Lifetime Occupational History Research Articles

Expert-based assessment of chemical and physical exposures, and organizational factors, in past agricultural jobs

BackgroundLimited data document the spectrum of exposures in the agricultural environment. We describe here the wide range of chemical and physical agents, and organizational factors, encountered in agricultural jobs held in the past in Canada and abroad. MethodsWe used data from a population-based case-control study of prostate cancer including 3,925 male participants residing in Montreal, Canada in 2005-2012. Lifetime occupational histories and detailed job descriptions were collected in-person. Industrial hygienists and an agronomist conducted semi-quantitative evaluations of exposure, including intensity and reliability, to some 300 chemical and physical agents in each job held. Analyses focused on the 156 agricultural jobs ever held in the study population. Clusters of agricultural co-exposures were derived. ResultsAgricultural jobs had taken place in 1946-2012, 53% ending in 1970 or after. Jobs were often (43%) held in Quebec, Canada; 22% in Italy, Portugal or Greece, and 10% in Haiti. Jobs entailed exposure to an average of 10 chemical agents (± 7) and most were characterized by long working hours, high physical activity levels, and did not provoke stress or anxiety. Few involved early morning shifts. Exposure to 78 agents was assigned with probable or definite certainty. The most common definite or probable carcinogens were ultraviolet radiation (92% of jobs), environmental tobacco smoke (39%), diesel engine exhaust (23%), wood dust (20%), lubricating oils and greases (20%) and lead (15%). Pesticide exposure (as a group) occurred in 31% of jobs. Fifty-four percent of jobs entailed exposure to ≥ 2 recognized carcinogens. Exposure clusters varied according to countries and type of agricultural activities (general, animal, crops, horticulture, vineyards, etc.). ConclusionsFindings highlight the heterogeneity of exposure patterns in past agricultural environments based on their setting and activities involved. Studies on health-related effects of farming should account for numerous potential exposures, beyond their typical focus on pesticides.

Occupational exposure to organic solvents and risk of bladder cancer

BackgroundBladder cancer has been linked to several occupations that involve the use of solvents, including those used in the dry-cleaning industry.ObjectivesWe evaluated exposure to solvents and risk of bladder cancer in 1182 incident cases and 1408 controls from a population-based study.MethodsExposure to solvents was quantitatively assessed using a job-exposure matrix (CANJEM). Exposure to benzene, toluene and xylene often co-occur. Therefore, we created two additional sets of metrics for combined benzene, toluene and xylene (BTX) exposure: (1) CANJEM-based BTX metrics and (2) hybrid BTX metrics, using an approach that integrates the CANJEM-based BTX metrics together with lifetime occupational histories and exposure-oriented modules that captured within-job, respondent-specific details about tasks and chemicals. Adjusted odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated using logistic regression.ResultsBladder cancer risks were increased among those ever exposed to benzene (OR = 1.63, 95% CI: 1.14–2.32), toluene (OR = 1.60, 95% CI: 1.06–2.43), and xylene (OR = 1.67, 95% CI: 1.13–2.48) individually. We further observed a statistically significant exposure-response relationship for cumulative BTX exposure, with a stronger association using the hybrid BTX metrics (ORQ1vsUnexposed = 1.26, 95% CI: 0.83–1.90; ORQ2vsUnexposed = 1.52, 95% CI: 1.00–2.31; ORQ3vsUnexposed = 1.88, 95% CI: 1.24–2.85; and ORQ4vsUnexposed = 2.23, 95% CI: 1.35–3.69) (p-trend=0.001) than using CANJEM-based metrics (p-trend=0.02).ImpactThere is limited evidence about the role of exposure to specific organic solvents, alone or in combination on the risk of developing bladder cancer. In this study, workers with increasing exposure to benzene, toluene, and xylene as a group (BTX) had a statistically significant exposure-response relationship with bladder cancer. Future evaluation of the carcinogenicity of BTX and other organic solvents, particularly concurrent exposure, on bladder cancer development is needed.

