A case-control study of employment experience and lung cancer among rubber workers

In this case-control study the detailed employment histories of 121 rubber plant employees who died of lung cancer from 1964 through 1973 were compared to those of 448 plant employees (controls) who died of other causes during the same calendar period. All subjects were white male hourly employees. Lung cancer cases and controls were matched individually on year of birth and year of first hire at the plant. Results of matched analyses indicated that there was no association between lung cancer mortality and employment in either rubber compounding and mixing jobs or curing jobs. Men who had worked for at least five years in rubber reclaim operations, where there was potentially heavy exposure to particulates and fumes, experienced a twofold increase in lung cancer risk. In addition, there was a 70% excess of lung cancer risk among men employed in making special products, where the primary production activity was fuel cell manufacturing. The latter two findings were marginally statistically significant.     

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.     

Association between petrochemical air pollution and adverse pregnancy outcomes in Taiwan

The petrochemical industry is the main source of industrial air pollution in Taiwan. To date, little is known about the possible effects of such pollution on the human fetus. In this study, the authors investigated the relationship between term low birthweight and preterm delivery and residence in a petrochemical industrial municipality (PIM). The study areas included 16 PIMs (which were defined as municipalities in which the number of workers in the petroleum and petrochemical industry made up at least 2% of the municipality's total population) and 16 matched reference municipalities (RFMs). Among 39,750 1st-parity singleton live births, the prevalences of preterm delivery in the PIMs and RFMs were 4.72% and 4.58%, respectively, and the prevalences of term low birthweight were 2.51% and 2.35%, respectively. When PIMs were compared with RFMs, and after controlling for possible confounders (including maternal age, marital status, maternal education, and gender of the baby), the adjusted odds ratios were 1.07 (95% confidence interval [CI] = 0.95, 1.22) for term low birthweight and 1.03 (95% CI = 0.94, 1.13) for preterm delivery, respectively.     

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

The possible association between the risk of rectal cancer and hardness levels in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. All eligible rectal cancer deaths (986 cases) of Taiwan residents from 1990 through 1994 were compared with deaths from other causes (986 controls), and the hardness levels of the drinking water used by these residents were determined. Data on water hardness throughout Taiwan were 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 rectal cancer mortality. Odds ratio and 95% confidence intervals were 1.24 (1.01-1. 55) and 1.38 (1.10-1.73), 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 rectal cancer with decreasing levels of hardness in drinking water. This is an important finding for the Taiwan water industry and human health.     

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.     

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     

A case-control study of lung cancer with special reference to the effect of air pollution in Poland.

STUDY OBJECTIVE--The aim of the study was to assess the affect of inhaled pollutants on lung cancer risk. DESIGN--The study was a retrospective case-control survey of lung cancer deaths over a six year period (1980-1985). Information on occupation, smoking habits, and residency was collected from next of kin. Classification of exposure to community air pollution was based on measured levels of total suspended particular matter and sulphur dioxide. SETTING--Cases and controls had been resident in the city of Cracow, Poland. PARTICIPANTS--Cases were male (n = 901, questionnaire response rate 70.7%) and female (n = 198, response rate 65.1%) lung cancer deaths; controls were deaths from other causes, excluding other respiratory diseases, and frequency matched by age and sex (males n = 875, response rate 73.5%; females n = 198, response rate 64.0%). MAIN RESULTS--Lung cancer risk was found to depend strongly on total cigarette consumption, on age at starting to smoke, and on time since stopping smoking. Relative risk estimates for occupational exposure in iron and steel foundries or in other industries were significantly increased in males. Relative risk in men for highest air pollution level was 1.48 (95% confidence interval 1.08-2.01), while in women the increase was not significant. The joint action of the risk facts of smoking, occupational exposure, and air pollution was found to fit almost perfectly into a multiplicative model. CONCLUSIONS--Under conditions found in Cracow, air pollution may increase lung cancer risk, acting multiplicatively with known risk factors such as smoking and industrial exposure.     

