05:05 PM ET 04/08/97
Environment may spark earlier puberty in U.S.
	 
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	    CHAPEL HILL, N.C. (Reuter) - American girls are beginning
puberty before the age of 10, much earlier than previously,
possibly because of exposure to estrogen in the environment, a
researcher said Tuesday.
	    Dr. Marcia Herman-Giddens, who also found that black girls
begin puberty shortly before the age of 9, said environmental
products such as plastics, hair care products and insecticides
could be causing this trend.
	    ``We really don't know (why),'' said Herman-Giddens of the
University of North Carolina at Chapel Hill School of Public
Health. ``This is purely speculation, but we do have to wonder
if the increasing amount of estrogen-like products in our
environment could have an effect.''
	    She noted research on links between lower sperm counts in
men and estrogen and said, ``If there are enough estrogens in
the environment to have that kind of effect, it may be affecting
young girls.''
	    According to the new American Academy of Pediatrics study,
for which Herman-Giddens was lead researcher, black girls begin
puberty shortly before the age of 9 on average, while white
girls begin just before the age of 10. Before the age of 8, 27
percent of blacks and almost 7 percent of whites already have
begun developing breasts, growing pubic and underarm hair, or
both.
	    Herman-Giddens said researchers also could not pinpoint a
reason for the difference between the races.
	    The study analyzed information from 17,077 girls seen in
doctors' offices nationwide. About 90 percent of the subjects
were white, the rest were black.
	    Analysis showed that by their ninth birthday, 48 percent of
black girls and slightly less than 15 percent of white girls had
begun puberty. And it said 3 percent of black girls and 1
percent of whites showed some sexual development by age 3.
	    She said earlier studies showed that several decades ago
girls began puberty at an older average age. For example, she
said a 1948 study of a much smaller sample of white girls showed
an average age of 10.8 years for the beginning of breast
development.
	    ``From what we've got, the data certainly suggests that they
are beginning puberty earlier. They are not really finishing
puberty earlier,'' Herman-Giddens said.
	    The researcher said the study could better guide schools and
parents on when to educate girls about their bodies, as well as
help doctors to provide proper medical care for children.
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