Cancer risk near a polluted river in Finland

The River Kymijoki in southern Finland is heavily polluted with polychlorinated dibenzo-p-dioxins and dibenzofurans and may pose a health threat to local residents, especially farmers. In this study we investigated cancer risk in people living near the river (less than 20.0 km) in 1980. We used a geographic information system, which stores registry data, in 500 m times 500 m grid squares, from the Population Register Centre, Statistics Finland, and Finnish Cancer Registry. From 1981 to 2000, cancer incidence in all people (N = 188884) and in farmers (n = 11132) residing in the study area was at the level expected based on national rates. Relative risks for total cancer and 27 cancer subtypes were calculated by distance of individuals to the river in 1980 (reference: 5.0-19.9 km, 1.0-4.9 km, less than 1.0 km), adjusting for sex, age, time period, socioeconomic status, and distance of individuals to the sea. The respective relative risks for total cancer were 1.00, 1.09 [95% confidence interval (CI), 1.04-1.13], and 1.04 (95% CI, 0.99-1.09) among all residents, and 1.00, 0.99 (95% CI, 0.85-1.15), and 1.13 (95% CI, 0.97-1.32) among farmers. A statistically significant increase was observed for basal cell carcinoma of the skin (not included in total cancers) in all residents less than 5.0 km. Several other common cancers, including cancers of the breast, uterine cervix, gallbladder, and nervous system, showed slightly elevated risk estimates at less than 5.0 km from the river. Despite the limitations of exposure assessment, we cannot exclude the possibility that residence near the river may have contributed to a small increase in cancer risk, especially among farmers.     

Exposure to cement dust at a Portland cement factory and the risk of cancer.

The relation between exposure to cement dust and cancer was examined in a population of 546 cement workers and a reference population of 858 randomly sampled men of similar age and area of residence. In 1974 all men gave lifelong occupational and smoking histories; information on incidence of cancer in the period 1974-85 was obtained from the Danish Cancer Registry. No increased risk of overall cancer was found among cement workers. Among men with more than 20 years exposure to cement dust, 14 cases of respiratory cancer were observed (observed/expected (O/E) 1.52, 95% confidence interval (95% CI) 0.90-2.57) when compared with all Danish men. Men with 1-20 years exposure had O/E 1.14 (95% CI 0.59-2.19) based on nine cases of cancer. After excluding all men with documented exposure to asbestos during employment in an asbestos cement factory no increased risk of overall cancer or respiratory cancer was found among cement workers compared with white collar workers from the local reference population, using a Cox regression model controlling for age and smoking habits. Relative risks were 0.5 (95% CI 0.1-1.5) and 1.0 (95% CI 0.4-2.6) for men with 1-20 and more than 20 years of exposure to cement dust respectively compared with white collar workers.     

Exposure to cement dust at a Portland cement factory and the risk of cancer.

The relation between exposure to cement dust and cancer was examined in a population of 546 cement workers and a reference population of 858 randomly sampled men of similar age and area of residence. In 1974 all men gave lifelong occupational and smoking histories; information on incidence of cancer in the period 1974-85 was obtained from the Danish Cancer Registry. No increased risk of overall cancer was found among cement workers. Among men with more than 20 years exposure to cement dust, 14 cases of respiratory cancer were observed (observed/expected (O/E) 1.52, 95% confidence interval (95% CI) 0.90-2.57) when compared with all Danish men. Men with 1-20 years exposure had O/E 1.14 (95% CI 0.59-2.19) based on nine cases of cancer. After excluding all men with documented exposure to asbestos during employment in an asbestos cement factory no increased risk of overall cancer or respiratory cancer was found among cement workers compared with white collar workers from the local reference population, using a Cox regression model controlling for age and smoking habits. Relative risks were 0.5 (95% CI 0.1-1.5) and 1.0 (95% CI 0.4-2.6) for men with 1-20 and more than 20 years of exposure to cement dust respectively compared with white collar workers.     

Respiratory health effects of industrial air pollution: a study in east Lancashire, UK.

