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RACHEL'S ENVIRONMENT & HEALTH WEEKLY #562
September 4, 1997
HEADLINES:
THE CAUSES OF LYMPH CANCERS
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THE CAUSES OF LYMPH CANCERS
Non-Hodgkin's lymphoma (NHL) is a group of cancers that arise in
the white blood cells. NHL is increasing rapidly in the U.S. and
elsewhere in the industrialized world. In the year 1950, 5.9
Americans per 100,000 were diagnosed with non-Hodgkin's lymphoma.
In 1985, the incidence (occurrence) rate of this disease had
risen to 13.1 per 100,000.[1] By 1991, the incidence rate had
reached 15.1 per 100,000 and was still climbing.[2]
Between 1973 and 1991, the incidence of non-Hodgkin's lymphoma
increased at the rate of 3.3% per year, making it the third
fastest-growing cancer (after prostate cancer, growing at 3.9%
per year, and melanoma of the skin, also growing at 3.9% per
year).[2] In recent years, AIDS patients have contributed to the
increase in NHL, but a steady rise in the incidence of this
disease was apparent long before the AIDS epidemic. Together the
known "risk factors" for NHL --including immune-suppressing
drugs, rare immune-system diseases, and AIDS, explain only a
small proportion of NHL cases.
About 50,900 new cases of NHL were diagnosed in the U.S. in 1995
and about 22,700 deaths from NHL were reported that year.[3] NHL
is a serious disease; half the people diagnosed with it are dead
within five years. The causes of NHL are not understood, but the
following factors have been implicated in many studies:
- Phenoxy herbicides, especially 2,4,5-T (the herbicide now
banned in the U.S.) and 2,4-D, the most popular chemical killer
of dandelions and crabgrass in lawns.[4] More than a dozen
studies now indicate that exposure to these herbicides increases
the likelihood of getting NHL.
- Viruses. The roles of viruses "appears to be minor," say Paul
Scherr and Nancy Mueller, who are experts in the viral causes of
cancer. However, the Epstein Barr virus (EBV) seems to be
implicated in some way in many cases of non-Hodgkin's lymphoma,
although the virus BY ITSELF does not seem to cause the
disease.[1,5]
- People with compromised immune systems and/or autoimmune
diseases have a substantially increased likelihood of getting
NHL. This is a consistent thread running throughout NHL
research: the NHL family of cancers tends to strike people whose
immune systems are degraded for one reason or another. This was
first discovered among people who had had organ transplants. The
body's immune system naturally tries to reject foreign organs.
To allow a foreign kidney or liver to be accepted, doctors
devised medications to suppress the immune system. In some
instances, suppressing the immune system gave rise to NHL. Since
that time, researchers have documented many different ways in
which suppressed or malfunctioning immune systems allow NHL to
develop.
In the authoritative reference book, CANCER EPIDEMIOLOGY AND
PREVENTION, Paul Scherr and Linda Mueller conclude[1] that there
are two clear threads visible in NHL research:
- People whose immune systems are continually challenged (for
example, by medications or by autoimmune diseases such as
rheumatoid arthritis, or by other factors) seem to lose control
of latent cancer-causing infections that may be caused by viruses
such as the Epstein Barr virus.
- "Another group who appears to be at increased risk are
individuals with occupational exposures to chemicals," say Scherr
and Mueller. They continue, "There is mounting evidence
implicating phenoxy herbicide exposures, although the evidence is
still not conclusive."[1]
Scherr and Mueller do not say so, but there is also evidence that
the likelihood of NHL is increased by exposure to DDT, the
well-known organochlorine pesticide.[6] In addition, recent
evidence suggests that another class of pesticides --the
organophosphates such as malathion and parathion --can cause
NHL.[7] Thus organochlorines, organophosphates, and phenoxy
herbicides are now all implicated in the mushrooming problem of
NHL.
Most recently, provocative new research indicates that PCBs, too,
can cause non-Hodgkin's lymphoma. From 1929 until just recently,
PCBs were used in electrical equipment as fire retardants. They
were also used in plastics, preservatives, varnishes, waxes, and
carbonless carbon paper.
The connection between PCBs and NHL was first suggested in 1996
by the Swedish researcher, Lennart Hardell.[8] Hardell studied a
small group (28 individuals) with NHL and compared them to a
control group of 17 surgical patients in the same Swedish
hospital who did not have cancer. Hardell took tissue samples
from both groups and analyzed them for DDT and its breakdown
product, DDE; dioxins; hexachlorobenzene (HCB); and PCBs. The
tissue concentrations of both groups were the same for DDT, DDE,
HCB and dioxins. However, when it came to PCBs, the group with
NHL has significantly[9] more PCBs in their tissues than the
control group did.
This finding is biologically plausible because PCBs are known to
suppress the immune system of animals and humans. Hardell
concluded his research report in 1996 saying, "Immunological
impairments have been shown after exposure to PCBs. Since
immunosuppression is an established risk factor for NHL, our
results are of interest in the etiology [causation] of NHL but
need to be confirmed in larger studies."
