Colon Cancer Mortality and Total Hardness Levels in Taiwan's Drinking Water

The possible association between the risk of colon cancer and hardness levels in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. All eligible colon cancer deaths (1,714 cases) of Taiwan residents from 1989 through 1993 were compared with deaths from other causes (1,714 controls) and the hardness levels of the drinking water used by these residents were determined. Data on water hardness throughout Taiwan have been collected from Taiwan Water Supply Corporation (TWSC). The control group consisted of people who died from other causes and the controls were pair matched to the cases by sex, year of birth, and year of death. The results show a significant negative relationship between drinking water hardness and colon cancer mortality. Odds ratio and 95% confidence intervals were 1.22 (1.04–1.43) and 1.46 (1.22–1.75), respectively, for exposure to moderately hard water and soft water compared with the use of hard water. Trend analyses showed an increasing odds ratio for colon cancer with decreasing levels of hardness in drinking water. This is an important finding for the Taiwan water industry and human health. Received: 8 July 1997/Accepted: 29 November 1997     

Esophageal cancer mortality and total hardness levels in Taiwan's drinking water

The possible association between the risk of esophageal cancer and hardness levels in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. All eligible esophageal cancer deaths (2084 cases) of Taiwan residents from 1987 through 1996 were compared with deaths from other causes (2084 controls), and the hardness levels of the drinking water used by these residents were determined. Data on water hardness throughout Taiwan have been collected from the Taiwan Water Supply Corporation (TWSC). The control group consisted of people who died from other causes and the controls were pair-matched to the cases by sex, year of birth, and year of death. The results show that there is a 42% excess risk of mortality from esophageal cancer in relation to the use of soft water (adjusted odds ratio and 95% confidence intervals was 1.42 (1.22-1.66). This is an important finding for the Taiwan water industry and human health.     

Gastric Cancer Mortality and Drinking Water Qualities in Taiwan

The possible association between the risk of gastric cancer and nitrate and hardness in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. Data on gastric cancer deaths among eligible residents in Taiwan from 1987 through 1991 (6,766 cases) were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes (6,766 controls) and were matched individually to the cases by sex, year of birth, and year of death. Data on nitrate–nitrogen (NO₃–N) and hardness levels in drinking water throughout Taiwan were collected from the Taiwan Water Supply Corporation (TWSC). The municipality of residence for cases and controls was assumed to be the source of the subject's nitrate and hardness exposure via drinking water. There was no difference in gastric cancer rates between the groups with different levels of nitrate. The odds ratios (95% confidence interval) for death from gastric cancer was 0.95 (0.87–1.03) for the group with water nitrate levels between 0.23 and 0.44 mg/L, and 1.02 (0.93–1.11) for the group with nitrate levels greater than 0.45 mg/L. However, the results show a significant negative relationship between drinking water hardness and gastric cancer mortality. Odds ratios were 1.16 (1.07–1.26) and 1.65 (1.52–1.79), respectively, for exposure to moderately hard water and soft water compared with the use of hard water. This is an important finding for the Taiwan water industry and human health risk. Received: 27 November 1996/Accepted: 16 April 1997     

Calcium and magnesium in drinking water and risk of death from acute myocardial infarction in Taiwan

Many studies have examined the association between cardiovascular disease mortality and water hardness. However, the results have not been consistent. This report examines whether calcium and magnesium in drinking water are protective against acute myocardial infarction (AMI). All eligible AMI deaths (10,094 cases) of Taiwan residents from 1994 to 2003 were compared with deaths from other causes (10,094 controls), and the levels of calcium and magnesium in drinking water of these residents were determined. Data on calcium and magnesium levels in drinking water throughout Taiwan have been obtained from the Taiwan Water Supply Corporation. The control group consisted of people who died from other causes and the controls were pair matched to the cases by sex, year of birth, and year of death. The adjusted odd ratios (95% confidence interval) were 0.79 (0.73-0.86) for the group with water calcium levels between 25.1 and 42.4 mg/L and 0.71 (0.65-0.77) for the group with calcium levels of 42.6 mg/L or more. After adjustment for calcium levels in drinking water, there was no difference between the groups with different levels of magnesium. The results of the present study show that there is a significant protective effect of calcium intake from drinking water on the risk of death from AMI.     

