Mortality and cancer incidence in a cohort of meatworkers

Long-term occupational exposures on disability-free survival and mortality in older adults

BACKGROUND

The impact of long-term occupational exposures on health in older adults is increasingly relevant as populations age. To date, no studies have reported their impact on survival free of disability in older adults.

AIMS

We aimed to investigate the association between long-term occupational exposure and disability-free survival (DFS), all-cause mortality and cause-specific mortality in initially healthy older adults.

METHODS

We analysed data from 12 215 healthy participants in the ASPirin in Reducing Events in the Elderly (ASPREE) study whose mean age was 75 years. Their work history was collated with the 'ALOHA-plus JEM' (Job Exposure Matrix) to assign occupational exposures. The primary endpoint, DFS, was a composite measure of death, dementia or persistent physical disability. The secondary endpoint, mortality, was classified according to the underlying cause. Cox proportional hazard models were used to calculate hazard ratios and 95% confidence intervals, adjusted for confounders.

RESULTS

A total of 1835 individuals reached the DFS endpoint during the median 4.7 years follow-up period. Both ever-high and cumulative exposure to all dusts and all pesticides during a person's working years were associated with reduced DFS. Compared to no exposure, men with high exposure to dusts and pesticides had a reduced DFS. Neither of these exposures were significantly associated with all-cause mortality. Men with high occupational exposure to solvents and women exposed to dusts experienced higher all-cause and cancer-related mortality.

CONCLUSIONS

Long-term occupational exposure to all dusts and pesticides was associated with a reduced DFS and increased mortality in community-dwelling healthy older adults.

Excess lung cancer occurrence in poultry plants. Occupational risk factors: Findings for oncogenic viruses exposure and other occupational exposures

Certain viruses naturally infect and cause cancer in chickens and turkeys. Humans are widely exposed. The viruses cause cancer in primates, and transform human cells in vitro, but it is not known if they cause cancer in humans, mainly because of the lack of epidemiologic evidence. We conducted cohort mortality studies of workers in poultry slaughtering/processing plants across the United States, because they have the highest human exposures. An excess of lung cancer and other deaths was recorded in the poultry workers. Here, we report on a case-cohort study of the lung cancer deaths nested within these cohorts, that was conducted to provide epidemiologic evidence linking these viruses with human cancer occurrence, while adjusting for possible confounders, including workplace chemical carcinogens. We obtained interviews for 339 lung cancer deaths and 457 controls, selected from our combined cohorts of 30,411 poultry plant workers and 16,405 non-poultry workers, belonging to United Food & Commercial Workers unions. Data was analyzed by both logistic regression and Cox regression, adjusting for smoking and other confounders. Lung cancer risk was independently associated with tasks or work areas indicative of exposure to both poultry oncogenic viruses and to workplace chemical carcinogens. The study provides an incremental piece of evidence (epidemiologic), indirectly linking the oncogenic viruses of poultry with the occurrence of cancer in humans, and thus may have public health implications, but the limitations highlighted must be considered. Confirmatory studies, particularly molecular studies providing definitive proof of poultry oncogenic retrovirus integration in human DNA are needed, before the findings observed in this study can be put into proper perspective.

Occupational exposures and colorectal cancers: A quantitative overview of epidemiological evidence

A traditional belief widespread across the biomedical community was that dietary habits and genetic predisposition were the basic factors causing colorectal cancer. In more recent times, however, a growing evidence has shown that other determinants can be very important in increasing (or reducing) incidence of this malignancy. The hypothesis that environmental and occupational risk factors are associated with colorectal cancer is gaining ground, and high risks of colorectal cancer have been reported among workers in some industrial branches. The aim of this study was to investigate the epidemiologic relationship between colorectal cancer and occupational exposures to several industrial activities, by means of a scientific literature review and meta-analysis. This work pointed out increased risks of colorectal cancer for labourers occupied in industries with a wide use of chemical compounds, such as leather (RR = 1.70, 95%CI: 1.24-2.34), basic metals (RR = 1.32, 95%CI: 1.07-1.65), plastic and rubber manufacturing (RR = 1.30, 95%CI: 0.98-1.71 and RR = 1.27, 95%CI: 0.92-1.76, respectively), besides workers in the sector of repair and installation of machinery exposed to asbestos (RR = 1.40, 95%CI: 1.07-1.84). Based on our results, the estimated crude excess risk fraction attributable to occupational exposure ranged from about 11% to about 15%. However, homogeneous pattern of association between colorectal cancer and industrial branches did not emerge from this review.

