Identification of occupational cancer risks in British Columbia. Part II: A population-based case-control study of 1516 Prostatic cancer cases

We have, as part of a program aimed at detecting occupational risk factors in British Columbia, collected lifetime occupational histories from 15,643 incident cancer cases, of whom 1519 had a diagnosis of prostate cancer. Occupational risks for this cancer site are examined using this large data set, and the results are presented in this report.     

Identification of occupational cancer risks in British Columbia. A population-based case-control study of 995 incident breast cancer cases by menopausal status, controlling for confounding factors

Lifetime occupational histories as well as information on known and suspected breast cancer risk factors were collected by means of a self-administered questionnaire from 1018 women with incident breast cancer ascertained from the British Columbia Cancer Registry, and from 1020 population controls. A matched case-control study design was used. Conditional logistic regression for matched sets data and the likelihood ratio were used in a two-step procedure and were performed separately for pre-menopausal women, post-menopausal women, and for all cases combined. Excess risk was noted for several white-collar occupations. Significantly increased risk was observed: (1) among pre-menopausal women: in electronic data-processing operators; barbers and hairdressers; in sales and material processing occupations; and in the food, clothing, chemical and transportation industries; (2) among post-menopausal women: in schoolteaching; in medicine, health, and nursing occupations; in laundry and dry-cleaning occupations; and in the aircraft and automotive, including gasoline service station, industries. Several significant associations were also seen in the combined group of pre- and post-menopausal women, particularly in crop farmers and in the fruit and vegetable, publishing and printing, and motor vehicle repair industries. The results of this study suggest excess breast cancer risk in a number of occupations and industries, notably those that entail exposure to solvents and pesticides.     

Identification of occupational cancer risks in British Columbia: a population-based case-control study of 1129 cases of bladder cancer

OBJECTIVE: We collected information on lifetime occupational histories, smoking, and alcohol consumption from 15,463 incident cancer cases. Occupational risk factors for bladder cancer are presented in this report. METHOD: A matched case-control design was used. All cases were diagnosed with bladder cancers, with controls being internal controls consisting of all other cancer sites, excluding lung and unknown primary. Data were analyzed using conditional logistic regression for matched sets data and the likelihood ratio test. RESULTS: Excess bladder cancer risks was observed in a number of occupation and industries, particularly those involving exposure to metals, including aluminum, paint and solvents, polycyclic aromatic hydrocarbons, diesel engine emissions, and textiles. CONCLUSIONS: The results of our study are in line with those from the literature and further suggest that exposure to silica and to electromagnetic fields may carry an increased risk of bladder cancer.     

Identification of occupational cancer risks in British Columbia: a population-based case-control study of 769 cases of non-Hodgkin's lymphoma analyzed by histopathology subtypes

We have, as part of a program aimed at detecting occupational risk factors in British Columbia, collected lifetime occupational histories as well as information on lifetime cigarette smoking and alcohol consumption from 15,643 incident cancer cases, of whom 782 had a diagnosis of non-Hodgkin's lymphoma (NHL). Occupational risks for this cancer site are examined using a matched case-control study design, and the results are presented in this report for all cases and for histopathology subtypes. The results of our study indicate excess NHL risk, particularly for a number of occupations that involve exposures to electromagnetic fields, treated and fresh wood, metals, and solvents.     

Socio-demographic correlates of cigarette smoking among high school students: results from the British Columbia youth survey on smoking and health

OBJECTIVE: To describe the association between selected socio-demographic factors (age, gender, ethnicity, and region) and the prevalence of smoking among adolescents in two regions of British Columbia, and to report recent findings related to the prevalence of tobacco use in British Columbia. METHODS: A cross-sectional school-based survey was conducted using a random sample of 3,280 students from 13 schools in two regions of British Columbia. Multivariate logistic regression analysis was used to determine the association between age, region, gender and ethnicity and smoking status. RESULTS: Ethnic group membership was strongly associated with smoking status, which changed very little after controlling for the other socio-demographic factors. Controlling for age and ethnicity, the effect of gender on smoking status was moderated by region. CONCLUSION: Reliance on general population tobacco use prevalence rates masks important ethnic and gender differences. To increase the effectiveness of tobacco control policies and programming, greater attention needs to be paid to the socio-demographic correlates associated with adolescents' tobacco use.     

