Environmental Engineering Reference
In-Depth Information
job losses and high crime rates. In these places, brownfi elds
represent socioeconomic burdens because they can lower
property taxes, diminish the natural beauty of the area, and
most importantly contaminate the water supply and the air.
Brownfi elds represent a signifi cant health hazard to the
community. An abandoned factory may become an explor-
atory playground for children who become unknowingly
exposed to toxins including mercury, lead, arsenic, and
solvents. Depending on the type and level of mercury con-
tamination, brownfi elds can release signifi cant amounts of
this toxin into the air (mercury compounds are notoriously
volatile) or drinking water. The practice of building of
new schools on brownfi elds may serve to perpetrate envi-
ronmental injustice with regard to mercury. Opponents
of the practice argue that children remain exposed to the
degassing of residual mercury (and other contaminants) in
the remediated brownfi elds and hence represent a liabil-
ity to the school system (Solitaire and Greenberg, 2002).
Proponents, including many developers, claim that brown-
fi elds can be cleaned up to acceptable levels for use in
building schools and that they pose a greater health risk
if left underdeveloped. There are currently no reliable data
to support either claim. Regardless, the hazard (mercury) is
never completely removed, and affected communities must
bear the burden of taking steps to shield themselves from
the risk of any residual mercury in the brownfi elds.
This section briefl y outlines selected cases from indigenous
peoples across North America who are exposed to mercury
from various local sources (e.g., cinnabar mines, hydroelec-
tric dams, chlor-alkali plants, pulp and paper mills, coal-
fi red power plants). In each case, the presence of mercury has
been shown to negatively impact the health, culture, spiritu-
ality, and identity of these communities. These communities
are cases for environmental injustice in the sense that they
have derived little or no benefi t from the products and ser-
vices of the industries that release the mercury and are now
bearing the burden of the wastes left behind.
Grassy Narrows, Ontario (Chlor-Alkali)
The Grassy Narrows First Nations People live in northwest-
ern Ontario, about 130 km downstream of Dryden. In the
mid-1900s a chlor-alkali plant was built in Dryden. Between
1962 and 1970 the plant discharged over 10,000 kg of mer-
cury into the English-Wabigoon river system (Armstrong
and Hamilton, 1973). Northern pike and walleye inhab-
iting these waters had mercury levels as high as 27.8 and
10.4 µg/g, respectively (Fimreite and Reynolds, 1973). Fish
levels that warrant regulatory action range between 0.5
and 1 µg/g. Contamination extended as far as 320 km
downstream of the Dryden discharge point (Fimreite and
Reynolds, 1973). Not surprisingly, many residents of Grassy
Narrows had extremely high levels of blood mercury,
including one individual with a level of 660 µg/L (Wheat-
ley and Paradis, 1995). Furthermore, reports revealed that
fi sh-eating wildlife, including mink and river otter, were
severely intoxicated (Wren, 1985). Owing to this contami-
nation and associated media reports (Wheatley and Paradis,
1995), in May 1970 the Ontario Ministry of Energy and
Resource Management halted fi shing in the region.
The people of Grassy Narrows were immediately
impacted by this fi shing ban. Locally caught fi sh were an
important component of their diet, spirituality, and cul-
ture. Fishing and fi shing-related industries, such as hunt-
ing and lodging, represented a primary source of income
for many people (Kinghorn et al., 2007). Community
members started to change their views towards traditional
foods (fi sh, plants) and lifestyles (hunting, fi shing, gather-
ing). Instead of subsistence hunting/fi shing, many started
to purchase and consume commercially available market
foods and adopt a more sedentary, Western lifestyle.
Thirty years have passed since mercury was discharged
into the English-Wabigoon river system but pollution con-
tinues to plague Grassy Narrows. In 2002, Kinghorn et al.
(2007) sampled fi sh in the region and found that walleye,
bass, and northern pike still had levels of mercury that
exceeded protective guidelines recommended by Health
Canada. A study on 57 residents of Grassy Narrows found
that a range of clinical symptoms related to mercury poison-
ing, including numbness, tremors, pain in the extremities,
and several sensory disturbances, still persisted (Harada
et al., 2005). It is evident that mercury pollution continues
Disproportionate Exposure around Hot Spots
of Mercury
Evidence that hot spots of mercury generally coincide with
areas that are home to communities of color, low-income
and immigrant communities, as well as tribes and indig-
enous peoples has been discussed above. These hot spots
impose a profound burden on subsistence and sport fi shers
and their families, for whom fi sh and fi shing are important
for physiologic, economic, social, political, cultural, and
spiritual health. Among the groups at risk, the local tribes
and indigenous peoples are the most vulnerable and often
the most highly exposed to mercury. Examples of such
communities include several indigenous peoples found
throughout North America, such as the Cree in Quebec
(Dumont et al., 1998; Muckle et al., 2001a), Ojibwe in the
Great Lakes basin (Dellinger, 2004) and Ontario (Kinghorn
et al., 2007), Rancheria in Northern California (Harnly
et al., 1997), and the Mohawk in Quebec (Chan et al., 1999)
and New York (Schell et al., 2003).
Using available databases, Roe (2003) identifi ed 655
watersheds across the United States where Native commu-
nities exist. By examining the concentrations of mercury in
fi sh within these watersheds, 19 Native communities were
classifi ed as having a severe risk for mercury intoxication,
70 as having a high risk, and 59 as having a moderate risk.
Such a comparison reveals that the geographic location of
tribes puts many Native peoples at a disproportionate risk
of mercury exposure (O'Neill, 2004).
