Occupational exposures and risk of pancreatic cancer

Association Between Dairy Products Consumption and Esophageal, Stomach, and Pancreatic Cancers in the PANESOES Multi Case-Control Study

Background/Objectives: This study explored the association between dairy products consumption (total and subgroups) and cancer of the esophagus, stomach, and pancreas within the PANESOES case-control study. Methods: Data from 1229 participants, including 774 incident cases of cancer and 455 controls matched by age, sex, and region, were analyzed. Dietary intake was assessed using a validated Food Frequency Questionnaire, categorizing dairy intake by total and subgroups (fermented dairy, sugary dairy desserts, and milk). Multinomial logistic regression was used to estimate relative risk ratios (RRRs), adjusting for confounders. Results: We found an inverse association between moderate dairy consumption (T2) and esophageal cancer (RRR T2 vs. T1 = 0.59 (95%CI: 0.37-0.96)). The highest tertile (T3) of fermented dairy was associated with a lower risk of esophageal (RRR T3 vs. T1 = 0.55 (0.33-0.90)) and stomach cancers (RRR T3 vs. T1 = 0.68 (0.47-0.97)). By contrast, the highest tertile of consumption of sugary dairy desserts was associated with a higher risk of stomach cancer (RRR T3 vs. T1 = 1.85 (1.30-2.64)). No association was found for milk. Conclusions: This study suggests that fermented dairy may reduce the risk of esophageal and stomach cancers, while sugary dairy desserts may increase the risk of stomach cancer.

Duration-response association between occupational exposure and pancreatic cancer risk: meta-analysis

BACKGROUND

Evidence is lacking on the occupational exposure time window to chemical agents related to pancreatic cancer risk.

AIMS

This study performed meta-regression and meta-analysis to examine the dose-response association between occupational exposure duration to chemical agents and pancreatic cancer risk.

METHODS

We searched and reviewed studies on exposure duration and pancreatic cancer in five databases (Cochrane Library, EMBASE, PubMed, ScienceDirect and Web of Science) from inception to 16 May 2022. Exposure refers to the years a worker was exposed to any chemical agent, and outcome variables were pancreatic cancer incidence and mortality.

RESULTS

We identified 31 studies, including 288 389 participants. In the meta-regression, the positive dose-response association indicated pancreatic cancer risk increased slightly with every additional year of exposure duration (slope = 1.01; 95% confidence interval [CI] 1.00-1.02). Pancreatic cancer risk increased with an exposure duration of 1-10 (relative risk [RR] = 1.04; 95% CI 1.02-1.06), 11-20 (RR = 1.11; 95% CI 1.05-1.16), and 21-30 years (RR = 1.39; 95% CI 1.12-1.73).

CONCLUSIONS

Pancreatic cancer risk increased as occupational exposure duration increased, with an exposure time window ranging from 1 to 30 years.

Association between residential exposure to petrochemical industrial complexes and pancreatic cancer: a systematic review and meta-analysis

Increased in the global demand-expansion of the petrochemical industry is a possible environmental risk factor pancreatic cancer among residents living close to petrochemical complexes. This meta-analysis aimed to estimate the pooled risk of pancreatic cancer among residents living near petrochemical industrial complexes. We systematically searched and reviewed published studies in six databases based on the inclusion criteria derived from the population, exposure, comparator, and outcomes framework (population: general population; exposure: residence near petrochemical industrial complexes/living in cities with petrochemical industrial complexes; comparators: residents living farther away from petrochemical industrial complexes/living in cities without petrochemical industrial complexes; outcome: pancreatic cancer). We identified seven studies, covering 1,605,568 residents. Pooled analysis showed a significantly higher risk of pancreatic cancer among residents living near petrochemical industrial complexes (relative risk [RR] = 1.31, 95% confidence interval [CI] = 1.21-1.42) than those living farther away from petrochemical industrial complexes. Such effect was higher in female residents (RR = 1.34, 95% CI = 1.18-1.53) than in male residents (RR = 1.26, 95% CI = 1.12-1.41). This study suggests that exposure to petrochemical industry-related activities should be recognized as a risk factor for pancreatic cancer among residents living near petrochemical industrial complexes.

