Why presumptions are important in occupational health: The example of COVID-19 infection as an occupational disease.

Workers who become ill or injured on the job while undertaking extraordinary risks on behalf of the public are, at times, granted facilitated access to workers' compensation (WC) benefits through the application of presumptions in the compensation process. Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, a broad range of occupational groups faced an elevated risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure at work to perform vital services to maintain our food supply, sustain needed transportation, provide health care, assure energy supply and others. Some states or jurisdictions in the United States recognized both the risk and the service of these workers by enacting COVID-19 presumption laws to streamline selected essential workers' eligibility for WC benefits. Other states did not. Results of these contrasting public approaches permit an examination of the impact of presumptions in compensation by examining the frequency and outcomes of COVID-19 claims in "COVID-19 presumption" and "nonpresumption" states. Despite state-level variations in economic response to the pandemic, industry mix, and presumption eligibility criteria, the use of COVID-19 presumptions appears to have substantially increased claim filing rates and improved access to benefits. Lastly, the additional costs of COVID-19 claims to employers and insurers were lower than initially predicted. In response to future airborne infectious disease outbreaks, workers' compensation presumption laws should be universally implemented to permit a broad range of high-risk workers to work on the public's behalf without fear of losing wages and incurring medical expenses associated with a work-related viral exposure.

Lung Cancer Screening in Asbestos-Exposed Populations.

Asbestos exposure is the most important cause of occupational lung cancer mortality. Two large randomized clinical trials in the U.S. and Europe conclusively demonstrate that annual low-dose chest CT (LDCT) scan screening reduces lung cancer mortality. Age and smoking are the chief risk factors tested in LDCT studies, but numerous risk prediction models that incorporate additional lung cancer risk factors have shown excellent performance. The studies of LDCT in asbestos-exposed populations shows favorable results but are variable in design and limited in size and generalizability. Outstanding questions include how to: (1) identify workers appropriate for screening, (2) organize screening programs, (3) inform and motivate people to screen, and (4) incorporate asbestos exposure into LDCT decision-making in clinical practice. Conclusion: Screening workers aged ≥50 years with a history of ≥5 years asbestos exposure (or fewer years given intense exposure) in combination with either (a) a history of smoking at least 10 pack-years with no limit on time since quitting, or (b) a history of asbestos-related fibrosis, chronic lung disease, family history of lung cancer, personal history of cancer, or exposure to multiple workplace lung carcinogens is a reasonable approach to LDCT eligibility, given current knowledge. The promotion of LDCT-based screening among asbestos-exposed workers is an urgent priority.

Lung cancer incidence among world trade center rescue and recovery workers.

BACKGROUND: Many World Trade Center disaster (WTC) rescue and recovery workers (WTC RRWV) were exposed to toxic inhalable particles. The impact of WTC exposures on lung cancer risk is unclear. METHODS: Data from the WTC Health Program General Responders Cohort (WTCGRC) were linked to health information from a large New York City health system to identify incident lung cancer cases. Incidence rates for lung cancer were then calculated. As a comparison group, we created a microsimulation model that generated expected lung cancer incidence rates for a WTC- and occupationally-unexposed cohort with similar characteristics. We also fitted a Poisson regression model to determine specific lung cancer risk factors for WTC RRWV. RESULTS: The incidence of lung cancer for WTC RRWV was 39.5 (95% confidence interval [CI]: 30.7-49.9) per 100,000 person-years. When compared to the simulated unexposed cohort, no significant elevation in incidence was found among WTC RRWV (incidence rate ratio [IRR] 1.34; 95% CI: 0.92-1.96). Predictors of lung cancer incidence included age, smoking intensity, and years since quitting for former smokers. In adjusted models evaluating airway obstruction and individual pre-WTC occupational exposures, only mineral dust work was associated with lung cancer risk (IRR: 2.03; 95% CI: 1.07-3.86). DISCUSSION: In a sample from a large, prospective cohort of WTC RRWV we found a lung cancer incidence rate that was similar to that expected of a WTC- and occupationally-unexposed cohort with similar individual risk profiles. Guideline-concordant lung cancer surveillance and periodic evaluations of population-level lung cancer risk should continue in this group.

