carrying pollutant have more boys - US study
Reuters News Service
WASHINGTON - Men who have higher levels
of polluting chemicals known as PCBs in their bodies are
slightly more likely to father boys, researchers said.
The researchers at Michigan State University
said their study showed that human beings can be affected
sexually by the chemicals, which cause sex-related defects
do not wish to say that having a baby boy is bad. It's
just that there were more of them," Wilfried Karmaus,
a epidemiologist who led the study, said in a statement.
change in the proportion of boys to girls, however, indicates
that environmental contaminants may play a role in human
are endocrine disruptors - chemicals that act like hormones.
They and related chemicals known as dioxins are reported
to have caused deformities of sexual organs in fish and
humans both dioxins and PCBs can cause cancer, infertility
and perhaps other sexual changes. Vietnam veterans exposed
to dioxin in Agent Orange, used to strip foliage in the
jungle, claim it has caused a variety of ills including
cancer and birth defects in their children.
used information from studies of men and women who liked
to fish in the Great Lakes, which are polluted with a
range of chemicals.
were recruited by the Michigan Department of Community
Health,' Karmaus said in a telephone interview. Their
blood levels of PCBs and other chemicals were measured.
101 families they studied had children born after 1963,
and both mother and father had detectable PCBs in their
blood. There was a total of 208 children.
these, 57 percent were boys, which is a slight increase
of the normal trend of about 51 percent. Usually, 105
boys are born for every 100 girls.
we did not detect that the PCB levels of mothers affected
the number of boys or girls," Karmaus said.
in the January issue of the Journal of Occupational and
Environmental Medicine, Karmaus stressed that his sample
was small, meaning he worked with too few people to have
a good idea of what the numbers meant.
noted that other studies had showed conflicting findings.
One after a dioxin accident in Italy in 1976 found people
who were exposed had more girls than boys. "Then there
are the Army servicemen who were exposed to Agent Orange
during the Vietnam war. They found fewer girls and more
boys," Karmaus said.
can come from many different industrial sources including
hydraulic fluids and oils, electrical capacitors and transformers.