Clean Air Reports
Search
•
RSS Feed
Executive Summary
As the new home of NCPIRG's environmental work,
Environment North Carolina can be contacted with any questions regarding this
report. On January 12, 2001, government
health officials issued new advisories warning women to limit fish consumption
during pregnancy to avoid exposing their unborn children to unsafe levels
of methylmercury. Methylmercury can cross the placenta and cause learning
deficits and developmental delays in children who are exposed even to
relatively low levels in the womb. The principal exposure route for the
fetus is fish consumption by the mother.
The Food and Drug Administration
(FDA), which regulates commercially sold fish, recommends that pregnant
and nursing women and young children not eat any shark, swordfish, tilefish,
or king mackerel, but then recommends 12 ounces per week of any other
fish. The Environmental Protection Agency (EPA), which makes recommendations
to states about safe mercury levels in sport fish, allows up to 8 ounces
of any fish per week for pregnant women with no prohibitions on consumption
of any individual fish caught recreationally.
These restrictions are steps
in the right direction, but they need to be tightened significantly to
adequately protect women and their unborn children from the toxic effects
of methylmercury.
The nutritional benefits of
fish complicate the task faced by health officials when protecting the
public from methylmercury. Protein, omega-3 fatty acids, Vitamin D, and
other nutrients make fish an exceptionally good food for pregnant mothers
and their developing babies. At the same time, there is no doubt that
methylmercury is toxic to the fetal brain and nervous system, and that
many beneficial fish species are contaminated. EPA's safe exposure estimate
for methylmercury has dropped twice in the past 16 years, as new science
has identified adverse effects in children exposed in the womb at lower
and lower doses. Emerging evidence indicates that the safe dose may drop
even lower in the future (NAS 2000). Just how long a fetus can tolerate
a dose of methylmercury above a "safe level" with no observable
adverse effects is a matter of ongoing debate.
Compounding this uncertainty
is the lack of effective education and outreach to pregnant women about
methylmercury risks and the near total absence of information for pregnant
women on the levels of mercury in the fish they buy. New data from the
Centers for Disease Control and Prevention (CDC) show that about 10 percent
of all women of childbearing age have blood methylmercury levels above
the dose that may put their fetus at risk for adverse neurological effects
(CDC 2001). If these women were to increase their consumption of certain
fish species in hopes of benefiting their babies during pregnancy, they
could expose their fetuses to potentially hazardous levels of methylmercury.
|
