Showing papers by "Elsebeth Lynge published in 1997"

Cancer Mortality in Workers Exposed to Phenoxy Herbicides, Chlorophenols, and Dioxins An Expanded and Updated International Cohort Study

Abstract: The authors examined cancer mortality in a historical cohort study of 21,863 male and female workers in 36 cohorts exposed to phenoxy herbicides, chlorophenols, and dioxins in 12 countries. Subjects in this updated and expanded multinational study coordinated by the International Agency for Research on Cancer were followed from 1939 to 1992. Exposure was reconstructed using job records, company exposure questionnaires, and serum and adipose tissue dioxin levels. Among workers exposed to phenoxy herbicides contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or higher chlorinated dioxins, mortality from soft-tissue sarcoma (6 deaths; standardized mortality ratio (SMR) = 2.03, 95% confidence interval (CI) 0.75-4.43) was higher than expected from national mortality rates. Mortality from all malignant neoplasms (710 deaths; SMR = 1.12, 95% CI 1.04-1.21), non-Hodgkin's lymphoma (24 deaths; SMR = 1.39, 95% CI 0.89-2.06), and lung cancer (225 deaths; SMR = 1.12, 95% CI 0.98-1.28) was slightly elevated. Risks for all neoplasms, for sarcomas, and for lymphomas increased with time since first exposure. In workers exposed to phenoxy herbicides with minimal or no contamination by TCDD and higher chlorinated dioxins, mortality from all neoplasms (398 deaths; SMR = 0.96, 95% CI 0.87-1.06), non-Hodgkin's lymphoma (9 deaths; SMR = 1.00), and lung cancer (148 deaths; SMR = 1.03) was similar to that expected, and mortality from soft-tissue sarcoma was slightly elevated (2 deaths; SMR = 1.35). In a Poisson regression analysis, workers exposed to TCDD or higher chlorinated dioxins had an increased risk for all neoplasms (rate ratio = 1.29, 95% CI 0.94-1.76) compared with workers from the same cohort exposed to phenoxy herbicides and chlorophenols but with minimal or no exposure to TCDD and higher chlorinated dioxins. These findings indicate that exposure to herbicides contaminated with TCDD and higher chlorinated dioxins may be associated with a small increase in overall cancer risk and in risk for specific cancers.

Organic solvents and cancer.

Abstract: Epidemiologic evidence on the relationship between organic solvents and cancer is reviewed. In the 1980s, more than a million persons were potentially exposed to some specific solvents in the United States; in Canada, 40 percent of male cancer patients in Montreal had experienced exposure to solvents; in the Finnish population, one percent was regularly exposed. There is evidence for increased risks of cancer following exposure to: trichloroethylene (for the liver and biliary tract and for non-Hodgkin's lymphomas); tetrachloroethylene (for the esophagus and cervix - although confounding by smoking, alcohol, and sexual habits cannot be excluded - and non-Hodgkin's lymphoma); and carbon tetrachloride (lymphohematopoietic malignancies). An excess risk of liver and biliary tract cancers was suggested in the cohort with the high exposure to methylene chloride, but not found in the other cohorts where an excess risk of pancreatic cancer was suggested. 1,1,1-trichloroethane has been used widely, but only a few studies have been done suggesting a risk of multiple myeloma. A causal association between exposure to benzene and an increased risk of leukemia is well-established, as well as a suggested risk of lung and nasopharynx cancer in a Chinese cohort. Increased risks of various gastrointestinal cancers have been suggested following exposure to toluene. Two informative studies indicated an increased risk of lung cancer, not supported by other studies. Increased risks of lymphohematopoietic malignancies have been reported in some studies of persons exposed to toluene or xylene, but not in the two most informative studies on toluene. Occupation as a painter has consistently been associated with a 40 percent increased risk of lung cancer. (With the mixed exposures, however, it is not possible to identify the specific causative agent[s].) A large number of studies of workers exposed to styrene have evidenced no consistent excess risk of all lymphohematopoietic malignancies, although the most sensitive study suggested an excess risk of leukemia among workers with a high exposure.

