Changes in human sex ratio and chemical contamination

Excerpt from Our Stolen Future here, reading in part:

'Several researchers, however, have reported apparent recent declines in the proportion of male births, in the US, Canada, Denmark and the Netherlands. These declines have been very small but statistically significant. Fewer boys are being born than would be expected on the basis of the recent historical worldwide average.

In addition to these general declines, several specific cases have been reported involving sharp alterations in the sex ratio of people because of industrial accident, occupational exposure, or because of exposure to air pollution from incinerators. For example, in Russia pesticide workers exposed to elevated dioxin and dioxin-like compounds are less likely to father boys. A similar pattern is observed in men exposed to a mixture of PCBs in Taiwan. Both these studies report no effect on the sex ratio of infants born to exposed women. The Taiwanese study also suggests that exposure before the age of 20 is necessary for there to be an effect on sex ratio.'

One of the co-authors is scheduled to present at the 2009 ideaCity Conference in Toronto, Ontario in June of this year.