Ddt Causes Male Defects, Researchers Say
Compiled From News Services, St Louis Post-Dispatch (MO)
American researchers reported today that they had discovered how the pesticide DDT causes sex abnormalities in males.
It has been known for years that DDT and other pesticides have alarming effects on male animals, causing them to develop abnormally small penises, undescended testicles and, in some cases, to become female.
Scientists thought this was because DDT somehow mimics the effects of estrogen, the main "female" hormone. But in a report in the science journal Nature, Bill Kelce and colleagues of the U.S. Environmental Protection Agency's Reproductive Toxicology Branch said the chemical instead attacks male hormones.
Instead of "feminizing" males, the chemical in fact "de-masculinizes" them, Kelce said. Kelce's team tested rats with DDE, which is a metabolized, or broken-down, form of DDT. They found that DDE interfered with male hormones such as testosterone.
Newborn male rats had nipples (males usually don't) and showed abnormalities of their reproductive systems.
Doctors say DDT has been found in the brains of stillborn infants, indicating that DDT crosses the placenta to affect developing fetuses. The chemical also accumulates in body fat.
Scientists around the world are becoming increasingly concerned about the threat to the male sex caused by environmental chemicals. …