Asbestos-associated cancers in the Ontario refinery and petrochemical sector

Asbestos has been widely used in the refinery and petrochemical sector. Mesothelioma has occurred among maintenance employees, and it was hypothesized that mesothelioma is a marker for exposures which might increase lung cancer risk. A death certificate-based case-control study of mesothelioma and lung cancer from 1980 to 1992 was conducted in an Ontario county with a substantial presence of these industries. Each of the 17 men who died of mesothelioma and 424 with lung cancer were matched with controls who died of other causes. The Job and Industry fields on the death certificates were abstracted. Employment as a maintenance worker in the refinery and petrochemical sector was associated with an increased risk of mesothelioma (odds ratio: 24.5; 90% confidence interval 3.1–102). The risk of lung cancer among petrochemical workers, in comparison with all other workers in the county, was 0.88. In an internal comparison of maintenance employees with other blue-collar workers in the refinery and petrochemical sector, the odds ratio for lung cancer was 1.73 (90% confidence interval 0.83–3.6). This finding is consistent with no difference in risk between maintenance and other employees, but it is also compatible with study power being too low to achieve statistical significance. The hypothesis of increased lung cancer risk could be examined more fully with nested case-control studies in existing cohorts. Meanwhile, it would be prudent to reinforce adherence to asbestos control measures in the refinery and petrochemical sector. © 1996 Wiley-Liss, Inc.     

Female lung cancer mortality and sex ratios at birth near a petroleum refinery plant

This study was conducted to assess whether female mortality from lung cancer is associated with residence in communities adjacent to a petroleum refinery plant and whether petroleum air pollution could affect the sex ratios of births. The Kaohsiung Refinery of the Chinese Petroleum Corp. is the oldest oil refinery in Taiwan and is located between the Tso-Ying and the Nan-Tzu municipalities. Standardized mortality ratios (SMRs) for female lung cancer and sex ratios of births were calculated for each municipality for the years 1971-1996. Cumulative-sum techniques were used to detect the occurrence of changes in the SMRs. The study results show that mortality from female lung cancer rose gradually about 30 to 37 years after the operation of a petroleum refinery plant began. However, the association between exposure to the petroleum air pollution and abnormal sex ratios at birth was not significant.     

Lung cancer in relation to environmental pollutants emitted from industrial sources

A case-control study of residents who lived in the vicinity of a primary zinc smelter and a large steel manufacturing plant in eastern Pennsylvania was undertaken to investigate the role of environmental pollutants in the etiology of lung cancer. Lifetime residential, occupational, and smoking histories were obtained from the next of kin of 335 white male lung cancer cases and 332 white male controls. Soil samples were collected and analyzed for content in ppm of arsenic, copper, lead, manganese, zinc, and cadmium. Relative risks were determined according to distance of residence from the zinc smelter and the steel plant, and according to residence in areas with heavy and light levels of various pollutants. Two-fold risks for lung cancer were associated with residence near the zinc smelter and with residence in areas with heavy levels of arsenic and cadmium, although the number of individuals living in these higher risk areas was small. These increases were not explained by the effects of cigarette smoking or by employment in the zinc or steel industry. No excess risk was associated with living near the steel plant. The limited size of the study precludes causal interpretation, but the findings suggest the need for further investigation of metallic air pollution and lung cancer.     

非吸烟女性肺癌危险因素的多分类logistic模型分析

目的 利用多分类logistic模型分析和评价非吸烟女性不同组织学类型肺癌的危险因素。方法 资料来源于非吸烟女性肺癌病例504例及人群对照601例，拟合多分类logistic回归模型估计各因素的比数比。结果 影响女性腺癌发病的危险因素是厨房小环境污染、经常食用菜油、BMI较低、一级亲属肺癌家族史，而保护因素是活产次数较多和胡罗卜素。女性鳞癌的危险因素则是厨房小环境污染和一级亲属肺癌家族史，保护因素是饮茶。女性其他类型肺癌危险因素主要是油炸烹饪次数较多等，而类型不明肺癌发病的危险因素类似于腺癌。结论 不同组织学类型的非吸烟女性肺癌病因可能存在一定的差异。     

Case–control study on cancer risk associated to residence in the neighbourhood of a petrochemical plant

The aim of the present study is to investigate cancer mortality and residence in the neighbourhood of the petrochemical plant located in Brindisi, South-eastern Italy. Cases were all subjects resident in Brindisi and in three neighbouring municipalities who died in the study area in 1996-1997 from lung cancer, pleural neoplasm, bladder cancer and lymphohematopoietic malignancies. Controls were subjects resident in the same area and deceased in 1996-1997 for any cause except those listed for the cases. Next of kin's of all study subjects were visited by an interviewer who collected anamnestic information. The main residence of each subject, defined as the longest held residence with exclusion of the last 10 years, was reported on a digitalized map of the study area (MapInfo). The study included 144 cases and 176 controls; response rate was 98%. Residence within 2 km from the centre of the petrochemical plant was associated with a 3 fold increase of the Odds ratios (OR) for lung cancer, which did not reach statistical significance. Living close to the petrochemical plant was associated with moderate increases of OR for bladder cancer and lymphohematopoietic neoplasms which did not reach statistical significance. In conclusion the present study has shown moderate increases in risk for lung, bladder and lymphohematopoietic neoplasms in the population resident within 2 km from the centre of the petrochemical plant in Brindisi. These figures were confirmed after adjusting for smoking habit, occupation and school level. Random misclassification may have somehow resulted in risk underestimation.     

