Documents Plato, Nils 9 results

The effect of exposure to man made vitreous fibers (MMVF) on workers in the prefabricated wooden house manufacturing industry was investigated. A model was developed to measure the past exposure to MMVF of 478 insulators among a staff of 2,807 workers at 11 factories in Sweden. The insulators who had a mean employment time of 9.6 years and never used respirators were identified as the workers at greatest risk of exposure to MMVF. One hundred and twenty samples were taken of airborne fiber in 11 facilities to determine current exposure levels. Using the model to estimate past exposure the highest mean fiber exposure level for insulators was calculated as 0.18 fiber/milliliter (f/ml), which occurred during the mid 1970s, compared to 0.10 f/ml at the end of the 1980s and the early 1960s. Changes in production rate, improved ventilation control, and the surface area of the total amount of MMVF sheets handled by the insulator were the most important variables in the model. No increased risk of lung cancer was found for the insulators who were presently working in the house prefabrication industry.

"INTRODUCTION: The Nordic Occupational Cancer study (NOCCA) is a cohort study based on employed populations in one or more censuses in Denmark, Finland, Iceland, Norway and Sweden. The large size of the cohort allows us to study rare cancers and to identify even small risks by occupation and by specific occupational exposures. This paper describes principles and experiences of the construction of job-exposure matrices (JEMs), an instrument to transform the history of occupational titles into quantitative estimates of exposure to potential carcinogenic substances.MATERIAL AND METHODS: For each Nordic country, a national JEM was constructed by a team of experts on the basis of the Finnish matrix (FINJEM) that has been used in similar national studies since the mid-1990s.RESULTS: The structure of the Nordic JEMs is three-dimensional (over 300 occupations, over 20 agents, 4 periods covering 1945-1994). Exposure is characterised by estimates of the prevalence and level of exposure. Important differences between the Nordic countries were observed for several exposures.DISCUSSION: The selection of priority agent-occupation combinations and the adoption of general principles in the beginning of the work were necessary because of the high number of estimates to be evaluated (over 50 000/country). The selective modification of an existing JEM for use in other countries was a feasible, albeit challenging task, because exposure data and information about the use of chemicals in the past was scanty. As compared to the use of FINJEM for all Nordic countries, the modification process will probably increase the validity of dose-response and risk estimates of occupational cancer which is to be expected soon as the main outcome of the NOCCA project."

"We investigated occupational exposure to diesel motor exhaust (DME) and the risk of lung cancer by histological subtype among men, using elemental carbon (EC) as a marker of DME exposure. 993 cases and 2359 controls frequency-matched on age and year of study inclusion were analyzed by unconditional logistic regression in this Swedish case-control study. Work and smoking histories were collected by a questionnaire and telephone interviews. DME was assessed by a job-exposure matrix. We adjusted for age, year of study inclusion, smoking, occupational exposure to asbestos and combustion products (other than motor exhaust), residential exposure to radon and exposure to air pollution from road traffic. The OR for lung cancer for ever vs. never exposure to DME was 1.15 (95% CI 0.94-1.41). The risk was higher for squamous and large cell, anaplastic or mixed cell carcinoma than for alveolar cell cancer, adenocarcinoma and small cell carcinoma. The OR in the highest quartile of exposure duration (≥34 years) vs. never exposed was 1.66 (95% CI 1.08-2.56; p for trend over all quartiles: 0.027) for lung cancer overall, 1.73 (95% CI 1.00-3.00; p: 0.040) for squamous cell carcinoma and 2.89 (95% CI 1.37-6.11; p: 0.005) for the group of undifferentiated, large cell, anaplastic and mixed cell carcinomas. We found no convincing association between exposure intensity and lung cancer risk. Long-term DME exposure was associated with an increased risk of lung cancer, particularly to squamous cell carcinoma and the group of undifferentiated, large cell, anaplastic or mixed carcinomas."