Performance of Risk Factor-Based Guidelines and Model-Based Chest CT Lung Cancer Screening in World Trade Center-Exposed Fire Department Rescue/Recovery Workers.

BACKGROUND: Lung cancer is a leading cause of cancer incidence and death in the United States. Risk factor-based guidelines and risk model-based strategies are used to identify patients who could benefit from low-dose chest CT (LDCT) screening. Few studies compare guidelines or models within the same cohort. We evaluate lung cancer screening performance of two risk factor-based guidelines (US Preventive Services Task Force 2014 recommendations [USPSTF-2014] and National Comprehensive Cancer Network Group 2 [NCCN-2]) and two risk model-based strategies, Prostate Lung Colorectal and Ovarian Cancer Screening (PLCOm2012) and the Bach model) in the same occupational cohort. RESEARCH QUESTION: Which risk factor-based guideline or model-based strategy is most accurate in detecting lung cancers in a highly exposed occupational cohort? STUDY DESIGN AND METHODS: Fire Department of City of New York (FDNY) rescue/recovery workers exposed to the September 11, 2001 attacks underwent LDCT lung cancer screening based on smoking history and age. The USPSTF-2014, NCCN-2, PLCOm2012 model, and Bach model were retrospectively applied to determine how many lung cancers were diagnosed using each approach. RESULTS: Among the study population (N = 3,953), 930 underwent a baseline scan that met at least one risk factor or model-based LDCT screening strategy; 73% received annual follow-up scans. Among the 3,953, 63 lung cancers were diagnosed, of which 50 were detected by at least one LDCT screening strategy. The NCCN-2 guideline was the most sensitive (79.4%; 50/63). When compared with NCCN-2, stricter age and smoking criteria reduced sensitivity of the other guidelines/models (USPSTF-2014 [44%], PLCOm2012 [51%], and Bach[46%]). The 13 missed lung cancers were mainly attributable to smoking less and quitting longer than guideline/model eligibility criteria. False-positive rates were similar across all four guidelines/models. INTERPRETATION: In this cohort, our findings support expanding eligibility for LDCT lung cancer screening by lowering smoking history from ≥30 to ≥20 pack-years and age from 55 years to 50 years old. Additional studies are needed to determine its generalizability to other occupational/environmental exposed cohorts.

Screening for Occupational Lung Cancer: An Unprecedented Opportunity.

Selected occupational populations are at the highest risk of lung cancer, because they smoke at increased rates and are concurrently exposed to workplace lung carcinogens. Low-dose computed tomography (CT)-based lung cancer screening has an enormous potential to reduce lung cancer mortality in these populations, as shown both in the lung cancer screening studies in the general population and in studies of workers at high risk of lung cancer. Pulmonologists can play a key role in identifying workers at high risk of lung cancer and ensuring that they are offered annual low-dose CT scans for early lung cancer detection.

Yield of Low-Dose Computerized Tomography Screening for Lung Cancer in High-Risk Workers: The Case of 7189 US Nuclear Weapons Workers.

OBJECTIVES: To determine the lung cancer screening yield and stages in a union-sponsored low-dose computerized tomography scan program for nuclear weapons workers with diverse ages, smoking histories, and occupations. METHODS: We implemented a low-dose computerized tomography program among 7189 nuclear weapons workers in 9 nonmetropolitan US communities during 2000 to 2013. Eligibility criteria included age, smoking, occupation, radiographic asbestos-related fibrosis, and a positive beryllium lymphocyte proliferation test. RESULTS: The proportion with screen-detected lung cancer among smokers aged 50 years or older was 0.83% at baseline and 0.51% on annual scan. Of 80 lung cancers, 59% (n = 47) were stage I, and 10% (n = 8) were stage II. Screening yields of study subpopulations who met the National Lung Screening Trial or the National Comprehensive Cancer Network Group 2 eligibility criteria were similar to those found in the National Lung Screening Trial. CONCLUSIONS: Computerized tomography screening for lung cancer among high-risk workers leads to a favorable yield of early-stage lung cancers. Public Health Implications. Health equity and efficiency dictate that screening high-risk workers for lung cancer should be an important public health priority.