Prevalent occupational exposures and risk of lung cancer among women: Results from the application of the Canadian Job-Exposure Matrix (CANJEM) to a combined set of ten case-control studies.

Worldwide, lung cancer is the second leading cause of cancer death in women. The present study explored associations between occupational exposures that are prevalent among women, and lung cancer. Data from 10 case-control studies of lung cancer from Europe, Canada, and New Zealand conducted between 1988 and 2008 were combined. Lifetime occupational history and information on nonoccupational factors including smoking were available for 3040 incident lung cancer cases and 4187 controls. We linked each reported job to the Canadian Job-Exposure Matrix (CANJEM), which provided estimates of probability, intensity, and frequency of exposure to each selected agent in each job. For this analysis, we selected 15 agents (cleaning agents, biocides, cotton dust, synthetic fibers, formaldehyde, cooking fumes, organic solvents, cellulose, polycyclic aromatic hydrocarbons from petroleum, ammonia, metallic dust, alkanes C18+, iron compounds, isopropanol, and calcium carbonate) that had lifetime exposure prevalence of at least 5% in the combined study population. For each agent, we estimated lung cancer risk in each study center for ever-exposure, by duration of exposure, and by cumulative exposure, using separate logistic regression models adjusted for smoking and other covariates. We then estimated the meta-odds ratios using random-effects meta-analysis. None of the agents assessed showed consistent and compelling associations with lung cancer among women. The following agents showed elevated odds ratio in some analyses: metallic dust, iron compounds, isopropanol, and organic solvents. Future research into occupational lung cancer risk factors among women should prioritize these agents.

Cohort Studies Versus Case-Control Studies on Night-Shift Work and Cancer Risk: The Importance of Exposure Assessment.

It is a general assumption that the prospective cohort study design is the gold standard approach and is superior to the case-control study design in epidemiology. However, there may be exceptions if the exposure is complex and requires collection of detailed information on many different aspects. Night-shift work, which impairs circadian rhythms, is an example of such a complex occupational exposure and may increase the risks of breast, prostate, and colorectal cancer. So far, for logistical reasons, investigators in cohort studies have assessed shift work rather crudely, lacking information on full occupational history and relevant shift-work metrics, and have presented mostly null findings. On the other hand, most cancer case-control studies have assessed the lifetime occupational histories of participants, including collection of detailed night-shift work metrics (e.g., type, duration, intensity), and tend to show positive associations. In this commentary, we debate why cohort studies with weak exposure assessment and other limitations might not necessarily be the preferred or less biased approach in assessing the carcinogenicity of night-shift work. Furthermore, we propose that risk-of-bias assessment and comparison of associations between studies with low versus high risks of bias be considered in future synthesis of the evidence.

Occupational quantitative exposure to crystalline silica, solvents and pesticides and risk of clinical forms of systemic sclerosis

Abstract Objectives To estimate the association between SSc clinical phenotypes and quantitative occupational exposure to crystalline silica, chlorinated solvents, trichloroethylene and pesticides using job-exposure matrices. Methods In the VISS-EXPOSITION transversal study, data on declarative occupational exposure to crystalline silica, solvents and pesticides were retrieved. In parallel, the lifetime occupational history was evaluated using a questionnaire and cursus laboris for SSc patients followed at Bordeaux University Hospital (France). Using job-exposure matrices, we assessed patients’ occupational exposure in relation to relevant clinical phenotypic forms of the disease. Results Toxic exposure to crystalline silica and pesticides is underestimated by patients. Non-biased job-exposure matrices retrieved more exposed patients than the declarative assessment (10.1% of patients by job-exposure matrices vs 6.3% by declaration for crystalline silica and 25.9% vs 12.2% for pesticides). Patients overestimate their solvent exposure (7.9% for chlorinated solvents and 4.8% for trichlorethylene assessed by job-exposure matrices and 24.4% declarative exposure to solvents at large). Clinical form evaluation revealed a non-significant trend toward an increased risk of crystalline silica occupational exposure in the pulmonary fibrotic group of SSc patients [odds ratio (OR) 3.12 (95% CI 0.80, 12.15)]. We also observed a non-significant trend toward an elevated OR ([2.89 (95% CI 0.93, 8.95)] for chlorinated solvent occupational exposure and the vascular phenotype of SSc. Of note, pesticide occupational exposure evaluation represents one of the largest to date in SSc patients. Conclusion This study emphasizes that many exposed SSc patients are unaware of their occupational exposure. Job-exposure matrices allow better exposure screening for SSc secondary prevention and occupational exposure compensation. Clinical trial registration clinicaltrials.gov (https://www.clinicaltrials.gov), NCT03543956