Adherence to Pro-Vegetarian Food Patterns and Risk of Oesophagus, Stomach, and Pancreas Cancers: A Multi Case-Control Study (The PANESOES Study)

We aimed to evaluate the association between three previously defined pro-vegetarian (PVG) food patterns and the cancers of the oesophagus, stomach, and pancreas in a multi case-control study. We analyzed data from a multi-case hospital-based study carried out in two Mediterranean provinces in Spain. A total of 1233 participants were included in the analyses: 778 incident cancer cases, histologically confirmed (199 oesophagus, 414 stomach, and 165 pancreas) and 455 controls. A dietary assessment was performed using a validated food frequency questionnaire (FFQ). Three PVG food patterns (general, healthful, and unhealthful) were estimated using 12 food groups for the general PVG (gPVG), scoring positive plant-based foods and negative animal-based foods, and 18 food groups, for the healthful (hPVG) and unhealthful (uPVG) food patterns. Multinomial logistic regression was used to estimate relative risk ratios (RRR) and confidence intervals (95% CI) for quintiles of adherence to PVG patterns and as a continuous variable. The RRR (95% CI) for the highest vs. the lowest quintile of gPVG were, RRR = 0.37 (0.32, 0.42) for the oesophagus, RRR = 0.34 (0.27, 0.43) for the stomach, and RRR = 0.43 (0.35, 0.52) for pancreas cancer. For the hPVG, the RRR were RRR = 0.72 (0.58, 0.90) for the oesophagus, RRR = 0.42 (0.34, 0.52) for the stomach, and RRR = 0.74 (0.59, 0.92) for pancreas cancer. The uPVG was associated with a higher risk of stomach cancer RRR = 1.76 (1.42, 2.18). Higher adherence to gPVG and hPVG food patterns is associated with a lower risk of oesophageal, stomach, and pancreas cancers, while a higher adherence to a uPVG food pattern is associated with a higher risk of stomach cancer.

Pesticides and pancreatic adenocarcinoma: A transversal epidemiological, environmental and mechanistic narrative review

Pancreatic adenocarcinoma (PA) incidence is rising worldwide, especially in France. The evolution of known risk factors such as tobacco smoking, obesity, type 2 diabetes, chronic pancreatitis, or constitutional mutations is not sufficient to explain this trend. Pesticides are known risk factors in other malignancies. Previous studies have outlined pesticides' influence in PA, such as dichlorodiphenyltrichloroethane as plausible risk factors. The general population is directly or indirectly exposed to pesticides through air, food or water. Some of these chemicals may accumulate in the body all along lifetime and may harm carriers. The toxic mixing effects of these chemicals are not well documented. Several hypotheses have been put forward to explain how pesticides can induce indirect (fatty pancreas, induced diabetes) or direct (oxidative stress, cell damage) carcinogenesis in pancreatic cells through inflammation. A strong corpus exists acknowledging pesticides as a PA risk factor. However, published studies do not provide a sufficient level of evidence to prove causality and current prospective case-control studies are still ongoing.

Nickel's Role in Pancreatic Ductal Adenocarcinoma: Potential Involvement of microRNAs

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancer types with a limited overall survival rate due to the asymptomatic progression of symptoms in metastatic stages of the malignancy and the lack of an early reliable diagnostic biomarker. MicroRNAs (miRs/miRNAs) are small (~18–24 nucleotides), endogenous, non-coding RNAs, which are closely linked to the development of numerous malignancies comprising PDAC. Recent studies have described the role of environmental pollutants such as nickel (Ni) in PDAC, but the mechanisms of Ni-mediated toxicity in cancer are still not completely understood. Specifically, Ni has been found to alter the expression and function of miRs in several malignancies, leading to changes in target gene expression. In this study, we found that levels of Ni were significantly higher in cancerous tissue, thus implicating Ni in pancreatic carcinogenesis. Hence, in vitro studies followed by using both normal and pancreatic tumor cell lines and increasing Ni concentration increased lethality. Comparing LC50 values, Ni-acetate groups demonstrated lower values needed than in NiCl₂ groups, suggesting greater Ni-acetate. Panc-10.05 cell line appeared the most sensitive to Ni compounds. Exposure to Ni-acetate resulted in an increased phospho-AKT, and decreased FOXO1 expression in Panc-10.05 cells, while NiCl₂ also increased PTEN expression in Panc-10.05 cells. Specifically, following NiCl₂ exposure to PDAC cells, the expression levels of miR-221 and miR-155 were significantly upregulated, while the expression levels of miR-126 were significantly decreased. Hence, our study has suggested pilot insights to indicate that the environmental pollutant Ni plays an important role in the progression of PDAC by promoting an association between miRs and Ni exposure during PDAC pathogenesis.

