Cancers in France in 2015 attributable to occupational exposures

Ovarian cancer deaths attributable to asbestos exposure in Lombardy (Italy) in 2000-2018

OBJECTIVES

We aimed to estimate the fraction of deaths from ovarian cancer attributable to asbestos exposure in Lombardy Region, Italy, using a novel approach that exploits the fact that ovarian cancer asbestos exposure is associated with pleural cancer and other risk factors for breast cancer.

METHODS

This ecological study is based on the Italian National Institute of Statistics mortality data. We formulate a trivariate Bayesian joint disease model to estimate the attributable fraction (AF) and the number of ovarian cancer deaths attributable to asbestos exposure from the geographic distribution of ovarian, pleural and breast cancer mortality at the municipality level from 2000 to 2018. Expected deaths and standardised mortality ratios were calculated using regional rates.

RESULTS

We found shared dependencies between ovarian and pleural cancer, which capture risk factors common to the two diseases (asbestos exposure), and a spatially structured clustering component shared between ovarian and breast cancer, capturing other risk factors. Based on 10 462 ovarian cancer deaths, we estimated that 574 (95% credibility interval 388-819) were attributable to asbestos (AF 5.5%; 95% credibility interval 3.7-7.8). AF reaches 34%-47% in some municipalities with known heavy asbestos pollution.

CONCLUSIONS

The impact of asbestos on ovarian cancer occurrence can be relevant, particularly in areas with high asbestos exposure. Estimating attributable cases was possible only by using advanced Bayesian modelling to consider other risk factors for ovarian cancer. These findings are instrumental in tailoring public health surveillance programmes and implementing compensation and prevention policies.

Multiple xenoestrogen air pollutants and breast cancer risk: Statistical approaches to investigate combined exposures effect

Studies suggested that exposure to air pollutants, with endocrine disrupting (ED) properties, have a key role in breast cancer (BC) development. Although the population is exposed simultaneously to a mixture of multiple pollutants and ED pollutants may act via common biological mechanisms leading to synergic effects, epidemiological studies generally evaluate the effect of each pollutant separately. We aimed to assess the complex effect of exposure to a mixture of four xenoestrogen air pollutants (benzo-[a]-pyrene (BaP), cadmium, dioxin (2,3,7,8-Tétrachlorodibenzo-p-dioxin TCDD)), and polychlorinated biphenyl 153 (PCB153)) on the risk of BC, using three recent statistical methods, namely weighted quantile sum (WQS), quantile g-computation (QGC) and Bayesian kernel machine regression (BKMR). The study was conducted on 5222 cases and 5222 matched controls nested within the French prospective E3N cohort initiated in 1990. Annual average exposure estimates to the pollutants were assessed using a chemistry transport model, at the participants' residence address between 1990 and 2011. We found a positive association between the WQS index of the joint effect and the risk of overall BC (adjusted odds ratio (OR) = 1.10, 95% confidence intervals (CI): 1.03-1.19). Similar results were found for QGC (OR = 1.11, 95%CI: 1.03-1.19). Despite the association did not reach statistical significance in the BKMR model, we observed an increasing trend between the joint effect of the four pollutants and the risk of BC, when fixing other chemicals at their median concentrations. BaP, cadmium and PCB153 also showed positive trends in the multi-pollutant mixture, while dioxin showed a modest inverse trend. Despite we found a clear evidence of a positive association between the joint exposure to pollutants and BC risk only from WQS and QGC regression, we observed a similar suggestive trend using BKMR. This study makes a major contribution to the understanding of the joint effects of air pollution.

Length of employment in workplaces handling hazardous chemicals and risk of cancer among Japanese men

OBJECTIVES

In Japan, the risk of developing cancer among workers employed in workplaces where chemical substances are handled is unclear. This study aimed to assess the association between cancer risk and employment in workplaces handling hazardous chemicals.

METHODS

The Inpatient Clinico-Occupational Survey of the Rosai Hospital Group data of 120 278 male patients with incident cancer and 217 605 hospital controls matched for 5-year age group, hospital (34 hospitals) and year of admission (2005-2019) were analysed. Cancer risk in relation to lifetime employment in workplaces using regulated chemicals was assessed while controlling for age, region and year of diagnosis, smoking, alcohol consumption and occupation. Further analysis stratified by smoking history was performed to examine interaction effects.

