Environmental Engineering Reference
In-Depth Information
(NHB) anglers, especially in urban areas are at increased
risk for exposure to methylmercury. About 90% of NHB
anglers fi sh in the Midwest, Northeast, and South regions
of the United States (Henderson, 2004), where most of
the fi sh advisories for mercury have been issued. It is not
a coincidence that the NHB population and the sources
of mercury contamination are often co-located within
and around urban areas. The persistence of subsistence
fi shing in polluted waters by non-Hispanic urban blacks
is driven by economic deprivation. They often live in
so-called food deserts of inner cities, where the supply
of fresh seafood is limited. Since many NHBs cannot
afford to buy boats, they are more likely to fi sh from the
shore for benthic organisms in the most contaminated
waters. Over 1 million NHB anglers fi sh for catfi sh, and
more black anglers consume catfi sh than do non-His-
panic white anglers in the United States (Weintraub and
Birnbaum, 2008). In fact, catfi sh consumption has been
shown to be a major contributor to elevated PCB levels
in an NHB population (Weintraub and Birnbaum, 2008),
and this is likely to be true for disparities in mercury
exposure.
A cultural angle to the fi shing practices of NHBs has
been advanced by Weintraub and Birnbaum (2008). During
slavery, fi shing for nocturnal catfi sh enabled NHB anglers
to supplement diets, develop knowledge of rivers along
the Underground Railroad, and, in some cases, earn
money (Cecelski, 2001). The Jim Crow legislation lim-
iting economic opportunity and access to arable land
further perpetuated subsistence fi shing. The historical
legacy may explain why the rate of fi shing among NHB
anglers is similar regardless of income levels (Henderson,
2004; Weintraub and Birnbaum, 2008). The way the fi sh
is prepared is a cultural trait that may result in increased
absorption of mercury by NHBs. Frying, for instance, can
reduce the water content of the fi sh, resulting in a fi nal
product with a higher methylmercury concentration
(Burger et al., 2003). Also, NHB anglers are less likely to
trim off the fat (where PCBs and other organic pollutants
tend to accumulate), and are more likely to eat whole fi sh
than non-Hispanic white anglers. Because tissue organs
accumulate mercury, consumption of the whole fi sh (ver-
sus fi llets) results in elevated exposures to mercury (Burger
et al., 2001).
Disparities in exposure and body burden of mercury
may also stem from racial differences in fi sh consump-
tion. The percentage of high-end consumers (respondents
that consumed fi sh three times a week or more) was sig-
nifi cantly higher for NHBs (15%) as compared with the
white sub-population (11.6%) (USEPA, 2000). Various other
surveys have reported that NHB anglers generally con-
sume 50-100% more fi sh than non-Hispanic white anglers
(Gibson and McClafferty, 2005). Studies in Pennsylvania
and South Carolina found that NHB anglers consume fi sh
at more than four times the rate of that of non-Hispanic
white anglers (Burger, 2002).
Curse from the Wind: Contamination
of the Arctic Region with Mercury
Mercury is released from many human industrial activi-
ties in a gaseous form. As such, it can travel long distances
through the atmosphere and be transported to remote eco-
systems (Mason and Fitzgerald, 1996; Van Oostdam et al.,
1999). A study of streams and rivers throughout the west-
ern United States detected mercury in every one of 2707
fi sh tested, and an atmospheric source was suggested as a
key factor responsible for mercury in these fi sh (Peterson et
al., 2007). Because of a variety of factors, the Arctic region
has become a major sink for mercury released from indus-
trial sources in Europe and Asia (Arctic Monitoring and
Assessment Programme [AMAP], 1998; 2005; Macdonald
et al., 2005). As the fl ux of mercury into the Arctic region
increases, the inorganic mercury becomes methylated and
biomagnifi ed in the local food chain, making the species
feeding at high trophic positions more vulnerable to mer-
cury exposure via their diet (AMAP, 2003).
The environmental and human health implications of
mercury pollution in Arctic region have been of public
health concern and scientifi c interest since the early 1970s.
The fl ux of industrial pollutants into the northern polar
region via atmospheric and oceanic long-range transport
mechanisms and the subsequent impacts on wildlife and
human health have been the focus of a number of major
initiatives, such as the Arctic Environmental Strategy's
Northern Contaminants Program initiated in 1991 by
the Canadian government and the Arctic Monitoring and
Assessment Programme, a circumpolar multicountry pro-
gram established to assess the state of multiple compart-
ments in the Arctic ecosystem, including human health
(AMAP, 1998). These programs have conducted detailed
investigations of the sources and extent of contamination
of the Arctic food chain with mercury, assessments of expo-
sure, characterizations of risk, human biomarkers, and risk-
benefi t analysis pertaining to mercury in the Arctic region
(AMAP, 2003, 2005; Braune et al., 2005; Macdonald et al.,
2005; van Oostdam et al., 2005). Results of these investiga-
tions provide solid evidence that mercury has increased in
the Arctic food chain to the point at which it represents a
hazard to human health. The studies also show signifi cant
differences in exposure and mercury levels among people
living in this region and in their vulnerability to the mer-
cury hazard. Mercury pollution in the Arctic is thus an
international environmental justice issue, since the com-
munities that are impacted negatively derive no benefi t
from the factories in North America, Europe, and Asia that
emit the mercury, nor do they have the opportunity to par-
ticipate in decisions on how to mitigate the mercury risk.
The indigenous people of the Arctic region have become
vulnerable to the risk of mercury exposure because they
rely heavily on natural resources for their livelihood. The
traditional foods of indigenous peoples in the circumpolar
countries consist of raw, boiled, or dried meat, blubber, and