The association between the incidence of postmenopausal breast cancer and occupational exposure to selected organic solvents, Montreal, Canada, 2008-2011.

Breast cancer is the most diagnosed cancer among women and recognized risk factors explain 25%-47% of cases. Organic solvents are used widely in the workplace and exposure may increase the risk of developing breast cancer, yet there are insufficient data to confirm this hypothesis. We sought to determine whether past occupational exposures to selected organic solvents were associated with the incidence of invasive breast cancer in postmenopausal women in Montréal, Canada. From a population-based case-control study (2008-2011), using in-depth interviews we elicited information on risk factors and lifetime occupational histories. Industrial hygienists and chemists translated job descriptions into specific chemical and physical exposures. We assessed 11 individual solvents and four solvent groups. Unconditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for metrics of past exposures to selected solvents. Exposure metrics included any previous exposure, average frequency in hours per week, duration in years, and average cumulative concentration weighted by hours per workweek exposed. We enrolled 695 cases and 608 controls. We found increased ORs for average cumulative concentration of exposure to mononuclear aromatic hydrocarbons (OR: 1.52, 95%CI: 1.04, 2.28), chlorinated alkanes (OR: 2.42, 95%CI: 1.23, 5.68), toluene (OR: 1.59, 95%CI: 1.02, 2.59), and a group of organic solvents with reactive metabolites (OR: 1.53, 95%CI: 1.08, 2.24). Positive associations were found across all exposure metrics and were higher among women with estrogen-positive/progesterone-negative tumors. Our findings suggest occupational exposure to certain organic solvents may increase the risk of incident postmenopausal breast cancer.

Occupational environment and ovarian cancer risk

ObjectivesTo investigate employment in an occupation or industry and specific occupational exposures in relation to ovarian cancer risk.MethodsIn a population-based case–control study conducted in Montreal, Canada (2011–2016), lifetime occupational histories...

Occupational exposures and small airway obstruction in the UK Biobank Cohort.

Small airways obstruction (SAO) is a key feature of both COPD and asthma, which have been associated with workplace exposures. Whether SAO, which may occur early in the development of obstructive lung disease and without symptoms, also associates with occupational exposures is unknown. Using UK Biobank data, we derived measurements of SAO from the 65 145 participants with high-quality spirometry and lifetime occupational histories. The ALOHA+ Job Exposure Matrix was used to assign lifetime occupational exposures to each participant. The association between SAO and lifetime occupational exposures was evaluated using a logistic regression model adjusted for potential confounders. A second logistic regression model was also run to account for potential co-exposures. SAO was present in varying proportions of the population depending on definition used: 5.6% (forced expiratory flow between 25 and 75% of the forced vital capacity (FEF25-75) < lower limit of normal (LLN)) and 21.4% (forced expiratory volume in 3 s (FEV3)/forced expiratory volume in 6 s (FEV6) <LLN). After adjustment for confounders and co-exposures, people in the highest category of exposure to pesticides were significantly more likely to have SAO (FEV3/FEV6 <LLN: OR 1.24, 95% CI 1.06-1.44). The association between pesticides and SAO showed an exposure-response pattern. SAO was also less likely among people in the highest exposure categories of aromatic solvents (FEV3/FEV6 <LLN: OR 0.85, 95% CI 0.73-0.99) and metals (FEV3/FEV6 <LLN: OR 0.77, 95% CI 0.62-0.94). Our findings suggest that occupational exposure to pesticides play a role in the SAO. However, further work is needed to determine causality, and identify the specific component(s) responsible and the underlying mechanisms involved.