Malignant mesothelioma due to asbestos exposure in dental tape.

Although most cases of malignant mesothelioma of the pleura are caused by one or more readily recognized sources of exposure to asbestos, cases of the disease with more occult exposure occur, especially since asbestos has been used in over 3,000 products. Dental lining tape contained asbestos from the 1930s until at least the 1970s and was used in the lost wax method of casting crowns, bridges, and other metal dental prosthetic devices. We report six cases of pathology-verified malignant mesothelioma, mostly among dentists, following exposure to airborne dust from asbestos dental tape, which resulted in asbestos tort litigation. According to evidence available at present, chrysotile asbestos was the type of asbestos used in dental tape in the past in the United States, and the described cases followed relatively brief and intermittent exposure to this type of asbestos. These cases underscore the need for comprehensive exposure histories to determine exposure scenarios. Am. J. Ind. Med. 60:437-442, 2017. © 2017 Wiley Periodicals, Inc.

Stomach cancer mortality among agricultural workers: results from a death certificate-based case-control study / Mortalidade por câncer de estômago em agricultores: resultados de estudo caso-controle baseado em certificado óbito

INTRODUCTION: Pesticide consumption is very high in Brazil. OBJECTIVE: The present study investigated the stomach cancer mortality among Brazilian agricultural workers in Rio de Janeiro state. METHODS: In this case-control study, cases were individuals of both genders, aged ≥20 years, for whom cause of death was ascertained as stomach cancer. Controls were individuals with causes of death other than neoplasm and diseases of the digestive system. Crude and adjusted analyses were carried out. Stomach cancer mortality risk was then estimated for the agricultural workers according to the pesticide expenditures per municipality. RESULTS: Agricultural workers showed an elevated risk of stomach cancer mortality (adjusted OR=1.42; 95%CI: 1.33-1.78). This risk was higher among male workers, aged 50-69 years, white, and among workers with 1-7 years of education. Results also showed increasing stomach cancer mortality along with the increase of pesticide expenditure per agricultural worker. CONCLUSION: Stomach cancer risk among agricultural workers may be associated with pesticide exposure. .

INTRODUÇÃO: O consumo de agrotóxicos é muito alto no Brasil. OBJETIVO: O presente estudo teve por objetivo investigar o risco de morte por câncer de estômago em trabalhadores agrícolas residentes no estado do Rio de Janeiro. MÉTODOS: Neste estudo do tipo caso-controle, casos consistiram em indivíduos de ambos os sexos com 20 anos ou mais, cuja causa de morte foi câncer de estômago. Controles foram indivíduos cuja causa de morte não tenha consistido em qualquer neoplasia ou doenças do sistema digestivo. Análises brutas e ajustadas foram realizadas. O risco de morte por câncer de estômago foi, em seguida, estimado para trabalhadores agrícolas de acordo com a exposição a agrotóxicos e local de residência. RESULTADOS: Trabalhadores agrícolas apresentaram um aumento no risco de morte por câncer de estômago: OR ajustada=1,42 (IC95%: 1,33-1,78). Esse risco foi ainda maior entre homens brancos entre 50 a 69 anos e entre trabalhadores agrícolas com 1 a 7 anos de estudo. Os resultados também mostraram um aumento no risco de morte por câncer de estômago em trabalhadores agrícolas com o aumento da exposição a agrotóxicos. CONCLUSÃO: O risco de morte por câncer de estômago entre trabalhadores agrícolas pode estar associado com exposição a agrotóxicos. .

Comparison of x-ray films and low-dose computed tomographic scans: demonstration of asbestos-related changes in 2760 nuclear weapons workers screened for lung cancer.

