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

Leukemia Incidence by Occupation and Industry: A Cohort Study of 2.3 Million Workers from Ontario, Canada

Although a significant body of evidence has attributed certain occupational exposures with leukemia, such as benzene, formaldehyde, 1,3-butadiene and ionizing radiation, more research is needed to identify work environments at increased risk for this disease. Our study aimed to identify occupational and industry groups associated with an elevated incidence of leukemia using a diverse cohort of workers' compensation claimants from Ontario, Canada. A total of 2,363,818 workers in the Occupational Disease Surveillance System (ODSS) cohort, with claims between 1983-2019, were followed for malignant leukemia diagnoses up to 31 December 2019. We used a Cox proportional-hazards model to estimate the relative incidence of leukemia in specific occupation and industry groups. After adjusting for age and birth year, males in protective services (HR = 1.17, 95% CI = 1.02-1.35), metal machining (HR = 1.23, 95% CI = 1.07-1.41), transport (HR = 1.15, 95% CI = 1.06-1.25), and mining occupations (HR = 1.28, 95% CI = 1.02-1.60) had elevated risks of leukemia compared to other workers in the ODSS, with comparable findings by industry. Among female workers, slight risk elevations were observed among product fabricating, assembling, and repairing occupations, with other increased risks seen in furniture and fixture manufacturing, storage, and retail industries. These findings underscore the need for exposure-based studies to better understand occupational hazards in these settings.

Asbestos-Related lung Cancer: An underappreciated oncological issue

Asbestos, a group of class I (WHO) carcinogenic fibers, is the main cause of mesothelioma. Asbestos inhalation also increases the risk to develop other solid tumours with lung cancer as the most prominent example [91]. The incidence of asbestos-related lung cancer (ARLC) is estimated to be to six times larger than the mesothelioma incidence thereby becoming an important health issue [86]. Although the pivotal role of asbestos in inducing lung cancer is well established, the precise causal relationships between exposures to asbestos, tobacco smoke, radon and 'particulate' (PM2.5) air pollution remain obscure and new knowledge is needed to establish appropriate preventive measures and to tailor existing screening practices[22,61,65]. We hypothesize that a part of the increasing numbers of lung cancer diagnoses in never-smokers can be explained by (historic and current) exposures to asbestos as well as combinations of different forms of air pollution (PM2.5, asbestos and silica).

Contemporary Concise Review 2023: Environmental and occupational lung diseases

Air pollutants have various effects on human health in environmental and occupational settings. Air pollutants can be a risk factor for incidence, exacerbation/aggravation and death due to various lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), hypersensitivity pneumonitis or pneumonia (HP), pulmonary fibrosis such as pneumoconiosis and malignant respiratory diseases such as lung cancer and malignant pleural mesothelioma. Environmental and occupational respiratory diseases are crucial clinical and social issues worldwide, although the burden of respiratory disease due to environmental and occupational causes varies depending on country/region, demographic variables, geographical location, industrial structure and socioeconomic situation. The correct recognition of environmental and occupational lung diseases and taking appropriate measures are essential to their effective prevention.

Mapping recommendations towards an Asian Code Against Cancer (ACAC) as part of the World Code Against Cancer Framework: an Asian National Cancer Centers Alliance (ANCCA) initiative

This paper outlines the process undertaken by Asian National Cancer Centers Alliance (ANCCA) members in working towards an Asian Code Against Cancer (ACAC). The process involves: (i) identification of the criteria for selecting the existing set of national recommendations for ACAC (ii) compilation of existing national codes or recommendations on cancer prevention (iii) reviewing the scientific evidence on cancer risk factors in Asia and (iv) establishment of one or more ACAC under the World Code Against Cancer Framework. A matrix of national codes or key recommendations against cancer in ANCCA member countries is presented. These include taking actions to prevent or control tobacco consumption, obesity, unhealthy diet, physical inactivity, alcohol consumption, exposure to occupational and environmental toxins; and to promote breastfeeding, vaccination against infectious agents and cancer screening. ANCCA will continue to serve as a supportive platform for collaboration, development, and advocacy of an ACAC jointly with the International Agency for Research on Cancer/World Health Organization (IARC/WHO).

Epidemiological trend of lung cancer burden caused by residential radon exposure in China from 1990 to 2019

OBJECTIVE

This study employed time series data to assess long-term changes in the burden of lung cancer (LC) caused by residential radon exposure, an important environmental risk factor, so as to develop evidence-based strategies for future public health management.

METHODS

Based on the open data from the Global Burden of Disease (GBD 2019) database, we conducted an analysis of the residential radon exposure-caused LC mortality, disability-adjusted life years (DALYs), and corresponding crude rates and age-standardized rates (ASRs) for various age groups. We employed the employed age-period-cohort (APC) model to investigate the age, period, and cohort effects of the data, allowing us to discern the trends in LC disease burden attributable to radon exposure in residential settings over time.