A case-referent study of lung cancer, occupational exposures and smoking. I. Comparison of title-based and exposure-based occupational information

The role of occupational exposures and smoking in the development of lung cancer has been studied among 176 male incident lung cancer cases and 176 referents admitted to two county hospitals in southeast Norway during 1979-1983. After the allocation of all occupational titles in the Nordic Classification of Occupations into three exposure groups according to potential exposure to respiratory carcinogens and other contaminants, each subject was classified according to exposure status of main occupation and number of years in each exposure category. An excess risk of lung cancer was observed both among those in possibly exposed occupations and among those definitely exposed. A more than threefold excess risk was observed among subjects with more than 30 years in exposed occupations. Exposure to 22 agents/processes was further assessed by a separate questionnaire and estimated simultaneously in a logistic regression model. Elevated risks were associated with exposure to asbestos and several other agents/processes, which largely correlated to each other. Smoking was strongly associated with all histological subtypes of lung cancer, while for occupational exposures the risk ratio was highest for small cell carcinoma and lowest for adenocarcinoma. Very high risk ratios for lung cancer were observed among heavy smokers in exposed occupations.     

Male bladder cancer risk and occupational exposure according to a job-exposure matrix-a case-control study in British Columbia, Canada

OBJECTIVES: The authors investigated the risk of bladder cancer in association with exposure to over 12 000 occupational chemical agents, complex mixtures, and other substances (hereafter referred to as chemical agents). METHODS: Adult males diagnosed with cancer between 1983 and 1990 in British Columbia, Canada, were surveyed. Detailed occupational histories and confounding information was provided by a self-administered questionnaire. Cancer controls were matched to bladder cancer cases, resulting in 1062 cases and 8057 controls for the analysis. An extensive United-States-based job-exposure matrix was applied to estimate cumulative exposure to occupational chemical agents. Odds ratios for bladder cancer due to exposure to chemical agents were estimated via conditional logistic regression analyses, adjusted for important confounders. RESULTS: A significantly (P<0.05) increased risk was detected for ever exposure to 635 chemical agents, and 341 chemical agents exhibited a significantly increasing dose-response relationship. Adjustment for multiple comparisons resulted in a subset of 29 chemical agents that continued to show significant results. A principal components analysis classified these 29 chemical agents into five independent groups, distinguished mainly by job. Exposures to these chemical agents were largely due to employment in the logging and construction industries and occupations involving motor vehicles. Consistent results were observed for bladder carcinogens reported in the literature. CONCLUSIONS: This study suggests that several specific chemical agents were significantly associated with the risk of bladder cancer. The chemical agents were mainly derivatives or combustion products of fossil fuels. The results corroborate important findings from the literature and document a risk for specific chemical agents not previously reported.     

A cohort analysis of lung cancer and smoking in British males

Lung cancer mortality in England and Wales among males in the age group 25 to 84 over the years 1941 to 1975 was analyzed. Using cigarette consumption information from the Tobacco Research Council and a statistical model, relative and attributable risks were estimated. The lung cancer deaths could be partitioned into deaths among smokers and deaths among nonsmokers; 88% of total male deaths during the study period could be attributed to smoking. Whereas the mortality rate among smokers increased over the entire span of the analysis, the rate among nonsmokers rose gradually until 1956-1960 and then declined until 1971-1975. The beginning of the decline was coincident with the implementation of the Clean Air Act of 1956. In order to address possible systematic biases in the smoking data, Monte Carlo simulations were performed.     

Alcohol, smoking, and occupational factors in cancer of the larynx: a case-control study.

A hospital-based case-control study of laryngeal cancer was conducted in Bremen in 1986 and 1987 with 100 prevalent male laryngeal cancer patients and 100 male hospital controls with diseases not considered to be related to smoking, alcohol, or occupational exposures, who were frequency matched by age. The odds ratio for heavy smoking (more than 30 pack-years) reached a value of 3.5 (95% confidence limits (CL) 1.1, 7.9). Ex-smokers showed a significant decrease in risk; this reached the level of those who had never smoked about 15 years after smoking cessation. For daily consumers of alcohol an odds ratio of 3.2 (95% CL 1.4, 7.5) was observed. Among the 17 occupations in which at least ten subjects had worked, excess risks were observed for stock keeping and transportation workers, and for leather and textile workers. The odds ratio was significantly increased for the latter (p less than 0.05). Among all those persons ever employed in a priori defined-risk occupations, an odds ratio of 2.74 (95% CL 1.23, 6.06) was observed. Considering responses to an exposure check-list, no increased risks could be shown for exposure to asbestos, coal tar, or welding fumes. On the other hand, excess risks were observed for exposures to diesel oil, gasoline, and mineral oil, controlling for smoking and alcohol. The findings in occupational and exposure subgroups were based on small numbers of cases and controls and, consequently, were subject to large sampling errors. Many of the results are consistent, however, with occupational risk factors reported from other studies.     