OBJECTIVE: Increased availability and technical improvements of computed tomographic (CT) scanning encourages its use for detecting asbestos-related disease. We compared low-dose scans and x-ray films in 2760 workers potentially exposed to asbestos, to assess their ability to detect interstitial lung disease (ILD) and pleural thickening (PT). METHODS: A total of 2760 nuclear workers received radiography and CT scanning (2006 to 2009). X-ray films were read by a B reader for ILD and PT and CT scans by a thoracic radiologist, using a protocol for nodules, ILD, and PT. RESULTS: Of the 2760 workers, 271 showed circumscribed PT on CT scans, and 73 on x-ray films, 54 (74%) of which were confirmed on CT scans; 76 showed ILD on CT scans, and 15 on x-ray film, 10 (67%) of which were confirmed on CT scans. CONCLUSIONS: Radiographic readings of PT and ILD were generally confirmed on CT scans. Computed tomographic scans detected three to five times more cases; the majority were minor.

Asbestos, asbestosis, smoking, and lung cancer. New findings from the North American insulator cohort.

RATIONALE: Asbestos, smoking, and asbestosis increase lung cancer risk in incompletely elucidated ways. Smoking cessation among asbestos-exposed cohorts has been little studied. OBJECTIVES: To measure the contributions of asbestos exposure, asbestosis, smoking, and their interactions to lung cancer risk in an asbestos-exposed cohort and to describe their reduction in lung cancer risk when they stop smoking. METHODS: We examined lung cancer mortality obtained through the National Death Index for 1981 to 2008 for 2,377 male North American insulators for whom chest X-ray, spirometric, occupational, and smoking data were collected in 1981 to 1983 and for 54,243 non-asbestos-exposed blue collar male workers from Cancer Prevention Study II for whom occupational and smoking data were collected in 1982. MEASUREMENTS AND MAIN RESULTS: Lung cancer caused 339 (19%) insulator deaths. Lung cancer mortality was increased by asbestos exposure alone among nonsmokers (rate ratio = 3.6 [95% confidence interval (CI), 1.7-7.6]), by asbestosis among nonsmokers (rate ratio = 7.40 [95% CI, 4.0-13.7]), and by smoking without asbestos exposure (rate ratio = 10.3 [95% CI, 8.8-12.2]). The joint effect of smoking and asbestos alone was additive (rate ratio = 14.4 [95% CI, 10.7-19.4]) and with asbestosis, supra-additive (rate ratio = 36.8 [95% CI, 30.1-45.0]). Insulator lung cancer mortality halved within 10 years of smoking cessation and converged with that of never-smokers 30 years after smoking cessation. CONCLUSIONS: Asbestos increases lung cancer mortality among nonsmokers. Asbestosis further increases the lung cancer risk and, considered jointly with smoking, has a supra-additive effect. Insulators benefit greatly by quitting smoking.

Cancer incidence in world trade center rescue and recovery workers, 2001-2008.

BACKGROUND: World Trade Center (WTC) rescue and recovery workers were exposed to a complex mix of pollutants and carcinogens. OBJECTIVE: The purpose of this investigation was to evaluate cancer incidence in responders during the first 7 years after 11 September 2001. METHODS: Cancers among 20,984 consented participants in the WTC Health Program were identified through linkage to state tumor registries in New York, New Jersey, Connecticut, and Pennsylvania. Standardized incidence ratios (SIRs) were calculated to compare cancers diagnosed in responders to predicted numbers for the general population. Multivariate regression models were used to estimate associations with degree of exposure. RESULTS: A total of 575 cancers were diagnosed in 552 individuals. Increases above registry-based expectations were noted for all cancer sites combined (SIR = 1.15; 95% CI: 1.06, 1.25), thyroid cancer (SIR = 2.39; 95% CI: 1.70, 3.27), prostate cancer (SIR = 1.21; 95% CI: 1.01, 1.44), combined hematopoietic and lymphoid cancers (SIR = 1.36; 95% CI: 1.07, 1.71), and soft tissue cancers (SIR = 2.26; 95% CI: 1.13, 4.05). When restricted to 302 cancers diagnosed ≥ 6 months after enrollment, the SIR for all cancers decreased to 1.06 (95% CI: 0.94, 1.18), but thyroid and prostate cancer diagnoses remained greater than expected. All cancers combined were increased in very highly exposed responders and among those exposed to significant amounts of dust, compared with responders who reported lower levels of exposure. CONCLUSION: Estimates should be interpreted with caution given the short follow-up and long latency period for most cancers, the intensive medical surveillance of this cohort, and the small numbers of cancers at specific sites. However, our findings highlight the need for continued follow-up and surveillance of WTC responders.