RESULTS

In the longest group of employment in tertiles, ORs were increased for all cancers (OR=1.13; 95% CI: 1.07 to 1.19) and lung (OR=1.82; 95% CI: 1.56 to 2.13), oesophageal (OR=1.73; 95% CI: 1.18 to 2.55), pancreatic (OR=2.03; 95% CI: 1.40 to 2.94) and bladder (OR=1.40; 95% CI: 1.12 to 1.74) cancers. Employment of 1+ years was associated with risk for lung cancer; 11+ years for pancreatic and bladder cancers; and 21+ years for all cancers and oesophageal cancer. These positive relationships were particularly obvious among patients with a history of smoking; however, no significant interaction between smoking and length of employment was observed.

CONCLUSIONS

There is a high risk of cancer among workers, especially smokers, employed in workplaces handling regulated chemicals in Japan. Thus, future measures for chemical management in workplaces are needed to prevent avoidable cancers.

A Multicenter Study to Assess a Systematic Screening of Occupational Exposures in Lung Cancer Patients

Occupational lung cancer cases remain largely under-reported and under-compensated worldwide. In order to improve the detection and compensation of work-related lung cancers, we implemented a systematic screening of occupational exposures, combining a validated self-administered questionnaire to assess occupational exposures and a specialized occupational cancer consultation. After a pilot study, the present prospective, open-label, scale-up study aimed to assess this systematic screening of occupational exposures in lung cancer patients in five sites in France by associating university hospitals with cancer centers. Patients with lung cancer were sent a self-administered questionnaire to collect their job history and potential exposure to lung carcinogens. The questionnaire was assessed by a physician to determine if a specialized occupational cancer consultation was required. During the consultation, a physician assessed if the lung cancer was occupation-related and, if it was, delivered a medical certificate to claim for compensation. Patients were offered help from a social worker for the administrative procedure. Over 15 months, 1251 patients received the questionnaire and 462 returned it (37%). Among them, 176 patients (38.1%) were convened to the occupational cancer consultation and 150 patients attended the consultation. An exposure to occupational lung carcinogen was identified in 133 patients and a claim for compensation was judged possible for 90 patients. A medical certificate was delivered to 88 patients and 38 patients received compensation. Our national study demonstrated that a systematic screening of occupational exposures is feasible and will bring a significant contribution to improve the detection of occupational exposures in lung cancer patients.

Occupational asbestos exposure and survival among lung cancer patients

OBJECTIVE

This study investigated the association between occupational asbestos exposure (OAE) and survival in patients with histologically confirmed lung cancer (LC).

METHODS

This monocentric study was conducted in the Comprehensive Cancer Centre Léon Bérard, Lyon, France. A systematic screening has been in place since 2014 for occupational exposure to carcinogens using a self-assessment questionnaire sent to all patients newly diagnosed with histologically confirmed LC identified through the multidisciplinary LC board from 2014 to 2019. When the physician suspected a work-related exposure from the questionnaire including job history, an occupational cancer consultation was carried out to detail carcinogen exposures and assess if the LC was work-related. Demographics, clinical characteristics and survival data were extracted from medical records. The association between asbestos exposure and overall survival (hazard ratio and 95% confidence intervals) was estimated by Cox proportional hazards regression.

RESULTS

Overall, 702 patients were eligible to the present study, including 180 patients with OAE. In the crude analysis, LCs assessed as moderately or highly attributable to OAE were associated with decreased overall survival (HR = 1.32, 95 %CI 1.04-1.67) compared to LC without OAE or with a low degree of imputability to OAE (median follow-up 28.8 months). After adjustment for confounding (age at diagnosis, smoking status, stage, brain metastasis at diagnosis, and histology), the association of OAE with overall survival was no longer statistically significant (HR = 1.21, 95 %CI 0.94-1.56).

CONCLUSION

Overall survival in occupationally asbestos exposed LC patients may be decreased in comparison with non-exposed LC patients, warranting further investigations in larger studies.

Estimated number of cancers attributable to occupational exposures in France in 2017: an update using a new method for improved estimates

BACKGROUND

Over the last 50 years, occupational exposure to carcinogenic agents has been widely regulated in France.

