Chemicals Turning Unborn Boys Into Girls
The chemicals turning unborn boys into girls
Paul Brown
September 22, 2007
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 Program.
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.
The scientists measured the man-made chemicals in women's blood that mimic human hormones and concluded they were capable of triggering changes in the sex of unborn children in the first three weeks of gestation.
Lars-Otto Reierson, executive secretary of AMAP, says: "We knew the levels of man-made chemicals were accumulating in the food chain, and that seals, whales and particularly polar bears were getting a dose a million times higher than that existing in plankton, and that this could be toxic to humans who ate these higher animals. What was shocking was that they were also able to change the sex of children before birth."
The sex balance of the human race — historically a slight excess of boys over girls — has recently begun to change. A paper published in the US National Institute of Environmental Health Sciences journal earlier this year said that in Japan and the US there were 250,000 boys fewer than would have been expected had the sex ratio existing in 1970 remained unchanged. The paper was unable to pin down a cause for the new excess of girls over boys.
The Arctic scientists have discovered that many of the babies born in Russia are premature and the boys are far smaller than girls.
Possible links between the pollutants and high infant mortality in the first year of life are also being investigated.
Scientists believe a number of man-made chemicals used in electrical equipment from generators to televisions and computers are implicated. They are carried by winds and rivers to the Arctic, where they accumulate in the food chain and in the bloodstreams of the largely meat and fish-eating Inuit communities.
Reierson says the accumulation of DDT, PCBs, flame-retardants and other endocrine disrupters has been known for some time and young women have been advised to avoid eating some Arctic animals to avoid excess contamination and possible damage to their unborn children.
Study results are now in for 480 families and the ratio remained the same. Full results for the survey are to be published next year.