Occupational heat exposure and prostate cancer risk: A pooled analysis of case-control studies

BackgroundHeat exposures occur in many occupations. Heat has been linked to key carcinogenic processes, however, evidence for associations with cancer risk is sparse. We examined potential associations between occupational heat exposure and prostate cancer risk in a multi-country study. MethodsWe analysed a large, pooled dataset of 3142 histologically confirmed prostate cancer cases and 3512 frequency-matched controls from three countries: Canada, France, and Spain. Three exposure indices: ever exposure, lifetime cumulative exposure and duration of exposure, were developed using the Finnish Job-Exposure Matrix, FINJEM, applied to the lifetime occupational history of participants. We estimated odds ratios (ORs) and 95% confidence intervals (CIs), using conditional logistic regression models stratified by 5-year age groups and study, adjusting for potential confounders. Potential interactions with exposure to other occupational agents were also explored. ResultsOverall, we found no association for ever occupational heat exposure (OR 0.97; 95% CI 0.87, 1.09), nor in the highest categories of lifetime cumulative exposure (OR 1.04; 95% CI 0.89, 1.23) or duration (OR 1.03; 95% CI 0.88, 1.22). When using only the Spanish case-control study and a Spanish Job Exposure Matrix (JEM), some weakly elevated ORs were observed. ConclusionsFindings from this study provide no clear evidence for an association between occupational heat exposure and prostate cancer risk.

Towards the Exposome Project for Health and Occupational Research (EPHOR) Mega Cohort

BACKGROUND AND AIM: Existing cohort studies in Europe capturing occupational information enrol millions of persons. They are invaluable resources for understanding relationships between occupation and health. Within the Exposome Project for Health and Occupational Research (EPHOR) we aim to systematically construct a mega cohort combining data from multiple individual cohort studies to study the working life exposome and health. METHODS: Participating cohorts are registered in an open online inventory containing cohort meta-data. A set of harmonised variables is being prepared, including occupational as well as non-occupational factors (personal, lifestyle, sociodemographic, other), and a framework for de-centralized large-scale pooling of data for epidemiological analyses is being implemented. Lifetime occupational histories are being coded and harmonised across coding systems and will be linked with a European Job-Exposure Matrix (JEM) being developed. A range of harmonised outcome data including cancer, as well as respiratory, metabolic and cardiovascular, neurodegenerative, and musculoskeletal diseases, mental disorders, and work participation will be defined based on registry, record, or other follow-up methods. RESULTS: The EPHOR mega cohort currently includes participation of 28 cohorts from eight European countries, as well as multi-country studies, containing data on over 20 million participants. Initial cohorts were selected from the inventory with cancer diagnoses, respiratory outcomes, and/or information on working time prioritised in this first phase. Additional cohorts will be invited to participate here. The mega cohort will be used for a range of exposome analyses including 1) systematic and agnostic exploration of multiple risk factors in relation to health outcomes, 2) to identify vulnerable life stages and population subgroups, 3) to study rare exposures/outcomes. CONCLUSIONS: We expect collaboration to be useful to explore relationships between occupations, multiple work-related exposures and health. The mega cohort is intended to be a long-term resource for occupational health researchers. KEYWORDS: cohorts, data pooling, exposome, harmonisation, occupation

Occupational heat exposure and prostate cancer risk: a pooled analysis of case-control studies

