Magazine article Science News

Dioxin Cuts the Chance of Fathering a Boy

Magazine article Science News

Dioxin Cuts the Chance of Fathering a Boy

Article excerpt

A 1976 explosion in an Italian factory rained TCDD over thousands of nearby homes. This unintended byproduct of herbicide manufacture is the most potent dioxin known. A new study finds that men who received large TCDD exposures from the accident have fathered fewer sons than expected. Indeed, the more dioxin a man picked up, the more likely he was to have daughters.

"In New York, Washington, Milan, and throughout the world, 106 males are typically born for every 100 females," observes Paolo Mocarelli of the University of Milano-Bicocca in Italy. He and his colleagues report that after the accident in Seveso, this sex ratio tilted sharply in the other direction. In the men with highest TCDD exposure, only 38 percent of their subsequent children were boys. That's only 62 males per 100 females.

An earlier study had found hints of such a trend in Seveso's most heavily exposed victims (SN: 4/4/98, p. 212). The new, larger analysis of 535 people exposed to a broad range of doses "shows that only the fathers' exposures--not the mothers'--are responsible for the altered sex ratio," Mocarelli says.

In the May 27 LANCET, his team also highlights the importance of the initial exposure. Though TCDD and other dioxins can persist within body fat for decades, their concentrations steadily fall if there's no further exposure. In many Seveso victims, dioxin concentrations had dropped to background levels before their children were conceived. Still, even if a man suffered high initial exposure from the accident before age 20, his likelihood of fathering sons was diminished. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.