BREAKDOWN products from the pesticide DDT have been detected for the first
time in the amniotic fluid of pregnant women.
Claude Hughes of the Cedars-Sinai Medical Center in Los Angeles and Siu Chan
of the University of Calgary in Canada led a study of amniotic fluid from 53
women in the Los Angeles area who were between 16 and 20 weeks pregnant. Thirty
per cent of the samples contained detectable levels of DDE鈥攁 breakdown
product of DDT, long outlawed in developed countries.
DDE can bind to and inactivate cell receptors for the hormone testosterone,
which plays an important role in the masculinisation of boys. Male fetuses tend
to have about twice as much testosterone in their blood as females, but
concentrations of DDE in amniotic fluid ranged from 0.1 to 0.63 nanograms per
millilitre鈥攁pproaching the level of testosterone normally found in female
fetal blood. The researchers fear that such levels could have a long-term effect
on male development and reproductive health, by reducing the amount of
testosterone binding to receptors.
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Although the researchers cannot be sure whether the DDE has any adverse
effects, Chan cites the example of alligators in Florida that were exposed to
the chemical after a spill. 鈥淚n males, the penis was much smaller than normal,鈥�
he says. Hughes, who presented the results at an Endocrine Society meeting in
San Diego last week, fears that DDE might lead to a low sperm count in
adulthood: 鈥淗ow much interference do you have to have before there is a change
in the sex hormone-related development of several structures?鈥�
The researchers are also concerned that amniotic fluid may act as a long-term
reservoir for other chemicals that usually flush through an adult body within a
few days. The team is planning a further study of a thousand women.