Background and aim: Heat exposures occur frequently in many indoor and outdoor occupations. In our previous work, we observed some evidence for a positive association of occupational heat exposure and breast cancer risk. Here we seek to examine potential associations with prostate cancer risk in a large multi-country study. Methods: We performed a pooled analysis of data from 3,175 histologically confirmed prostate cancer cases and 3,529 frequency-matched controls from studies in three different countries, Spain, France, and Canada. The Finnish job exposure matrix, FINJEM, was used to apply estimates of occupational heat exposure to the lifetime occupational history of participants. Three main exposure indices were used: ever vs. never exposed, lifetime cumulative exposure (heat stress years) and duration of exposure (years) with a lag period of 5 years. We estimated odds ratios (ORs) and 95% confidence intervals (CIs), using conditional logistic regression models stratified by 5-year age groups and study and adjusted for potential confounders. Results: A total of 32% of cases and 33% of controls were classified as being ever occupationally exposed to heat. Highest heat exposed occupations included ore and metal furnace operators, firefighters, and bakers. We found no evidence for an association of ever occupational heat exposure and prostate cancer risk (OR 0.92; 95% CI 0.83, 1.03). There were also no associations observed in the highest categories of lifetime cumulative exposure or duration, and there was no evidence for a trend. Results did not change when stratifying by Gleason scores. When analysing the Spanish case-control study separately using a Spanish job exposure matrix developed for local working conditions, some odds ratios were elevated, though results were imprecise. Conclusions: Findings from this pooled study have provided no strong evidence for an association between occupational heat exposure and prostate cancer risk. Keywords: prostate cancer, occupational exposures, heat, pooled analysis

Occupational Exposure to Polycyclic Aromatic Hydrocarbons and Lung Cancer Risk: Results from a Pooled Analysis of Case-Control Studies (SYNERGY).

Exposure to polycyclic aromatic hydrocarbons (PAH) occurs widely in occupational settings. We investigated the association between occupational exposure to PAH and lung cancer risk and joint effects with smoking within the SYNERGY project. We pooled 14 case-control studies with information on lifetime occupational and smoking histories conducted between 1985 and 2010 in Europe and Canada. Exposure to benzo[a]pyrene (BaP) was used as a proxy of PAH and estimated from a quantitative general population job-exposure matrix. Multivariable unconditional logistic regression models, adjusted for smoking and exposure to other occupational lung carcinogens, estimated ORs, and 95% confidence intervals (CI). We included 16,901 lung cancer cases and 20,965 frequency-matched controls. Adjusted OR for PAH exposure (ever) was 1.08 (CI, 1.02-1.15) in men and 1.20 (CI, 1.04-1.38) in women. When stratified by smoking status and histologic subtype, the OR for cumulative exposure ≥0.24 BaP μg/m3-years in men was higher in never smokers overall [1.31 (CI, 0.98-1.75)], for small cell [2.53 (CI, 1.28-4.99)] and squamous cell cancers [1.33 (CI, 0.80-2.21)]. Joint effects between PAH and smoking were observed. Restricting analysis to the most recent studies showed no increased risk. Elevated lung cancer risk associated with PAH exposure was observed in both sexes, particularly for small cell and squamous cell cancers, after accounting for cigarette smoking and exposure to other occupational lung carcinogens. The lack of association between PAH and lung cancer in more recent studies merits further research under today's exposure conditions and worker protection measures.

Occupation and prostate Cancer risk: results from the epidemiological study of prostate cancer (EPICAP)

BackgroundAlthough prostate cancer (PCa) is the most frequent male cancer in industrialized countries, little is known about its aetiology. The literature has suggested an influence of the environment, including occupational exposures, but results are inconsistent. In this context, we investigated PCa risk associated to employment among several occupations using data from EPICAP study.MethodsEPICAP is a French population-based case-control study including 819 PCa incident cases and 879 controls frequency-matched on age. In-person interviews gathered data on potential risk factors and lifetime occupational histories for each job held at least 6 months. Then, occupations were coded using ISCO 68. Unconditional logistic regressions were performed to assess the association between occupations (ever occupied and by duration) and PCa risk, whether all and aggressive, after adjusting for potential confounders.ResultsFor ≥10 years of employment, we found positive associations with PCa, whether overall and aggressive, among Medical, Dental and Veterinary workers (OR (odds ratios) =5.01 [95% confidence interval] [1.27; 19.77]), Members of the armed forces (OR = 5.14 [0.99; 26.71]) and Fishermen, hunters and related workers (OR = 4.58 [1.33; 15.78]); whether overall and non-aggressive PCa, among Legislative officials and Government administrators (OR = 3.30 [1.10; 9.84]) or Managers (OR = 1.68 [1.18; 2.41]); however a negative association, whether overall and non-aggressive PCa, among Material-Handling and Related Equipment Operators, Dockers and Freight Handlers (OR = 0.40 [0.17; 0.97]).ConclusionExcess PCa risks were observed in the EPICAP study mostly among white collar workers exposed to several factors in their work environment. These emerging associations can be used to lead future research investigating specific occupational exposures.