STUDY OBJECTIVE: To determine whether there was a higher incidence of respiratory ill health in children living near to a cement works than in those from a different area, and if so whether the higher incidence was due to the use of a hazardous waste-derived fuel at the works. STUDY DESIGN: A sample of the population of children living near the cement works (the study area) was compared with a sample of children living between 9 and 19 km away from the site (the control area). SETTING: The cement works is located on the north eastern edge of a small rural town in east Lancashire. METHODS: Data were collected via the use of a health questionnaire. This was distributed through selected primary schools to families who had one or more children of primary school age (5-11 years). MAIN RESULTS: The study and control populations were comparable in terms of response rates, gender, and socioeconomic indicators. There was no significant difference in the incidence of asthma (as diagnosed by a general practitioner) between the two areas when adjustment for hayfever was made. The incidence of sore throat was significantly higher in the case area, a difference not explained by other factors. For two other non-specific indicators of respiratory health (blocked nose and sore eyes) there was a significantly higher incidence in the study area, although hayfever and mould were also significant influences. CONCLUSIONS: The results indicated that certain non-specific health indicators were more common in the children living near a cement works. This excess may be due to exposure to emissions from the site. However, it is not possible to draw firm conclusions because there are no epidemiological data predating the use of the hazardous waste derived fuel.     

Risks of developing cancer relative to living near a municipal solid waste landfill site in Montreal, Quebec, Canada.

In this study, we sought to determine whether men who lived near the Miron Quarry municipal solid waste landfill site in Montreal, Quebec, Canada, were at higher risk for developing cancer than individuals who lived at more remote locations. Subjects were selected from a previously completed population-based, interview, cancer case-control study of men who lived in metropolitan Montreal. Thirteen sites of cancer (n = 2 928 subjects) and a population-based control group (n = 417) were analyzed. We used the exact street address at the time of diagnosis to classify subjects by geographic zones and distance from the site. We used unconditional logistic regression to estimate odds ratios (ORs) and associated 95% confidence intervals (CIs) for each site of cancer, adjusted for key covariates. In the exposure zone nearest to the site, elevated risks were found for cancers of the pancreas (adjusted OR = 1.4 [95% CI = 0.8, 2.6]); liver (OR = 1.8 [95% CI = 0.8, 4.3]); and prostate (OR = 1.5 [95% CI = 1.0, 2.1]). A high risk was also found for pancreatic cancer (OR = 1.7 [95% CI = 0.9, 3.5]) and the non-Hodgkin's lymphomas (OR = 1.5 [95% CI = 0.8, 2.6]) in a subexposure zone approximately downwind from the site. We used distance from the site as another exposure metric, and higher-than-expected risks were found for pancreatic cancer (OR for living within 1.25 km of the site [OR<1.25km] = 2.2 [95% CI = 1.0, 4.6]); liver cancer (OR<1.5km = 2.1 [95% CI = 0.8, 5.3]); kidney cancer (OR<2 km = 1.4 [95% CI = 0.9, 2.3]); and the non-Hodgkin's lymphomas (OR<1km = 2.0 [95% CI = 1.0, 4.0]). Data from this study and from a previous investigation at the same site suggest that men who lived near this landfill site may have been-and may continue to be-at excess risk of cancers of the liver, kidney, pancreas, and non-Hodgkin's lymphomas.     

Wisconsin Farmer Cancer Mortality, 1981 to 1990: Selected Malignancies

Abstract: Cancer mortality risks for Wisconsin white male farmers were examined during the years 1981 to 1990. Four malignancies were studied: Non-Hodgkin's lymphoma, melanoma, colon cancer, and rectal cancer. Occupation coded deaths were segmented into farmer and nonfarmer groups and population counts for the groups were estimated from 1980 and 1990 Bureau of the Census data. Standardized mortality ratios (SMRs) were constructed from the ratio of observed farmer deaths and the expected number of farmer deaths. Expected deaths were generated from the underlying statewide nonfarmer rate for the malignancy multiplied into the farmer population at risk. Farmers had significantly lower mortality risks for melanoma (SMR: 0.659; 95% CI: 0.993-0.326) and colon cancer (SMR: 0.763; 95% CI: 0.928-0.599). Farmers also exhibited a nonsignificant decrement for non-Hodgkin's lymphoma (SMR 0.930; 95% CI: 1.214-0.645). For rectal cancer, farmers experienced a slightly higher but essentially the same risk as nonfarmers (SMR: 1.013; 95%CI: 1.418-0.608)—the SMR was not significant. This study corroborates a number of cancer incidence and mortality investigations demonstrating that farmers generally experience the same or lower mortality risks for these malignancies.     

