More studies are confirming that exposure to neurodevelopmental
toxins, like the mercury in the vaccine additive thimerosal,
may increase the risk of autism and attention-deficit hyperactivity
disorder. The researchers found that exposure to toxins such
as ethanol and heavy metals (including lead, aluminum and
the mercury-containing preservative thimerosal) interrupt
growth factor signaling. This negatively impacts methylation
reactions, which are critical to proper neurological development
in infants and children.
Further, according to an Environmental Protection Agency
(EPA) study, about 630,000 children are born with an increased
risk of lowered intelligence and learning problems due to
exposure to high levels of mercury in the womb, and one in
every six women has enough mercury in her blood to harm a
developing child--nearly twice the EPA’s previous estimate
of one in every 12 women.
The estimate increased after data collected by the Centers
for Disease Control and Prevention (CDC) showed that level
of mercury in the umbilical cord blood of newborns is 1.7
times higher than the mercury level in their mother's blood.
That means women with a mercury level of only 3.5 ppb have
enough mercury in their blood to cause a fetus' blood to cross
the 5.8 ppb safety threshold. An alarming 16 percent of women
have mercury blood levels of 3.5 ppb or higher.
One of the main sources of mercury exposure to humans is
fish consumption. Typically, the larger species, such as shark,
swordfish and some tuna, contain the most mercury. Correspondingly,
the CDC found that women who had eaten fish two or more times
a week had mercury levels that were seven times higher than
those who had not eaten fish in the previous month.
Long-term exposure to small amounts of mercury can harm adults,
however fetuses and young children face an even greater risk
because their nervous systems are not fully developed.
Molecular
Psychiatry January 27, 2004
Seattle
PI February 5, 2004
