Changing smoking habits and the occurrence of lung cancer in Sweden-a population analysis.

BACKGROUND: The objective is to estimate the importance of the decrease of smoking habits in Sweden for the occurrence of lung cancer. METHODS: The change in smoking habits in the general population was retrieved from surveys and on taxation of sale of cigarettes. We used data from the Swedish Cancer Register on incidence of lung cancer between 1970 and 2021, stratified for sex, age and cell type, and compared the occurrence overtime in ages between 40 and 84 years. RESULTS: The sale of cigarettes peaked in 1980 to 1800 cigarettes per person and decreased to 600 per person in 2021. The change in incidence rates of squamous cell cancer and other cell types varied over time, sex, and age in a pattern that partly seems to be explained by change in the prevalence of daily smokers. The incidence of adenocarcinoma was similar in men and women 1970-2021 and increased, e.g. for women and men 75-79 years of age from around 20 cases in early 1970s to around 120 cases per 100 000 person-years in the 2020s. CONCLUSIONS: Our data indicate that the risk of lung cancer several years after smoking cessation is less favourable than previously studies have indicated. There is a similar increase in the incidence of adenocarcinoma in men and women which is hard to explain only with changing smoking habits. The change from non-filter to filter cigarettes in the 1960s-1970s may be a contributing factor.

Occupational physical activity and resting blood pressure in male construction workers.

OBJECTIVE: This study investigated the association between occupational physical activity (OPA) and resting blood pressure in a cohort of Swedish construction workers. METHODS: The final sample included 241,176 male construction workers. Occupations with low OPA were foremen and white-collar workers. The most frequent occupations in the medium OPA group were electricians, pipe workers, and machine operators, and in the high OPA group woodworkers, concrete workers, and painters. RESULTS: Mixed effects models showed higher systolic and lower diastolic blood pressure with higher OPA, but the associations varied depending on the year of participation and participant age as shown by significant interaction terms (OPA*age, OPA*calendar year, age*calendar year). Age-stratified linear regression analyses showed a pattern of slightly higher systolic (1.49, 95% confidence interval: 1.08-1.90 mmHg) and lower diastolic (0.89, 95% confidence interval: 0.65-1.13 mmHg) blood pressure when comparing low with high OPA, but not among the oldest age groups. CONCLUSION: Despite a rather large contrast in OPA, the differences in systolic and diastolic blood pressure according to OPA were small.

Cancer incidence in a cohort of Swedish merchant seafarers between 1985 and 2011.

PURPOSE: Lung cancer, mesothelioma and several lifestyle-associated cancer forms have been reported more common in merchant seafarers. However, few studies reflect recent occupational settings and women seafarers are usually too scarce for meaningful analyses. We conducted a study on cancer incidence between 1985 and 2011 in a Swedish cohort consisting of male and female seafarers. METHODS: All seafarers in the Swedish Seafarers' Register with at least one sea service between 1985 and 2011 and a cumulated sea service time of ≥ 30 days (N = 75,745; 64% men, 36% women; 1,245,691 person-years) were linked to the Swedish Cancer Register and followed-up until 31 December 2011. Standardized incidence ratios (SIR) were calculated with the general population as reference. RESULTS: There were 4159 cancer cases in total, with 3221 among men and 938 among women. Male seafarers had an increased risk of total cancer (SIR 1.05; 95% CI 1.01-1.09), lung cancer (SIR 1.51; 95% CI 1.35-1.67) and urinary bladder cancer (SIR 1.17; 95% CI 1.02-1.33). Several lifestyle-associated cancer forms were more common in men. Previous work on tankers was associated with leukaemia (SIR 1.41; 95% CI 1.00-1.86). The risk of cancer decreased with a start as a male seafarer after 1985, with a significant trend for total cancer (P < 0.001), lung cancer (P = 0.001) and, for tanker seafarers, leukaemia (P = 0.045). Women seafarers had an increased risk of lung cancer (SIR 1.54; 95% CI 1.23-1.87) but the risk of total cancer was not increased (SIR 0.83; 95% CI 0.78-0.89). CONCLUSIONS: In this cohort of merchant Swedish seafarers 1985-2011, the risk of total cancer was increased in men but not in women compared to the general population. Lung cancer was increased in both genders. The risk of cancer seems to decrease over the last decades, but better exposure assessments to occupational carcinogens and longer observation times are needed.

