No Mandatory Limits Set on Cadmium
October 28, 2010 The U.S. Consumer Product Safety Commission (CPSC) reached a decision (10/22/10) regarding cadmium and is now urging jewelry industries to use accepted levels in children's jewelry. Scientists at the CPSC have concluded that children can safely ingest 0.1 micrograms per kilogram a day for an extended period, and 11 micrograms per day at once. The CPSC's decision not to set mandatory limits now allows the industry to police itself.
According to CPSC's chairman, Inez Tenenbaum, "The agency is required by law to give industry a chance to craft standards before the government acts."
Cadmium is a known carcinogen and health officials have found that long-term exposure can damage bones and kidneys. Research also suggests it can harm brain development in children.
Metal jewelry manufacturers have been using cadmium instead of lead after Congress banned its use. <http://www.ibtimes.com>
Association Between Elevated Levels of
Lead, Cadmium & Delayed Puberty in Girls
Announced by NIH
September 1, 2010 Researchers at the
National Institutes of Health and other
institutions have found that exposure to lead in
childhood may delay the onset of puberty in
young girls, with higher doses increasing the
chance for later maturation.
The researchers analyzed data on blood
drawn from more than 700 girls ages 6 to 11.
They found that girls with elevated levels of
lead (at or above five micrograms of lead per
deciliter of blood) were 75 percent less likely
than girls with low levels of lead to have key
adolescent hormones at levels that are
associated with the beginning of puberty. In
girls with elevated levels of both lead and
cadmium, this pattern was even more pronounced.
The researchers speculate that lead,
alone or in concert with cadmium, might suppress
the ovary's production of hormones that prepare
a young girl's body to ovulate, or release an
egg, for the first time.
Previous studies have shown that exposure to
such heavy metals can disrupt normal hormone
patterns or, in some cases, reproductive
development. The Centers for Disease Control
and Prevention advise treatment for lead
exposure at levels exceeding 10 micrograms of
lead per deciliter of blood (http://ephtracking.cdc.gov/showChildhoodLeadPoisoning.action),
but the study authors believe their findings
suggest that lead exposure may have harmful
effects at even lower levels.
"Our findings suggest childhood
exposure to lead has worrisome effects as
children age and reach adolescence," said lead
first author Audra L. Gollenberg, Ph.D., a
fellow at the NIH's Eunice Kennedy Shriver
National Institute of Child Health and Human
Development (NICHD), where the research was
conducted. "These issues are of concern in some
parts of the United States as well as in
countries where children are exposed to leaded
gasoline, paint or industrial pollutants."
Dr.
Gollenberg worked with NICHD colleagues Mary L.
Hediger, Ph.D., and Germaine M. Buck Louis,
Ph.D., Peter A. Lee, M.D., of Penn State College
of Medicine, Hershey, Pa. and John H. Himes,
Ph.D., M.P.H., of the University of Minnesota
School of Public Health, Minneapolis.
According to the U.S. Environmental Protection
Agency, the most common sources of lead exposure
are deteriorating lead-based paint, lead
contaminated dust, and lead contaminated
residential soil (http://www.epa.gov/lead/).
The findings appear in Environmental
Health Perspectives, published by the National
Institute of Environmental Health Sciences.
The researchers worked with data on blood
and urine samples taken as part of the Third
National Health and Nutrition Examination Survey
between 1988 and 1994. They compared levels of
lead and cadmium to levels of the reproductive
hormone inhibin B, an indicator of the
development of previously dormant egg cells in
the ovaries. Inhibin B is known to increase
steadily before the start of puberty.
Designating a specific threshold level for
inhibin B, which indicated puberty, the
researchers calculated the likelihood that girls
with low, medium, or high levels of exposure to
lead would reach that threshold. For all age
groups, the researchers found that girls with
higher blood levels of lead had reduced levels
of inhibin B, and so were less likely to reach
the threshold. High levels of lead and cadmium
together were even more likely to be associated
with low levels of inhibin B. (Cadmium levels of
.27-3.7 nanograms per milliliter of urine were
considered to be high.) According to the Centers
for Disease Control and Prevention, cadmium
damages the kidneys, lungs and bones and
increases the risk for cancer. Breathing
cigarette smoke is a principal source of cadmium
exposure. (http://www.atsdr.cdc.gov/tfacts5.html)
In addition, the findings suggested the pubertal
delay associated with lead was more prevalent in
girls with iron deficiencies. Girls with even
moderate levels of lead and low iron levels were
much less likely to have reached the inhibin B
threshold levels indicating puberty than their
counterparts with low lead exposure and normal
iron levels.
"Iron deficiency appears to be a critical
factor in the context of lead exposure," Dr.
Gollenberg said. "Health care providers may wish
to pay particular attention to the importance of
screening for iron deficiency among girls at
high risk for exposure to lead."
The NICHD sponsors research on development,
before and after birth; maternal, child, and
family health; reproductive biology and
population issues; and medical rehabilitation.
For more information, visit the Institute's Web
site at <http://www.nichd.nih.gov/>.
The National Institutes of Health (NIH)
-- The Nation's Medical Research Agency --
includes 27 Institutes and Centers and is a
component of the U.S. Department of Health and
Human Services. It is the primary federal agency
for conducting and supporting basic, clinical
and translational medical research, and it
investigates the causes, treatments, and cures
for both common and rare diseases. For more
information about NIH and its programs, visit <www.nih.gov>.