Does calcium in drinking water modify the association between nitrate in drinking water and risk of death from colon cancer?

The objective of this study was to explore whether calcium (Ca) levels in drinking water modified the effects of nitrate on colon cancer risk. A matched case–control study was used to investigate the relationship between the risk of death from colon cancer and exposure to nitrate in drinking water in Taiwan. All colon cancer deaths of Taiwan residents from 2003 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by gender, year of birth and year of death. Information on the levels of nitrate-nitrogen (NO₃-N) and Ca in drinking water have been collected from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cases and controls was assumed to be the source of the subject's NO₃-N and Ca exposure via drinking water. We observed evidence of an interaction between drinking water NO₃-N and Ca intake via drinking water. This is the first study to report effect modification by Ca intake from drinking water on the association between NO₃-N exposure and risk of colon cancer mortality.     

Effect modification of the association between trihalomethanes and pancreatic cancer by drinking water hardness: Evidence from an ecological study

The objective of this study was to examine the relationship between total trihalomethanes (TTHM) levels in public water supplies and risk of pancreatic cancer and to determine whether calcium (Ca) and magnesium (Mg) levels in drinking water modify the effects of TTHM on risk to develop pancreatic cancer. A matched case-control study was used to investigate the relationship between the risk of death attributed to pancreatic cancer and exposure to TTHM in drinking water in 53 municipalities in Taiwan. All pancreatic cancer deaths in the 53 municipalities from 1998 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair matched to the cancer cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on TTHM levels in drinking water were collected from Taiwan Environmental Protection Administration. Information on the levels of Ca and Mg in drinking water was obtained from the Taiwan Water Supply Corporation. The municipality of residence for cancer cases and controls was presumed to be the source of the subject's TTHM, Ca, and Mg exposure via drinking water. Relative to individuals whose TTHM exposure level<4.9 ppb, the adjusted OR (95% CI) for pancreatic cancer was 1.01 (0.85-1.21) for individuals who resided in municipalities served by drinking water with a TTHM exposure>4.9 ppb. There was no evidence of an interaction of drinking water TTHM levels with low Ca intake via drinking water. However, we observed evidence of an interaction between drinking water TTHM concentrations and Mg intake via drinking water. Our findings showed that the correlation between TTHM exposure and risk of pancreatic cancer is influenced by Mg in drinking water. Increased knowledge of the interaction between Mg and TTHM in reducing pancreatic cancer risk will aid in public policy making and standard setting.     

Gastric cancer mortality and nitrate levels in Wisconsin drinking water.

The association between nitrate levels in public and private sources of drinking water and gastric cancer mortality in Wisconsin was investigated in a case-control study. All gastric cancer deaths of Wisconsin residents from 1982 through 1985 were compared with deaths from other causes (controls), and nitrate levels in the home drinking water of these residents were determined. Nitrate measures for public sources were obtained from historic nitrate data from municipal sources that existed in 1970. Nitrate measures for private water sources were obtained by testing the wells individually at the existing residences. Controls were matched individually to gastric cancer cases with respect to sex, year of birth, year of death, Wisconsin birth, and Wisconsin residency at the time of death. Matched-pair analyses were performed on the paired data, and the following levels of nitrate-nitrogen exposure were used as indicators of exposure: 0.5, 2.5, 5.0, and 10.0 mg/l. Matched-pair analysis was also performed for which private water supply constituted exposure. Odds ratios and 95% confidence intervals were, respectively, 0.92 (0.75, 1.12); 0.97 (0.74, 1.35); 0.86 (0.69, 1.08); 1.50 (0.12, 18.25); and 1.09 (0.82, 1.47) for exposure to private well-water sources. These results did not indicate an increased risk of gastric cancer at any level.     