Smoking, occupational exposures, and idiopathic pulmonary fibrosis among Swedish construction workers.

BACKGROUND: Cigarette smoking and occupational exposures each have been reported to increase the risk of idiopathic pulmonary fibrosis (IPF), a disease previously considered of unknown origin. We investigated the risk of IPF mortality associated with combined smoking and occupational exposures. METHODS: A registry study of Swedish construction workers (N = 389,132), linked baseline smoking and occupational data with registry data on cause of death and hospital care diagnoses. Occupation was classified by the likelihood of exposure to vapors, gases, dusts, or fumes using a job-exposure matrix. Those likely exposed to asbestos or silica were excluded from the analysis. Age-adjusted relative risks [RRs] were calculated using Poisson regression. Follow-up observation began at age 40 and ended at age 89. RESULTS: Heavy smokers at baseline who were exposed to inorganic dusts during their working life had an increased risk of IPF mortality (RR 1.70; 95% confidence interval [CI] 1.11-2.60), while there was no statistically increased risk in the other exposure groups. There were dose-response relationships between smoking at baseline and IPF mortality among both unexposed and dust exposed workers, with similar risk for dust exposed and unexposed, except among baseline heavy smokers, where workers exposed to inorganic dust manifested the highest risk (RR 4.22; 95% CI 2.69-6.60). Excluding workers with chronic obstructive pulmonary disease or emphysema did not affect the results substantively. CONCLUSION: A clear dose-response relationship was seen between smoking at baseline and IPF, supporting a causal relationship. Occupational exposure to inorganic dusts, excluding silica and asbestos, was associated with increased risk of IPF in baseline heavy current smokers.

Height, body mass index and prostate cancer risk and mortality by way of detection and cancer risk category.

Obesity is a risk factor for advanced, but not localised, prostate cancer (PCa), and for poor prognosis. However, the detection of localised PCa through asymptomatic screening might influence these associations. We investigated height and body mass index (BMI) among 431 902 men in five Swedish cohorts in relation to PCa risk, according to cancer risk category and detection mode, and PCa-specific mortality using Cox regression. Statistical tests were two-sided. Height was positively associated with localised intermediate-risk PCa (HR per 5 cm, 1.03, 95% CI 1.01-1.05), while overweight and obesity were negatively associated with localised low- and intermediate-risk PCa (HRs per 5 kg/m2 , 0.86, 95% CI 0.81-0.90, and 0.92, 95% CI 0.88-0.97). However, these associations were partially driven by PCa's detected by asymptomatic screening and, for height, also by symptoms unrelated to PCa. The HR of localised PCa's, per 5 kg/m2 , was 0.88, 95% CI 0.83 to 0.92 for screen-detected PCa's and 0.96, 95% CI 0.90 to 1.01 for PCa's detected through lower urinary tract symptoms. BMI was positively associated with PCa-specific mortality in the full population and in case-only analysis of each PCa risk category (HRs per 5 kg/m2 , 1.11-1.22, P for heterogeneity = .14). More active health-seeking behaviour among tall and normal-weight men may partially explain their higher risk of localised PCa. The higher PCa-specific mortality among obese men across all PCa risk categories in our study suggests obesity as a potential target to improve the prognosis of obese PCa patients.

Impact of changes in welfare legislation on the incidence of disability pension. A cohort study of construction workers.

Aims: Study objectives were to investigate how changes in social insurance legislation influenced the incidence of disability pension. Methods: The study included 295,636 male construction workers who attended health examinations between 1971 and 1993, aged 20-60 years and without previous disability pension. Via the Swedish National Insurance Agency national register we identified 66,046 subjects who were granted disability pension up until 2010. The incidence rates were calculated and stratified according to age and diagnosis. Results: The incidence rate of disability pension was fairly stable until the 1990s when large variations occurred, followed by a strong decreasing trend from the early 2000s to 2010. Trends in incidence rates, stratified by age and diagnosis, showed a consistent decrease in cardiovascular disease for all age groups. In subjects aged 30-49 years there was a high peak around 2003 for musculoskeletal diseases and psychiatric diseases. For the age group 50-59 years, musculoskeletal diagnosis, the most common cause of disability pension, had a sharp peak around 1993 and then a decreasing trend. In the 60-64 age group, the incidence rate for psychiatric diagnosis was stable, while incidence rates for musculoskeletal diagnosis varied during the 1990s. Conclusions: There are considerable variations in the incidence rate of disability pension over time, with different patterns depending on age and diagnosis. Changes in social insurance legislation, as well as in administration processes, seem to influence the variation.