Chemical Risk Factors of Primary Liver Cancer: An Update

Primary liver cancer has the sixth highest incidence and fourth highest cancer mortality worldwide. Hepatitis B is the leading cause of liver cancer, though its incidence is decreasing with vaccination. Alcohol is the leading cause of liver transplant, cirrhosis, and cancer in the developed world, and is projected to surpass hepatitis B as the leading hepatic cancer etiology worldwide. Tobacco smoking has shown a positive association with liver cancer in a majority of studies, though not all. Aflatoxin, a mycotoxin produced by Aspergillus, is estimated to account for 3–20% of global liver cancer cases, 40% of which occur in sub-Saharan Africa. These statistics are confounded by the prevalence of hepatitis B, which may have a synergistic effect on hepatic carcinogenesis. Aflatoxin is ingested and likely inhaled from agricultural products, placing farmers, food processors, and textile workers in developing nations at risk. Vinyl-chloride is used in the production of PVC plastics and causes rare liver angiosarcoma, hepatocellular carcinoma, and other neoplasms. Arsenic and cadmium are naturally-occurring, hepatocarcinogenic metals with high occupational exposure in industries involving coal, metals, plastics, and batteries. Millions of laborers in waste-disposal and manufacturing are exposed to organic solvents and N-nitrosamines, which vary from carcinogenic (group 1) to possibly carcinogenic (group 2B) in their IARC designation. Insecticide DDT is possibly hepatocarcinogenic (group 2B), though continues to be used for malaria control in the developing world. While suggested by case reports, anabolic steroids and oral contraceptives have not been shown to increase liver cancer risk in large studies.

Gallbladder disease, cholecystectomy, and pancreatic cancer risk in the International Pancreatic Cancer Case-Control Consortium (PanC4)

BACKGROUND

The association among gallbladder disease, cholecystectomy, and pancreatic cancer is unclear. Moreover, time interval between gallbladder disease or cholecystectomy and pancreatic cancer diagnosis is not considered in most previous studies.

AIM

To quantify the association among gallbladder disease, cholecystectomy, and pancreatic cancer, considering time since first diagnosis of gallbladder disease or cholecystectomy.

METHODS

We used data from nine case-control studies within the Pancreatic Cancer Case-Control Consortium, including 5760 cases of adenocarcinoma of the exocrine pancreas and 8437 controls. We estimated pooled odds ratios and the corresponding 95% confidence intervals by estimating study-specific odds ratios through multivariable unconditional logistic regression models, and then pooling the obtained estimates using fixed-effects models.

RESULTS

Compared with patients with no history of gallbladder disease, the pooled odds ratio of pancreatic cancer was 1.69 (95% confidence interval, 1.51-1.88) for patients reporting a history of gallbladder disease. The odds ratio was 4.90 (95% confidence interval, 3.45-6.97) for gallbladder disease diagnosed <2 years before pancreatic cancer diagnosis and 1.11 (95% confidence interval, 0.96-1.29) when ≥2 years elapsed. The pooled odds ratio was 1.64 (95% confidence interval, 1.43-1.89) for patients who underwent cholecystectomy, as compared to those without cholecystectomy. The odds ratio was 7.00 (95% confidence interval, 4.13-11.86) for a surgery <2 years before pancreatic cancer diagnosis and 1.28 (95% confidence interval, 1.08-1.53) for a surgery ≥2 years before.

CONCLUSIONS

There appears to be no long-term effect of gallbladder disease on pancreatic cancer risk, and at most a modest one for cholecystectomy. The strong short-term association can be explained by diagnostic bias and reverse causation.

Regional Variation of Pancreatic Cancer Incidence in the Nile Delta Region of Egypt over a Twelve-Year Period

BACKGROUND

Pancreatic cancer is one of the deadliest forms of cancer, with incidence rates rising in many countries around the world. Geographic variation in pancreatic cancer incidence has not been studied extensively, especially in low- and middle-income countries. The aim of this study was to characterize the distribution of pancreatic cancer incidence in the central Nile Delta region of Egypt and to examine differences by urban and rural patient residence using the nation's only population-based cancer registry.

METHODS

Utilizing the Gharbiah province population-based cancer registry, data were abstracted for 1,089 pancreatic cancer cases diagnosed over twelve years from 1999 to 2010. Age- and sex-specific incidence rates were calculated and compared for urban and rural areas of the eight districts of Gharbiah.