Adapting Decision Rules to Estimate Occupational Metalworking Fluid Exposure in a Case-Control Study of Bladder Cancer in Spain.

We adapted previously developed decision rules from the New England Bladder Cancer Study (NEBCS) to assign occupational exposure to straight, soluble, and synthetic metalworking fluids (MWFs) to participants of the Spanish Bladder Cancer Study (SBCS). The SBCS and NEBCS are case-control studies that used the same lifetime occupational history and job module questionnaires. We adapted published decision rules from the NEBCS that linked questionnaire responses to estimates of the probability (<5, ≥5 to <50, ≥50 to <100, and 100%), frequency (in h week-1), and intensity (in mg m-3) of exposure to each of the three broad classes of MWFs to assign exposure to 10 182 reported jobs in the SBCS. The decision rules used the participant's module responses to MWF questions wherever possible. We then used these SBCS module responses to calculate job-, industry-, and time-specific patterns in the prevalence and frequency of MWF exposure. These estimates replaced the NEBCS-specific estimates in decision rules applied to jobs without MWF module responses. Intensity estimates were predicted using a previously developed statistical model that used the decade, industry (three categories), operation (grinding versus machining), and MWF type extracted from the SBCS questionnaire responses. We also developed new decision rules to assess mineral oil exposure from non-machining sources (possibly exposed versus not exposed). The decision rules for MWF and mineral oil identified questionnaire response patterns that required job-by-job expert review. To assign MWF exposure, we applied decision rules that incorporated participant's responses and job group patterns for 99% of the jobs and conducted expert review of the remaining 1% (145) jobs. Overall, 14% of the jobs were assessed as having ≥5% probability of exposure to at least one of the three MWFs. Probability of exposure of ≥50% to soluble, straight, and synthetic MWFs was identified in 2.5, 1.7, and 0.5% of the jobs, respectively. To assign mineral oil from non-machining sources, we used module responses for 49% of jobs, a job-exposure matrix for 41% of jobs, and expert review for the remaining 10%. We identified 24% of jobs as possibly exposed to mineral oil from non-machining sources. We demonstrated that we could adapt existing decision rules to assess exposure in a new population by deriving population-specific job group patterns.

Inter-rater reliability of occupational exposure assessment in a case-control study of female breast cancer

The objective of this paper was to estimate the inter-rater reliability of expert assessments of occupational exposures. An inter-rater reliability sub-study was conducted within a population-based case-control study of postmenopausal breast cancer. Detailed information on lifetime occupational histories was obtained from participants and two industrial hygienists assigned exposures to 185 jobs using a checklist of 293 agents. Experts rated exposure for each job–agent combination according to exposure status (unexposed/exposed), confidence that the exposure occurred (possible/probable/definite), intensity (low/medium/high), and frequency (% time per week). The statistical unit of observation was each job–agent assessment (185 jobs × 293 agents = 54,205 assessments per expert). Crude agreement, Gwet AC1/2 statistics, and Cohen’s Kappa were used to estimate inter-rater agreement for confidence and intensity; for frequency, the intra-class correlation coefficient (ICC) was used. The majority of job–agent combinations were evaluated by the two experts to be not exposed (crude agreement >98% of decisions). The degree of agreement between the experts for the confidence of exposure status was Gwet AC1/2 = 0.99 (95% CI: 0.99–0.99), and for intensity, a Gwet AC2 = 0.99 (95% CI: 0.99–0.99). For frequency, an ICC of 0.31 (95% CI: 0.26–0.35) was found. A sub-analysis restricted to job–agent combinations for which the two experts agreed on exposure status revealed a moderate agreement for confidence of exposure (Gwet AC2 = 0.66) and high agreement for intensity (Gwet AC2 = 0.96). For frequency, the ICC was 0.52 (95% CI: 0.47–0.57). A high level of inter-rater agreement was found for identifying exposures and for coding intensity, but agreement was lower for the coding of frequency of exposure.