[Biosafety of working in cold storage units: from the profit margin to the safety margin]

The cold storage unit and meat production industry has made Brazil one of the leading suppliers and exporters of products of animal origin. The rapid expansion of the market has led to a rise in competitiveness from a capitalist standpoint, and in this respect corporate profit often leads to the need to adapt human actions to new functions in order to reduce costs and maximize production. These routine activities involve repetitive work, multi-tasking, long hours and operating machines with the use of sharp cutting tools, which is why the work is conducted wearing protective gear. Among the main hazards present, biological risks are the most important due to direct exposure to internal organs, blood, fecal matter, urine and placental or fetal fluids from slaughtered animals that may be infected with pathogens of zoonotic origin. This paper discusses the risks to which slaughterhouse-cold storage unit professionals are exposed, conducting a thorough bibliographical review of the literature that takes into consideration the conceptual framework of Biosafety, which contributes to improve the safety and health conditions of these workers.

Metagenomic detection of viruses in aerosol samples from workers in animal slaughterhouses

Published studies have shown that workers in animal slaughterhouses are at a higher risk of lung cancers as compared to the general population. No specific causal agents have been identified, and exposures to several chemicals have been examined and found to be unrelated. Evidence suggests a biological aetiology as the risk is highest for workers who are exposed to live animals or to biological material containing animal faeces, urine or blood. To investigate possible biological exposures in animal slaughterhouses, we used a metagenomic approach to characterise the profile of organisms present within an aerosol sample. An assessment of aerosol exposures for individual workers was achieved by the collection of personal samples that represent the inhalable fraction of dust/bioaerosol in workplace air in both cattle and sheep slaughterhouses. Two sets of nine personal aerosol samples were pooled for the cattle processing and sheep processing areas respectively, with a total of 332,677,346 sequence reads and 250,144,492 sequence reads of 85 bp in length produced for each. Eukaryotic genome sequence was found in both sampling locations, and bovine, ovine and human sequences were common. Sequences from WU polyomavirus and human papillomavirus 120 were detected in the metagenomic dataset from the cattle processing area, and these sequences were confirmed as being present in the original personal aerosol samples. This study presents the first metagenomic description of personal aerosol exposure and this methodology could be applied to a variety of environments. Also, the detection of two candidate viruses warrants further investigation in the setting of occupational exposures in animal slaughterhouses.

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.

Lung cancer and occupation: A New Zealand cancer registry-based case-control study

BACKGROUND

There are many proven and suspected occupational causes of lung cancer, which will become relatively more important over time, as smoking prevalence decreases.

METHODS

We interviewed 457 cases aged 20-75 years notified to the New Zealand Cancer Registry during 2007-2008, and 792 population controls. We collected information on demographic details, potential confounders, and employment history. Associations were estimated using logistic regression adjusted for gender, age, ethnicity, smoking, and socio-economic status.

RESULTS

Among occupations of a priori interest, elevated odds ratios (ORs) were observed for sawmill, wood panel and related wood-processing plant operators (OR 4.63; 95% CI 1.05-20.29), butchers (OR 8.77, 95% CI 1.06-72.55), rubber and plastics products machine operators (4.27; 1.16-15.66), heavy truck drivers (2.24; 1.19-4.21) and workers in petroleum, coal, chemical and associated product manufacturing (1.80; 1.11-2.90); non-significantly elevated risks were also observed for loggers (4.67; 0.81-27.03), welders and flame-cutters (2.50; 0.86-7.25), pressers (5.74; 0.96-34.42), and electric and electronic equipment assemblers (3.61; 0.96-13.57). Several occupations and industries not of a priori interest also showed increased risks, including nursing associate professionals (5.45; 2.29-12.99), enrolled nurses (7.95; 3.10-20.42), care givers (3.47; 1.40-8.59), plant and machine operators and assemblers (1.61; 1.20-2.16), stationary machine operators and assemblers (1.67; 1.22-2.28), food and related products processing machine operators (1.98; 1.23-3.19), laborers and related elementary service workers (1.45; 1.05-2.00), manufacturing (1.34; 1.02-1.77), car retailing (3.08; 1.36-6.94), and road freight transport (3.02; 1.45-6.27).

CONCLUSIONS

Certain occupations and industries have increased lung cancer risks in New Zealand, including wood workers, metal workers, meat workers, textile workers and drivers. Am. J. Ind. Med. 54:89-101, 2011. © 2010 Wiley-Liss, Inc.