"Background
There is little information on the dose–response relationship between exposure to occupational carcinogenic agents and mesothelioma. This study aimed to investigate this association as well as the existence of agents other than asbestos that might cause mesothelioma.
Methods
The Swedish component of the Nordic Occupational Cancer (NOCCA) study consists of 6.78 million individuals with detailed information on occupation. Mesothelioma diagnoses recorded in 1961–2009 were identified through linkage to the Swedish Cancer Registry. We determined cumulative exposure, time of first exposure, and maximum exposure intensity by linking data on occupation to the Swedish NOCCA job-exposure matrix, which includes 29 carcinogenic agents and corresponding exposure for 283 occupations. To assess the risk of mesothelioma, we used conditional logistic regression models to estimate hazard ratios and 95% confidence intervals.
Results
2,757 mesothelioma cases were identified in males, including 1,416 who were exposed to asbestos. Univariate analyses showed not only a significant excess risk for maximum exposure intensity, with a hazard ratio of 4.81 at exposure levels 1.25–2.0 fb/ml but also a clear dose–response effect for cumulative exposure with a 30-, 40-, and 50-year latency time. No convincing excess risk was revealed for any of the other carcinogenic agents included in the Swedish NOCCA job-exposure matrix.
Conclusion
When considering asbestos exposure, past exposure, even for short periods, might be enough to cause mesothelioma of the pleura later in life."

"Objectives
The aim of this study was to investigate if exposure to chemicals in the workplace was associated with an increased risk of postmenopausal breast cancer.
Methods
The study comprised women born 1923–1950 living in Malmö city, Sweden, 1991–1996, and enrolled for a prospective population cohort study. Occupational exposure to various chemicals was assessed from job-exposure matrices. An extensive set of individual data on hormonal breast cancer risk factors were collected via a baseline questionnaire and used for confounding control. First time diagnoses of invasive breast cancer were identified through the Swedish Cancer Registry until end of follow-up on 31 December 2013.
Results
Of 16 084 women, 1011 were diagnosed with breast cancer. Women exposed to chemicals in their occupational environment had a statistically significant increased risk [adjusted hazard ratio (HRadj) 1.26, 95% confidence interval (CI) 1.02–1.54] of breast cancer, and the risk correlated with duration of exposure. Investigation of risk in association with specific chemicals showed a non-significantly elevated risk after exposure to organic solvents. More than ten years of exposure to diesel exhaust was associated with an increased risk (HRadj 1.69, 95% CI 1.01–2.82). Occupational chemical exposures account for 2% of the breast cancer cases in this population.
Conclusions
Occupational exposure to chemicals in general was associated with an elevated risk of breast cancer. A slight elevation of risk was seen after exposure to organic solvents. A statistically significant elevation of risk after >10 years of exposure to diesel exhaust was an unexpected finding."

"Abstract
Objectives Occupational exposure to respirable crystalline silica (RCS) is common. The study aimed to assess the risk for acute myocardial infarction (AMI) after long-term exposure to RCS and to explore differences in risk between men and women.
Methods
The cohort included all manual workers identified from the Swedish National Census in 1980 using data on job titles and demography altogether from five censuses from 1960 to 1990, in total 605 246 men and 480 607 women. Information on AMI was obtained from nationwide registers from 1992 to 2006. Exposure to RCS was assessed with a job-exposure matrix. HRs and 95% CIs were estimated by Cox regression, adjusted for age, socioeconomic status and urbanisation index.
Results
Among manual workers ever exposed to RCS, the adjusted risk of AMI was HR 1.29 (95% CI 1.15 to 1.46) in women, and HR 1.02 (95% CI 1.00 to 1.04) in men. In the highest quartile of cumulative exposure, the risk of AMI was HR 1.66 (95% CI 1.27 to 2.18) for women, and HR 1.06 (95% CI 1.03 to 1.10) for men, respectively. The risk of AMI increased with cumulative exposure to RCS both in women (p=0.001) and in men (p=0.016). An interaction analysis showed that the relative risk from exposure to RCS was statistically significantly lower in men than in women at similar exposure levels.
Conclusions
Occupational exposure to RCS was related to the risk of AMI. Women were more sensitive to exposure to RCS than men.