Industry-related urothelial carcinogens: application of a job-exposure matrix to census data

A job-exposure matrix has been developed linking the work tasks in the Swedish National Census of population 1960 to exposure to 50 single agents or groups of substances. All 1,905,660 men, aged 20-64 years in 1960, reporting themselves as gainfully employed in the Census, were observed for the occurrence of urothelial cancer 1961-1979 by linkage to the National Swedish Cancer Registry. Subjects classified as exposed to creosote had a relative risk (with 95% confidence interval) of 2.6 (1.2-5.9) for renal pelvis cancer and 1.3 (1.0-1.8) for urinary bladder cancer; subjects exposed to polychlorinated biphenyls (PCB) had a relative risk of 1.3 (1.0-1.8) for urinary bladder cancer. Adjustment was made for age, socioeconomic group, and degree of urbanization. Exposure to combustion gases from coal gave a relative risk of 1.2 (1.0-1.4) for bladder cancer. The study carries several sources of nondifferential misclassification diluting the estimates of the relative risks toward 1.0. The limitations of exposure classification by job-exposure matrices are discussed.     

Occupation and prostate cancer risk in Sweden

To provide new leads regarding occupational prostate cancer risk factors, we linked 36,269 prostate cancer cases reported to the Swedish National Cancer Registry during 1961 to 1979 with employment information from the 1960 National Census. Standardized incidence ratios for prostate cancer, within major (1-digit), general (2-digit), and specific (3-digit) industries and occupations, were calculated. Significant excess risks were seen for agriculture-related industries, soap and perfume manufacture, and leather processing industries. Significantly elevated standardized incidence ratios were also seen for the following occupations: farmers, leather workers, and white-collar occupations. Our results suggest that farmers; certain occupations and industries with exposures to cadmium, herbicides, and fertilizers; and men with low occupational physical activity levels have elevated prostate cancer risks. Further research is needed to confirm these findings and identify specific exposures related to excess risk in these occupations and industries.     

Cancer mortality in counties near two former nuclear materials processing facilities in Pennsylvania, 1950-1995

There has been concern that living near nuclear installations might increase the risk of cancer, including childhood leukemia, in surrounding communities. Such concern has been voiced by residents in Armstrong and Westmoreland Counties in Western Pennsylvania in conjunction with the operation of two former nuclear materials processing facilities located in the Apollo borough and the Parks township, just three miles apart. These facilities began operating in 1957 and 1960 and processed uranium and plutonium for commercial and naval applications. To evaluate the possibility of increased cancer rates in communities around the Apollo-Parks nuclear facilities, a cancer incidence and a cancer mortality survey were conducted. The county mortality findings are reported here. Nearly 40,000 cancer deaths occurred in the population residing in Armstrong and Westmoreland Counties from 1950 through 1995. Each of these two study counties was matched for comparison to three control counties in the same region on the basis of age, race, urbanization, and socioeconomic factors available from the 1990 U.S. Census. There were over 77,000 cancer deaths in the 6 control counties during the 45 y studied. Following similar methods used by the National Cancer Institute, Standardized Mortality Ratios (SMRs) were computed as the ratio of observed numbers of cancers in the study and control counties compared to the expected number derived from general population rates of the United States. Relative risks (RR) were computed as the ratios of the SMRs for the study and the control counties. There were no significant increases in the study counties for any cancer when comparisons were made with either the U.S. population or the control counties. In particular, deaths due to cancers of the lung, bone, liver, and kidney were not more frequent in the study counties than in the control counties. These are the cancers of a priori interest given that uranium and/or plutonium might be expected to concentrate in these tissues. Deaths from all cancers combined also were not increased in the study counties, and the RRs of cancer mortality before the facilities operated (1950-1964), during plant operations (1965-1980) and after plant closure (1980-1995) were similar: 0.96, 0.95 and 0.98, respectively. For childhood leukemia mortality, the relative risk comparing the study counties with their controls before plant start-up was 1.02, while during operations (RR 0.81) and after closure (RR 0.57) the relative risks were lower. The study is limited by the correlational approach and the relatively large size of the geographic areas of the counties studied.     