OBJECTIVE

Report population-attributable fraction (PAF) and number of attributable cancer cases linked to occupational exposure in France based on an updated method to estimate lifetime occupational exposure prevalence.

METHODS

Population-level prevalence of lifetime exposure to ten carcinogenic agents (asbestos, benzene, chromium VI, diesel engine exhaust, formaldehyde, nickel compounds, polycyclic aromatic hydrocarbons, silica dust, trichloroethylene, wood dust) and two occupational circumstances (painters and rubber industry workers) were estimated using the French Census linked with MATGÉNÉ job-exposure matrices and French occupational surveys. PAF and number of attributable cancer cases were calculated using the estimated prevalence, relative risks from systematic review and national estimates of cancer incidence in 2017.

RESULTS

The lifetime occupational exposure prevalences were much higher in men than in women ranging from 0.2% (workers in the rubber industry) to 10.2% in men (silica), and from 0.10% (benzene, PAH and workers in the rubber industry) to 5.7% in women (formaldehyde). In total, 4,818 cancer cases (men: 4,223; women: 595) were attributable to the ten studied carcinogens and two occupational circumstances, representing 5.2% of cases among the studied cancer sites (M: 7.0%; W: 1.9%). In both sexes, mesothelioma (M: 689 cases; W: 160) and lung cancer (M: 3,032; W: 308) were the largest cancer sites impacted by the studied occupational agents and circumstances.

SIGNIFICANCE

A moderate proportion of the cancer cases in France is linked to carcinogens in occupational settings. Our method provides more precise estimates of attributable cancer taking into account evolution of exposure to occupational agents by sex, age and time. This methodology can be easily replicated using cross-sectional occupational data to aid priority making and implementation of prevention strategies in the workplace.

Estimating 10-year risk of lung and breast cancer by occupation in Switzerland

Introduction

Lung and breast cancer are important in the working-age population both in terms of incidence and costs. The study aims were to estimate the 10-year risk of lung and breast cancer by occupation and smoking status and to create easy to use age-, and sex-specific 10-year risk charts.

Methods

New lung and breast cancer cases between 2010 and 2014 from all 5 cancer registries of Western Switzerland, matched with the Swiss National Cohort were used. The 10-year risks of lung and breast cancer by occupational category were estimated. For lung cancer, estimates were additionally stratified by smoking status using data on smoking prevalence from the 2007 Swiss Health Survey.

Results

The risks of lung and breast cancer increased with age and were the highest for current smokers. Men in elementary professions had a higher 10-year risk of developing lung cancer compared to men in intermediate and managerial professions. Women in intermediate professions had a higher 10-year risk of developing lung cancer compared to elementary and managerial professions. However, women in managerial professions had the highest risk of developing breast cancer.

Discussion

The 10-year risk of lung and breast cancer differs substantially between occupational categories. Smoking creates greater changes in 10-year risk than occupation for both sexes. The 10-year risk is interesting for both patients and professionals to inform choices related to cancer risk, such as screening and health behaviors. The risk charts can also be used as public health indicators and to inform policies to protect workers.

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.

Pleural plaques and risk of lung cancer in workers formerly occupationally exposed to asbestos: extension of follow-up

BACKGROUND

Occupational asbestos exposure is associated with pleural plaques (PP), a benign disease often seen as a marker of past exposure to asbestos and lung cancer. The association between these two diseases has not been formally proved, the aim of this study was to evaluate this association in the asbestos-related disease cohort (ARDCO) cohort.

METHODS

ARDCO is a French multicentric cohort including workers formerly occupationally exposed to asbestos from 2003 to 2005. CT scan was performed to diagnose PP with double reading and lung cancer (incidence and mortality) was followed through health insurance data and death certificates. Cox models were used to estimate the association between PP and lung cancer adjusting for occupational asbestos exposure (represented by cumulative exposure index, time since first exposure and time since last exposure) and smoking status.

RESULTS

A total of 176 cases (of 5050 subjects) and 88 deaths (of 4938 subjects) of lung cancer were recorded. Smoking status was identified as an effect modifier. Lung cancer incidence and mortality were significantly associated with PP only in non-smokers, respectively, HR=3.13 (95% CI 1.04 to 9.35) and HR=16.83 (95% CI 1.87 to 151.24) after adjustment for age, occupational asbestos exposure and smoking status.

