PCBs, dioxins, and related persistent organic pollutants have potential
to affect children's behavioral and psychological functioning. The excerpt
below is from the book "Silent Scourge: Children, pollution, and why scientists
disagree" (2003). Click here to
go to a website with reviews of the book, pdf files you can download, and
some links to interesting web pages.
The following excerpt is from Chapter 3, PCBs, Copyright 2003, Oxford University
Press, all rights reserved.
"... When the infants were 7 months old, the researchers found
that PCBs in the umbilical cord blood were related to performance on an infant
test that measures memory (the Fagan Test of Infant Intelligence). In the
Fagan test, the infant is first shown two pictures that are identical, and
then one of the pictures is changed. Because at that age infants have a preference
for novelty in these kinds of tests of visual attention, the amount of time
the infant spends looking at the new picture tells whether the infant noticed
that it was different from the original one. Even after adjusting for family
background variables such as socioeconomic status, maternal education, maternal
vocabulary, and social quality of the home, PCBs in the umbilical cord accounted
for about 10% of the differences among infants in their performance on the
test (S. Jacobson et al., 1985). The infants in the very highest exposure
group showed no evidence of noticing the switch between the original and the
novel pictures at 7 months of age. Because infant performance on the Fagan
test has been shown in other research to have a positive relationship to
IQ test scores in childhood, these results are a cause for concern.
But do the differences due to prenatal PCB exposure last
into childhood? Yes. When the children were 4 years old, the researchers assessed
them very thoroughly. They administered standardized intelligence tests,
plus laboratory tests of sustained attention and memory, and response speed
in a visual discrimination task. They measured the children’s physical growth
and collected behavior ratings from the research staff member who assessed
the child, and from the mother. The results showed that prenatal PCB exposure
was related to worse performance on... " to read more, link to
my page on children and pollution.
"PCB Pollution “Hot Spots” in the United States
Because of their widespread use in electrical equipment
and heavy industrial equipment, and because they were formerly presumed to
be safe, PCBs are found in many Superfund hazardous waste sites in the U.
S. In addition to having been discharged directly into waterways before they
were regulated, PCBs were sometimes present in industrial waste oil that was
recycled by spreading it on dirt roads to control dust (see Chapter 6, which
considers the effects that toxic waste dumps can have on communities).
Even though PCBs are no longer used in the U.S. and the
European Union, clean up continues to be costly to both taxpayers and corporations
that are found to be responsible. As an example, General Electric Corporation
reported that it spent $241 million dollars on environmental remediation in
1998 and 1999, and that it expected to spend a similar amount in 2000 and
2001 (General Electric, 1999). That amount includes environmental cleanups
of chemicals other than PCBs, but PCBs in the Hudson River are a major part
of that expenditure (see section below on the Hudson River). Even though the
dollar costs are high, for a huge corporation like GE, environmental cleanup
costs are usually a very small percentage of their funds. In 1999 cleanup
costs were only 1/10th of a percent of GE’s total revenues, and only 1.06%
of net earnings. The former CEO of GE, Jack Welch, said that the controversy
about cleaning up PCBs “is not about money. We'll pay whatever it takes to
do the right thing” (Welch, 2001).
The annual corporate reports of many electric utilities
mention that they are considered by the EPA to be “potentially responsible
parties” for cleanup under the Superfund law (for two examples, see Potomac
Electric Power Co., 2000, or Sierra Pacific Resources, 2000). It might be
interesting to you to look up the annual report for the electric utility company
operating in your area (these are available on-line either on the company’s
own website, or on the website of the U.S. Securities Exchange Commission).
The annual reports of most corporations assure the stockholders that environmental
costs (including litigation) will not materially affect the financial condition
of the company. From that I conclude, with the former CEO of G.E., that environmental
cleanup should be about doing the right thing for future generations.
In this section I highlight just a few locations where
PCB contamination has created local controversies, beginning with the Great
Lakes. There are many other such situations in the U.S. and in most industrialized
countries around the world.
PCB Pollution in the Great Lakes: One Fifth of the World’s Fresh Water
Lake Michigan is one of the five Great Lakes (Erie, Huron,
Ontario, Michigan, and Superior) that form part of the border between the
U.S. and Canada. Several Native American tribes also hold treaty rights to
the fisheries of the Great Lakes. The Great Lakes are an international resource--uniquely
valuable freshwater ecosystems that contain approximately one-fifth of our
planet’s fresh water. They also have the world’s largest fresh water fishery
(Johnson et al., 1999; Schantz et al., 1999). Estimates are that 4.7 million
people (about 8% of the population of the Great Lakes States) ate Great Lakes
sport fish in 1993 (Tilden et al., 1997). Approximately 25% of Canada’s population
and 10% of the U.S. population lives in the Great Lakes drainage area. Many
large cities and industries are situated on the shores of the Great Lakes
in both countries. In Canada we find Toronto, Hamilton and Windsor directly
on the shores of Lakes Ontario and Erie. The cities of Buffalo, Rochester,
Detroit, Toledo, Cleveland, Chicago, and Milwaukee all front the beautiful
shores of the Great Lakes.
The Great Lakes have absorbed more than their share of
pollution. In the past it was thought that the way to safely dispose of industrial
wastes, including PCBs, was by diluting them. The Great Lakes allow dilution
because they hold such a large volume of water. However, pollutants like PCBs
(and other persistent organic pollutants or POPs, as well as mercury) bio-accumulate
or multiply as they move up the food chain. Bio-accumulation makes dilution
ineffective. Additionally, the large quantity of fresh water held in the
Great Lakes implies that pollutants that enter them will be there for centuries
before they are eventually flushed out to sea. And once the pollutants reach
the Atlantic Ocean, bioaccumulation in sea life can occur.
The Great Lakes contain at least 362 kinds of chemical
pollutants. The U.S. and Canada have jointly identified 11 chemicals as critical
Great Lakes pollutants because they are known to be toxic to fish, wildlife,
and people. PCBs are on that list. (Johnson et al., 1999). Salmon1 and trout
in the Great Lakes contain relatively high amounts of PCBs because they are
a relatively oily predator fish near the top of the aquatic food chain. It
is estimated that Lake Ontario salmon and trout have almost 3 million times
the concentration of PCBs as that found in the water (Johnson et al., 1999).
It has now been over 20 years since PCBs were last manufactured in the U.S.
and most countries.
Yet Another Persistent Pollutant--PBDEs
Researchers at the University of Wisconsin recently identified
a new persistent chemical pollutant in Lake Michigan salmon, a family of widely
used flame retardant chemicals known as PBDEs (polybrominated diphyenyl ethers).
The chemical structure of PBDEs is similar to that of PCBs, but PBDEs are
still in use. The concentrations of PBDEs and PCBs in the salmon tested showed
that the higher the PCBs in a fish, the higher the PBDEs, and vice versa.
..."
To read more, link to my page on Children and Pollution
by clicking here.
The book "Silent Scourge: Children, pollution, and why scientists disagree"
covers the behavioral and psychological effects of pollutants that we commonly
encounter in the environment. The book is written by Colleen Moore (Professor
of Psychology, University of Wisconsin-Madison, and covers these topics.
Chapter 1 covers lead
Chapter 2 covers mercury.
Chapter 3 covers PCBs
Chapter 4 covers certain pesticides
Chapter 5 covers the effects of noise on children's development
Chapter 6 covers community pollution disasters including Chernobyl, Three
Mile Island, Love Canal
Chapter 7 Precautionary principle and decision making issues in environmental
policy
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