Mortality of butchers and cooks identified from the 1961 census of England and Wales

Work environment factors and respiratory complaints in Norwegian cooks

PURPOSE

Norwegian cooks exhibit relatively high mortality, particularly from respiratory diseases. Both occupational hazards and lifestyle factors have been suggested as possible explanations. Negative health effects from exposure to cooking fumes are well documented in non-Western populations, and it has been claimed that cooking fumes in Western style cooking might be substantially different. We hypothesise that exposure to cooking fumes contributes to respiratory diseases also in professional cooks in Western countries. The aim of this study was to elucidate if specific work environment factors related to cooking fume exposure are determinants for respiratory morbidity in Norwegian cooks.

METHODS

We surveyed specific work environment factors and respiratory complaints in 553 subjects that were currently working as skilled cooks. Inclusion was based on the register of people that had graduated as skilled cooks in central Norway between 1988 and 2008. Determinants for the occurrence of respiratory complaints were explored by logistic regression.

RESULTS

Overall, 17.2% of subjects reported respiratory complaints at work, while 8.1% had chronic bronchitis. Those who performed frying for over half of their workday exhibited an increased odds ratio for having chronic bronchitis of 2.5 (95% CI 1.2-5.3). Using gas for frying and using a fryer in the kitchen were also related to the occurrence of respiratory complaints.

CONCLUSIONS

This study in Norwegian cooks demonstrates a relationship between the extent of frying and the occurrence of work-related respiratory complaints. Therefore, reducing exposure to cooking fumes could reduce respiratory complaints in cooks, and potentially help alleviate excess morbidity and mortality in this occupation.

Association between butchers and cancer mortality and incidence: A systematic review and meta-analysis

BACKGROUND

In this study, we evaluated whether increased risks of mortality and cancer incidence exist among butchers worldwide. To achieve this goal, we conducted a systematic review and meta-analysis to investigate the correlations of the risks of cancer death and incidence with male and female butchers.

METHODS

We obtained data by performing a comprehensive literature search in several databases for eligible studies published before March 2017. Multivariable-adjusted standardized mortality ratios (SMRs) and odds ratio (OR), as well as associated 95% confidence intervals (CIs) and those by subgroups, were extracted and pooled.

RESULTS

A total of 17 observational studies comprising 397,726 participants were included in the meta-analysis. The butcher occupation was not associated with all-cancer mortality risk, with pooled overall SMRs of 1.07 (95% CI 0.96-1.20). However, the pooled ORs revealed that butchers hold an elevated risk of total cancer incidence (OR, 1.51; 95% CI, 1.33-1.73). No proof of publication bias was obtained, and the findings were consistent in the subgroup analyses.

CONCLUSION

Our results suggest that working as butchers did not significantly influence all-cancer mortality risk but significantly contributed to elevated all-cancer incidence risk. Nevertheless, well-designed observational studies on this topic are necessary to confirm and update our findings.

Long-Term Nonmalignant Disease Mortality in Subjects Exposed to Transmissible Agents Present in Animals Used for Food

OBJECTIVE

To study mortality from nonmalignant diseases in subjects with high exposure to transmissible agents present in animals used for food, and in their raw or inadequately cooked products.

METHODS

Mortality was compared in a cohort of meat handlers in slaughtering and processing plants with that of the U.S. general population.

RESULTS

Excess mortality was observed for conditions known to be associated with infections-these include, septicemia, chronic nephritis, diseases of the kidney and ureter, diseases of the pancreas, cirrhosis of the liver, acute and subacute endocarditis, acute rheumatic fever, functional diseases of the heart, aortic aneurysm, intracranial and intraspinous abscess, and meningitis. Excess mortality was also observed for ischemic heart disease and diabetes, conditions without an established infectious etiology, but which have been linked with infections.

CONCLUSIONS

If transmissible agents present in food animals and their raw products cause long-term diseases and mortality in humans, this study importantly points to the likely diseases, many of which are already known to be associated with infections. The excess mortality observed for ischemic heart disease and diabetes is consistent with existing evidence linking these conditions with infections, and gives rise to the novel hypothesis that microbial agents present in food animals and their products may be candidates for an infective role in the occurrence of these conditions, and therefore needs further investigation.

Lung cancer risk among cooks when accounting for tobacco smoking: a pooled analysis of case-control studies from Europe, Canada, New Zealand, and China

OBJECTIVES

To investigate the risk of lung cancer among cooks, while controlling for smoking habits.