Mortality in persons with disability pension due to common mental disorders: A cohort study of Swedish construction workers.

Aims: This study investigated mortality in disability pensions due to common mental disorder, and variation over time after first receiving disability pension. Methods: Objectives were explored in 301,863 construction workers (97.2% men) recruited through healthcare examinations from 1971-1993. By linking with the Swedish National Insurance Agency registers, disability pensions until 2014 were identified. Common mental disorder was defined as disability pension diagnosis due to anxiety, stress-related disorders or moderate depression. Mortality was calculated in all-psychiatric diagnosis and diagnostic sub-groups, and compared to persons without disability pensions, using Poisson regression. Additional analyses were stratified by age at follow-up. Results: In total 6030 subjects received disability pensions based on psychiatric diagnoses, and 2624 constituted common mental disorder. Analyses in an all-psychiatric diagnosis displayed increased mortality risks in men (relative risk 3.6; 95% confidence interval 3.3-3.9) and women (relative risk 2.1; 95% confidence interval 1.6-2.6). Common mental disorder was associated with mortality, especially in men (relative risk 2.5; 95% confidence interval 2.2-2.8). Increased relative risks in alcohol and substance abuse were also observed. Results in analyses stratified by age at follow-up displayed persistent high relative risks for mortality in older ages (75-89 years) in men in all-psychiatric disability pensions diagnosis (relative risk 2.8; 95% confidence interval 2.1-3.7) and common mental disorder diagnosis (relative risk 2.6; 95% confidence interval 1.8-3.6), compared to men without disability pensions. Similar results were found in women, but few cases lowered the precision of estimates. Conclusions: This study shows that disability pension based on common mental disorders, often regarded as a 'lighter' psychiatric diagnosis, is a risk for early mortality in construction workers, even several years after first receiving disability pension.

Occupational exposure to noise and cold environment and the risk of death due to myocardial infarction and stroke.

PURPOSE: The present study examined a possible association between occupational exposure to noise, working and living in cold conditions, and the risk of mortality in myocardial infarction and stroke. METHODS: The present cohort study consists of 194,501 workers in the Swedish construction industry that participated in health examinations between 1971 and 1993. Noise exposure was defined on a job-exposure matrix based on a survey of the working conditions carried out during the mid 1970s. All workers were categorised into three main regions of Sweden, differing in temperature: Reference (Götaland), colder (Svealand), and coldest (Norrland). Relative risks (RR) were analysed by negative binomial regression adjusting for age, BMI, and smoking habits. RESULTS: Moderate and high noise exposure was associated with increased risk of myocardial infarction (RR 1.10-1.13 with 95% CI over unit) and stroke mortality (RR 1.15 to 1.19 with 95% CI over unit). There was an increased risk for myocardial infarction (RR 1.10, 95% CI 1.01-1.20), but not for stroke mortality (RR 1.09, 95% CI 0.94-1.25) associated with living and working in the coldest region. There was an interaction on the risk of myocardial infarction mortality between different regions and noise exposure (p = 0.016), but not for stroke mortality (p = 0.88). CONCLUSIONS: The study indicates an interaction between working at hazardous noise levels and living and working in cold conditions for increased mortality in myocardial infarction.

Hematologic malignancy in tanker crewmembers: A case-referent study among male Swedish seafarers.