Lung cancer mortality among men living near an arsenic-emitting smelter

Etiologic factors for lung cancer were studied by the case-control technique among 636 men, including 212 with pulmonary carcinoma, who had died between 1961 and 1979 in a county in northern Sweden. Data on smoking habits, occupation, and residence were obtained from a next of kin to each study subject. Validation against data from other sources indicated that the exposure information was of high quality. A relative risk of 2.0 for lung cancer was seen among men who had lived within approximately 20 km from a large copper smelter. The increased risk, which is statistically significant (p less than 0.05), could not be explained by smoking habits or occupational background. Smelter workers and miners had relative risks for lung cancer of 3.0 and 4.1, respectively. No firm conclusions can be drawn on the cause of excess lung cancer risk in the smelter area, but it seems plausible that the very substantial emissions to air from the smelter, especially of arsenic, may have played a role.     

室内空气污染与女性肺癌

为探讨室内空气燃料污染,被动吸烟,烹饪与女性肺癌的关系。搜索经省级医院确诊的哈尔滨市女性原发性肺癌１１５例及对照１２４例进行调查及单因素Ｌｏｇｉｓｔｉｃ回归分析。结果表明冬天取暖和做饭室内有烟,被动吸烟年限均与女性肺癌有关系显著,女性患肺癌危险性与终动吸烟总量呈明显的剂量－效应关系。     

Lung cancer in Florida. Risks associated with residence in the central Florida phosphate mining region

A case-control study that included 25,398 cases of lung cancer among Florida residents, first diagnosed in 1981-1983, was conducted to determine if residence in the central Florida phosphate mining region was associated with an increased risk of lung cancer. A twofold increase in lung cancer risk was observed among male nonsmokers who lived in the study area. Risks were elevated for all major lung cancer cell types, with the highest risks observed for small cell carcinoma of the lung. Among cigarette smokers, a slight, but not statistically significant, additional increase in risk was associated with residence in the study area. Among women, no significant elevations in risk were observed for persons who lived in the study area. The greatest increase in risk among women was for small cell carcinomas, but the elevations were not statistically significant.     

Lung cancer and indoor air pollution arising from Chinese-style cooking among nonsmoking women living in Shanghai, China.

Associations between indoor air pollution from Chinese-style cooking and lung cancer have been found in several investigations. To provide more detailed estimates of the associations while accounting for key confounding factors, we conducted a population-based, case-control study of lung cancer among nonsmoking women living in Shanghai, the People's Republic of China. Five hundred four incident, primary lung cancer cases diagnosed from February 1992 through January 1994 were identified through the population-based Shanghai Cancer Registry. A control group of 601 nonsmoking women was selected randomly from the Shanghai-Residential Registry, and they were frequency-matched to the expected age distribution of the cases. Exposure to indoor air pollutants from Chinese-style cooking was ascertained through in-person interviews. We estimated adjusted odds ratios (OR) and 95% confidence intervals (CI) by unconditional logistic regression. There were similar patterns of excess risk for exposure to indoor air pollutants from Chinese-style cooking across different histological types of lung cancer. Women who did not have a separate kitchen experienced a 28% increased risk of lung cancer (OR = 1.28; 95% CI = 0.98-1.68). We found little association with area of the windows of the apartment where subjects had lived for the longest period of time. Heating cooking oils to high temperatures was associated with a 1.64-fold increased risk of lung cancer (95% CI = 1.24-2.17). An 84% excess risk was found among women who most often cooked with rapeseed oil (OR = 1.84; 95% CI = 1.12-3.02). Lung cancer risks were also related to "considerable" smokiness of the kitchen during cooking (OR = 2.38; 95% CI = 1.58-3.57), frequent eye irritation during cooking (OR = 1.68; 95% CI = 1.02-2.78), to a more than weekly use of frying (OR = 2.09; 95% CI = 1.14-3.84) and deep-frying (OR = 1.88; 95% CI = 1.06-3.32). This population-based case-control study confirmed that exposure to indoor air pollution from Chinese-style cooking, especially cooking unrefined rapeseed oil at high temperatures in woks, may increase the risk of lung cancer.     