Now a larger study by the National Cancer Institute (NCI) has
confirmed Hardell's results.[10] NCI researchers set out to
explore whether people with NHL had more than their fair share of
DDT in their tissues. They examined blood that had been taken
from nearly 26,000 healthy individuals in 1974 --a prospective
study known as the Campaign Against Cancer and Stroke [or CLUE I]
being conducted at Johns Hopkins University in Baltimore. Within
the large group, they identified 74 individuals who had
eventually contracted NHL, and they matched them against 147
controls who did not have NHL.
The NCI researchers did not find any connection between DDT and
NHL but, quite unexpectedly, they found a 4.5-fold increase in
non-Hodgkin's lymphomas among people who had 1050 parts per
billion (ppb) of PCBs in the fat globules of their blood,
compared to people who had only 250 to 650 ppb PCBs. The study
found a clear dose-response relationship between PCBs in the
blood and the likelihood of having NHL.
Furthermore, this NCI study provided additional evidence of the
role of the Epstein Barr virus in NHL. Individually, PCBs and EBV
each increased the likelihood of NHL. However, together, the
presence of BOTH Epstein Barr virus AND elevated PCBs in
individuals had a synergistic effect, combining to produce a
22-fold increase in the likelihood of NHL.
The solution to this problem has two parts. One part involves the
use of pesticides. Organochlorines, organophosphates, and
phenoxy herbicides all increase the dangers of NHL. In the case
of these chemicals, it is not too late to make sensible,
precautionary decisions. In our homes, our public buildings, our
schools, and our businesses we could avoid these products like
the plague. Alternative ways of dealing with pests are
well-known. If pesticides are needed at all, they are needed
only in emergencies.
The second part of the problem is PCBs. Some 3.4 billion pounds
of PCBs were distributed into the environment --all of them
manufactured or licensed for manufacture by one corporation,
Monsanto of St. Louis, Missouri.[11]
The whereabouts of 30 percent of all PCBs (roughly a billion
pounds) remains unknown. Another 30 percent resides in
landfills, in storage, or in the sediments of lakes, rivers, and
estuaries. Some 30 percent to 60 percent remains in use. The
characteristics of PCBs (their stability and their solubility in
fat) tend to move them into the oceans as time passes. There
they decimate wildlife. It is estimated that only one percent of
all PCBs have, so far, reached the oceans.
Without major efforts to locate, capture, and destroy the
one-to-two billion pounds of PCBs that are "out there," future
generations will continue to be poisoned by PCBs, at great social
and individual cost.
Recently, we hear a drum beat of public relations from Monsanto,
claiming that it has turned over a new leaf and is now committed
to behaving in a civilized fashion. If this is so, Monsanto
could demonstrate its awakening by leading a global effort to
locate and destroy PCBs, cleansing the planet (to the extent
possible) of this brain-damaging, immune-suppressing,
cancer-causing substance. Has anyone seen a sign of serious
intentions from St. Louis?
--Peter Montague
(National Writers Union, UAW Local 1981/AFL-CIO) |
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| [1] Paul A. Scherr and Nancy E. Mueller, "Non-Hodgkin's
lymphomas," in David Schottenfeld and Joseph F. Fraumeni, Jr.,
editors, CANCER EPIDEMIOLOGY AND PREVENTION (New York: Oxford
University Press, 1996), pgs. 920-945.
[2] Angela Harras and others, editors, CANCER RATES AND RISKS 4TH
EDITION [NIH Publication No. 96-691] (Bethesda, Maryland:
National Cancer Institute, 1996), pg. 17.
[3] C.L. Kosary and others, editors, SEER CANCER STATISTICS
REVIEW 1973-1992 [National Institutes of Health Publication No.
96-2789] (Bethesda, Md.: National Cancer Institute, 1995), Table
I-1, pg. 15.
[4] For example, see Shelia Hoar Zahm and others, "A Case-Control
Study of Non-Hodgkin's Lymphoma and the Herbicide
2,4,-Dichlorophenoxyacetic Acid (2,4-D) in Eastern Nebraska,"
EPIDEMIOLOGY Vol. 1, No. 5 (September 1990), pgs. 349-356. And:
Donald T. Wigle and others, "Mortality Study of Canadian Male
Farm Operators: Non-Hodgkin's Lymphoma Mortality and
Agricul-tural Practices in Saskatchewan," JOURNAL OF THE NATIONAL
CANCER INSTITUTE Vol. 82, No. 7 (April 4, 1990), pgs. 575-582.