BACKGROUND: Work on Swedish petroleum tankers before the late 1980s has been associated with an increased risk of hematologic malignancy (HM). Since then, ship modernizations have decreased occupational exposure to gases, including the carcinogen benzene. We explored the risk of HMs in Swedish seafarers who had worked on newer types of tankers. METHODS: A case-referent study in male seafarers from a cohort of all Swedish seafarers was set up by record linkage with the Swedish Cancer Registry using the subjects' personal identification number. For each case (N = 315), five referents were randomly chosen from within the cohort, matched by birth year and three different periods of first sea service (<1985, 1985-1991, and ≥1992). Information on the type of ship and dates of service was retrieved from the Swedish Seafarers' Registry. Odds ratios (OR) were calculated by conditional logistic regression together with 95% confidence intervals (CI). RESULTS: The OR of HM was 1.07 (95% CI, 0.80-1.42) for work on tankers. In seafarers that had started to work on tankers ≥1985, the OR was 0.85 (95% CI, 0.50-1.43). For those who started to work on tankers before 1985, the OR was 1.17 (95% CI, 0.84-1.21) and 1.32 (95% CI, 0.86-2.03) if the cumulative time on tankers exceeded 5 years of service. In this last group, the OR of multiple myeloma was 5.39 (95% CI, 1.11-26.1). CONCLUSION: Although limited by crude exposure contrast and a short follow-up, work on tankers after 1985 was not associated with an increased risk of HM among Swedish seafarers.

Occupational biomechanical risk factors for radial nerve entrapment in a 13-year prospective study among male construction workers.

OBJECTIVES: The aim was to assess the association between occupational biomechanical exposure and the occurrence of radial nerve entrapment (RNE) in construction workers over a 13-year follow-up period. METHODS: A cohort of 229 707 male construction workers who participated in a national occupational health surveillance programme (1971-1993) was examined prospectively (2001-2013) for RNE. Height, weight, age, smoking status and job title (construction trade) were obtained on health examination. RNE case status was defined by surgical release of RNE, with data from the Swedish national registry for out-patient surgery records. A job exposure matrix was developed, and biomechanical exposure estimates were assigned according to job title. Highly correlated exposures were summed into biomechanical exposure scores. Negative binomial models were used to estimate the relative risks (RR) (incidence rate ratios) of RNE surgical release for the biomechanical factors and exposure sum scores. Predicted incidence was assessed for each exposure score modelled as a continuous variable to assess exposure-response relationships. RESULTS: The total incidence rate of surgically treated RNE over the 13-year observation period was 3.53 cases per 100 000 person-years. There were 92 cases with occupational information. Increased risk for RNE was seen in workers with elevated hand-grip forces (RR=1.79, 95% CI 0.97 to 3.28) and exposure to hand-arm vibration (RR=1.47, 95% CI 1.08 to 2.00). CONCLUSIONS: Occupational exposure to forceful handgrip work and vibration increased the risk for surgical treatment of RNE.

Exposure to whole-body vibration and hospitalization due to lumbar disc herniation.

OBJECTIVE: The aim was to examine if exposure to whole-body vibration (WBV) increases the risk for hospitalization due to lumbar disc herniation. METHODS: The study basis is a cohort of 288,926 Swedish construction workers who participated in a national occupational health surveillance programme from 1971 until 1992. Job title, smoking habits, body weight, height and age were registered at the examinations. Assessment of WBV were made for each of the constituent occupations by constructing a job-exposure matrix (JEM). Exposure to WBV was graded on a scale from 0 to 5. In addition, the occurrence of hospitalization due to lumbar disc herniation from January 1st 1987 until December 31st 2010 was collected from a linkage with the Swedish Hospital Discharge Register. Poisson regressions were used to estimate relative risk with 95 percent confidence intervals (95% CI), adjusting for age, height, weight and smoking, using white-collar workers and foremen as a reference group. RESULTS: There was an increased risk for hospitalization due to lumbar disc herniation for workers in the construction industry exposed to medium to high WBV compared to white-collar workers and foremen 1.35 (1.12-1.63). When restricting the analyses to include workers 30-49 years of age at the time of the hospital admission the risk was 1.69 (95% CI 1.29-2.21). CONCLUSION: This study further supports that occupational exposure to whole-body vibration increases the risk for hospitalization due to lumbar disc herniation.

Effect of reduced use of organic solvents on disability pension in painters.