RESULTS

Age-adjusted incidence of pancreatic cancer within Gharbiah varied considerably by urban/rural patient residence and by district. Incidence rates were 1.3 times higher in urban compared to rural areas (4.45 per 100,000 in urban areas and 3.43 per 100,000 in rural areas). The highest incidence rates were observed in urban centers of Kotour, El Santa, and Kafr El-Zayat districts (12.94, 8.32, and 7.89, respectively).

CONCLUSION

Incidence rates varied greatly by urban and rural areas and by district of residence in the Nile Delta region of Egypt. Future studies should examine potential environmental risk factors that may contribute to the geographic distribution of pancreatic cancer in this region.

An examination of the association between lifetime history of prostate and pancreatic cancer diagnosis and occupation in a population sample of Canadians

BACKGROUND

Occupation was assessed as possible risk factors for prostate (PCa) and pancreatic cancer in a large Canadian worker cohort.

METHODS

The Canadian Census Health and Environment Cohort (CanCHEC) was derived from linking the 1991 Canadian Census Cohort to the Canadian Cancer Database (1969-2010), Canadian Mortality Database (1991-2011), and Tax Summary Files (1981-2011). From the total sample of 1,931,110 persons, we identified and derived two samples of 28,610 men and 3,220 men and women with a past history of PCa and pancreatic cancer diagnoses, respectively. Cox proportional hazards models were used to estimate hazards ratios and 95% confidence intervals for occupation.

RESULTS

In Canadian men aged 24-64 years, the highest elevated risks of PCa were observed for library clerks (HR = 2.36, 95% CI:1.12-4.97), medical radiation technologists (HR = 1.66, 95% CI:1.04-2.65), telecommunications and line cable workers (HR = 1.62, 95% CI: 1.22-3.16) and commissioned police officers (HR = 1.54, 95% CI: 1.10-2.16. The highest elevated risk for pancreatic cancer were observed for commissioned police officers (HR = 4.34, 95% CI: 1.85-10.21), photographic and film processors (HR = 3.97, 95% CI:1.69-9.34), railway and motor transport labourers (HR = 3.94, 95% CI: 1.67-9.29), and computer engineers (HR = 3.82, 95%CI: 1.52-9.61).

CONCLUSION

These findings emphasize the need for further study of job-related exposures and the potential influence of non-occupational factors such as screening practices.

Risk of cancer and longest-held occupations in Japanese workers: A multicenter hospital-based case-control study

Objectives

Little is known about the risk of developing various cancers according to occupation and occupational physical activity.

Methods

Using nationwide clinical inpatient data (1984‐2017) in Japan, we undertook a multicentered, matched case‐control study with regard to the risk of developing various cancers according to occupation and using patients admitted with fractures as controls. Using standardized national occupation and industrial classifications, we first identified the longest‐held job for each patient. Using sales workers as the reference group, odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by conditional logistic regression, adjusted for age, admission period, and the admitting hospital, with smoking, alcohol consumption, and lifestyle diseases as covariates. The risk of high and low occupational physical activity was also estimated.

Results

Across all occupations, a reduced risk for all common cancers among males was observed among those occupations associated with high physical activities, such as agriculture. People in these occupations tended to show a lower risk for most cancers, including, for example, prostate cancer (OR 0.58, 95% CI 0.45‐0.75) and lung cancer (OR 0.63, 95% CI 0.51‐0.76). For females, the breast cancer risk was low in women engaged in agriculture (OR 0.58, 95% CI 0.45‐0.75) and in those occupations with high levels of occupational physical activity (OR 0.58, 95% CI 0.52‐0.66).

Conclusions

This study revealed differences in cancer risk among diverse occupations in Japan. Specifically, those occupations associated with high levels of physical activity may be associated with a decreased risk of cancer.

Occupational Class Groups as a Risk Factor for Gastrointestinal Cancer: A Case-Control Study

BACKGROUND

Cancer has a high mortality rate in both developing and developed countries. 11%-15% of cancers are attributable to occupational risk factors.

OBJECTIVE

To determine if specific occupational classes, based on the International Standard for Classification of Occupations 2008 (ISCO-08), are risk factors for gastrointestinal (GI) cancer.

METHODS

In this case-control study, 834 cancer patients were interviewed by a single physician. Cases included patients with GI cancer. Age-matched controls were selected from non-GI cancer patients. Each year of working, up until 5 years before the diagnosis, was questioned and categorized by the ISCO classification.