Pesticide use and non-Hodgkin's lymphoma mortality in Brazil.

INTRODUCTION: Brazil is one of the major pesticide consumers in the world. The continuous exposure to these substances may be etiologically associated with the development of Non-Hodgkin's Lymphoma (NHL). OBJECTIVE: Estimate the correlation between the per capita sales of pesticides in 1985 (exposure) and NHL mortality rates between 1996 and 2005 (outcome), by Brazilian micro-regions. METHOD: In this ecological descriptive study, the per capita consumption of pesticides in 1985 was used as a proxy of the population exposure to these chemicals in Brazil. All deaths by NHL occurred in the 446 non-urban micro-regions, between 1996 and 2005, among individuals with ages between 20 and 69, of both sexes, were retrieved from the Brazilian Mortality Information System. Micro-regions were then categorized into low, medium, high and very high pesticide consumption, according to the quartiles of per capita consumption of pesticides. NHL mortality rates and rate ratios for each quartile were obtained using the lowest quartile as reference. In addition, the Spearman's correlation coefficient between pesticide consumption and NHL mortality rates was estimated. RESULTS: A moderate correlation between per capita pesticides consumption and standardized mortality rate for NHL was observed (r=0.597). In addition, using the lowest quartile of pesticide consumption as a reference, the higher the quartile of pesticide consumption, the higher was NHL mortality risk: men - (second quartile - MRR=1.69, CI 95% 1.68-1.84; third quartile - MRR=2.41, CI 95% 2.27-2.57; fourth quartile - MRR=2.92, CI 95% 2.74-3.11) and females (second quartile - MRR=1.87, CI 95% 1.69-2.06; third quartile - MRR=2.28, IC 95% 2.10-2.47; fourth quartile - MRR=3.20; CI 95% 2.98-3.43). CONCLUSION: Our results suggest that pesticide exposure may play a role in the etiology of NHL.

White blood cell global methylation and IL-6 promoter methylation in association with diet and lifestyle risk factors in a cancer-free population.

Altered levels of global DNA methylation and gene silencing through methylation of promoter regions can impact cancer risk, but little is known about their environmental determinants. We examined the association between lifestyle factors and levels of global genomic methylation and IL-6 promoter methylation in white blood cell DNA of 165 cancer-free subjects, 18-78 years old, enrolled in the COMIR (Commuting Mode and Inflammatory Response) study, New York, 2009-2010. Besides self-administrated questionnaires on diet and physical activity, we measured weight and height, white blood cell (WBC) counts, plasma levels of high sensitivity C-reactive protein (hs-CRP), and genomic (LINE-1) and gene-specific methylation (IL-6) by pyrosequencing in peripheral blood WBC. Mean levels of LINE-1 and IL-6 promoter methylation were 78.2% and 57.1%, respectively. In multivariate linear regression models adjusting for age, gender, race/ethnicity, body mass index, diet, physical activity, WBC counts and CRP, only dietary folate intake from fortified foods was positively associated with LINE-1 methylation. Levels of IL-6 promoter methylation were not significantly correlated with age, gender, race/ethnicity, body mass index, physical activity or diet, including overall dietary patterns and individual food groups and nutrients. There were no apparent associations between levels of methylation and inflammation markers such as WBC counts and hs-CRP. Overall, among several lifestyle factors examined in association with DNA methylation, only dietary folate intake from fortification was associated with LINE-1 methylation. The long-term consequence of folate fortification on DNA methylation needs to be further evaluated in longitudinal settings.

Biologic and epigenetic impact of commuting to work by car or using public transportation: a case-control study.