Update of cancer and non-cancer mortality in the Missouri poultry cohort

BACKGROUND

workers in poultry slaughtering and processing plants have one of the highest human exposures to transmissible agents that cause cancer and other diseases in chickens and turkeys, and also have other occupational carcinogenic exposures. The general population is also exposed to these transmissible agents.

METHODS

we investigated mortality in workers who belong to a poultry union in Missouri, and estimated standardized mortality ratios.

RESULTS

significantly increased mortality was observed for some leukemias, benign neoplasms, thyroid diseases, bacterial infections, and schizophrenic disorders. The risk of breast cancer and several non-cancer conditions was significantly depressed.

CONCLUSION

the findings add to the growing evidence suggesting that workers occupationally exposed to transmissible agents and carcinogens in the poultry industry, are at increased risk of dying from certain chronic diseases, including cancer.

Cancer mortality in poultry slaughtering/processing plant workers belonging to a union pension fund

BACKGROUND

The role of zoonotic biological agents in human cancer occurrence has been little studied. Humans are commonly exposed to viruses that naturally infect and cause cancer in food animals such as poultry that constitute part of the biological environment. It is not known if these viruses cause cancer in humans.

OBJECTIVE

To study cancer mortality in the largest cohort to date, of 20,132 workers in poultry slaughtering and processing plants, a group with the highest human exposures to these viruses.

METHODS

Mortality in poultry workers was compared with that in the US general population through the estimation of standardized mortality ratios.

RESULTS

Significantly increased risks were observed in the cohort as a whole or in subgroups, for several cancer sites, viz: cancers of the buccal cavity and pharynx; pancreas; trachea/bronchus/lung; brain; cervix; lymphoid leukemia; monocytic leukemia; and tumors of the hemopoietic and lymphatic systems. Elevated SMRs that were not statistically significant were observed for cancers of the liver, nasopharynx, myelofibrosis, and myeloma. New sites observed to be significantly in excess in this study were cancers of the cervix and penis.

CONCLUSION

This large study provides evidence that a human group with high exposure to poultry oncogenic viruses has increased risk of dying from several cancers. Other occupational carcinogenic exposures could be of importance in explaining some of the findings, such as fumes from wrapping machines. These findings may have implications for public health amongst persons in the general population who may also be exposed to these viruses. What is needed now are epidemiologic studies that can demonstrate whether the excess of specific cancers can be attributed to specific occupational exposures while adequately controlling for other potential occupational and non-occupational carcinogenic exposures.

Mortality in the Baltimore union poultry cohort: non-malignant diseases

BACKGROUND

Workers in poultry plants have high exposure to a variety of transmissible agents present in poultry and their products. Subjects in the general population are also exposed. It is not known whether many of these agents cause disease in humans. If they do, we reason this would be readily evident in a highly exposed group such as poultry workers. We report here on mortality from non-malignant diseases in a cohort of poultry workers.

METHODS

Mortality was compared with that of the US general population, and with that of a comparison group from the same union. Risk was estimated by standardized mortality ratio, proportional mortality ratio, and directly standardized risk ratio.

RESULTS

Poultry workers as a group had an overall excess of deaths from diabetes, anterior horn disease, and hypertensive disease, and a deficit of deaths from intracerebral hemorrhage. Deaths from zoonotic bacterial diseases, helminthiasis, myasthenia gravis, schizophrenia, other diseases of the spinal cord, diseases of the esophagus and peritonitis were non-significantly elevated overall by all analyses, and significantly so in particular race/sex subgroups.

CONCLUSIONS

Poultry workers may have excess occurrence of disease affecting several organs and systems, probably originating from widespread infection with a variety of microorganisms. The results for neurologic diseases could well represent important clues to the etiology of these diseases in humans. The small numbers of deaths involved in some cases limit interpretation.

Psychosocial factors at work and perceived health among agricultural meat industry workers in France

OBJECTIVE

The objective of this study was to describe the perceived health status of the meat industry employees--i.e., working in the slaughtering, cutting, and boning of large animals and poultry--and its relation to their organisational and psychosocial constraints at work.

METHODS

This postal survey included all 3,000 employees of the meat industry (beef, pork and poultry) in four districts in Brittany, France, whose companies were affiliated with the agricultural branch of the national health insurance fund. The questionnaire asked for social and demographic data and information describing their job and the organisation of their work. The psychosocial factors at work were described according to Karasek's questionnaire (demand, latitude and social support at work). Perceived health was measured with the Nottingham Health Profile perceived health indicator.