RESULTS

243 GI cancer cases and 243 non-GI cancer patients (486 in total) were studied. Working in ISCO class 8 (plant and machine operators, and assemblers) was significantly associated with higher risk of GI cancer (OR 1.63, 95% CI 1.05 to 2.52). Working in ISCO class 6 (skilled agricultural, forestry and fishery workers) and 9 (elementary occupations) were also associated with higher incidence of GI cancers.

CONCLUSION

Working in ISCO classes of 8, 6, and 9, which are usually associated with low socio-economic status, can be considered a risk factor for GI cancers.

Cancer risks in a population-based study of 70,570 agricultural workers: results from the Canadian census health and Environment cohort (CanCHEC)

BACKGROUND

Agricultural workers may be exposed to potential carcinogens including pesticides, sensitizing agents and solar radiation. Previous studies indicate increased risks of hematopoietic cancers and decreased risks at other sites, possibly due to differences in lifestyle or risk behaviours. We present findings from CanCHEC (Canadian Census Health and Environment Cohort), the largest national population-based cohort of agricultural workers.

METHODS

Statistics Canada created the cohort using deterministic and probabilistic linkage of the 1991 Canadian Long Form Census to National Cancer Registry records for 1992-2010. Self-reported occupations were coded using the Standard Occupational Classification (1991) system. Analyses were restricted to employed persons aged 25-74 years at baseline (N = 2,051,315), with follow-up until December 31, 2010. Hazard ratios (HR) and 95% confidence intervals (CI) were modeled using Cox proportional hazards for all workers in agricultural occupations (n = 70,570; 70.8% male), stratified by sex, and adjusted for age at cohort entry, province of residence, and highest level of education.

RESULTS

A total of 9515 incident cancer cases (7295 in males) occurred in agricultural workers. Among men, increased risks were observed for non-Hodgkin lymphoma (HR = 1.10, 95% CI = 1.00-1.21), prostate (HR = 1.11, 95% CI = 1.06-1.16), melanoma (HR = 1.15, 95% CI = 1.02-1.31), and lip cancer (HR = 2.14, 95% CI = 1.70-2.70). Decreased risks in males were observed for lung, larynx, and liver cancers. Among female agricultural workers there was an increased risk of pancreatic cancer (HR = 1.36, 95% CI = 1.07-1.72). Increased risks of melanoma (HR = 1.79, 95% CI = 1.17-2.73), leukemia (HR = 2.01, 95% CI = 1.24-3.25) and multiple myeloma (HR = 2.25, 95% CI = 1.16-4.37) were observed in a subset of female crop farmers.

CONCLUSIONS

Exposure to pesticides may have contributed to increased risks of hematopoietic cancers, while increased risks of lip cancer and melanoma may be attributed to sun exposure. The array of decreased risks suggests reduced smoking and alcohol consumption in this occupational group compared to the general population.

Use of job-exposure matrices to estimate occupational exposure to pesticides: A review

The health effects of pesticides have been extensively studied in epidemiology, mainly in agricultural populations. However, pesticide exposure assessment remains a key methodological issue for epidemiological studies. Besides self-reported information, expert assessment or metrology, job-exposure matrices still appear to be an interesting tool. We reviewed all existing matrices assessing occupational exposure to pesticides in epidemiological studies and described the exposure parameters they included. We identified two types of matrices, (i) generic ones that are generally used in case-control studies and document broad categories of pesticides in a large range of jobs, and (ii) specific matrices, developed for use in agricultural cohorts, that generally provide exposure metrics at the active ingredient level. The various applications of these matrices in epidemiological studies have proven that they are valuable tools to assess pesticide exposure. Specific matrices are particularly promising for use in agricultural cohorts. However, results obtained with matrices have rarely been compared with those obtained with other tools. In addition, the external validity of the given estimates has not been adequately discussed. Yet, matrices would help in reducing misclassification and in quantifying cumulated exposures, to improve knowledge about the chronic health effects of pesticides.