Shared occupational risks for transitional cell cancer of the bladder and renal pelvis among men and women in Sweden

BACKGROUND: Unlike cancer of the bladder, cancer of the renal pelvis is not considered an occupational cancer and little is known about risks among women. METHODS: Using the Swedish national census and cancer registry-linked data (1971-1989), we identified transitional cell cancers of the renal pelvis (N = 1,374) and bladder (N = 21,591). Correlation between cancer sites for the standardized incidence ratios (SIR) were determined using Pearson's coefficient of the log SIR. Relative risks of job exposure matrix variables were calculated using Poisson regression. RESULTS: Both cancer sites were significantly elevated among women and men employed in the machine/electronics industry, sedentary work, and indoor work, and men in the metal industry. The highest proportion of the bladder (12%) and renal pelvis (14%) cancers occurred among men employed in shop and construction metal work. Risks by industry were more correlated among women (r = 0.49, P = 0.002) than men (r = 0.24, P = 0.04). Cancers of the renal pelvis were elevated in several occupational and industry groups for which there was no elevated bladder cancer risk. CONCLUSION: Cancers of the renal pelvis and bladder share common occupational risk factors that may be more frequent among women. In addition, there may be some jobs that pose an increased risk specifically for cancer of the renal pelvis but not bladder.     

Effects of dioxins in the development of malignant tumors and disorders of reproductive health of the population

The mortality caused by malignant tumors in the town of Chapaevsk, characterized by increased level of dioxins in the environment, is statistically higher than the expected values. For men the relative risk of general morbidity is 1.9 and mortality, 1.8; for lung cancer: morbidity, 3.3 and mortality 3.1; for urogenital cancer: morbidity, 3.6 and mortality, 2.6; for gastric cancer: morbidity 1.9 and mortality, 1.7. In women the morbidity and mortality due to breast cancer (relative risks 1.9 and 2.1, respectively) and cancer of the cervix uteri (relative risks 2.1 and 1.8, respectively) are increased. Changes in the reproductive health of residents of this town are as follows: high incidence of spontaneous abortions, appearance of small-for-date babies, and genital disorders in body (cryptorchidism, phimosis, hypospadia, delayed sexual development).     

Mortality of workers at a plant manufacturing nickel alloys, 1958-2000

BACKGROUND: Excess risks of respiratory cancer have been demonstrated in some groups of nickel-exposed workers. It is clear, however, that not all forms of nickel exposure are implicated in these excess risks. Aim To determine whether occupational exposures received in the manufacture of nickel alloys lead to increased risks of cancer, in particular nasal cancer and lung cancer. METHODS: The mortality experienced by a cohort of 1999 workers employed at a plant manufacturing nickel alloys has been investigated. Study subjects were all those male workforce employees first employed in the period 1953-1992 who had at least 5 years employment with the company. Observed numbers of cause-specific deaths were compared with expectations based on national mortality rates. Standardized mortality ratios (SMRs) were calculated by period from commencing employment and by operating area of first job. In addition, rate ratios derived from Poisson regression and based on an internal standard were calculated by levels of duration of employment. RESULTS: SMRs were significantly below 100 for all causes (observed 557, expected 704.3, SMR 79), all neoplasms (observed 169, expected 209.4, SMR 81) non-malignant diseases of the respiratory system (observed 50, expected 73.0, SMR 69) and diseases of the circulatory system (observed 261, expected 335.5, SMR 78). Significantly elevated SMRs were not shown for any cause of death and mortality was below expectation for stomach cancer (observed 8, expected 16.0, SMR 50), lung cancer (observed 64, expected 73.6, SMR 87) and bladder cancer (observed 3, expected 8.0, SMR 38). There were no deaths from nasal cancer (expected 0.33). More detailed findings were unexceptional. CONCLUSIONS: The analyses did not suggest the presence of an occupational cancer hazard in the mortality experience of the cohort.     

Environmental Asbestos Exposure and Cancer Mortality

From 1970 to 1980, mortality from cancer of the lung and stomach was analyzed in a town with asbestos deposits and in a town with asbestos processing. The populations of the entire country, the province, the district, and of all communities of the same size and agricultural index were used as references. In the town with asbestos contamination of air and water from natural tremolite deposits and an endemic occurrence of pleural plaques, no increased risk for lung or stomach cancer was found. In the town with asbestos cement production lung cancer rates were lower in males and higher in females, and stomach cancer rates were lower than expected. No significant differences could be attributed to environmental asbestos exposure.     

