Title
Drinking water and cancer incidence in Iowa. II. Radioactivity
in drinking water.
Author
Bean JA; Isacson P; Hahne RM; Kohler J
Address
Source
Am J Epidemiol, 1982 Dec, 116:6, 924-32
Abstract
Iowa towns of 1000-10,000 population, whose water came solely
from wells of over 500
feet (152 meters) in depth and was not treated by a process that
would remove radioactivity,
were identified. Age-adjusted, sex-specific, cancer incidence
rates were determined for these
towns for the years 1969-1978 (excluding 1972) and related to
the mean level of
radium-226 in the municipal water supply. Incidence rates of
cancers of the lung and
bladder among males and of cancers of the breast and lung among
females were higher in
towns with a radium-226 level in the water supply exceeding 5.0
pCi/l. A gradient of
increasing cancer incidence associated with rising radioactivity
level for three time periods
was also seen for lung cancer among males. The associations between
cancer incidence and
radioactivity of water supply could not be explained by smoking
patterns, water treatment
factors, other water quality measurements, or known socio-demographic
features.
Title
Drinking water and cancer incidence in Iowa. I. Trends and incidence
by source of drinking
water and size of municipality.
Author
Bean JA; Isacson P; Hausler WJ Jr; Kohler J
Address
Source
Am J Epidemiol, 1982 Dec, 116:6, 912-23
Abstract
Age-adjusted, sex-specific cancer incidence rates for the years
1969-1978 were determined
for municipalities in Iowa having a population of 1000 or over
and public water supply that
had remained stable for a minimum of 14 years. The incidence
rates for the municipalities
were examined according to major source of water supply (surface
or ground) and depth of
well. As municipality size increased, incidence rates increased
for cancer of the lung among
males and females. A slight gradient of increasing cancer incidence
was seen for cancer of
the bladder among males and females. When stratified for population
size, incidence rates
for cancers of the lung and rectum among males and females were
higher for municipalities
on surface water compared with those on ground sources. Incidence
rates for cancer of the
prostate rose as well depth increased, while a trend was seen
toward decreasing incidence
rates for cancer of the colon among females as well depth increased.
When time trends were
examined, an increase in cancer rates over time was seen for
several cancer sites, with the
increase most noticeable in municipalities supplied by surface
water or shallow wells. These
results are not always consistent with the hypothesis of an association
between cancer and
chlorinated water.
Title
Drinking water and cancer in Louisiana. A retrospective mortality
study.
Author
Gottlieb MS; Carr JK; Clarkson JR
Address
Source
Am J Epidemiol, 1982 Oct, 116:4, 652-67
Abstract
Thirteen Louisiana parishes (counties) using the Mississippi
river as a source of potable
water have the highest mortality rates (1950-1969) in the drinking
water source, a
comparison of cancer deaths and noncancer deaths from 1960-1975
in selected southern
Louisiana parishes was conducted. Parishes were grouped for similarities
in industrialization
and approximately equal exposure of the population to surface
water and ground water.
Cancers were studied in groups by hypothesized risk: high for
bladder, colon, kidney, liver,
lymphoma, rectum, and stomach; low for Hodgkin's lymphoma, leukemia,
lung, malignant
melanoma, multiple myeloma, and prostate; and questionable for
breast, brain, esophagus,
and pancreas. Noncancer deaths were randomly selected and matched
1:1 to cancer deaths
on age, race, sex, and year and parish group of death. Water
source at death was based on
residence at death, surface or ground water, and chlorinated
or nonchlorinated water. The
risk associated with using surface water least likely due solely
to change occurred for cancer
of the rectum. Other risks which were lower but still greater
than 1.0 occurred for cancer of
the kidney and breast. No risk was observed for other cancers
of the gastrointestinal or
urinary tract. Risk for multiple myeloma was associated with
use of ground water.
Title
Source of drinking water at home and site-specific cancer incidence
in Washington County,
Maryland.
Author
Wilkins JR 3d; Comstock GW
Address
Source
Am J Epidemiol, 1981 Aug, 114:2, 178-90
Abstract
A nonconcurrent prospective study was conducted to investigate
the postulated relationship
between organic chemical by-products of water chlorination and
risk of human cancer. Vital
records and nonofficial census data available for each of nearly
31,000 study subjects were
used to compute selected sex- and site-specific cancer incidence
rates in a well-defined
county population. Age, socioeconomic status, smoking history,
source of drinking water at
home, and other individual characteristics of the study population
were examined in relation
to the cancer rates. The drinking water source variable consisted
of three historical cohorts,
each distinguished by a different degree of exposure to chloroform
and other chlorination
byproducts. Incidence rates for cancer of the bladder among men
and for cancer of the liver
among women were nearly twofold higher in the drinking water
cohort that had been
supplied chlorinated surface water at home when compared to the
cohort with a history of
consumption of unchlorinated ground water. The differences, however,
were not statistically
significant. A complementary mortality study also suggested an
association of chlorinated
water with cancer of the liver and urinary tract. The findings
in Washington County indicate
the need for further studies of individuals with different histories
of exposure to chlorinated
and unchlorinated drinking water.
