Pollution eyed in dip in U.S. male births

CHICAGO, May 25 (UPI) -- Experts say they suspect industrial pollutants are one possible cause of a statistical downturn in the number of boys being born in the United States.

A decline in the ratio of boys to girls born since 1970 has translated to 17 fewer males per 10,000 births, and analysts aren't sure what is going on, the Chicago Tribune reported Sunday.

"It is important to look at the really big picture here, which is that there are global indications that something unusual is going on," said Devra Davis, director of the Center for Environmental Oncology at the University of Pittsburgh, and a frequent critic of toxic chemicals in the environment.

Davis told the newspaper that sex ratios are a measure of the health of the overall population and that people should be concerned when things start getting out of balance.

The Tribune said scientists are concerned that various pollutants hamper the production of testosterone in males, which is associated with the production of male offspring.

Other analysts, however, suspect he statistical changes are part of a natural population cycle.