CONCLUSIONS

ARDCO study was the first to study this association considering equal asbestos exposure, and more specifically, our study is the first to test smoking as an effect modifier, so comparison with scientific literature is difficult. Our results seem to consolidate the hypothesis that PP may be an independent risk factor for lung cancer but they must be interpreted with caution.

Collective Protection Measures for Occupational Exposure to Carcinogenic Chemicals in France: The Links between Regulations on Chemicals and Effective Implementation

European directives stipulate that French employers take all available measures to reduce the use of carcinogenic agents. Our study explores the links between regulations on chemicals and the effective implementation of collective protection measures in France to occupational exposure to carcinogenic chemicals. Individual data from the French national cross-sectional survey of occupational hazards, conducted in 2017, were analysed. We investigated whether stricter regulations and longer exposures were associated with a higher level of collective protection using multivariate logistic regressions. In 2017, any collective protection measures were implemented for 35% of occupational situations involving exposure to a carcinogen. A total of 21% of exposure situations benefited from source-based controls (e.g., isolation chamber and local exhaust ventilation) and 26% from general ventilation, for which the effect is limited as collective protection. Our regressions showed that longer exposure durations were associated with more collective protection. Exposure situations to chemicals classified as proven carcinogens by the European Union (category 1A) benefited more from collective protections, which is not the case for products only classified as suspected carcinogens (category 1B). Exposures to products with a Binding Occupational Exposure Limit Value benefited more from source-based controls. Nonetheless, the time spent on the IARC list of carcinogens did not appear to influence the implementation of collective protection measures, except for local exhaust ventilation. At a time when efforts to improve the implementation of protective measures in order to drastically reduce the risks of occupational cancers are still necessary, stricter European and national regulations, but above all, better coordination with the work of the IARC and its classification, are avenues to pursue.

Frequency of Asbestos Exposure and Histological Subtype of Ovarian Carcinoma

The International Agency for Research on Cancer established a causal link between asbestos exposure and ovarian cancer. However, the exposure frequency and histological characteristics of asbestos-associated ovarian cancers remain to be investigated in detail. This multicenter case-case study assessed the asbestos exposure in ovarian carcinoma (OC) patients, alongside its association with histological subtype. Women were recruited in four hospitals in Lyon, France. Histological reports were reviewed by a pathologist. Patient and family members' data were collected by phone-based questionnaires. Asbestos exposure was defined as direct (occupational and environmental) and indirect (via parents, partners, and children). An industrial hygienist assessed the probability and level of exposure. The 254 enrolled patients (mean age 60 years) reported having an average of 2.3 different jobs (mean working duration 29 years). The prevalence of direct and indirect asbestos exposure was 13% (mean exposure duration 11 years) and 46%, respectively. High-grade serous carcinoma accounted for 73% of all OCs and 82% of histological subtypes in women with direct exposure. After adjustment on a familial history of OC, no significant associations between asbestos exposure (direct and/or indirect) and high-grade serous carcinoma were found. Women with OC had a high prevalence of asbestos exposure. Establishing risk profiles, as reported here, is important in facilitating compensation for asbestos-related OCs and for the surveillance of women at risk.

Contribution of causal factors to disease burden: how to interpret attributable fractions

What proportion of the risk in a given population is attributable to a risk factor? The population attributable fraction (PAF) answers this question. "Attributable to" is understood as "due to", which makes PAFs closely related to the concept of potential impact or potential benefits of reducing the exposure. The PAF is a tool at the border between science and decision making. PAFs are estimated based on strong assumptions and the calculations are data intensive, making them vulnerable to gaps in knowledge and data. Current misconceptions include summing up PAFs to 100% or subtracting a PAF for a factor from 100% to deduce what proportion is left to be explained or prevented by other factors. This error is related to unrecognised multicausality or shared causal responsibility in disease aetiology. Attributable cases only capture cases in excess and should be regarded as a lower bound for aetiological cases, which cannot be estimated based on epidemiological data alone (exposure-induced cases). The population level might not be relevant to discuss prevention priorities based on PAFs, for instance when exposures concentrate in a subgroup of the population, as for occupational lung carcinogens and other workplace hazards. Alternative approaches have been proposed based on absolute rather than relative metrics, such as estimating potential gains in life expectancy that can be expected from a specific policy (prevention) or years of life lost due to a specific exposure that already happened (compensation).