Environmental asbestos exposure and cancer mortality

From 1970 to 1980, mortality from cancer of the lung and stomach was analyzed in a town with asbestos deposits and in a town with asbestos processing. The populations of the entire country, the province, the district, and of all communities of the same size and agricultural index were used as references. In the town with asbestos contamination of air and water from natural tremolite deposits and an endemic occurrence of pleural plaques, no increased risk for lung or stomach cancer was found. In the town with asbestos cement production lung cancer rates were lower in males and higher in females, and stomach cancer rates were lower than expected. No significant differences could be attributed to environmental asbestos exposure.     

Stomach cancer and occupation in Sweden: 1971-89

Objectives: To examine the relation between gastric cancer and occupation among men and women gainfully employed in 1970 in Sweden for the period 1971–89 and, more specifically, to evaluate whether any excess of incidence of gastric cancer had also occurred among the subcohort of people reporting the same occupation in 1960 and 1970.

Methods: In both sexes and cohorts, relative risks adjusted for age, period of diagnosis, and geographical risk area were computed for occupational codes specified at one, two, or three level (occupational sector, occupational group, and occupation, respectively). Relative risks were calculated with all other occupations as reference and then, to take socioeconomic status into account, solely other occupations within the same occupational sector were used.

Results: Among men, occupations with increased risk included miners and quarrymen, construction and metal processing workers, supporting the possible causative role of dusty environments in stomach cancer. In men, the results also provide support for increased risks among electrical and mechanical engineers, fishermen, petrol station workers, motor vehicle drivers, butchers and meat preparers, dockers, freight handlers, launderers and dry cleaners. Furthermore, it is worth noting interesting results for women, whose occupational risks have been studied less. Excess risks were found for practical nurses, cashiers, bank employees, engineering and electronic industry workers, food industry, housekeeping and cleaning workers. Due to the many occupations studied, several significant associations may be expected by chance.

Conclusions: The study is explorative but provides support for the relations suggested previously between occupational exposure to dusty environments and stomach cancer, together with some new high risk occupations which should be further studied.

     

Mortality among unionized construction plasterers and cement masons

BACKGROUND: Plasterers perform a variety of duties including interior and exterior plastering of drywall, cement, stucco, and stone imitation; the preparation, installation, and repair of all interior and exterior insulation systems; and the fireproofing of steel beams and columns. Some of the current potential toxic exposures among plasterers include plaster of Paris, silica, fiberglass, talc, and 1,1,1-trichloroethylene; asbestos had been used by the plasterers in the past. Cement masons, on the other hand, are involved in concrete construction of buildings, bridges, curbs and gutters, sidewalks, highways, streets and roads, floors and pavements and the finishing of same, when necessary, by sandblasting or any other method. Exposures include cement dust, silica, asphalt, and various solvents. METHODS: Proportionate mortality ratios (PMRs) and proportionate cancer mortality ratios (PCMRs) were calculated for 99 causes of death among 12,873 members of the Operative Plasterers' and Cement Masons' International Association who died between 1972 and 1996 using United States age-, race-, and calender-specific death rates. Statistical significance (P value) of results was based upon the Poisson distribution. RESULTS: Among plasterers, statistically significant elevated mortality was observed for asbestosis, where the PMR reached 1,657 (P < 0.01) with eleven observed deaths and less than one death expected, for lung cancer (PCMR = 124, P < 0.01), and for benign neoplasms (PMR = 210, P < 0.05). Among cement masons, statistically significant elevated mortality was observed for cancer of the stomach (PCMR = 133, P < 0.01), benign neoplasms (PMR = 132, P < 0.01), and poisonings (PMR = 159, P < 0.05). Except for poisonings, which were not thought to be occupationally related, all of the statistically significant results occurred among those members who entered the union prior to 1950. However, the risk for lung cancer among plasterers was still elevated among those entering the union after 1970 as was the risk for stomach cancer among cement masons who entered the union after 1950. CONCLUSIONS: The present study suggests that plasterers and cement masons still have elevated risks for certain diseases, especially lung and stomach cancer. Therefore, union members currently living should be screened for asbestos-related diseases and educated about the future risks for these diseases.     