The earliest report came from Lennart Hardell, "Malignant
lymphoma of histiocytic type and exposure to phenoxyacetic acids
or chlorophenols," LANCET Vol. 1, No. 8106 (January 6, 1979),
pgs. 55-56. Numerous other relevant studies are reviewed and
cited in Paul A. Scherr and Nancy E. Mueller, "Non-Hodgkin's
lymphomas," in David Schottenfeld and Joseph F. Fraumeni, Jr.,
editors, CANCER EPIDEMIOLOGY AND PREVENTION (New York: Oxford
University Press, 1996), pgs. 920-945, and in Nathaniel Rothman
and others, "A nested case-control study of non-Hodgkin lymphoma
and serum organochlorine residues," THE LANCET Vol. 350 (July 27,
1997), pgs. 240-244.
[5] Nancy E. Mueller and others, "Viruses," in David Schottenfeld
and Joseph F. Fraumeni, Jr., editors, CANCER EPIDEMIOLOGY AND
PREVENTION (New York: Oxford University Press, 1996), pgs.
502-531.
[6] J.S. Woods and others, "Soft tissue sarcoma and non-Hodgkin's
lymphoma in relation to phenoxyherbicide and chlorinated phenol
exposure in western Washington," JOURNAL OF THE NATIONAL CANCER
INSTITUTE Vol. 78, No. 5 (May 1987), pgs. 899-910. And: K.P.
Cantor and others, "Pesticides and other agricultural risk
factors for non-Hodgkin's lymphoma among men in Iowa and
Minnesota," CANCER RESEARCH Vol. 52, No. 9 (May 1992), pgs.
2447-2455. And: S.H. Zahm and others, "The role of agricultural
pesticide use in the development of non-Hodgkin's lymphoma in
women," ARCHIVES OF ENVIRONMENTAL HEALTH Vol. 48, No. 5
(September 1993), pgs. 353-358.
[7] Two studies are described briefly in John Wargo, OUR
CHILDREN'S TOXIC LEGACY (New Haven, Connecticut: Yale University
Press, 1996), pg. 237, footnote 13. And see S.H. Zahm and
others, "The role of agricultural pesticide use in the
development of non-Hodgkin's lymphoma in women," ARCHIVES OF
ENVIRONMENTAL HEALTH Vol. 48, No. 5 (September 1993), pgs.
353-358, which found a 4-fold increase in NHL among women exposed
to organophosphates.
[8] Lennart Hardell and others, "Higher concentrations of
specific polychlorinated biphenyl congeners in adipose tissue
from non-Hodgkin's lymphoma patients compared with controls
without a malignant disease," INTERNATIONAL JOURNAL OF ONCOLOGY
Vol. 9 (1996), pgs. 603-608.
[9] p < 0.06.
[10] Nathaniel Rothman and others, "A nested case-control study
of non-Hodgkin lymphoma and serum organochlorine residues," THE
LANCET Vol. 350 (July 26, 1997), pgs. 240-244. And see J. Raloff,
"PCBs linked to rise in lymph cancers," SCIENCE NEWS Vol. 152
(August 9, 1997), pg. 85.
[11] Carol W. Bason and Theo Colborn, "U.S. Application and
Distribution of Pesticides and Industrial Chemicals Capable of
Disrupting Endocrine and Immune Systems," in Theo Colborn and
Coralie Clement, editors, CHEMICALLY-INDUCED ALTERATIONS IN
SEXUAL AND FUNCTIONAL DEVELOPMENT: THE WILDLIFE/HUMAN CONNECTION
[Advances in Modern Environmental Toxicology Vol. XXI]
(Princeton, N.J.: Princeton Scientific Publishing Co., 1992),
pgs. 335-345.
4th NATIONAL GRASS-ROOTS CONVENTION OCTOBER 3-5
The CCHW Center for Health, Environment and Justice will sponsor
its fourth national grass-roots convention October 3-5 in
Arlington, Va., just outside Washington, D.C.
CCHW conventions provide grass-roots activists a chance to
celebrate victories, create and renew friendships, develop
strategies and learn specific skills for use in local fights.
This convention will be an exceptionally good one.
The agenda includes numerous practical workshops on a broad range
of subjects like "advanced organizing" and SLAPP suits and how to
do research.
In addition, there will be thought-provoking sessions on
big-picture topics, such as: sustainable economic development;
coalition building; expanding and diversifying the grass-roots
movement; "It's the economy, stupid;" and challenging corporate
control of our society.
Personally, I wouldn't miss this convention for anything. --Peter
Montague
For more details, contact CCHW: P.O. Box 6806, Falls Church, VA
22040; telephone (703) 237-2249.
Descriptor terms: cancer; carcinogens; non-hodgkin's lymphoma;
nhl; blood; lymph system; lymphomas; disease statistics;
morbidity; mortality; immune system; epstein barr virus; ebv;
phenoxy herbicides; viruses; infectious cancer-causing diseases;
paul scherr; nancy mueller; organ transplants; rheumatoid
arthritis; ddt; dde; organophosphates; malathion; parathion;
pcbs; polychlorinated biphenyls; lennart hardell; monsanto; hcb;
hexachlorobenzene; 2,4,5-T; 2,4-D; synergism; precautionary
principle; pesticides; |
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--Peter Montague, Editor
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