Lung Cancer Mortality in the Swiss Working Population: The Effect of Occupational and Non-Occupational Factors

OBJECTIVE

To assess the effect of occupational exposures on lung cancer mortality in Switzerland after adjustment for non-occupational lung carcinogens.

METHODS

Using data on 4,351,383 Swiss residents, we used negative binomial regression to assess the effect occupation on lung cancer mortality between 1990 and 2014, accounting for socio-demographic factors, predicted probabilities of smoking and measured environmental radon exposure.

RESULTS

After adjustment, male machine operators and workers in mining, stone working and building materials manufacturing showed the highest risk. Women working in electrical engineering, electronics, watchmaking, vehicle construction and toolmaking, and transport occupations also remained at high risk. Radon exposure had no effect on lung cancer mortality, while smoking demonstrated a significant effect in both sexes.

CONCLUSIONS

The results suggest the presence of occupational exposures to lung carcinogens in addition to non-occupational factors.

Population attributable fraction in textbooks: Time to revise

Introduction

The population attributable fraction is an important measure for assessing the impact of intervention on the disease risk in populations, but it is frequently misused in the research literature.

Methods

In this study, we review the definition, calculation, interpretation and assumptions of PAF in 43 textbooks and highlight important shortcomings.

Results

While the Levin formula was proposed as a method of calculation in 29 (67%) textbooks, only in 4 (9%) was the Miettinen formula or its generalization for multilevel exposure recommended to calculate a confounding-adjusted population attributable fraction. Other concepts such as generalized impact fraction and prevented and preventable fractions were briefly discussed in few textbooks.

Discussion

We recommend the authors revise the textbooks in light of our proposed framework for teaching the population attributable fraction.

Cancer risk from chronic exposures to chemicals and radiation: a comparison of the toxicological reference value with the radiation detriment

This article aims at comparing reference methods for the assessment of cancer risk from exposure to genotoxic carcinogen chemical substances and to ionizing radiation. For chemicals, cancer potency is expressed as a toxicological reference value (TRV) based on the most sensitive type of cancer generally observed in animal experiments of oral or inhalation exposure. A dose-response curve is established by modelling experimental data adjusted to apply to human exposure. This leads to a point of departure from which the TRV is derived as the slope of a linear extrapolation to zero dose. Human lifetime cancer risk can then be assessed as the product of dose by TRV and it is generally considered to be tolerable in a 10^-6-10^-4 range for the public in a normal situation. Radiation exposure is assessed as an effective dose corresponding to a weighted average of energy deposition in body organs. Cancer risk models were derived from the epidemiological follow-up of atomic bombing survivors. Considering a linear-no-threshold dose-risk relationship and average baseline risks, lifetime nominal risk coefficients were established for 13 types of cancers. Those are adjusted according to the severity of each cancer type and combined into an overall indicator denominated radiation detriment. Exposure to radiation is subject to dose limits proscribing unacceptable health detriment. The differences between chemical and radiological cancer risk assessments are discussed and concern data sources, extrapolation to low doses, definition of dose, considered health effects and level of conservatism. These differences should not be an insuperable impediment to the comparison of TRVs with radiation risk, thus opportunities exist to bring closer the two types of risk assessment.

Malignant mesothelioma: Ongoing controversies about its etiology in females

Malignant mesothelioma (MM) is one of the most aggressive cancers with the poorest of outcomes. There is no doubt that mesothelioma in males is related to asbestos exposure, but some authors suggest that most of the cases diagnosed in females are "idiopathic." In our assessment of the science, the "low risk" of mesothelioma in females is because of the nonsystematic recording of exposure histories among females. Indeed, asbestos exposure is mentioned in only some of the studies that include females. We estimate the risk of MM among females to be close to that in males. The absence of detailed exposure histories should be rectified in future studies involving ​women. As a matter of social justice, the ongoing failure to recognize asbestos as the cause of a majority of cases of MM in females does them, and their kin, a profound disservice.

An innovative method to estimate lifetime prevalence of carcinogenic occupational circumstances: the example of painters and workers of the rubber manufacturing industry in France

BACKGROUND

Existing methods to estimate lifetime exposure to occupational carcinogenic agents could be improved.

OBJECTIVE

We propose a new method to estimate the lifetime prevalence of exposure to occupational carcinogens using the example of painters and workers of the rubber industry in France.