BACKGROUND AND AIMS: Commuting by public transportation (PT) entails more physical activity and energy expenditure than by cars, but its biologic consequences are unknown. METHODS: In 2009-2010, we randomly sampled New York adults, usually commuting either by car (n=79) or PT (n=101). Measures comprised diet and physical activity questionnaires, weight and height, white blood cell (WBC) count, C reactive protein, (CRP) gene-specific methylation (IL-6), and global genomic DNA methylation (LINE-1 methylation). RESULTS: Compared to the 101 PT commuters, the 79 car drivers were about 9 years older, 2 kg/m(2) heavier, more often non-Hispanic whites, and ate more fruits and more meats. The 2005 guidelines for physical activity were met by more car drivers than PT users (78.5% vs. 65.0%). There were no differences in median levels of CRP (car vs. PT: 0.6 vs. 0.5mg/dl), mean levels of WBC (car vs. PT: 6.7 vs. 6.5 cells/mm(3)), LINE-1 methylation (car vs. PT: 78.0% vs. 78.3%), and promoter methylation of IL-6 (car vs. PT: 56.1% vs. 58.0%). CONCLUSIONS: PT users were younger and lighter than car drivers, but their commute mode did not translate into a lower inflammatory response or a higher DNA methylation, maybe because, overall, car drivers were more physically active.

Enfermedades pulmonares no malignas entre obreros del cemento-asbesto en Brasil: un estudio de prevalencia / Non-malignant pulmonary diseases among asbestos cement workers in Brazil: a prevalence study

A pesar del impacto social y económico, las enfermedades pulmonares no malignas relacionadas con el asbesto han sido subestimadas. Las alteraciones radiológicas y la disminución de la capacidad pulmonar suceden tardíamente, años después de abandonar el trabajo. Es fundamental aclarar la alta prevalencia de las enfermedades que conlleva las lesiones físicas y sociales. Realizamos un estudio de prevalencia en 145 personas seleccionadas al azar de una población de 2.124 ex obreros que habían trabajado en una fábrica de fibrocemento entre 1983 y 1993. El criterio de elegibilidad de la muestra fue la latencia en el transcurso de 20 años entre la primera exposición y la recopilación de datos. Se realizaron cuestionarios sobre ocupación y respiración, examen físico, prueba de función pulmonar y radiografía. La prevalencia de las enfermedades pulmonares no malignas relacionadas con el asbesto fue del 39,3 por ciento considerando las alteraciones radiológicas. Ha habido una asociación importante entre el tiempo trabajado y las placas pleurales (p < 0,001), asbestosis (p = 0,05) y las enfermedades pulmonares no malignas (p < 0,001). Existe una relación importante entre la dosis de exposición con las placas pleurales (p = 0,0001) y la asbestosis (p = 0,0005). La latencia fue un factor sumamente importante para la asbestosis (p = 0,037-OR 21,1)y las enfermedades pulmonares no malignas (p < 0,001-OR 2,1). Como conclusión, ha habido una alta prevalencia de enfermedades pulmonares no malignas relacionadas con el asbesto entre exobreros de fibrocemento. Según los resultados, se destacan un aumento relacionado con la latencia, la exposición de la dosis y el tiempo trabajado.

In spite of the social and economic impact, non-malignant pulmonary diseases related to asbestos have been undervalued. Radiological alterations and decrease of pulmonary capacity happen belatedly after years that leave the job. It is fundamental to clarify the high prevalence that carry for physical and social prejudices. We performed a prevalence survey in 145 people randomly selected from a population of 2.125 former workers that had been worked in a fiber cement factory between 1983 and 1993. The eligible criteria of sample were latency over 20 years between first exposure and data collection. Occupational and breathing questionnaire, physical exam, pulmonary function and X-ray were performed. The prevalence of non-malignant pulmonary diseases related to asbestos was 39,3percent considering radiological alterations. There has been a significant association between time work and Pleural Plaques (p < 0,001), Asbestosis (p = 0,05) and non-malignant pulmonary diseases (p < 0,001). An important relationship between exposure dose with Pleural Plaques (p = 0,0001) and Asbestosis (p = 0,0005). Latency was a highly significant to Asbestosis (p = 0,037-OR 21.1) and non-malignant pulmonary diseases (p < 0,001-OR 2.1). Concluding, there has been a high prevalence of non-malignant pulmonary diseases related to asbestos among fiber cement former workers and results highlight an increase related to latency, dose exposure and time work.

Esophageal cancer among Brazilian agricultural workers: case-control study based on death certificates.