Female lung cancer and petrochemical air pollution in Taiwan.

To investigate the relationship between petrochemical air pollution and female lung cancer, we conducted a matched case-control study among women who had died in Taiwan from 1990 through 1994. Data about all eligible female lung cancer deaths were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. The control group included women who died from nonneoplasms and diseases that were not associated with respiratory problems. We pair-matched the controls to the cases by sex, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each case. We used the proportion of a municipality's total population employed in the petrochemical manufacturing industry as an indicator of a resident's exposure to air emissions from the petrochemical manufacturing industry. The subjects were divided into tertiles according to the above indicator. Women who lived in the 2 groups of municipalities characterized by higher levels of petrochemical pollution had a statistically significant higher risk of developing lung cancer than the group that lived in municipalities with the lowest petrochemical air pollution levels (after controlling for possible confounders). The linear trend was also statistically significant (p < .05). The results of this study shed important light on the relationship between the Taiwan petrochemical industry and the resulting risk to human health.     

Beer consumption and rectal cancer

The association of beer drinking with cancer of the rectum was investigated in a case-control study of 130 male and 88 female rectal cancer cases and 336 male and 249 female controls. Information was obtained on consumption of beer, wine, and hard liquor throughout adulthood (quantity and duration), as well as on smoking and sociodemographic characteristics. Beer intake was not significantly associated with estimated risk of rectal cancer in females but was in males, with an increasing gradient in the odds ratio (OR) with increasing beer consumption. For drinkers of 32 or more ounces of beer per day, the OR was 3.5 (95% CI 1.8-7.0). No association was seen with duration of beer drinking. Wine and hard liquor consumption showed no association with the development of rectal cancer. In multiple logistic regression analyses, the relative risk for beer drinking was reduced slightly when potential confounding variables were included in the model (RR adjusted for religion and education: 2.7, 95% CI 1.3-5.7). The study results are discussed in the light of other epidemiological studies of rectal cancer and beer drinking. We conclude from the aggregate evidence that the association of beer drinking with rectal cancer is probably not causal and that the slightly elevated OR's observed for males in this study are most likely due to incomplete control for confounding variables.     

Daily intake of magnesium and calcium from drinking water in relation to myocardial infarction

BACKGROUND: A decreased risk for cardiovascular disease has been related to the hardness of drinking water, particularly high levels of magnesium. However, the evidence is still uncertain, especially in relation to individual intake from water. METHODS: We used data from the Stockholm Heart Epidemiology Program, a population-based case-control study conducted during 1992-1994, to study the association between myocardial infarction and the daily intake of drinking water magnesium and calcium. Our analyses are based on 497 cases age 45-70 years, and 677 controls matched on age, sex, and hospital catchment area. Individual data on magnesium, calcium, and hardness of the domestic drinking water were assessed from waterwork registers or analyses of well water. RESULTS: After adjustment for the matching variables and smoking, hypertension, socioeconomic status, job strain, body mass index, diabetes, and physical inactivity, the odds ratio for myocardial infarction was 1.09 (95% confidence interval = 0.81-1.46) associated with a tap water hardness above the median (>4.4 German hardness degrees) and 0.88 (0.67-1.15) associated with a water magnesium intake above the median (>1.86 mg/d). There was no apparent sign of any exposure-response pattern related to water intake of magnesium or calcium. CONCLUSIONS: This study does not support previous reports of a protective effect on myocardial infarction associated with consumption of drinking water with higher levels of hardness, magnesium, or calcium.     