Health-related quality of life in a general population sample in Kazakhstan and its sociodemographic and occupational determinants

BackgroundHealth-related quality of life (HRQL) in the general population of Kazakhstan has never been characterized. We constructed this population-based study of the largest city in Kazakhstan, Almaty with the aim to quantitatively assess HRQL and ascertain whether occupation and lifestyle are associated with HRQL in this population.MethodsIn a random sample (N = 1500) of general population in Almaty (median age 49 (interquartile range 28) years, 50% women), we collected data on demographics, socioeconomic status, lifestyle, lifetime occupational history and general HRQL using SF-8 instrument. The association of demographic and occupational predictors with HRQL was tested in multiple regression models.ResultsNo occupational associations were found for physical component score in the models adjusted for age, sex, income, cigarette and waterpipe smoking, electronic cigarette use, physical activity, alcohol and exposure to secondhand smoke. Ever being a manager (β − 1.63 (95% confidence interval (CI) − 2.92; − 0.34)), a welder (β − 5.11 (95% CI − 8.77; − 1.46)) and a secretary (β − 5.06 (95% CI − 8.56; − 1.56)) for one year or more was associated with poorer mental component score in the models adjusted for age, sex, income, cigarette smoking, physical activity and each other. Age, income and physical activity were independent predictors of both physical and mental components.ConclusionsOccupational history is associated with HRQL in the general population in Almaty, Kazakhstan, but the mechanism explaining this association should be further elucidated.

Abstract 861: Diesel engine exhaust is associated with TP53 mutations and high-risk non-muscle invasive bladder cancer

Abstract Background: Second to cigarette smoking, occupational exposures are a leading risk factor for the development of bladder cancer. Occupational exposure to diesel exhaust in particular has been linked to increased bladder cancer risk in several epidemiologic studies. To provide insight into possible mechanisms that influence this association, we examined the relationship between diesel exhaust and somatic mutations in bladder tumors. Methods: Targeted sequencing of frequently mutated genes in bladder cancer was conducted in formalin-fixed paraffin-embedded bladder tumors from a population-based case-control study in New England. Lifetime occupational histories combined with exposure-oriented questions were used to estimate cumulative exposure to respirable elemental carbon (REC), a primary index for diesel exhaust. REC exposure was modeled both continuously (per 100 μg/m3-yrs) and categorically (by tertiles). Two-stage polytomous logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate etiologic heterogeneity by tumor subtypes using data on 797 cases and 1,418 controls. Results: We observed significant heterogeneity in the relationship between diesel exhaust and risk of bladder cancer by TP53 mutation status (p-heterogeneity=0.013). When comparing patients with TP53+ tumors to controls, there was a strong association with increasing cumulative REC exposure (ORTertile 1 vs. Unexposed=1.4, 95% CI=0.7, 2.8; ORTertile 2 vs. Unexposed=1.3, 95% CI=0.6, 2.7; ORTertile 3 vs. Unexposed=2.8, 95% CI=1.4, 5.7; p-trend=0.003), while there was no apparent association between cumulative REC exposure and bladder cancer among patients with wild-type TP53 tumors (p-trend=0.603). Subtype analyses that incorporate clinical features (stage: non-muscle invasive/muscle-invasive and grade: low-grade/high-grade) with TP53 mutation, also indicate etiologic heterogeneity in the relationship between diesel exhaust and bladder cancer (p-het=0.002), with the strongest association observed between increasing cumulative REC and risk of bladder cancer among cases with non-muscle invasive, high-grade tumors (including carcinoma in situ) with TP53 mutations (OR per 100 μg/m3-yrs =1.14, 95% CI=1.00, 1.29). Conclusions: Our results suggest that diesel engine exhaust may influence bladder cancer risk by impacting the cell cycle, especially among patients with high-risk non-muscle invasive tumors that are more likely to progress to invasive disease. More work will be needed to understand the impact of diesel-generated oxidative stress on tumor suppressor genes like TP53 and cell cycle regulation in the development of bladder cancer. Citation Format: Nicole Gonzalez, Nina Rao, Michael Dean, Ludmila Prokunina-Olsson, Dalsu Baris, Molly Schwenn, Alison Johnson, Nathaniel Rothman, Debra Silverman, Stella Koutros. Diesel engine exhaust is associated with TP53 mutations and high-risk non-muscle invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 861.