RESULTS

This study shows the high prevalence of poor health reported by the workers in this industry. This poor perceived health was worse in women and increased regularly with age. Among the psychosocial factors studied, high quantitative and qualitative demand at work, inadequate resources for good work and to a lesser extent, inadequate prospects for promotion appear especially associated with poor perceived health. Other factors often associated with poor perceived health included young age at the first job and work hours that disrupt sleep rhythms (especially for women).

CONCLUSION

Our results show that this population of workers is especially vulnerable from the point of view of perceived physical and psychological health and is exposed to strong physical, organisational and psychosocial constraints at work. They also demonstrate that poor perceived health is associated with some psychosocial (such as high psychological demand and insufficient resources) and organisational factors at work. These results, in conjunction with those from other disciplines involved in studying this industry, may help the companies to develop preventive activities.

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.

Empowerment como forma de prevenção de problemas de saúde em trabalhadores de abatedouros

O objetivo do artigo foi ressaltar a necessidade de esforços educativos que visem ao empowerment de funcionários de abatedouros, baseado nos principais problemas de saúde por eles enfrentados. A rotina em abatedouros consiste em tarefas estressantes e cansativas. As conseqüências incluem problemas músculo-esqueléticos, transmissão de zoonoses, problemas de pele e acidentes com materiais pérfuro-cortantes e animais. Esses trabalhadores geralmente não são especializados, não têm controle sobre suas tarefas, e podem não estar conscientes dos determinantes que afetam sua saúde. Os veterinários são geralmente responsáveis pela rotina de trabalho nesses locais e conhecem os riscos à saúde que a execução dessas tarefas representam. Portanto, esses profissionais poderiam participar mais ativamente na educação para o empowerment dos trabalhadores e não se concentrarem apenas em questões referentes à segurança alimentar.

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 mortality among butchers: a 24-state death certificate study

OBJECTIVE

The objective of this study was to document cancer mortality among American butchers.

METHODS

Death certificates collected in 24 American states were used to calculate mortality odds ratios (ORs) and their confidence intervals (CIs) for 18,639 butchers.

RESULTS

Butchers experienced an increased mortality of cancer of the oral cavity (OR, 1.40; 95% CI = 1.09-1.81), esophagus (OR, 1.19; 95% CI = 1.01-1.40), pharynx (OR, 1.22; 95% CI = 0.91-1.64), and larynx (OR, 1.19; 95% CI = 0.92-1.54), as well as a reduced mortality from melanoma (OR, 0.70; 95% CI = 0.52-0.94), non-Hodgkin lymphoma (OR, 0.82; 95% CI = 0.69-0.97), and breast cancer (OR, 0.76; 95% CI = 0.58-0.99).

CONCLUSIONS

It is likely that occupational exposures experienced by butchers have contributed to the increased risk of cancers of the oral cavity and esophagus.

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.

Lung cancer risk and occupational exposure to meat and live animals

An increased risk of lung cancer has been reported for butchers and meat workers in several cohort studies, although confounding from tobacco smoking could not be ruled out in any of these studies. These exposures, as well as a potential risk associated with contact with live animals, are addressed here in a large case-control study with full adjustment for smoking. More than 5,900 subjects were included in a case-control study conducted in 7 European countries. For each job they employed local experts who assessed the exposure to a number of occupational agents, including (i) meat aerosols and (ii) live animals, on the basis of detailed occupational questionnaires. Information on tobacco consumption and other risk factors was also collected. A small increased risk of lung cancer was observed with exposure to meat aerosols, after adjusting for smoking, (odds ratio (OR)=1.27, 95% confidence interval (CI): 0.92, 1.75), which was most apparent for the upper tertile of cumulative exposure (OR=1.73, 95% CI: 1.03, 2.92). A similar overall effect was observed for exposure to live animals, with an increased risk observed for a high frequency of exposure, (OR=1.69, 95% CI: 1.21, 2.36) and a high intensity of exposure, (OR=1.85, 95% CI: 1.16, 2.94), with significant trends for increasing frequency (p=0.012), intensity (p=0.015) and cumulative exposure (p=0.024). In conclusion, this study provides evidence for an association between exposure to meat aerosols and lung cancer apparent in the highest tertile of exposure. The authors identified a more consistent association with exposure to live animals.