OBJECTIVE: To investigate whether the decreased use of paints based on organic solvents has caused a decreased risk for neuropsychiatric disorders in painters by studying their incidence in disability pensions. METHODS: The incidence of disability pension in Swedish painters who had participated in health examinations between 1971 and 1993 was studied through linkage with Swedish registers of disability pension over 1971-2010 and compared with the incidence in other construction workers as woodworkers, concrete workers and platers. When phasing out began in the 1970s, about 40% of paints were based on organic solvents and it had decreased to 4% in 1990s. The analysis was adjusted for age, time period, body mass index and smoking. RESULTS: The painters (n=23 065) had an increased risk of disability pension due to neurological diagnosis (n=285, relative risk (RR) 1.92, 95% CI 1.67 to 2.20) and psychiatric diagnosis (n=632, RR=1.61, 95 % CI 1.42 to 1.82). For neurological disorders there was a time trend with a continuously decreasing risk from 1980 onwards, but there was no such trend for psychiatric disorders. CONCLUSIONS: High exposure to organic solvents increased the risk for disability pension in neurological disorders, and the risk decreased when the use of organic solvents decreased. The painters also had an increased risk of disability pension due to psychiatric disorders, but the causes have to be further investigated.

Influence of obesity and physical workload on disability benefits among construction workers followed up for 37 years.

OBJECTIVES: The objectives of this study are to investigate the relation between obesity and labour force exit via diagnosis-specific disability benefits, and whether physical workload modifies this association. METHODS: A longitudinal analysis was performed among 3 28 743 Swedish construction workers in the age of 15-65 years. Body weight and height were measured at a health examination and enriched with register information on disability benefits up to 37 years later. Diagnoses of disability benefits were categorised into cardiovascular diseases (CVDs), musculoskeletal diseases (MSDs), mental disorders and others. A job exposure matrix, based on self-reported lifting of heavy loads and working in bent forward or twisted position, was applied as a measure of physical workload. Cox proportional hazards regression analyses were performed, and the relative excess risk due to interaction (RERI) between obesity and physical workload was calculated. RESULTS: Obese construction workers were at increased risk of receiving disability benefits (HR 1.70, 95% CI 1.65 to 2.76), mainly through CVD (HR 2.30) and MSD (HR 1.71). Construction workers with a high physical workload were also more likely to receive a disability benefit (HR 2.28, 95% CI 2.21 to 2.34), particularly via MSD (HR 3.02). Obesity in combination with a higher physical workload increased the risk of disability benefits (RERI 0.28) more than the sum of the risks of obesity and higher physical workload, particularly for MSD (RERI 0.44). CONCLUSIONS: Obesity and a high physical workload are risk factors for disability benefit. Furthermore, these factors are synergistic risk factors for labour force exit via disability benefit through MSD. Comprehensive programmes that target health promotion to prevent obesity and ergonomic interventions to reduce physical workload are important to facilitate sustained employment.

Work environment and safety climate in the Swedish merchant fleet.

PURPOSE: To get knowledge of the work environment for seafarers sailing under the Swedish flag, in terms of safety climate, ergonomical, chemical and psychosocial exposures, and the seafarers self-rated health and work ability. METHODS: A Web-based questionnaire was sent to all seafarers with a personal e-mail address in the Swedish Maritime Registry (N = 5608). Comparisons were made mainly within the study population, using Student's t test, prevalence odds ratios and logistic regressions with 95% confidence intervals. RESULTS: The response rate was 35% (N = 1972; 10% women, 90% men), with 61% of the respondents working on deck, 31% in the engine room and 7% in the catering/service department (1% not classifiable). Strain on neck, arm or back and heavy lifting were associated with female gender (p = 0.0001) and younger age (below or above 30 years of age, p < 0.0001). Exposures to exhausts, oils and dust were commonly reported. Major work problems were noise, risk of an accident and vibrations from the hull of the ship. The safety climate was high in comparison with that in land-based occupations. One-fourth had experienced personal harassment or bullying during last year of service. CONCLUSIONS: Noise, risk of accidents, hand/arm and whole-body vibrations and psychosocial factors such as harassment were commonly reported work environment problems among seafarers within the Swedish merchant fleet.