A Population-Based Feasibility Study of Occupation and Thoracic Malignancies in New Mexico.

Occupational exposures in mining and oil/gas extraction are known risk factors for thoracic malignancies (TMs). Given the relatively high proportion of these industries in New Mexico (NM), we conducted a feasibility study of adult lifetime occupational history among TM cases. We hypothesized a higher proportion of occupational TM in NM relative to the estimated national average of 10-14%. We identified incident TM cases through the population-based New Mexico Tumor Registry (NMTR), from 2017-2018. Cases completed a telephone interview. An adjudication panel reviewed case histories and classified cancers as probable, possible, or non-occupational related, taking into account the presence, duration, and latency of exposures. We characterized recruitment and describe job titles and exposures among those with occupational TMs. We also compared the distributions of industry between those with and without occupational TM. The NMTR identified 400 eligible TM cases, 290 of which were available to be recruited (n=285 lung/bronchial cancer; n=5 mesotheliomas). Of the latter, 60% refused and 18% were deceased, 9% had invalid addresses, 11% were unable to be reached by telephone, and 3% were too ill to participate. The 43 cases who completed an interview held 236 jobs. A total of 33% of cases were classified as probable occupational TM and 5% as possible occupational TM. High rates of early mortality and refusals were significant barriers to study participation. Nonetheless, the proportion of probable occupational TMs greatly exceeded the estimated national average, highlighting the need for further study of occupational TM in the state.

Associations of residential and occupational history with the distribution of mixtures of persistent pollutants in adipose tissue

BackgroundThis research aims to explore patterns of distribution of 15 persistent pollutants in the adipose tissue of 227 individuals of an adult cohort from Granada, Southern Spain.MethodsInformation about lifetime residential and occupational history was gathered by means of validated questionnaires. Clusters of pollutants in the study population were identified by Principal Component Analyses (PCA). The first 3 components were mainly represented by 3 major groups of pollutants: PC1: a group of metals, namely aluminium, arsenic, chromium, nickel and lead; PC2: predominantly by Organochlorine Pesticides (OCPs); PC3: mainly by a mixture of Polychlorinated Biphenyls (PCB-138, PCB-153 and PCB-180) and metals (cadmium, cobalt and chromium). The patterns of distribution of individual pollutants and their mixtures were explored through Geographic Information Systems and Generalized Linear Models.ResultsCurrent and lifetime residence history in rural areas was associated with decreased levels of the mixture of “PCBs and metals/metalloids”, as well as of the combination of OCPs. Current residents in Granada Metropolitan Area showed the highest levels in the “metals/metalloids” component. Occupational history related to agriculture/food industry was associated with the highest levels of the mixture of “metals/metalloids”, whereas those involved in motor and industrial activities showed increased levels of the combination of OCPs. Participants working in motor/industry at recruitment showed the highest levels in the “PCBs and metals/metalloids” component.ConclusionsOur results revealed interesting clusters of exposure, and emphasized the need for further epidemiological studies to address the effect of environmental pollutants from a mixture perspective. Our results also highlight the potential of adipose tissue as a matrix for exposure assessment to combinations of different families of contaminants, that will definitely shed light on their potential effects.

Role of occupational exposures in lung cancer risk among women

ObjectivesTo explore possible associations between selected occupational agents and lung cancer risk among women.MethodsA population-based case–control study on lung cancer was conducted from 1996 to 2001 in Montreal, Canada. Cases...