Serum insulin-like growth factor I and subsequent risk of colorectal cancer among Japanese-American men

Recent reports suggest that colorectal cancer is positively related to insulin-like growth factor I (IGF-I) and inversely related to insulin-like growth factor binding protein 3 (IGFBP-3). To evaluate these associations further and separately for colon and rectal cancer, the authors conducted a nested case-control study in a cohort of 9,345 Japanese-American men examined in Hawaii in 1971-1977. A total of 177 incident colon cancer cases and 105 incident rectal cancer cases were identified from 1972 to 1996. These patients' stored sera and those of 282 age-matched controls were measured for IGF-I and IGFBP-3. The adjusted mean level of IGF-I was higher in colon cancer cases than in controls (154.7 ng/ml vs. 144.4 ng/ml; p = 0.01). However, the multivariate odds ratio for the highest quartile compared with the lowest was just 1.8 (95% confidence interval: 0.8, 4.3). Adjusted mean IGF-I levels were similar between rectal cancer cases and their controls. For IGFBP-3, adjusted mean levels were lower for both colon and rectal cancer cases than for their matched controls, but the differences were not significant. The IGF-I results weakly support findings from other studies and suggest that there are differences in IGF-I findings between colon and rectal cancer cases. It is possible that IGF-related risk is confounded by other factors that may vary among different cohorts. Further research is needed to clarify these relations.     

广东省揭阳市居民食管癌发病危险因素的 病例对照研究

目的：筛选广东省揭阳市食管癌的危险因素。方法：1999年在揭阳市人民医院接受治疗的214例食管癌和贲门癌病人纳入病例组,均经过病理学诊断,214名健康人为对照组,按病例组的性别,年龄和居住地（镇）的构成情况从人群中随机抽取。研究对象均在揭阳市居住20年以上,用统一的调查进行问卷调查。用非条件logistic回归进行多因素分析。结果：主要的危险因素是饮烫茶(OR:1．39－3．74）,吃饭快（OR：1．54－4．10）,吃硬饭（OR：1．32－4．27）,猪油（OR：3．57－42．03）和肉类（OR：1．36－5．05）;保护性因素是饮用自来水20年以上（OR：0．13－0．51）,未发现吸烟史、食管癌家族史与食管癌有关联。结论：本研究筛选出的因素普遍暴露于揭阳市民民中,多数因素与其它地区的同类研究一致,但猪油和肉类是本研究中提出的影响因素,有待于实验研究证实。     

地方性砷中毒病区癌症死亡情况初步调查

内蒙古土默特左旗黑河村,是天然高砷饮水引起的地方性砷中毒病区.我们通过回顾性队列分析,算出SMR,判明在1961～1991年间饮高砷水的居民中,30～60岁的全死因、全癌及肺癌的实际死亡数与预期死亡数有显著性差异.     

Waterborne cholera outbreak following Cyclone Aila in Sundarban area of West Bengal, India, 2009

Following Cyclone Aila, a block of Sundarban area, West Bengal, India, reported an increased number of diarrhoea cases at the end of May 2009. This study was performed to identify the agent and source of the outbreak as well as to propose control measures. The outbreak is described by time, place and person. A matched case-control study was conducted and rectal swabs and water specimens were collected. In total, 1076 probable case patients and 14 deaths (attack rate 44/10 000) were identified. Vibrio cholerae El Tor Ogawa was isolated from two of five probable case patients’ stool specimens. The outbreak started in the fourth week of May, with two peaks in the second and fourth weeks of June, and lasted until August 2009. Compared with controls, cases were more likely to drink non-chlorinated piped water [matched odds ratio (MOR) = 16, 95% CI 4.9-51; population attributable fraction 58%) and were less likely to drink chlorine-treated water (MOR = 0.06, 95% CI 0.02-0.18). Villagers broke the water pipelines near their houses for easy access to water. Piped water specimens and stored drinking water were positive for faecal contamination. Contaminated drinking water was the probable source of the cholera outbreak. Repairing the pipelines, chlorination at household level and educating villagers regarding the danger of breached water pipe connections controlled the outbreak.     