Environmental risk factors for pancreatic cancer: an update

Pancreatic cancer (PC) is one of the most aggressive diseases. Only 10 % of all PC cases are thought to be due to genetic factors. Here, we analyzed the most recently published case-control association studies, meta-analyses, and cohort studies with the aim to summarize the main environmental factors that could have a role in PC. Among the most dangerous agents involved in the initiation phase, there are the inhalation of cigarette smoke, and the exposure to mutagenic nitrosamines, organ-chlorinated compounds, heavy metals, and ionizing radiations. Moreover, pancreatitis, high doses of alcohol drinking, the body microbial infections, obesity, diabetes, gallstones and/or cholecystectomy, and the accumulation of asbestos fibers seem to play a crucial role in the progression of the disease. However, some of these agents act both as initiators and promoters in pancreatic acinar cells. Protective agents include dietary flavonoids, marine omega-3, vitamin D, fruit, vegetables, and the habit of regular physical activity. The identification of the factors involved in PC initiation and progression could be of help in establishing novel therapeutic approaches by targeting the molecular signaling pathways responsive to these stimuli. Moreover, the identification of these factors could facilitate the development of strategies for an early diagnosis or measures of risk reduction for high-risk people.

Risk of Pancreatic Cancer in Female Textile Workers in Shanghai, China, Exposed to Metals, Solvents, Chemicals, and Endotoxin: Follow-Up to a Nested Case-Cohort Study

OBJECTIVE

We studied associations between pancreatic cancer and occupational exposures to metals, solvents, chemicals, and endotoxin in a cohort of female textile workers in Shanghai, China. To assess the longer-term influences of these agents on pancreatic cancer we extended follow-up of this previously studied cohort.

METHODS

We utilized a job exposure matrix to assess occupational exposures for 481 pancreatic cancer cases and a randomly selected sub-cohort of 3191 non-cases. We calculated hazard ratios and 95% confidence intervals using Cox proportional hazards modeling adapted for the case-cohort design.

RESULTS

We observed a statistically significant trend of increasing hazard ratios associated with solvent exposure, but no associations with any of the remaining occupational exposures, including endotoxin and metals.

CONCLUSIONS

Our findings of increasing risk of pancreatic cancer with solvent exposures are consistent with published literature.

Exposure to environmental chemicals and heavy metals, and risk of pancreatic cancer

PURPOSE

Exposure to various chemicals and heavy metals has been associated with risk of different cancers; however, data on whether such exposures may increase the risk of pancreatic cancer (PC) are very limited and inconclusive. We examined PC risk with self-reported exposures to chemicals and heavy metals.

METHODS

The design was a clinic-based, case-control study of data collected from 2000 to 2014 at Mayo Clinic in Rochester, Minnesota, USA. Cases were rapidly ascertained patients diagnosed with pancreatic ductal adenocarcinoma (n = 2,092). Controls were cancer-free patients in primary care clinics (n = 2,353), frequency-matched to cases on age, race, sex, and state/region of residence. Cases and controls completed identical risk factor questionnaires, which included yes/no questions about regular exposure to pesticides, asbestos, benzene, chlorinated hydrocarbons, chromium, and nickel. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) comparing those who affirmed exposure to each of the chemicals/heavy metals to those who reported no regular exposure, adjusting for potential confounders.

RESULTS

Self-reported regular exposure to pesticides was associated with increased odds of PC (OR 1.21, 95% CI 1.02-1.44). Regular exposure to asbestos (OR 1.54, 95% CI 1.23-1.92), benzene (OR 1.70, 95% CI 1.23-2.35), and chlorinated hydrocarbons (OR 1.63, 95% CI 1.32-2.02) also was associated with higher odds of PC. Chromium and nickel exposures were not significantly associated with PC.

CONCLUSIONS

These findings add to the limited data suggesting that exposure to pesticides, asbestos, benzene, and chlorinated hydrocarbons may increase PC risk. They further support the importance of implementing strategies that reduce exposure to these substances.

Use of the Finnish Information System on Occupational Exposure (FINJEM) in epidemiologic, surveillance, and other applications

This paper reviews the use of the Finnish Information System on Occupational Exposure (Finnish job-exposure matrix, FINJEM) in different applications in Finland and other countries. We describe and discuss studies on FINJEM and studies utilizing FINJEM in regard to the validity of exposure estimates, occupational epidemiology, hazard surveillance and prevention, the assessment of health risks and the burden of disease, the assessment of exposure trends and future hazards, and the construction of job-exposure matrices (JEMs) in countries other than Finland. FINJEM can be used as an exposure assessment tool in occupational epidemiology, particularly in large register-based studies. It also provides information for hazard surveillance at the national level. It is able to identify occupations with high average exposures to chemical agents and can therefore serve the priority setting of prevention. However, it has only limited use at the workplace level due to the variability of exposure between workplaces. The national estimates of exposure and their temporal trends may contribute to the assessment of both the recent and future burden of work-related health outcomes. FINJEM has also proved to be useful in the construction of other national JEMs, for example in the Nordic Occupational Cancer study in the Nordic countries. FINJEM is a quantitative JEM, which can serve many purposes and its comprehensive documentation also makes it potentially useful in countries other than Finland.