Lung cancer mortality among women employed in high-risk industries and occupations in Harris County, Texas, 1977-1980

Lung cancer is rapidly becoming the leading cause of cancer mortality among women. Interviews conducted with 259 women with lung cancer and 278 women without lung cancer or with their next-of-kin in Harris County, Texas from July 1, 1977 to June 30, 1980 revealed that 12 (4.6%) of the women with lung cancer had never smoked cigarettes. The odds ratio (OR) for current smoking was 15.7. Odds ratios for smoking for living women (OR = 17.5) were higher than for those who were deceased (OR = 12.6). Lifetime occupational histories were classified a priori into high- and low-risk categories. Data were stratified according to employment in a high-risk industry or occupation, a high-risk industry, a high-risk occupation, or both a high-risk industry and occupation. Although not statistically significant, odds ratios for employment in high-risk categories support earlier estimates that attributed 5% of lung cancer mortality in women to employment in hazardous occupations. Employment of a husband or household member in selected industries and occupations yielded significantly increased odds ratios. More cases (15.9%) than controls (6.9%) reported a family history of lung cancer (OR = 2.4). No significant increase in smoking-adjusted odds ratios was found for the use of hair spray, hand-held dryers, or alcohol, or for having lived with a household member who smoked cigarettes.     

A case-control study of air pollution and tobacco smoking in lung cancer among women in Athens

BACKGROUND. A case-control study exploring the role of smoking and outdoor air pollution in the causation of lung cancer, by histologic type, in nonsmoking women, was undertaken in Athens between 1987 and 1989. METHODS. One hundred one women with lung cancer and 89 comparison women with fractures or other orthopedic conditions, all permanent residents of Greater Athens, were included in the study. Smoking habits were ascertained through interviews, whereas lifetime exposure to air pollution was assessed by linking blindly lifelong residential and employment addresses of all subjects with objectively estimated or presumed air pollution levels. RESULTS. The age-adjusted relative risk and 95% confidence intervals for lung cancer among current smokers compared with nonsmokers was 3.40 (1.75-6.61); it was 7.43 (2.88-19.13) among those smoking for more than 30 years and 7.46 (2.40-23.17) among those smoking more than 20 cigarettes per day. The age-adjusted relative risk was 1.70 (0.75-3.89) for adenocarcinoma and 6.45 (2.73-15.25) for other histologic types of lung cancer; statistically significant dose-response trends were evident for both histologic groups. Air pollution levels were associated with increased risk for lung cancer but the relative risk was small and statistically not significant. However, when both air pollution and duration (or quantity) of tobacco smoking, as well as their interaction, were introduced in a multiple logistic regression model, the interaction term was significant at the suggestive level of 0.10. CONCLUSION. Whereas there is no effect of air pollution among nonsmokers, the relative risk contrasting extreme quartiles of air pollution among smokers of 30 years duration was 2.23. The interaction was almost exclusively accounted for by the nonadenocarcinoma lung tumors.     

A study of a possible association between breast cancer and gallbladder disease

Because gallstones and breast cancer were reported to have several of the same risk factors, a study was conducted in Washington County, Maryland to determine if women with breast cancer have an increased risk of prior gallbladder disease. Living white female breast cancer cases (n = 133), who were diagnosed from 1973 to 1983, were identified from the county's cancer registry and interviewed along with an equal number of sex-, race-, and age-matched controls about a history of gallbladder disease and other risk factors. Medical records were used to verify a history of gallbladder disease in interviewed cases and controls and to search for a diagnosis of gallbladder disease in 52 white female breast cancer cases who were diagnosed and died between 1974 and 1983, and 52 matched controls. No difference was found in gallbladder disease frequency among living or deceased cases and their matched controls. The results confirm the known association of several risk factors with breast cancer and with gallbladder disease, but most of the risk factors hypothesized to be the same for the two diseases were not the same. However, an unexpectedly strong association was found between gallbladder disease and history of myocardial infarction; this result deserves further study.     

Does breast feeding protect against breast cancer? An epidemiological study]

The association between breastfeeding and the risk of breast cancer was studied as part of a Dutch population-based epidemiological study of the aetiology of female breast cancer. A total of 484 breast cancer patients and 484 controls (matched for age; age range: 20-54 years) were compared with regard to their breastfeeding habits. There was no clear association between breastfeeding and breast cancer risk. After adjustment for confounders women who had ever breastfed had no lower risk of breast cancer than women who never had given breastfeeding. Women who had breastfed for prolonged periods (total lifetime nursing of 44 weeks or more) had, after adjustment for confounders, a 29% lower risk of breast cancer compared to women who had never breastfed, but this risk reduction was not statistically significant. These results do not support the hypothesis that (short) periods of breastfeeding reduce the risk of breast cancer in young women. A possible protective effect of longer periods of breastfeeding, which is suggested more strongly in the literature, could not be investigated in this study because the women breastfed their children for relatively short periods.