Case control study of the geographic variability of exposure to disinfectant byproducts and risk for rectal cancer

Background  

Levels of byproducts that result from the disinfection of drinking water vary within a water distribution system. This prompted us to question whether the risk for rectal cancer also varies, depending upon one's long term geographic location within the system. Such a geographic distribution in rectal cancer risk would follow naturally from an association between level of byproduct and rectal cancer risk. We assess the effects of estimated geographic variability in exposure to some of the components of the trihalomethane group of disinfectant byproducts (DBPs) on the odds ratios and probabilities for rectal cancer in white males in a case control study of 128 cases and 253 controls, conducted in Monroe County, Western New York State, U.S.A. The study was designed around health data initially collected at the University at Buffalo (Department of Social and Preventative Medicine) as part of the Upstate New York Diet Study, and trihalomethane (THM) data collected from a separate independent study of THMs conducted by Monroe County Department of Health. Case participants were chosen from hospital pathology records. The controls are disease-free white males between 35–90 years old, living in Monroe County, and chosen from control groups for studies from cancer of five other (unrelated) sites. Using a combination of case control methodology and spatial analysis, the spatial patterns of THMs and individual measures of tap water consumption provide estimates of the effects of ingestion of specific amounts of some DBPs on rectal cancer risk. Trihalomethane (THM) data were used to spatially interpolate levels at the taps of cases and controls, and odds ratios were estimated using logistic regression to assess the effects of estimated THM exposure dose on cancer risk, adjusting for alcohol, dietary beta carotene intake, tap water intake, and total caloric intake.     

An outbreak of gastroenteritis from a non-chlorinated community water supply

STUDY OBJECTIVE: To determine the source and the extent of a community wide outbreak of gastroenteritis. DESIGN: A matched case-control study with postal questionnaires. Subtyping of campylobacter strains by pulsed field gel electrophoresis (PFGE). SETTING: A rural municipality with a population of 8600 in southern Finland, August 2000. Two thirds of the population receive non-chlorinated ground water from the municipal water supply. PARTICIPANTS: Cases were randomly selected among residents of the municipality who contacted the municipal health centre because of gastroenteritis and had illness onset between 31 July and 20 August 2000. Community controls were identified from the population registry and matched according to sex, year of birth, and postal code. Main results: Four hundred and sixty three persons contacted the municipal health centre because of gastroenteritis. Campylobacter jejuni was isolated from stool samples of 24 persons. One hundred and thirty seven cases and 388 controls were enrolled in the case-control study. In multivariate analysis, drinking unboiled water from the municipal supply was significantly associated with illness (odds ratio 11.1, 95% confidence interval 1.4 to 90.2). C jejuni was isolated from one tap water sample. The water isolate and all but one of the patient isolates were indistinguishable by PFGE. CONCLUSIONS: Combining epidemiological investigation with molecular subtyping methods provided strong evidence that water was the source of the outbreak. Non-chlorinated small ground water systems may be susceptible to waterborne outbreaks and constitute a risk to rural populations.     

Ecological analyses and case-control studies of gastric cancer and leukaemia in relation to DBCP in drinking water in Fresno County, California.

Through ecological analyses and case-control studies, the possible relation of gastric cancer and leukaemia to dibromochloropropane (DBCP) contamination of drinking water in Fresno County, California, has been examined. The ecological analyses examined the correlation between gastric cancer and leukaemia (including the lymphatic varieties), mortality rates, and DBCP concentrations in drinking water by census tract in Fresno County, 1960-83. No correlation was found between gastric cancer or leukaemia and DBCP. The gastric cancer case-control study consisted of 263 deaths from gastric cancer in the county, 1975 to mid-1984, and 1044 controls, using information on residential history and occupation of both cases and controls. Analyses were based on residence at death, as well as one and ten years before death. The case-control study did not find any relation between gastric cancer and DBCP in drinking water. Hispanics in the county were found to experience a relative risk of gastric cancer of 2.77, compared with non-Hispanics. A similar case-control study consisting of 259 cases of leukaemia and 1161 controls found no relation between all leukaemia or lymphatic leukaemia and DBCP in drinking water. Farm workers, however, do appear to have an increased risk of leukaemia.     