METHODS

From census, we calculated the proportion of painters and rubber industry workers using predefined occupational codes related to each occupation by sex and 10-year age group in 1982, 1990, 1999, 2007, and 2013. Using a beta-regression model, we obtained the yearly prevalence of exposure by 10-year age group over the period 1967-2007. We estimated the age- and sex-specific lifetime prevalence of exposure of the population in 2017 over 1967-2007, summing up the estimated prevalence of exposure for years 1967, 1977, 1987, 1997, and 2007 combined with a sex- and age-specific turnover factor. Corresponding population-attributable fractions were estimated for lung and bladder cancers in 2017.

RESULTS

In 2017, we estimated that 5.6 and 0.2% of men in France had ever worked as a painter or in the rubber industry, respectively, during their working time. The lifetime prevalence of ever having worked as a painter or in the rubber industry was much lower in women: 1.8% and 0.1%, respectively. We estimated that 950 lung cancer and 40 bladder cancer cases were attributable to these occupations in 2017.

SIGNIFICANCE

Based on accurate data and taking into account evolution of specific jobs over time, the proposed method provides good estimates of lifetime prevalence of exposure to occupational carcinogens. It could be applied in any other country with similar data.

Lifetime occupational exposure proportion estimation methods: a sensitivity analysis in the general population

OBJECTIVE

To present a sensitivity analysis of the most widely used means of estimating lifetime occupational exposure proportion (LOEP) and their respective impacts on LOEP and population-attributable fraction (PAF) estimates.

METHODS

A French population-based sample with full job history (N = 10,010) was linked with four Matgéné job-exposure matrices: flour, cement, silica and benzene. LOEP and the 95% confidence interval were estimated using four methods: the maximum exposure probability during the career (Proba_max), two methods subdividing careers into job-periods (job-period_M1, job-period_M2) and one into job-years (job-year). To quantify differences between methods, percentages of variation were calculated for proportion values and PAF, and compared with published results for France using cross-sectional proportion multiplied by a factor.

RESULTS

For each agent, LOEP estimated from the maximum probability during the career (Proba_max) was consistently lower than proportion taking account of job-periods or job-years. LOEP on Proba_max for flour, cement, silica and benzene were, respectively, 4.4% 95% CI (4.0-4.7), 4.3% (3.9-4.6), 6.1% (5.7-6.5) and 3.9% (3.6-4.2). Percentage of variation ranged from 0 to 55.8% according to the agent. The number of cancer cases varied by a twofold factor for exposure to silica and lung cancer and by a fourfold factor for exposure to benzene and acute myeloid lymphoma.

CONCLUSIONS

The present study provides a description of several LOEP estimation methods based on exposure assessment over the entire career and describes their impact on PAF. For health monitoring purposes, we recommend to report a range of LOEP with low and high estimates obtained using job-periods (job-period_M1 and job-period_M2).

Occupational cancer burden: the contribution of exposure to process-generated substances at the workplace

Respirable crystalline silica in mineral dust, wood dust, diesel engine exhaust emissions and welding fumes are among the most common process-generated substances to which millions of workers are exposed daily. The composition of process-generated substances can vary substantially, depending on the parameters of the underlying processes; for example, the composition and intensity of diesel motor emissions differs among the various generations of diesel engines and working environments (e.g. surface or underground mining). We illustrate how common these occupational exposures are and discuss challenges in estimating their global prevalence and their contribution to the burden of occupational cancer. Estimates of the number and proportion of workers exposed in most countries and on a global scale are generally scarce. A remarkable exception is based on the proactive bottom-up estimates generated within the European Network for Silica. Actions to reduce exposures and research to fill gaps in knowledge adapted to local settings are warranted to mitigate the occupational cancer burden, especially in under-researched settings including low- and middle-income countries.

Association of 13 Occupational Carcinogens in Patients With Cancer, Individually and Collectively, 1990-2017

IMPORTANCE

Occupational exposure to carcinogens has been shown to pose a serious disease burden at the global, regional, and national levels. Based on epidemiologic studies and clinical observations, working environment appears to have important effects on the occurrence of human malignant tumors; however, to date, no systematic articles have been published that specifically investigated cancer burden due to occupational exposure in an individual and collective manner.