METHODS

We used data from the SYNERGY project including pooled information on lifetime work histories and smoking habits from 16 case-control studies conducted in Europe, Canada, New Zealand, and China.

RESULTS

Before adjustment for smoking, we observed an increased risk of lung cancer in male cooks, but not in female cooks. After adjusting, there was no increased risk and no significant exposure-response relationship. Nevertheless, subgroup analyses highlighted some possible excess risks of squamous cell carcinoma and small cell carcinoma in female cooks.

CONCLUSIONS

There is evidence that lung cancer risks among cooks may be confounded by smoking. After adjustment, cooks did not experience an increased risk of lung cancer overall. The subgroup analyses showing some excess risks among female cooks require cautious interpretation.

Research at the interface between human and veterinary health

Epidemiology is currently undergoing changes in its underlying philosophy and approach, as a result of the rapid global changes which are transforming the world in which epidemiologists live and work. This necessitates a multidisciplinary "population approach" involving "multilevel thinking" about the determinants of disease. These issues are of relevance to the interface between human and animal epidemiology, which has received considerable attention in recent years, particularly as a result of the arrival of H1N1 influenza, and the increasingly obvious need for coordinated systems of surveillance for human and animal infectious diseases. However, the need for coordination between human and veterinary epidemiology is broader than that, and there is no need to restrict the "one world one health" concept to communicable disease. In the current paper we will therefore consider the interface between human and animal health for the study of non-communicable disease, particularly those involving occupational and environmental risk factors. These issues are illustrated with two examples: one involving environmental health (asthma); and one involving occupational health (cancer). We will also discuss the potential to use animal health data as indicators for human environmental health risks.

Cancer mortality in workers employed in cattle, pigs, and sheep slaughtering and processing plants

OBJECTIVES

We studied mortality in two separate cohorts of workers in abattoirs (N=4996) and meat processing plants (N=3642) belonging to a meatcutters' union, because they were exposed to viruses that cause cancer in food animals, and also to chemical carcinogens at work.

METHODS

Standardized mortality ratios (SMRs) and proportional mortality ratios (PMRs) were estimated for each cohort as a whole and in subgroups defined by race and sex, using the US general population mortality rates for comparison. Study subjects were followed up from January 1950 to December 2006, during which time over 60% of them died.

RESULTS

An excess of deaths from cancers of the base of the tongue, esophagus, lung, skin, bone and bladder, lymphoid leukemia, and benign tumors of the thyroid and other endocrine glands, and possibly Hodgkin's disease, was observed in abattoir and meat processing workers. Significantly lower SMRs were recorded for cancer of the thymus, mediastinum, pleura, etc., breast cancer, and non-Hodgkin's lymphoma.

CONCLUSION

This study confirms the excess occurrence of cancer in workers in abattoirs and meat processing plants, butchers, and meatcutters, previously reported in this cohort and other similar cohorts worldwide. Large nested case-control studies are now needed to examine which specific occupational and non-occupational exposures are responsible for the excess. There is now sufficient evidence for steps to be taken to protect workers from carcinogenic exposures at the workplace. There are also serious implications for the general population which may also be exposed to some of these viruses.

Occupational exposures, environmental tobacco smoke, and lung cancer

BACKGROUND

There is uncertainty regarding the association of occupational exposures with lung cancer. We have studied the association between 52 high-risk job titles and lung cancer incidence in a large prospective study, with more than 200,000 participants followed for more than 6 years and 809 incident cases of lung cancer.

METHODS

Hazard ratios and 95% confidence intervals were computed by the Cox proportional-hazard regression model, adjusting for country, age, sex, social class, diet, physical activity, and smoking habits. We used a CAREX-based job-exposure matrix to infer exposure to lung carcinogens. False-positive report probability was calculated as a measure of potentially false-positive results.

RESULTS

Eighteen occupations, mainly related with agriculture, constructions, and metal processing, were associated with increased risk. In addition, incidence tended to increase with the number of hazardous jobs reported. When the occupations were classified according to the presumed exposure to specific carcinogenic agents, the hazard ratios were 1.5 (95% confidence interval = 1.2-1.9) for asbestos, 1.4 (1.1-1.8) for heavy metals, 1.4 (1.1-1.8) for polycyclic aromatic hydrocarbons, and 1.6 (1.2-2.1) for work-related environmental tobacco smoke. The estimated population attributable risk for employment in at least 1 at-risk job was 16% in men and 12% in women.