Ecological analyses and case-control studies of gastric cancer and leukaemia in relation to DBCP in drinking water in Fresno County, California

Through ecological analyses and case-control studies, the possible relation of gastric cancer and leukaemia to dibromochloropropane (DBCP) contamination of drinking water in Fresno County, California, has been examined. The ecological analyses examined the correlation between gastric cancer and leukaemia (including the lymphatic varieties), mortality rates, and DBCP concentrations in drinking water by census tract in Fresno County, 1960-83. No correlation was found between gastric cancer or leukaemia and DBCP. The gastric cancer case-control study consisted of 263 deaths from gastric cancer in the county, 1975 to mid-1984, and 1044 controls, using information on residential history and occupation of both cases and controls. Analyses were based on residence at death, as well as one and ten years before death. The case-control study did not find any relation between gastric cancer and DBCP in drinking water. Hispanics in the county were found to experience a relative risk of gastric cancer of 2.77, compared with non-Hispanics. A similar case-control study consisting of 259 cases of leukaemia and 1161 controls found no relation between all leukaemia or lymphatic leukaemia and DBCP in drinking water. Farm workers, however, do appear to have an increased risk of leukaemia.     

Moderate beer consumption and the risk of colorectal cancer

The relationship between beer consumption and the risk of colon and rectal cancer was considered in a case‐control study conducted in northern Italy. The study was based on 828 histologically confirmed incident cases of colon cancer, 498 of rectal cancer, and 2,024 controls in hospital for a wide spectrum of acute, nonneoplastic, nonalcohol‐related diseases. Beer drinking was reported by 6% of colon cancer cases, 7% of rectal cancer cases, and 10% of controls; regular beer drinkers (≥1 drinks/day) made up 2.6% of colon cancer cases, 3.2% of rectal cancer cases, and 4.1% of controls. Thus the multivariate relative risks (RR) for irregular drinkers were 0.6 [95% confidence interval (CI) 0.4–1.0] for colon and 0.7 (95% CI 0.4–1.2) for rectum. Corresponding values for regular drinkers were 0.7 (95% CI 0.4–1.2) for colon and 0.9 (95% CI 0.5–1.5) for rectal cancer. Despite the low frequency of beer drinking in this study, and hence its limited statistical power, the originality of the population in terms of colorectal cancer incidence, patterns of risk factor exposure, and the large dataset provide interesting and useful confirmation that moderate beer drinking is not associated with elevated colon or rectal cancer risk.     

Case-control study of bladder cancer and drinking water arsenic in the western United States

Numerous epidemiologic investigations have identified links between high concentrations of arsenic in drinking water and cancer, although the risks at lower exposures are largely unknown. This paper presents the results of a case-control study of arsenic ingestion and bladder cancer in seven counties in the western United States. These counties contain the largest populations historically exposed to drinking water arsenic at concentrations near 100 microg/liter. All incident cases diagnosed from 1994 to 2000 were recruited. Individual data on water sources, water consumption patterns, smoking, and other factors were collected for 181 cases and 328 controls. Overall, no increased risks were identified for arsenic intakes greater than 80 microg/day (odds ratio=0.94, 95% confidence interval: 0.56, 1.57; linear trend, p=0.48). These risks are below predictions based on high dose studies from Taiwan. When the analysis was focused on exposures 40 or more years ago, an odds ratio of 3.67 (95% confidence interval: 1.43, 9.42; linear trend, p<0.01) was identified for intakes greater than 80 microg/day (median intake, 177 microg/day) in smokers. These data provide some evidence that smokers who ingest arsenic at concentrations near 200 microg/day may be at increased risk of bladder cancer.