Title
Case-control study of bladder cancer and water disinfection methods
in Colorado.
Author
McGeehin MA; Reif JS; Becher JC; Mangione EJ
Address
Department of Environmental Health, Colorado State University,
Fort Collins.
Source
Am J Epidemiol, 1993 Oct, 138:7, 492-501
Abstract
A population-based case-control study of bladder cancer and drinking
water disinfection
methods was conducted during 1990-1991 in Colorado. Surface water
in Colorado has
historically been disinfected with chlorine (chlorination) or
with a combination of chlorine
and ammonia (chloramination). A total of 327 histologically verified
bladder cancer cases
were frequency matched by age and sex to 261 other-cancer controls.
Subjects were
interviewed by telephone about residential and water source histories.
This information was
linked to data from water utility and Colorado Department of
Health records to create a
drinking water exposure profile. After adjustment for cigarette
smoking, tap water and
coffee consumption, and medical history factors by logistic regression,
years of exposure to
chlorinated surface water were significantly associated with
risk for bladder cancer (p =
0.0007). The odds ratio for bladder cancer increased for longer
durations of exposure to a
level of 1.8 (95% confidence interval 1.1-2.9) for more than
30 years of exposure to
chlorinated surface water compared with no exposure. The increased
bladder cancer risk
was similar for males and females and for nonsmokers and smokers.
Levels of total
trihalomethanes, nitrates, and residual chlorine were not associated
with bladder cancer risk
after controlling for years of exposure to chlorinated water.
Title
Carcinogenicity of the drinking water mutagen
3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone in the rat
[see comments]
Author
Komulainen H; Kosma VM; Vaittinen SL; Vartiainen T; Kaliste Korhonen
E; Lötjönen S;
Tuominen RK; Tuomisto J
Address
Division of Environmental Health, National Public Health Institute,
Kuopio, Finland.
Source
J Natl Cancer Inst, 1997 Jun, 89:12, 848-56
Abstract
BACKGROUND: Several epidemiologic studies have suggested that
the consumption of
chlorinated drinking water may be associated with the development
of certain cancers in
humans. 3-Chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone
(MX), a byproduct of the
chemical reactions that occur in chlorinated drinking water,
has been found to be mutagenic
in bacteria and mammalian cells; however, its potential to cause
tumors in animals has not
been tested previously. PURPOSE: The objective of this study
was to evaluate the
carcinogenicity of MX in rats given MX in their drinking water.
METHODS: MX was
administered to male and female Wistar rats (50 rats per dose
group) in drinking water for
104 weeks at concentrations yielding the average daily doses
of MX of 0.4 mg/kg of animal
weight (low dose), 1.3 mg/kg (mid dose), and 5.0 mg/kg (high
dose) for males and 0.6
mg/kg, 1.9 mg/kg, and 6.6 mg/kg for females, respectively. Control
rats received water
from the same source used for preparation of the MX dose formulations
(after its
adjustment to the same pH range). Body weight, clinical signs,
and food and water
consumption were recorded regularly. At the end of the treatment
period, the animals were
killed and full histopathologic analysis was performed on 47
tissues and all lesions.
RESULTS: Dose-dependent increases in tumor incidence were observed
in rats given
MX-containing drinking water; the same MX doses had no obvious
toxic effects on
animals. MX consumption increased most drastically the prevalence
of follicular adenoma
(up to 43% and 72% in high-dose males and females, a test [one-sided]
for positive trend in
all dose groups P = .0045 and P = .0000, respectively) and carcinoma
(55% [P = .0000] and
44% [P = .0000], respectively) in thyroid glands and cholangioma
in the liver (8% [P =
.0009] and 66% [P = .0000] in the high-dose males and females,
respectively). Among rats
given the higher doses of MX in their drinking water, cortical
adenomas of the adrenal
glands were increased in both sexes, alveolar and bronchiolar
adenomas of the lungs and
Langerhans' cell adenomas of the pancreas were increased in males,
and lymphomas,
leukemias, and adenocarcinomas and fibroadenomas of the mammary
glands were
increased in females. Even the lowest MX dose studied was carcinogenic.
CONCLUSION:
MX is a potent carcinogen in both male and female rats, and it
causes tumors at doses that
are not overtly toxic to rats. IMPLICATIONS: Although these findings
cannot be
extrapolated to humans, MX should be studied as a candidate risk
factor in the possible
association between consumption of chlorinated drinking water
and cancer in humans.
Title
Drinking water and cancer incidence in Iowa. III. Association
of cancer with indices of
contamination.