Smoking and the Risk of Hospitalization for Symptomatic Diverticular Disease: A Population-Based Cohort Study from Sweden.

BACKGROUND: Current studies reporting on the risk of smoking and development of symptomatic diverticular disease have reported conflicting results. OBJECTIVE: The aim of this study was to investigate the association between smoking and symptomatic diverticular disease. DESIGN: This is a cohort study SETTINGS: : Information was derived from the Swedish Construction Workers Cohort 1971-1993. PATIENTS: Patients were selected from construction workers in Sweden. MAIN OUTCOME MEASURES: The primary outcome measured was the development of symptomatic diverticular disease and complicated diverticular disease (abscess and perforation) as identified in the Swedish Hospital Discharge Register. Adjusted relative risks of symptomatic diverticular disease according to smoking status were estimated by using negative binomial regression analysis. RESULTS: In total, the study included 232,685 men and 14,592 women. During follow-up, 3891 men and 318 women had a diagnosis of later symptomatic diverticular disease. In men, heavy smokers (≥15 cigarettes a day) had a 1.6-fold increased risk of developing symptomatic diverticular disease compared with nonsmokers (adjusted relative risk, 1.56; 95% CI, 1.42-1.72). There was evidence of a dose-response relationship, because moderate and ex-smokers had a 1.4- and 1.2-fold increased risk compared with nonsmokers (adjusted relative risk, 1.39; 95% CI, 1.27-1.52 and adjusted relative risk, 1.14; 95% CI, 1.04-1.27). These relationships were similar in women, but the risk estimates were less precise owing to smaller numbers. Male ever-smokers had a 2.7-fold increased risk of developing complicated diverticular disease (perforation/abscess) compared with nonsmokers (adjusted relative risks, 2.73; 95% CI, 1.69-4.41). LIMITATIONS: We were unable to account for other confounding variables such as comorbidity, prescription medication, or lifestyle factors. CONCLUSIONS: Smoking is associated with symptomatic diverticular disease in both men and women and with an increased risk of developing complicated diverticular disease.

Disability Pensions due to Skin Diseases: A Cohort Study in Swedish Construction Workers.

Disability pensions due to skin diseases in Swedish male construction workers were studied by linking data from pension registers and an occupational health service. Incidence rates of disability pensions for cement workers, painters and plumbers were compared with 2 control groups. A total of 623 disability pensions were granted during 4 decades of follow-up. The main diagnoses were eczema (36%) and psoriasis (49%). Pensions were mostly granted in the age range 55-64 years. Among painters, cement workers and plumbers the incidence rates for disability pensions were 33.3, 24.5 and 20.4 cases/100,000 person-years, respectively, compared with 13.7 and 9.2 cases/100,000 person-years in control groups. Relative risks were highest for eczema, and were notable for psoriasis. Attributable fractions for eczema were 90% in cement workers and painters and 75% in plumbers compared with control groups. Attributable fractions for psoriasis in the occupational groups studied were in the range 54-67%. In conclusion, eczema and psoriasis have a high impact on loss of work ability, as reflected by disability pensions.

Emerging evidence that the ban on asbestos use is reducing the occurrence of pleural mesothelioma in Sweden.

AIMS: Several countries have banned the use of asbestos. The future health impacts of previous use have been modeled but there are to our knowledge no convincing studies showing a decreased occurrence of asbestos-related diseases due to a ban. The aim of our study was to estimate the effects of the ban and other measures to decrease the use of asbestos in Sweden. METHODS: The effect was measured through comparing the incidence of pleural malignant mesothelioma in birth cohorts who started to work before and after the decrease in the use of asbestos, i.e. in mid-1970s. Cases were identified through the Swedish Cancer Registry and the analysis was restricted to persons born in Sweden. RESULTS: Men and women born 1955-79 had a decreased risk of malignant pleural mesothelioma compared to men and women born 1940-49 (RR 0.16, 95% CI 0.11-0.25; and RR 0.47, 95% CI 0.23-0.97 respectively). The decreased use of asbestos prevented each year about 10 cases in men and two cases in women below the age of 57 years in 2012. CONCLUSIONS: The ban and decreased use of asbestos in Sweden can be measured today in birth cohorts that started their working career after the decrease.