Reevaluation of the confounding effect of cigarette smoking on the relationship between alcohol use and lung cancer risk, with larynx cancer used as a positive control

BACKGROUND: The effect of smoking on lung cancer risk has been well documented, while the effect of alcohol remains controversial. We examined the hypothesis that the apparent association between alcohol intake and lung cancer risk is fully due to the confounding effect of cigarette smoke. METHODS: Our sample of hospitalized patients included 2,953 male and 1,622 female lung cancer cases; 521 male and 159 female larynx cancers cases; and 8,169 male and 4,154 female controls, admitted to participating hospitals between 1981 and 1994. All controls had been diagnosed with non-smoking-related diseases. Larynx cancer was used as a positive control for lung cancer. Relative risks were estimated through odds ratios, adjusted through multiple logistic regression. RESULTS: Although the odds ratios for alcohol had been significantly elevated prior to adjustment for smoking (OR = 2.4, 95% CI = 2.0-2.8), alcohol had no effect on lung cancer following this adjustment (OR = 1.2, 95% CI = 1.0-1.4). By contrast, the effect of alcohol on larynx cancer remained high even after adjustment for smoking (OR = 5.6, 95% CI = 3.7-8.6). CONCLUSION: The often-reported association between alcohol and lung cancer risk can be fully explained by the confounding effect of cigarette use.     

Lung cancer in asbestos cement workers in Denmark.

OBJECTIVES: To study the relative and absolute risks of main types of lung cancer in a cohort of asbestos cement workers from Denmark. METHOD: A cohort of 7887 men and 576 women employed between 1928 and 1984 was compiled from the personnel files of Danish Eternit Production. The cohort was followed up for deaths, emigrations, and incident cancer cases during the period 1943-90. The observed number of lung cancer cases in the cohort was compared with the expected number based on incidences for the Danish population. Internal comparison was made with Poisson modelling. RESULTS: A total of 226 lung cancer cases were observed (223 men and three women). The standardised incidence ratio (SIR) for all lung cancer among men was 1.7 (observed number 223, expected number 129.7, 95% confidence interval (95% CI) 1.5-2.0). The SIRs were raised for all main types of lung cancer; adenocarcinoma 2.6, squamous cell carcinoma 1.7, and anaplastic carcinoma 1.5. The higher SIR for adenocarcinomas was found particularly with a latency period of 25 years or more. Among the 93 excess lung cancer cases, 36 were squamous cell carcinomas and 32 were adenocarcinomas. CONCLUSION: Asbestos cement work is associated with an increased risk of lung cancer of all main types. During the first 25 years after the start of employment this excess risk is shared almost equally between the different histological types of lung cancer, but the risk of adenocarcinomas is clearly higher after this point.     

Risk of adverse reproductive outcomes associated with proximity to municipal solid waste incinerators with high dioxin emission levels in Japan

BACKGROUND: Great public concern about health effects of dioxins emitted from municipal solid waste incinerators has increased in Japan. This paper investigates the association of adverse reproductive outcomes with maternal residential proximity to municipal solid waste incinerators. METHODS: The association of adverse reproductive outcomes with mothers living within 10 km from 63 municipal solid waste incinerators with high dioxin emission levels (above 80 ng international toxic equivalents TEQ/m3) in Japan was examined. The numbers of observed cases were compared with the expected numbers calculated from national rates adjusted regionally. Observed/expected ratios were tested for decline in risk or peak-decline in risk with distance up to 10 km. RESULTS: In the study area within 10 km from the 63 municipal solid waste incinerators in 1997-1998, 225,215 live births, 3,387 fetal deaths, and 835 infant deaths were confirmed. None of the reproductive outcomes studied here showed statistically significant excess within 2 km from the incinerators. However, a statistically significant peak-decline in risk with distance from the incinerators up to 10 km was found for infant deaths (p=0.023) and infant deaths with all congenital malformations combined (p=0.047), where a "peak" is detected around 1-2 km. CONCLUSION: Our study shows a peak-decline in risk with distance from the municipal solid waste incinerators for infant deaths and infant deaths with all congenital malformations combined. However, due to the lack of detailed exposure information to dioxins around the incinerators, the observed trend in risk should be interpreted cautiously and there is a need for further investigation to accumulate good evidence regarding the reproductive health effects of waste incinerator exposure.