Author
Isacson P; Bean JA; Splinter R; Olson DB; Kohler J
Address
Source
Am J Epidemiol, 1985 Jun, 121:6, 856-69
Abstract
With data from the Iowa Cancer Registry, age-adjusted sex-specific
cancer incidence rates
for the years 1969-1981 were determined for towns with a population
of 1,000-10,000 and
a public water supply from a single stable ground source. These
rates were related to levels
of volatile organic compounds and metals found in the finished
drinking water of these
towns in the spring of 1979. Results showed association between
1,2 dichloroethane and
cancers of the colon and rectum and between nickel and cancers
of the bladder and lung. The
effects were most clearly seen in males. These associations were
independent of other water
quality and treatment variables and were not explained by occupational
or other
sociodemographic features including smoking. Because of the low
levels of the metals and
organics, the authors suggest that they are not causal factors,
but rather indicators of possible
anthropogenic contamination of other types. The data suggest
that water quality variables
other than chlorination and trihalomethanes deserve further consideration
as to their role in
the development of human cancer.
Title
Disinfection of drinking water, disinfection by-products and
cancer: what about Australia?
Author
Pilotto LS
Address
National Centre for Epidemiology and Population Health, Australian
National University,
Canberra.
Source
Aust J Public Health, 1995 Feb, 19:1, 89-93
Abstract
Chlorine, commonly used to disinfect drinking water, produces
by-products known from
animal studies to be carcinogenic and mutagenic. Most epidemiological
studies into the
possible association between chlorination by-products in drinking
water and cancer have
been ecological in nature, or have relied on case-control designs
based on death certificates.
Interpretation of results arising from these studies is limited.
Individual levels of toxicant
exposure and many potential confounders and effect modifiers
are unable to be accounted
for in the analyses. At best, these studies generate hypotheses
that require more definitive
investigation. Misclassification of individuals based on inaccurate
assessment of the level of
exposure is probable. The few analytic studies able to overcome
or minimise these
problems suggest a clear link between exposure to chlorinated
drinking water and the
development of urinary bladder cancer. They also suggest a possible
link with rectal cancer.
However, these studies have classified subjects by exposure to
chlorinated drinking water,
rather than to levels of chlorine and its by-products in drinking
water. To date, the link
between levels of chlorine and its by-products in water, levels
of consumption and cancer
has not been made. Information on the levels of chlorine and
some by-products is available
in many water jurisdictions in Australia. Further, epidemiological
methods can be employed
to quantify water consumption. Case-control studies linking these
parameters would help us
to understand the magnitude of the risk to human populations
and provide a basis to
investigate mechanisms for risk reduction.
Title
Drinking water and cancer.
Author
Cantor KP
Address
Occupational Epidemiology Branch, Division of Cancer Epidemiology
and Genetics,
National Cancer Institute, Bethesda, Maryland 20892, USA.
Source
Cancer Causes Control, 1997 May, 8:3, 292-308
Abstract
Epidemiologic evidence on the relation between contaminants in
drinking water and cancer
is reviewed. The reviewed studies cover exposure to: disinfection
byproducts; nitrate;
arsenic and other metals; volatiles and contaminants from hazardous
waste sites;
asbestiform fibers; radionuclides; and fluoride. Most investigations
are ecologic, with some
confirmation of elevated risk from individual-based studies.
In the case of waterborne
arsenic, and possibly chlorination byproducts, there is a consistent
but small body of
epidemiologic evidence of an association with one or more types
of cancer. Nitrate in
groundwater has increased greatly over the years, and the demonstration
of endogenous
nitrosation among highly exposed subjects raises concern of elevated
cancer risk. However,
the epidemiologic data are not yet sufficient to draw a conclusion.
There is a diversity of
studies among populations exposed to water contaminated with
pesticides, volatile organics,
or mixtures from hazardous waste sites. Studies of asbestiform
fibers and radionuclides in
water are not conclusive, but there are suggested elevations
of several cancer sites in highly
exposed populations. There is no suggestion that fluoride in
drinking water is linked with
elevated risk of cancer. As topics for epidemiologic evaluation,
drinking water contaminants
pose methodologic problems common to studies designed to detect
relatively small
elevations in risk, with the added challenge of assessing exposures
for many years in the
past. Nevertheless, epidemiologic assessment is valuable and
clearly warranted, given the
potential public health impact of small risk elevations among
very large exposed
populations, and the limitations of toxicologic experiments in
assessing carcinogenic risk of
complex mixtures or of compounds for which appropriate animal
models are not available.
Title
Drinking water and cancer mortality.
Author
Clark RM; Goodrich JA; Deininger RA
Address
Source
Sci Total Environ, 1986 Sep, 53:3, 153-72
Abstract
The problem of understanding the possible adverse health effects
of organic chemical
contaminants in drinking water is not new, but national concern
has intensified in recent
years. Despite this concern and regulatory efforts, no definitive
relationship has been
established between organic contamination and human health effects.
This paper examines
some of the sources of possible organic contamination, current
knowledge concerning
human health effects and the most current epidemiological data.
Historic CCE and CAE
data were extracted from STORET and used in regression analyses.
Age-adjusted 20-year
average cancer mortality rates were regressed against the sum
of CAE and CCE for those
counties with STORET monitoring data of their drinking water
source. Results indicate
statistically highly significant relationships particularly for
GI-urinary tract cancers.
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