Several studies suggest that agricultural workers are at higher risk to develop and die by certain types of cancer. Esophageal cancer is not commonly listed among these types. However, some recent studies indicated that if there is an association between agricultural working and esophageal cancer, it s more likely to be observed among workers highly exposed to pesticides. In the present study, the magnitude of the association between agricultural working and esophageal cancer mortality was evaluated in a high pesticide use area in Brazil, through a death certificate-based case-control study. Cases were individuals from both genders, 30-59 years old, for whom basic cause of death was ascertained as cancer of the esophagus. For each case, one control was randomly selected from all possible controls for which the basic cause of death was ascertained as different from neoplasm and diseases of the digestive system. In addition, controls matched their cases by sex, age, year of death, and state of residence. Crude and adjusted odds ratios were then calculated to estimate the magnitude of the risk. Results showed that, in general, agricultural workers were at significantly higher risk to die by esophageal cancer, when compared to non-agricultural workers. Stratified analysis also revealed that the magnitude of such risk was slightly higher among illiterate agricultural workers, and simultaneous adjustment for several covariates showed that the risk was quantitatively higher among younger southern agricultural workers. These results suggest the esophageal cancer may be included among those types of cancer etiologically associated to agricultural working.

Ability of low-dose helical CT to distinguish between benign and malignant noncalcified lung nodules.

STUDY OBJECTIVES: Low-dose helical CT scanning identifies early stage lung malignancies and also a large proportion of lung nodules of uncertain diagnostic and prognostic significance (ie, indeterminate nodules). The sensitivity, specificity, and predictive value of these indeterminate nodules detected by CT scanning as part of a lung cancer screening program is largely unknown. We therefore calculated the sensitivity, specificity, and predictive values of CT-detected lung nodules that were followed up at least 18 months. DESIGN: Single-arm screening trial with longitudinal follow-up. SETTING: Rural areas of United States, from 2000 to 2004. PARTICIPANTS: Former and current nuclear weapons workers, >/= 45 years old, including smokers and never-smokers, with variable exposure to occupational lung carcinogens. INTERVENTIONS: A total of 4,401 participants were CT scanned for lung cancer with an initial full chest low-dose CT scan, interval CT scans at 3, 6, and 12 months for indeterminate lung nodules (eg, nodules not immediately suspicious for lung cancer), and a 18-month, full-chest, low-dose incidence CT scan. RESULTS: We achieved follow-up for a minimum of 18 months for > 95% of 807 participants with indeterminate or suspicious lung nodules. Only 3 of 727 indeterminate nodules were identified as being malignant during the subsequent 18 months. The radiologist's designation of a nodule as suspicious had a sensitivity of 84.2% and a specificity of 96.6%. Given a prior probability of lung cancer of 2.4%, positive and negative predictive values were 37.2% and 99.6%. Overall, we detected 33 primary lung cancers, including 19 stage I cancers, 5 stage II cancers, 7 stage III-IV cancers, and 3 limited-stage small cell cancers. CONCLUSIONS: Helical CT scanning detects many indeterminate nodules, but few are malignant. CT scanning has high sensitivity and specificity to detect early lung cancer. The problem of false-positive results in helical CT scanning is limited and can be rationally managed. Current CT follow-up recommendations are supported.

Continued epidemic of bladder cancer in workers exposed to ortho-toluidine in a chemical factory.

Ortho-toluidine (o-toluidine), an aromatic amine, is classified by the International Agency for Research on Cancer as a probable human carcinogen. A cohort study published in 1991 reported a 6.5-fold excess incidence of bladder cancer in a chemical plant that used o-toluidine. We report 19 additional cases of bladder cancer among workers in this cohort, yielding a total of 34 cases of bladder cancer in the cohort to date. The number of bladder cancers diagnosed in the recent period has increased. The timing of onset of exposure to o-toluidine of numerous cases of bladder cancer after 1968, and especially 1975, suggests that potentially confounding occupational exposures other than o-toluidine were not responsible for the observed excess bladder cancer. A formal cohort update is strongly indicated. This study further supports the human bladder carcinogenicity of o-toluidine.