length (sometimes referred to as fresh-water shrimp) that live on the bottom of
the Great Lakes, have been wiped out in portions of Lake Erie, Lake Michigan,
Saginaw Bay, and Lake Ontario. About 44,000 km
2 of the Great Lakes no
longer have diporeia. Research biologists indicated that they have never seen
such a phenomenon before. In the 1980s, the scientists found densities of
diporeia between 3860 and 7720 per km
2 of sediment in parts of the Great
Lakes. The researchers state that no diporeia are now found in many of the
same spots. Diporeia are a main food source for many fish in the Great Lakes.
Whitefish have become one of the first casualties of the loss of diporeia. Until
recently, whitefish could be found that were about 0.6 m long and 2.3 kg. Now
whitefish range from 0.51 to 0.56 m. The decline of the diporeia population
remains somewhat of a mystery to fish researchers. They have examined whether
the decline is a result of contaminants, but, so far, there is no conclusive answer.
CASE STUDY 2.2
Around the middle of the 1960s, New York City’s Hudson River was found to
be ‘‘dying’’ as a result of severe water pollution. The sources of the pollution
were found to be raw sewage being dumped into the river by the city; discharge
of large quantities of paint from a factory; oil dumping from Penn Central
Railroad; and discharge of water at elevated temperatures from a nuclear power
plant. There is, however, reason to be encouraged. In 1966, several fishermen
formed the Hudson River Fishermen’s Association. Mainly because of their
efforts and those of others who joined subsequently, much improvement has
been made. Beginning in 1968, a number of polluters were forced to spend
millions of dollars remediating the Hudson. The by-product of these actions was
one of the greatest environmental success stories of the 20th century. Today, the
Hudson produces more fish per hectare than most other major estuaries of the
North Atlantic. Fish and fishermen, boaters, and swimmers have reportedly
returned to the river.
13
2.1.5 SOIL POLLUTION
Another major concern is the possible deleterious effect of the release of an
increasing number of toxic synthetic chemicals into the environment. This
leads to soil pollution, in addition to air and water pollution, and food
contamination. Moreover, the release of these chemicals is not limited to areas
adjacent to point sources, such as industrial facilities. Rather, the chemicals
can be transferred to distant areas and regions where they may elicit adverse
effects on living organisms.
In the U.S., an assessment of the extent and severity of contamination is
further complicated by the nearly exponential growth of the synthetic organic
chemicals industry since the early 1940s. About 70,000 chemicals are estimated
to be in common industrial and commercial use in the U.S. and this number
continues to grow by about 1000 new compounds every year. Only a limited
number of ecological assessments on the bulk of the chemicals on the market or
those introduced each year have been undertaken. The human health effects of
Environmental Change and Health
19
[16:55 26/8/04 P:/CRC PRESS/4365 MING-HO.751 (1670)/4365-002.3d]
Ref: 4365 MING-HO YU Chap-002 Page: 19 13-30
the Great Lakes, have been wiped out in portions of Lake Erie, Lake Michigan,
Saginaw Bay, and Lake Ontario. About 44,000 km
2 of the Great Lakes no
longer have diporeia. Research biologists indicated that they have never seen
such a phenomenon before. In the 1980s, the scientists found densities of
diporeia between 3860 and 7720 per km
2 of sediment in parts of the Great
Lakes. The researchers state that no diporeia are now found in many of the
same spots. Diporeia are a main food source for many fish in the Great Lakes.
Whitefish have become one of the first casualties of the loss of diporeia. Until
recently, whitefish could be found that were about 0.6 m long and 2.3 kg. Now
whitefish range from 0.51 to 0.56 m. The decline of the diporeia population
remains somewhat of a mystery to fish researchers. They have examined whether
the decline is a result of contaminants, but, so far, there is no conclusive answer.
CASE STUDY 2.2
Around the middle of the 1960s, New York City’s Hudson River was found to
be ‘‘dying’’ as a result of severe water pollution. The sources of the pollution
were found to be raw sewage being dumped into the river by the city; discharge
of large quantities of paint from a factory; oil dumping from Penn Central
Railroad; and discharge of water at elevated temperatures from a nuclear power
plant. There is, however, reason to be encouraged. In 1966, several fishermen
formed the Hudson River Fishermen’s Association. Mainly because of their
efforts and those of others who joined subsequently, much improvement has
been made. Beginning in 1968, a number of polluters were forced to spend
millions of dollars remediating the Hudson. The by-product of these actions was
one of the greatest environmental success stories of the 20th century. Today, the
Hudson produces more fish per hectare than most other major estuaries of the
North Atlantic. Fish and fishermen, boaters, and swimmers have reportedly
returned to the river.
13
2.1.5 SOIL POLLUTION
Another major concern is the possible deleterious effect of the release of an
increasing number of toxic synthetic chemicals into the environment. This
leads to soil pollution, in addition to air and water pollution, and food
contamination. Moreover, the release of these chemicals is not limited to areas
adjacent to point sources, such as industrial facilities. Rather, the chemicals
can be transferred to distant areas and regions where they may elicit adverse
effects on living organisms.
In the U.S., an assessment of the extent and severity of contamination is
further complicated by the nearly exponential growth of the synthetic organic
chemicals industry since the early 1940s. About 70,000 chemicals are estimated
to be in common industrial and commercial use in the U.S. and this number
continues to grow by about 1000 new compounds every year. Only a limited
number of ecological assessments on the bulk of the chemicals on the market or
those introduced each year have been undertaken. The human health effects of
Environmental Change and Health
19
[16:55 26/8/04 P:/CRC PRESS/4365 MING-HO.751 (1670)/4365-002.3d]
Ref: 4365 MING-HO YU Chap-002 Page: 19 13-30