CONCLUSIONS

This large prospective study suggests that exposure to occupational lung carcinogens is still a problem, with such exposures producing moderate to large increases in risk.

Non-malignant disease mortality in meat workers: a model for studying the role of zoonotic transmissible agents in non-malignant chronic diseases in humans

BACKGROUND

Current research efforts have mainly concentrated on evaluating the role of substances present in animal food in the aetiology of chronic diseases in humans, with relatively little attention given to evaluating the role of transmissible agents that are also present. Meat workers are exposed to a variety of transmissible agents present in food animals and their products. This study investigates mortality from non-malignant diseases in workers with these exposures.

METHODS

A cohort mortality study was conducted between 1949 and 1989, of 8520 meat workers in a union in Baltimore, Maryland, who worked in manufacturing plants where animals were killed or processed, and who had high exposures to transmissible agents. Mortality in meat workers was compared with that in a control group of 6081 workers in the same union, and also with the US general population. Risk was estimated by proportional mortality and standardised mortality ratios (SMRs) and relative SMR.

RESULTS

A clear excess of mortality from septicaemia, subarachnoid haemorrhage, chronic nephritis, acute and subacute endocarditis, functional diseases of the heart, and decreased risk of mortality from pre-cerebral, cerebral artery stenosis were observed in meat workers when compared to the control group or to the US general population.

CONCLUSIONS

The authors hypothesise that zoonotic transmissible agents present in food animals and their products may be responsible for the occurrence of some cases of circulatory, neurological and other diseases in meat workers, and possibly in the general population exposed to these agents.

Occupational exposure to meat and risk of lymphoma: A multicenter case-control study from Europe

Several studies have suggested an increased risk of lymphoma among workers exposed to meat, without conclusive evidence. We conducted a multicenter case-control study during 1998-2004 in the Czech Republic, France, Germany, Ireland, Italy and Spain, including 2,007 cases of non-Hodgkin lymphoma, 339 cases of Hodgkin lymphoma and 2,462 controls. We collected detailed information on occupational history and assessed exposure to meat in general and several types of meat via expert assessment of the questionnaires. The odds ratio (OR) of non-Hodgkin lymphoma for ever occupational exposure to meat was 1.18 (95% confidence interval [CI] 0.95-1.46), that for exposure to beef meat was 1.22 (95% CI 0.90-1.67), and that for exposure to chicken meat was 1.19 (95% CI 0.91-1.55). The ORs were higher among workers with longer duration of exposure. An increased risk among workers exposed to beef meat was mainly apparent for diffuse large B-cell lymphoma (OR 1.49, 95%CI 0.96-2.33), chronic lymphocytic leukemia (OR 1.35, 95% CI 0.78-2.34) and multiple myeloma (OR 1.40, 95%CI 0.67-2.94). The latter 2 types were also associated with exposure to chicken meat (OR 1.55, 95% CI 1.01-2.37, and OR 2.05, 95%CI 1.14-3.69). Follicular lymphoma and T-cell lymphoma, as well as Hodgkin lymphoma did not show any increase in risk. Occupational exposure to meat does not appear to represent an important risk factor of lymphoma, although an increased risk of specific types of non-Hodgkin lymphoma cannot be excluded.

Cancer risk among Finnish food industry workers

Occupational cancer risks suggested among food industry workers are inconclusive. The objective of our study was to assess associations between different cancers and working in the food industry in Finland. The carcinogenic exposures are mainly inhalatory, and we were therefore interested in respiratory cancers in particular. We followed up a cohort of all economically active Finns born between 1906 and 1945 for 30 million person-years during 1971-95. The 1970 Census data on occupations were linked with data on subsequent incident cancer cases. Standardized incidence ratios (SIR) and 95% confidence intervals (CI) were calculated for each occupation using the economically active population as the reference. A total of 2,526 incident cancer cases were observed. Elevated risks were observed among male food industry workers for pancreatic (SIR=1.50, CI=1.13-1.96) and kidney cancers (1.51, 1.16-1.94). With respect to specific occupations, there was an excess of lung cancer among female bakers (1.38, 1.01-1.85) and laryngeal cancer among male grain millers (2.60, 1.05-5.36). Occupational exposure is unlikely to be a major risk factor for cancer among Finnish workers employed in typical food industry occupations.

Mortality and cancer incidence in New Zealand meat workers

AIMS

To ascertain whether there is an increased risk of cancers of the lung and lymphohaematopoietic tissue in workers employed in the New Zealand meat processing industry, and to identify exposures associated with any increased risks.