Smoking, use of moist snuff and risk of celiac disease: a prospective study.

BACKGROUND: Smoking status has been linked to several chronic inflammatory conditions but earlier research on smoking and celiac disease (CD) is contradictive. There are little data on moist snuff use and CD. The purpose of this study was to investigate the association between smoking, moist snuff use and later CD. METHODS: We identified individuals with biopsy-verified CD (villous atrophy, histopathology stage Marsh III) through biopsy-reports from Sweden's 28 pathology departments. Data on smoking and moist snuff were collected from the Swedish construction worker database "Bygghälsan" that includes preventive health care check-up data. Through poisson regression we calculated relative risks (RRs) for later CD according to smoking status (n = 305,722), and moist snuff status (n = 199,200) adjusting for age, sex and decade. RESULTS: During follow-up 488 individuals with smoking data, and 310 with moist snuff data had a diagnosis of CD. The risk of CD was independent of smoking status with all RRs being statistically insignificant and ranging between 0.9 and 1.0. Compared to non-smokers, neither current smokers (RR = 0.93; 95% CI = 0.76-1.14) nor ex-smokers (RR = 0.98; 95% CI = 0.75-1.28) were at increased or decreased risk of CD. Risk estimates were similar in moderate smokers (RR = 0.92; 0.72-1.16) and heavy smokers (RR = 0.95; 0.74-1.24), and did not change when we examined the risk more than ten years after health examination (RR-moderate: 0.90; and RR-heavy: 0.95; both p > 0.05). Moist snuff use was not associated with later CD (RR = 1.00; 0.78-1.28), or with CD after more than ten years of follow-up (RR = 1.05; 0.80-1.38). CONCLUSIONS: We found no association between smoking, moist snuff use and future CD.

Evidence-based evaluation of information: the centrality and limitations of systematic reviews.

This introductory paper considers the value and limitations of the methodology of systematic reviews especially according to the evidence-based movement. It explains some terms and organisations producing systematic reviews. It also discusses controversies. The first concerns the criteria by which the quality of individual studies is assessed, the second the possible effects of the affiliation of some reviewers, and the third the value of formalisation of procedure (i.e. the tensions between formal tools and professional judgments). The article contrasts the evidence-based formalism with other formalisms as those by the Intergovernmental Panel on Climate Change and the International Agency for Research on Cancer. It discusses systematic reviews in social science where interventions are complex, difficult to blind, and depend on context. Systematic reviews in working life research are often focusing on prevention. The formal evidence-based process may devaluate or disregard findings from mechanistic and observational studies. Hence such reviews may falsely conclude that existing knowledge about the risk of the factor is limited or nonexistent.

The impact of asbestos exposure in Swedish construction workers.

OBJECTIVE: To study the occurrence of pleural mesothelioma as a measure of the impact on health from asbestos exposure in the construction industry. METHODS: The occurrence of pleural mesothelioma in different occupations, time periods and birth cohorts was studied in a cohort of construction workers. They were prospectively followed after they had participated in health examinations between 1971 and 1993. The analysis was restricted to men and in total 367,568 men was included in the analysis. RESULTS: In total there were 419 cases of pleural mesotheliomas between 1972 and 2009. As expected the age adjusted incidence was high in insulation workers and plumbers (39 and 16 cases per 100,000 person-years, respectively). However, only 21% of the pleural mesotheliomas occurred in those occupational groups. Occupational groups with many cases of pleural mesothelioma were concrete workers (N = 56), wood workers (N = 55), painters (N = 32), electricians (N = 48), and foremen (N = 37). The highest risk was in birth cohorts born between 1935 and 1945. Between 1995 and 2009 around one-third of all male cases in the country occurred in this birth cohort. The risk seemed to decrease considerably in men born after 1955. CONCLUSION: In Sweden a considerable proportion of pleural mesotheliomas occur among construction workers; and not only in jobs traditionally associated with asbestos exposure such as insulators and plumbers but also among electricians, for example. The results shows that asbestos exposure occurs in many occupational groups, indicating that safe handling of asbestos is a very difficult or even impossible task in the construction industry.