A job-exposure matrix for research and surveillance of occupational health and safety in Spanish workers: MatEmESp

BACKGROUND

In this study we describe a general-population job-exposure matrix (MatEmESp) for Spanish workers covering the period 1996-2005.

METHODS

The Finnish job-exposure matrix (FINJEM) provided the default value estimates for occupational exposure to chemical, physical and biological agents. These estimates were adapted to Spanish working conditions by local experts. Spanish surveys were used to obtain exposure estimates for ergonomic and psychosocial risk factors. Employment and socio-demographic conditions for Spanish workers were obtained from the Spanish National Statistics Institute.

RESULTS

MatEmESp provides a large amount of national and occupation-specific data on the major occupational exposures in Spain. As some examples, the data show that the most prevalent occupational hazards are repetitive movements and a lack of support from co-workers. In addition, 10% of the Spanish working population perform night shifts, and bricklayers and concrete workers are the job titles with the highest risk of exposure to quartz dust.

CONCLUSIONS

MatEmESp can be a useful tool for research and surveillance, and can help set priorities for occupational illness and injury prevention in Spain.

Aggregation of exposure level and probability into a single metric in job-exposure matrices creates bias

Job-exposure matrices (JEMs) are often used in occupational epidemiological studies to provide an exposure estimate for a typical person in a 'job' during a particular time period. A JEM can produce exposure estimates on a variety of scales, such as (but not limited to) binary assessments of presence or absence of exposure, ordinal ranking of exposure level and frequency, and quantitative exposure estimates of exposure intensity and frequency. Specifically, one popular approach to construct a JEM, engendered in a Finnish job exposure matrix (FINJEM), provides a probability that a worker within an occupational group is exposed and an estimate of intensity of exposure among the exposed workers within this occupation. Often the product of the probability and intensity (aka level) is used to obtain the estimate of exposure for the epidemiological analyses. This procedure aggregates exposure across exposed and non-exposed individuals and the effect of this particular procedure on epidemiological analyses has never been studied. We developed a theoretical framework for understanding how these aggregate exposure estimates relate to true exposure (either unexposed or log-normally distributed for 'exposed'), assuming that there is no uncertainty about estimates of level and probability of exposure. Theoretical derivations show that multiplying occupation-specific exposure level and probability of non-zero exposure results in both systematic and differential measurement errors. Simulations demonstrated that under certain conditions bias in odds ratios in a cohort study away from the null are possible and that this bias is smaller when (a) arithmetic rather than geometric mean is used to assess exposure level and (b) exposure level and prevalence are positively correlated. We illustrate the potential impact of using the specified JEM in a simulation based on a case-control study of non-Hodgkin lymphoma and exposure to ionizing and non-ionizing radiation. Inflation of standard errors in the log-odds was observed as well as bias away from null for two out of three specific exposures/data structures. Overall, it is clear that influence of the phenomenon we studied on epidemiological results is complex and difficult to predict, being influenced a great deal by the structure of data. We recommend exploring the influence of JEMs that use the product of exposure level and probability in epidemiological analyses through simulations during planning of such studies to assess both the expected extent of the potential bias in risk estimates and impact on power. The SAS and R code required to implement such simulations are provided. All our calculations are either theoretical or based on simulated data.

Occupational risk factors and pancreatic cancer: a review of recent findings

Several occupational exposures have been linked to excess risk of pancreatic cancer; however, most associations are not well established. The objective of this review article is to report on the more recently published studies (1998-2010), and provide a summary of the most consistently reported occupational risk factors for pancreatic cancer, including exposure to chlorinated hydrocarbon compounds, pesticides, polycyclic aromatic hydrocarbons (PAHs), metals, nitrosamines, radiation, various airborne particles, and employment in sedentary occupations. We conclude that the strongest and most consistent findings linking occupational exposures with pancreatic cancer risk to date are for chlorinated hydrocarbons and PAHs.

The Rotterdam Study: 2012 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.