Environmental Engineering Reference
In-Depth Information
to affect the developing brain, children whose mothers ate
larger amounts of seafood (defi ned in this study as >340 g/wk)
during pregnancy experienced better neurodevelopmental
outcomes. Children whose mothers ate smaller amounts of
seafood, however, were not protected from certain adverse
neurodevelopmental outcomes, such as suboptimal IQ and
social development scores. The authors concluded that
limiting seafood consumption during pregnancy could
actually be detrimental and that the risk of harm from a
loss of nutrients can be greater than the risk of harm from
exposure to presumably trace amounts of contaminants in
seafood.
foods to replace missing traditional foods (Kuhnlein and
Receveur, 1996; Egeland and Middaugh, 1997). A number
of studies have, in fact, shown a decrease in the nutritional
and health statuses of traditional populations following
advice to limit fi sh consumption, as noted by Egeland and
Middaugh (1997) and the Institute of Medicine (2007).
In addition, diets can vary signifi cantly among individ-
ual traditional populations, and therefore may confer dif-
ferent risks and benefi ts. For instance, as mentioned earlier,
the net impact of fi sh on a population's neurodevelop-
mental or cardiovascular health may be infl uenced by the
ratio of mercury to selenium or omega-3 PUFAs contained
in the fi sh. Because of this, fi sh-consumption advisories
that do not consider the specifi c dietary intakes of specifi c
groups, and instead are based on the idea that “one size fi ts
all traditional populations,” could actually unnecessarily
eliminate certain dietary benefi ts.
EFFORTS TO BALANCE RISKS AND BENEFITS
Recognizing that the developing fetus is sensitive to mer-
cury but may also derive cognitive developmental or
other benefi ts from fi sh, the 2004 joint mercury advisory
issued by the USEPA and USFDA (USEPA and USFDA, 2004)
encourages women of reproductive age to eat fi sh, but to
choose fi sh that are lower in mercury. Not only does the
advisory list fi sh that should be avoided, but it also lists
examples of fi sh that are lower in mercury and empha-
sizes the nutritional benefi ts that can be obtained from
fi sh. Assuming reproductive-age women follow the advice
as intended—that is, by avoiding or reducing their intake
of fi sh with high mercury content, rather than avoiding
or reducing fi sh intake altogether—they would be likely
to minimize the risks and maximize the benefi ts of eating
fi sh. The joint advisory was one of the earliest to include
information about the benefi ts of fi sh for reproductive-age
women.
SOCIOCULTURAL RISKS OF LIMITING FISH IN DIETS
In addition to having nutritional impacts, limiting fi sh in
the diets of traditional populations may also have social
and cultural impacts. Fishing is of great social and cultural
signifi cance to many traditional populations. A report
from the Columbia River Inter-Tribal Fish Commission
(CRITFC, 1994) captures this idea, stating: “Fish is not just
a major food source for tribal members, it is the essence
of the tribes' cultural, economic, and spiritual well-being.”
Restricting or removing fi shing may lead to a decrease in
culture-specifi c food activities and knowledge (Kuhnlein
and Receveur, 1996) and undermine some of the social
stability that contributes to good health.
Also notable is the fact that some traditional populations
view fi sh-consumption advisories as a sign of disrespect to
their cultures. The advisories are seen as excusing polluters
from the responsibility of cleaning contaminated waters and
passing the negative impacts of contamination on to socio-
economically disadvantaged communities (USEPA, 2000).
Populations with Potentially High Mercury Exposures
NUTRITIONAL RISKS OF LIMITING FISH IN DIETS
The restriction or removal of fi sh from the diet may also
lessen benefi ts or introduce risks in traditional or subsis-
tence populations for which fi sh is a dietary staple, and
therefore a major source of nutrients. For instance, in
a study of the James Bay Cree of Canada, Dewailly et al.
(2002) determined that omega-3 PUFAs may favorably
infl uence some risk factors for cardiovascular disease, and
concluded that the Cree should therefore be encouraged to
maintain their traditional fi sh-based diet. Similarly, Dellinger
(2004) reported that in some Great Lakes tribes with diets
rich in locally caught fi sh, the body burden of mercury is
low, while obesity, diabetes, and heart disease are major
health concerns. The author suggested that, for these tribes,
replacing the traditional fi sh diet with a highly processed,
market-based diet that is potentially higher in saturated
fats and lower in omega-3 PUFAs may in fact do more harm
than good. Indeed, because traditional populations are
often remotely located, it may be too diffi cult or too expen-
sive for them to obtain a healthy variety of commercial
TRADITIONAL ECOLOGIC KNOWLEDGE
AND FISH CONSUMPTION
Another important consideration to take into account
when weighing the risks and benefi ts of fi sh consumption
in traditional populations is the role that traditional eco-
logic knowledge can play in infl uencing health.
Tradit ional
ecologic knowledge
refers to knowledge about the natural
world acquired over generations by indigenous and other
peoples through direct interaction with their local envi-
ronment. Traditional ecologic knowledge often leads to
the adoption of behaviors that are sustainable for both the
environment and the community that depends on that
environment. Dellinger et al. (2005) hypothesized that
some traditional ecologic knowledge-based cultural prac-
tices may be among the fi rst mercury “guidelines” ever
developed for fi sh consumption.