OBJECTIVE

To estimate the degree of exposure and evaluate the cancer burden attributable to occupational carcinogens (OCs) individually and collectively by sex, age, year, and location.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study including data on 195 countries from the Global Burden of Diseases, Injuries, and Risk Factors Study from January 1, 1990, to December 31, 2017. Data were analyzed from June 24, 2020, to July 20, 2020.

EXPOSURES

Thirteen OCs (ie, arsenic, asbestos, benzene, beryllium, cadmium, chromium, diesel engine exhaust, formaldehyde, nickel, polycyclic aromatic hydrocarbons, silica, sulfuric acid, and trichloroethylene).

MAIN OUTCOMES AND MEASURES

The degree and change patterns of exposure as well as the attributable cancer burden, including deaths and disability-adjusted life years (DALYs), by sex, age, year, and location for 13 OCs. The calculation of the population-attributable fraction was based on past exposure in the population and relative risks.

RESULTS

Based on the GBD 2017 study, 13 OCs attributable to 7 cancer types were included. Most summary exposure values for the 13 OCs, particularly those of diesel engine exhaust (35.6% increase; 95% uncertainty interval [UI], 32.4%-38.5%) and trichloroethylene (30.3% increase; 95% UI, 27.3%-33.5%), increased from 1990 to 2017. Only exposure to asbestos decreased by 13.8% (95% UI, -26.7% to 2.2%). In 2017, 319 000 (95% UI, 256 000-382 000) cancer deaths and 6.42 million (95% UI, 5.15 million to 7.76 million) DALYs were associated with OCs combined, accounting for 61.0% (95% UI, 59.6%-62.4%) of the total cancer deaths and 48.3% (46.3% to 50.2%) of the DALYs. Among the 13 OCs, the 3 leading risk factors for cancer burden were asbestos (71.8%), silica (15.4%), and diesel engine exhaust (5.6%). For most OCs, the attributed cancer outcome was tracheal, bronchial, and lung cancer, which accounted for 89.0% of attributable cancer deaths. China (61 644 cancer deaths), the US (42 848), and Japan (20 748) accounted for the largest number of attributable cancer deaths in 2017; for DALYs, China (1.47 million), the US (0.71 million), and India (0.37 million) were the 3 leading countries.

CONCLUSIONS AND RELEVANCE

Results of this study suggest that although OC exposure levels have decreased, the overall cancer burden is continuously increasing.

[Better screening for work-related cancers: The experience of Brest University Hospital Occupational Disease Center inpatient service]

INTRODUCTION

An in-patient clinical service has been set up in March 2016 in the Occupational Diseases Center of Brest University Hospital, France, to seek for work-relatedness of diseases in patients hospitalized into the oncology and hematology departments. We present here data after two years of existence.

METHODS

All cases of cancers or malignant hematological diseases (ICD-10 codes C00 to C97 and D37 to D48) seen between March 1, 2016, and March 1, 2018, have been identified. We present sociodemographic data, occupational exposures, occupation, business sector, and tobacco consumption. The causation level between the disease and each of the occupational exposures has been rated as strong, intermediate, weak or null by the occupational medicine specialist of the Occupational Diseases Center.

RESULTS

Among the 196 patients encountered, there are 127 work-related diseases and 82 of these had one occupational exposure rated as strong or intermediate. The most frequent occupational hazards were asbestos (48 cases) and ionizing radiation (23 cases). The most frequent business sectors were metallurgy, mechanical engineering, and agriculture. Lung cancer was the most frequently reported disease (49 cases).

DISCUSSION

. We identified well-known couples with occupational exposures and diseases, such as asbestos and lung cancer. We also identified a link between pesticides and leukemias. This in-patient clinical service is helpful to identify work-related exposures and in helping patients to get compensated.

Assessment of the future mesothelioma disease burden from past exposure to asbestos in ship recycling yards in India

The recycling of end-of-life vessels is a complex activity that generates an enormous amount of hazardous waste, including asbestos-containing materials (ACM). Efforts by the Government of India to comply with national and international regulations and improved standard operating procedures are expected to lower the exposure risk of the workforce to hazardous substances, including asbestos. The current workers are likely to face lesser risks than did those exposed in the past. The present study assesses the health risks from past exposure of asbestos for those workers engaged in handling and removing ACM in ship recycling yards before environmentally sound recycling of obsolete ships was introduced in the early 2000s. Estimates were made of the number of workers exposed, and the intensity of exposure and these data were used to estimate the likely number of mesothelioma deaths in the future. It was estimated that nearly 15% of the total workforce engaged in ship recycling will suffer from mesothelioma which translates to about 4,513 mesothelioma deaths among the total of 31,000 workers estimated to be ever employed in the yards from 1994 till 2002. Recommendations are made for a practical approach to the safe handling of ACMs in Indian ship recycling yards.