Cancer Mortality in Workers Exposed to Phenoxy Herbicides, Chlorophenols, and Dioxins

Abstract: The authors examined cancer mortality in a historical cohort study of 21,863 male and female workers in 36 cohorts exposed to phenoxy herbicides, chlorophenols, and dioxins in 12 countries. Subjects in this updated and expanded multinational study coordinated by the International Agency for Research on Cancer were followed from 1939 to 1992. Exposure was reconstructed using job records, company exposure questionnaires, and serum and adipose tissue dioxin levels. Among workers exposed to phenoxy herbicides contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or higher chlorinated dioxins, mortality from soft-tissue sarcoma (6 deaths; standardized mortality ratio (SMR) = 2.03, 95% confidence interval (CI) 0.75-4.43) was higher than expected from national mortality rates. Mortality from all malignant neoplasms (710 deaths; SMR = 1.12, 95% CI 1.04-1.21), non-Hodgkin's lymphoma (24 deaths; SMR = 1.39, 95% CI 0.89-2.06), and lung cancer (225 deaths; SMR = 1.12, 95% CI 0.98-1.28) was slightly elevated. Risks for all neoplasms, for sarcomas, and for lymphomas increased with time since first exposure. In workers exposed to phenoxy herbicides with minimal or no contamination by TCDD and higher chlorinated dioxins, mortality from all neoplasms (398 deaths; SMR = 0.96, 95% CI 0.87-1.06), non-Hodgkin's lymphoma (9 deaths; SMR = 1.00), and lung cancer (148 deaths; SMR = 1.03) was similar to that expected, and mortality from soft-tissue sarcoma was slightly elevated (2 deaths; SMR = 1.35). In a Poisson regression analysis, workers exposed to TCDD or higher chlorinated dioxins had an increased risk for all neoplasms (rate ratio = 1.29, 95% CI 0.94-1.76) compared with workers from the same cohort exposed to phenoxy herbicides and chlorophenols but with minimal or no exposure to TCDD and higher chlorinated dioxins. These findings indicate that exposure to herbicides contaminated with TCDD and higher chlorinated dioxins may be associated with a small increase in overall cancer risk and in risk for specific cancers.

Risk of Cancer and Exposure to Gasoline Vapors

Abstract: Until the introduction of self-service around 1970, service station workers in the Nordic countries were exposed to gasoline vapors. Based on measurements reported in the literature, the 8-hour time-weighted average benzene exposure was estimated to be in the range of 0.5-1 mg/m3. We studied the cancer incidence in a cohort of 19,000 service station workers from Denmark, Norway, Sweden, and Finland. They were identified from the 1970 censuses and followed through 20 years, where 1,300 incident cancers were observed. National incidence rates were used for comparison. The incidence was not increased for leukemia (observed = 28, standardized incidence ratio (SIR) = 0.9, 95% confidence interval (CI) 0.6-1.3) not for acute myeloid leukemia (observed = 13, SIR = 1.3, 95% CI 0.7-2.1). The incidence was slightly elevated for kidney cancer observed = 57, SIR = 1.3, 95% CI 1.0-1.7) and for pharyngeal, laryngeal, and lung cancer. A 3.5-fold risk of nasal cancer was found (observed = 12, SIR = 3.5, 95% CI 1.8-6.1). This cohort exposed to gasoline vapors with benzene levels estimated to be 0.5-1 mg/m3 showed no excess risk of leukemia or acute myeloid leukemia, a 30% elevated risk of kidney cancer, and a previously unnoticed risk of nasal cancer.

Non-progression of cervical intraepithelial neoplasia estimated from population-screening data

Abstract: Non-progression and duration of preclinical neoplastic lesions of the cervix uteri were studied using screening data from a previously unscreened population, Maribo County, Denmark (1966-82). To estimate regression rates, the incidence of clinical cancer before the screening programme was related to the prevalence and incidence of preclinical lesions estimated from the detection rates of first smear and third and subsequent smears respectively. Duration was estimated from the time lag between the cumulative incidence of preclinical lesions and the combined cumulative incidence of clinical cancer and the estimated 'incidence of regression'. Of all preclinical lesions in women aged 25-50, 24% progressed, 39% regressed and 38% remained. Even if we assume no onset of preclinical lesions above age 50, we estimated that 48% of the preclinical lesions would not progress to clinical cancer in the women's lifetime. The estimated mean duration of preclinical lesions was 16 years. In Maribo County during the 1970s, the positive rate (1.6%) was low compared with current rates in several countries. We conclude that the detection of non-progressive lesions was outweighed by the prevention of clinical cancer.

Unemployment and cancer: a literature review.

Abstract: With a tenth of the labour force involuntarily out of work, unemployment has become an important element among the socioeconomic determinants of health in the rich countries. Unemployed men have an excess cancer mortality of close to 25% compared with that of all men in the labour force. The available data from various countries indicate that this excess risk is found both in periods when the unemployment rate is about 1% and in periods when it is about 10%. Furthermore, it persists long after the start of unemployment and it does not disappear when social class, smoking, alcohol intake, and previous sick days are controlled for. The excess cancer mortality comes mainly from lung cancer, and the increased risk of lung cancer does not disappear when social class and number of previous sick days are controlled for. Unemployment does not increase smoking, but unemployed men have a slightly higher smoking prevalence before unemployment. However, as the excess lung cancer risk among unemployed men remains after controlling for social class, it seems unlikely that it can be explained only by differences in smoking prior to unemployment.