METHODS

A cohort of 6647 individuals assembled from personnel records from three plants was followed from 1988 until 2000. The observed number of deaths and cancer registrations was compared with expected numbers using five year age and gender specific rates for the New Zealand population. Subgroup analyses evaluated the effect of duration of exposure to selected agents, based on job titles and departments.

RESULTS

Vital status was determined for 84% of the cohort, and 92% of the total possible person-years. Mortality from all causes and all cancers was increased, and there was a significant excess of lung cancer. There were significant trends of increasing risk of lung and lymphohaematopoietic cancer with increasing duration of exposure to biological material.

CONCLUSIONS

Excess risks were observed for mortality from all causes, all cancers, and lung cancer. Although the increased risk of lung cancer may be partly due to confounding by smoking, it is unlikely to be entirely due to this cause. Furthermore, the dose-response relation observed for lung cancer suggests the effect is related to exposure to biological material contained in animal urine, faeces, and blood. Although numbers were small, the risk of lymphohaematopoietic cancer was also associated with increasing duration and level of exposure to biological material.

A Prospective Study of Occupation and Prostate Cancer Risk

A wide variety of occupations has been associated with prostate cancer in previous retrospective studies. Most attention has been paid to farming, metal working, and the rubber industry. Today, these results cannot be affirmed with confidence, because many associations could be influenced by recall bias, have been inconsistent, or have not been confirmed satisfactory in subsequent studies. This study was conducted to investigate and confirm these important associations in a large prospective cohort study. The authors conducted a prospective cohort study among 58,279 men. In September 1986, the cohort members (55-69 years) completed a self-administered questionnaire on potential cancer risk factors, including job history. Related job codes were clustered in professional groups. These predefined clusters were investigated in 3 time windows: 1) profession ever performed, 2) longest profession ever held, and 3) last profession held at baseline. Follow up for incident prostate cancer was established by linkage to cancer registries until December 1993. A case-cohort approach was used based on 830 cases and 1525 subcohort members. To minimize false-positive results, 99% confidence intervals (99% CI) were calculated. Although moderately decreased prostate cancer risks were found for electricians, farmers, firefighters, woodworkers, textile workers, butchers, salesmen, teachers, and clerical workers, none of the relative risks (RR) were found to be statistically significant. For road transporters, metal workers, and managers, no association with prostate cancer risk was found. Although the RR for railway workers, mechanics, welders, chemists, painters, and cooks was moderately increased, these estimates were not statistically significant. For men who reported to have ever worked in the rubber industry, we found a substantially increased prostate cancer risk, but not statistically significant (RR, 4.18; 99% CI = 0.22-80.45). For policemen, we found a substantial and marginally statistically significant increased prostate cancer risk, especially for those who reported working as a policeman for most of their occupational life (RR, 3.91; 99% CI = 1.14-13.42) or as the last profession held at baseline (RR, 4.00; 99% CI = 1.19-13.37). Most of the previously investigated associations between occupation and prostate cancer risk could not be confirmed with confidence in this prospective study. The lack of statistical significance for rubber workers could be caused by the scarcity of rubber workers in this cohort and subsequent lack of power. The results for policemen were substantial and statistically significant, although a conservative value for significance level was used.

Environmental and occupational cancer in Argentina: a case-control lung cancer study

The main objective of this study was to analyze the risks for lung cancer associated with occupational exposures in a developing country where lung cancer is the first cause of mortality from cancer in men. The study involved 200 men with lung cancer and 397 hospital controls. The OR for current smokers was 8.5, whereas former smokers displayed an OR of 5.3. The fraction attributable to smoking was 85%. Statistically significant high ORs were observed for employment in the alcoholic beverages (4.5, 95% CI: 1.02-20.2), sawmills and wood mills (4.6, 95% CI:1.1-18.4), chemicals/plastics (1. 8, 95% CI:1.04-3.2), and pottery, glass, or mineral manufactures (3.4, 95% CI:1.1-10.6). Other high (but not statistically significant) risks were observed for employment in leather shoe industry and repair (2.1, 95% CI:0.8-5.4), rubber industries (3.4, 95% CI:0.9-12.4), metal workers, including welders (1.9, 95% CI:0.8-4.4), motor vehicle mechanics (2.0, 95% CI:0.9-4.2), workers in cleaning services (1.9, 95% CI: 0.8-4.5), and for workers in agriculture (2.4, 95% CI:0.9-6.0). Although some of the present results may be due to chance, most are consistent with those of previous investigations in other countries.