Geographic Co-Occurrence of Mesothelioma and Ovarian Cancer Incidence

Background: Asbestos is an established cause of several cancers, including mesothelioma and ovarian cancer. Incidence of mesothelioma, the sentinel asbestos-associated cancer, varies by state, likely reflecting different levels of asbestos exposure. We hypothesized that states with high mesothelioma incidence may also have high ovarian cancer incidence. Materials and Methods: Using data from the Centers for Disease Control and Prevention National Program for Cancer Registries and the National Cancer Institute Surveillance, Epidemiology, and End Results Program, we examined the geographic co-occurrence of mesothelioma and ovarian cancer incidence rates by U.S. state for 2003-2015. Results: By state, mesothelioma incidence ranged from 0.5 to 1.3 cases per 100,000 persons and ovarian cancer incidence ranged from 9 to 12 cases per 100,000 females. When states were grouped by quartile of mesothelioma incidence, the average ovarian cancer incidence rate was 10% higher in states with the highest mesothelioma incidence than in states with the lowest mesothelioma incidence. Ovarian cancer incidence tended to be higher in states with high mesothelioma incidence (Pearson correlation r = 0.54; p < 0.0001). Conclusions: Data from state cancer registries show ovarian cancer incidence was positively correlated with mesothelioma incidence, suggesting asbestos may be a common exposure. The potential for asbestos exposure has declined since the 1970s because fewer products contain asbestos; however, some products, materials, and buildings may still release asbestos and thousands of workers may be exposed. Ensuring that people are protected from exposure to asbestos in their workplaces, homes, schools, and communities may reduce the risk of several cancers.

Changes in the Selected Antioxidant Defense Parameters in the Blood of Patients after High Resolution Computed Tomography

Ionizing radiation generated during high resolution computed tomography (HRCT) scanning may have an indirect effect on the mechanisms regulating the oxidative-antioxidant balance in the human body, which is one of the necessary factors ensuring the maintenance of its homeostasis. The aim of the study was to analyze the response of antioxidant systems through the determination of the antioxidant markers in the blood of patients exposed to oxidative stress resulting from the routine HRCT examination of the chest. Blood of 35 people aged 60.77 ± 10.81 taken before and at four time points after the examination constituted the test material. The determination of the total antioxidant capacity expressed as ferric reducing ability of plasma (FRAP) and ferric reducing antioxidant activity and ascorbic acid concentration (FRASC) were performed together with an examination of catalase activity and the concentration of the reduced glutathione. The organism’s response to ionizing radiation was associated with a significant decrease in the antioxidant markers’ levels at all time-points and showed a significant negative correlation depending on the radiation dose. Visible down-regulation of these markers is a response to increased oxidative stress. In light of the obtained results, the measurement of the selected markers of antioxidant defense may be a useful parameter of oxidative stress caused by ionizing radiation.

[Occupational cancers: Risks and prevention]

Since 2008, cancer became the first cause of death in France, exceeding cardiovascular diseases. The part of occupational cancers is close to 5% of all cancers but may still be widely underestimated. The detection of occupational cancer risk factors remains complicated. Indeed, most occupational risk factors are also present in the general environment. Thus far, 36 substances and 13 activities have been classified as carcinogenic (Group 1) and 37 substances and 6 activities have been classified as probably carcinogenic (Group 2A) by the International Agency for Research on Cancer (IARC). The most common cancer site is the lung, followed by bladder and skin (except melanoma). The most frequently observed occupational exposure was chemicals, building and construction, mining, metal production and coal transformation. Thus far, preventive actions are mandatory in occupational health in France, and are about occupational exposure monitoring, protection of vulnerable populations and reinforced medical supervision. Research must be continued to improve the knowledge on occupational carcinogens, in order to better protect the health of workers.