Cancer incidence of sulfite pulp workers in Denmark.

Abstract: Objectives Studies have indicated an excess risk of stomach cancer, pancreas cancer, and non-Hodgkin's lymphoma for sulfite pulp mill workers, and therefore cancer incidence was evaluated for 2 Danish sulfite mills. Methods Altogether 2238 workers employed in 1955--1990 were included in a historic cohort and followed until 31 December 1993. National cancer rates were used to calculate the expected number of cancer cases. Results The overall cancer risk was close to the expected, the standardized incidence ratio (SIR) being 1.01. The risk of stomach cancer was doubled [10 observed, SIR 1.99, 95% confidence interval (95% CI) 0.95--3.66], as was the risk of pancreatic cancer (7 observed, SIR 1.88, 95% CI 0.75--3.88). For the men with known pulp exposure, lung cancer was slightly increased (SIR 1.53, 95% CI 0.94--2.37). Other cancers with elevated risks were leukemia (7 observed, SIR 1.84) and soft-tissue sarcomas (4 observed, SIR 2.37). The risk of non-Hodgkin's lymphoma was not increased. Conclusion The excess risk of stomach cancer and pancreatic cancer found in this study was in accordance with that of other studies from sulfite pulp mills.

Socioeconomic group, occupation and incidence of breast cancer and genital cancer among women in Denmark

Abstract: Most studies of occupational cancer have included only male employees. In Denmark more than 40% of the labour force have been women since the 1970s and a large proportion of Danish women may have had occupational exposures, including exposures to carcinogens. In a register linkage study we investigated cancer incidence in a cohort of 1.4 million women, categorized by occupation in the 1970 census. Professionals, salaried employees and unskilled workers all had a slightly increased overall cancer risk. The risk of breast cancer was significantly increased in several groups of professionals such as lawyers, medical doctors, dentists and physiotherapists, nurses and clerks, but in only 2 groups of blue-collar workers: skilled tobacco workers and bookbinders. Ovarian cancer incidence was significantly elevated among clerks, while travelling saleswomen, furriers, hairdressers, nurses, and clerks had a significant excess of uterine corpus cancer. Uterine cervix cancer was almost exclusively elevated in a variety of unskilled occupations. Women should be included in studies of occupation and cancer. Although occupational hazards cannot be excluded for some associations found in this study, reproductive and lifestyle factors may also influence cancer risk and need to be considered in studies of occupation and cancer in women.

Unemployment and cancer in Denmark, 1970-1975 and 1986-1990.

Abstract: We have analysed cancer mortality and cancer incidence among unemployed persons identified from the Danish linkage studies based on the 1970 census and the 1986 register-based census. In 1970, 1% of Danish men were unemployed; in 1986, 14% were unemployed. In both periods, unemployed men had an excess cancer mortality of close to 25% when they were followed-up for a five-year period and their mortality was compared with that of all men in the labour force. Unemployed women in the 1970 cohort also had an excess cancer mortality of 25%. Cancer incidence data were not available for the 1986 cohort. For both cohorts, the excess risk came mainly from lung cancer. Survey data from Denmark in the 1980s indicated that unemployed men had a slightly higher smoking prevalence before unemployment than men who continued working, and that unemployment did not increase smoking. It is therefore unlikely that the excess lung cancer risk among unemployed men is explained by differences in smoking habits alone.

Risk of cancer among paper recycling workers.

Abstract: OBJECTIVES: Studies in traditional paper mills have indicated an excess cancer risk, and mutagenic compounds have been identified in the industry. No studies have reported on risk of cancer in paper recycling. Therefore the cancer incidence in Danish paper recycling mills was investigated. METHODS: 5377 employees in five paper recycling plants were included in a historical cohort study. The workers had been employed in paper recycling in 1965-90, and the cohort was followed up until 31 December 1993. The expected number of cancer cases was calculated from national rates. RESULTS: There was significantly more pharyngeal cancer among male workers (seven observed (standardised incidence ratio (SIR) 3.33, 95% confidence interval (95% CI) 1.34 to 6.87)). There was slightly more lung cancer among male workers in production (39 observed, SIR 1.21, 95% CI 0.86 to 1.65). Risk of Hodgkin9s disease was doubled in male production worker (four observed, SIR 1.90, 95% CI 0.51 to 4.85). CONCLUSIONS: The increased risk of pharyngeal cancer found in this study is interesting but may be influenced by confounders such as smoking and alcohol intake. This study also indicates an excess risk of Hodgkin9s disease, which is in accordance with some studies in the traditional paper mills. As this is the first report on risk of cancer in paper recycling, further studies are needed.