANGES. I am sure AMAP has written to the New York Times protesting already.