External cause-specific summaries of occupational fatal injuries. Part I: an analysis of rates

BACKGROUND: Industries and occupations vary with respect to the incidence of fatal injuries and their causes. METHODS: Fatalities from the National Traumatic Occupational Fatality database (years 1983-1994) serve as the basis for examining external cause of death code specific rates. Industries and occupations are compared with respect to rate and frequency of fatal injuries. In addition, external causes of injury (E-codes) are examined across all industries and occupations as well as within industries and occupations to evaluate which events would be identified by frequency ordered comparisons versus injury rate ordered comparisons. RESULTS: Machinery, electric current, homicide, falls, and transportation-related events are identified by high frequency and rate of occurrence. CONCLUSIONS: The external cause categories of homicide, machinery-related, motor-vehicle-related, electric current, and falls, account for over one-half of all occupational fatal injuries. Targeted interventions in homicide may be especially warranted in sales and service occupations and in the retail trade and services industries. In addition, younger workers might be targeted for special interventions designed to identify hazardous practices, procedures, and solutions to reduce fatalities associated with electrocution or falls from buildings.     

Oesophageal cancer mortality: relationship with alcohol intake and cigarette smoking in Spain.

STUDY OBJECTIVE--The aim of the study was to explore temporal changes in mortality from oesophageal cancer that could be related to tobacco and alcohol consumption. DESIGN--The study used mortality trends from oesophageal cancer over the period 1951-1985. In addition, available trends on per capita consumption of alcohol and cigarettes are also presented. SETTING--Data for this study were derived from Spain's National Institute for Statistics. MAIN RESULTS--Age standardised mortality rates from oesophageal cancer have increased significantly among men in Spain from 1951 to 1985 (p less than 0.01). Mortality rates in women have not changed significantly during the same period, although there is evidence of a certain decrease in recent years. Trends of per capita cigarette consumption from 1957 to 1982 related positively with oesophageal cancer mortality among men, whereas no significant relationship was observed in women. Trends of beer, spirits, and total alcohol consumption were also positively correlated with oesophageal cancer mortality in men. Among women, a weaker relationship was found. Wine consumption showed no relationship with oesophageal cancer mortality either in men or women. CONCLUSIONS--These results are similar to those found in other studies, supporting a role of alcohol (spirits and beer) and cigarette consumption in causation of oesophageal cancer. No relationship was observed with wine consumption.     

Depressive symptoms, smoking, and cigarette price elasticity: results from a population-based survey in Taiwan

Objectives  

To understand the association between depressive symptoms and smoking. In addition, we investigate how smokers with and without depressive symptoms may respond to cigarette price change differently.     

Occupations,cigarette smoking,and lung cancer in the epidemiological follow-up to the NHANES I and the California Occupational Mortality Study.

What jobs are associated with the highest and lowest levels of cigarette use and of lung cancer? Are there gender differences in these jobs? Two data sets-the Epidemiological Follow-up to the National Health and Nutrition Examination Survey (NHEFS) and the California Occupational Mortality Study (COMS) were analyzed to answer these questions. For females, the broad occupations ranking from highest to lowest cigarette use in the NHEFS was: transportation operators, managers, craft workers, service workers, operatives, laborers, technicians, administrative workers, farm owners and workers, sales workers, no occupation, and professionals. The corresponding ranking for males was: transportation operators, no occupation, laborers, craft workers, service workers, technicians, and professionals. The highest-ranking jobs in the COMS were waitresses, telephone operators, and cosmetologists for women, and water-transportation workers, roofers, foresters and loggers for men. Teachers were especially low on all four lists. This study could not determine whether employment within any occupation encouraged smoking or if smokers selected certain occupations.     

A case-referent study of lung cancer, occupational exposures and smoking. III. Etiologic fraction of occupational exposures

The proportion of lung cancer related to occupational exposure to respiratory carcinogens and other workplace contaminants has been studied in a hospital-based case-referent study of 176 incident cases and 176 referents, recruited from the medical ward of two county hospitals in southern Norway. On the basis of job title and exposure information, three different approaches for the estimation of etiologic fraction were used, all based upon a trichotomous categorization of the exposure variable. Among the definitely exposed subjects, the etiologic fraction for lung cancer related to occupational exposure factors was from 22 to 35%, increasing to 37-47% when the "possibly exposed" categories were included. When asbestos was the only factor to be eliminated, the etiologic fraction estimate suggested a 23% reduction in the lung cancer incidence in the study population. More than 90% of the lung cancer cases would theoretically have been prevented if smoking had been completely removed. The relative merits of preventing one or several of the study factors simultaneously is discussed.