Mortality among Swedish chimney sweeps (1952-2006): an extended cohort study
ABSTRACT We extended a cohort study of Swedish chimney sweeps and prolonged follow-up in order to increase power and study those first employed after 1950 when oil began to replace wood as a main fuel for heating in Sweden.
Male Swedish chimney sweeps who were members of the national trade union in 1981-2006 were identified (n=1087) and included to a previous cohort of those employed in 1918-1980 (n=5287). All employment histories were updated, and the total extended cohort (n=6374) was linked to the registers of Causes of Death and Total Population and followed for mortality from 1952 through 2006. Standardised mortality ratios (SMRs) were estimated using the Swedish male population as reference.
1841 observed deaths resulted in an SMR for all causes of deaths of 1.29 (95% CI 1.24 to 1.36). Mortality was significantly increased for all malignant tumours, oesophageal cancer, bowel cancer, liver cancer, lung cancer, alcoholism, ischaemic heart disease, non-malignant respiratory diseases, liver cirrhosis, external causes and suicides. The lung cancer SMR remained increased, although attenuated, after adjustment for group-level smoking data, SMR of 1.52 (95% CI 1.26 to 1.89). Duration of employment showed no consistent evidence of dose-response associations. Alcohol-related deaths (liver cirrhosis and alcoholism) were not increased among those employed >30 years. Mortality among those employed after 1950 was similar to that of the entire cohort.
Chimney sweeps are exposed to high levels of toxic substances in the occupation, but excess alcohol and smoking habits were also observed, and the results must be interpreted cautiously. However, group-level data on tobacco smoking indicated that the lung cancer excess only to some extent could be explained by smoking habits, and the increased mortality from oesophageal cancer and ischaemic heart disease among chimney sweeps employed >30 years is less likely to be caused by excess alcohol habits.
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ABSTRACT: OBJECTIVES: Previous studies of chimney sweeps have shown an excess mortality from cardiovascular diseases, although the extent of confounding from tobacco smoking is uncertain. The present study used referents of similar socioeconomic background as the chimney sweeps in order to reduce confounding, included both lethal and surviving cases of myocardial infarction, and investigated dose-response in terms of duration of employment. METHODS: A cohort of 4436 male chimney sweeps was identified from nationwide trade union records from 1918 to 2006. Myocardial infarctions during 1991-2005 were identified from the Swedish nationwide register of first-time myocardial infarctions. Standardised incidence ratios (SIRs) were estimated using skilled manual workers in the service sector in Sweden to calculate expected numbers. RESULTS: There was a strong and statistically significant excess of myocardial infarction among the chimney sweeps, SIR 1.39 (95% CI 1.24 to 1.55). The excess was observed among both short- and long-term employed. CONCLUSIONS: While the excess of myocardial infarction among the short-term employed may be due to tobacco and, possibly, alcohol use, it is likely that the excess noted among the long-term employed was caused by the high exposure to combustion products, particles or metals still occurring among chimney sweeps. Preventive measures to reduce hazardous occupational exposures as well as smoking and alcohol use among chimney sweeps are urgently needed.Occupational and environmental medicine 04/2013; 70(7). DOI:10.1136/oemed-2013-101371 · 3.23 Impact Factor
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ABSTRACT: Tobacco smoking is considered the greatest risk factor for death caused by noncommunicable diseases. In contrast to extensive research on the association between tobacco smoking and diseases such as heart attack, stroke, and cancers, studies on the association between tobacco smoking and seizures or epilepsy are insufficient. The exact roles tobacco smoking and nicotine use play in seizures or epilepsy have not been well reviewed. We reviewed available literature and found that 1) there are vast differences between tobacco smoke and nicotine based on their components and their effects on seizures or epilepsy; 2) the seizure risk in acute active tobacco smokers, women who smoke during pregnancy, electronic cigarette smokers, and the role of smoking in sudden unexplained/unexpected death in epilepsy remain unclear; 3) seizure risks are higher in acute secondhand smokers, chronic active smokers, and babies whose mothers smoke; 4) tobacco smoke protects against seizures in animal models whereas nicotine exerts mixed effects in animals; and 5) tobacco smoking agents can be noneffective, proconvulsant, or anticonvulsant. Finally, the opportunities for future research on this topic is discussed.Epilepsy & Behavior 01/2014; 31C:210-218. DOI:10.1016/j.yebeh.2013.11.022 · 2.06 Impact Factor
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ABSTRACT: Previous research has shown that those employed in certain occupations, such as doctors and farmers, have an elevated risk of suicide, yet little research has sought to synthesise these findings across working-age populations. To summarise published research in this area through systematic review and meta-analysis. Random effects meta-analyses were used to calculate a pooled risk of suicide across occupational skill-level groups. Thirty-four studies were included in the meta-analysis. Elementary professions (e.g. labourers and cleaners) were at elevated risk compared with the working-age population (rate ratio (RR) = 1.84, 95% CI 1.46-2.33), followed by machine operators and deck crew (RR = 1.78, 95% CI 1.22-2.60) and agricultural workers (RR = 1.64, 95% CI 1.19-2.28). Results suggested a stepwise gradient in risk, with the lowest skilled occupations being at greater risk of suicide than the highest skill-level group. This is the first comprehensive meta-analytical review of suicide and occupation. There is a need for future studies to investigate explanations for the observed skill-level differences, particularly in people employed in lower skill-level groups.The British journal of psychiatry: the journal of mental science 12/2013; 203(6):409-16. DOI:10.1192/bjp.bp.113.128405 · 6.62 Impact Factor