RESULTS

From 1990 to 2019, age-standardized mortality rates (ASMR) and age-standardized DALYs rates of LC caused by residential radon exposure in China demonstrated an overall increasing trend, with males higher than females. The CMR and crude DALYs rate for males were higher than those for females across all age groups. The APC analysis revealed that the local drift of LC death and DALYs rates in males and females showed a decreasing trend before 60 and an increasing trend after 60.

CONCLUSION

The persistent presence of residential radon exposure as a crucial risk factor for LC underscores the need for public health authorities and policymakers to take more proactive measures to reduce radon exposure. Particularly, attention should be paid on the elderly population and male patients.

Surveillance of Occupational Exposure to Volatile Organic Compounds at Gas Stations: A Scoping Review Protocol

Health surveillance guides public policies, allows for the monitoring of occupational exposures that may cause health risks, and can prevent work-related diseases. The scoping review protocol herein is designed to map studies on the surveillance of occupational exposure to volatile organic compounds (VOCs) in gas stations and identify the governmental agencies and public health measures in different countries. This review protocol is based on the Joanna Briggs Institute manual and guided by the PRISMA Extension for Scoping Reviews. It includes research articles, theses, dissertations, and official documents on surveillance measures for occupational exposure to VOCs (i.e., benzene, ethylbenzene, toluene, and xylene) in gas stations from different countries. All languages and publication dates will be considered, and a spreadsheet will be used to extract and analyze qualitative and quantitative data. The final version will present the main surveillance measures implemented, responsible entities, results, challenges, limitations, and potential gaps in gas stations.

Granulysin-mediated reduction of PDZRN3 induces Cx43 gap junctions activity exacerbating skin damage in trichloroethylene hypersensitivity syndrome

Trichloroethylene (TCE)-induced hypersensitivity syndrome (THS) has been a concern for many researchers in the field of environmental and occupational health. Currently, there is no specific treatment for THS, leaving patients to contend with severe infections arising from extensive skin lesions, consequently leading to serious adverse effects. However, the pathogenesis of severe skin damage in THS remains unclear. This study aims to investigate the specific danger signals and mechanisms underlying skin damage in THS through in vivo and in vitro experiments. We identified that cell supernatant containing 15 kDa granulysin (GNLY), released from activated CD3-CD56+NK cells or CD3+CD56+NKT cells in PBMC induced by TCE or its metabolite, promoted apoptosis in HaCaT cells. The apoptosis level decreased upon neutralization of GNLY in the supernatant by a GNLY-neutralizing antibody in HaCaT cells. Subcutaneous injection of recombinant 15 kDa GNLY exacerbated skin damage in the THS mouse model and better mimicked patients' disease states. Recombinant 15 kDa GNLY could directly induce cellular communication disorders, inflammation, and apoptosis in HaCaT cells. In addition to its cytotoxic effects, GNLY released from TCE-activated NK cells and NKT cells or synthesized GNLY alone could induce aberrant expression of the E3 ubiquitin ligase PDZRN3, causing dysregulation of the ubiquitination of the cell itself. Consequently, this resulted in the persistent opening of gap junctions composed of connexin43, thereby intensifying cellular inflammation and apoptosis through the "bystander effect". This study provides experimental evidence elucidating the mechanisms of THS skin damage and offers a novel theoretical foundation for the development of effective therapies targeting severe dermatitis induced by chemicals or drugs.

Global, regional, and national burden of non-communicable diseases attributable to occupational asbestos exposure 1990-2019 and prediction to 2035: worsening or improving?

Understanding the burden associated with occupational asbestos exposure on a global and regional scale is necessary to implement coordinated prevention and control strategies. By the GBD Study 2019, we conducted a comprehensive assessment of the non-communicable diseases burden attributable to occupational asbestos exposure. In 2019, 239,330 deaths and 4,189,000 disability-adjusted life years (DALYs) worldwide due to occupational asbestos exposure occurred. 1990-2019, deaths and DALYs attributed to occupational asbestos exposure increased by 65.65% and 43.66%, respectively. Age-standardized mortality rate (ASMR) and age-standardized DALYs rate (ASDR) decreased, with the most rapid declines in high Socio-Demographic Index (SDI) regions, with average annual percent change (AAPC) of - 1.05(95%CI: -1.2, -0.89) and -1.53(95%CI: -1.71, -1.36), respectively. Lung cancer, mesothelioma and ovarian cancer were the top three contributors to the increase in deaths and DALYs, accounting for more than 96%. AAPCs of ASMR and ASDR were positively associated with SDI. Global deaths from occupational asbestos exposure were predicted to increase and ASMR to decrease by 2035, mostly in males. Due consideration should be given to the susceptibility of the elderly, the lag of asbestos onset, and the regional differences, and constantly improve the prevention and control measures of occupational asbestos exposure and related diseases.

An umbrella review of the evidence associating occupational carcinogens and cancer risk at 19 anatomical sites

Occupational exposure to carcinogens of increasing cancer risk have been extensively suggested. A robust assessment of these evidence is needed to guide public policy and health care. We aimed to classify the strength of evidence for associations of 13 occupational carcinogens (OCs) and risk of cancers. We searched PubMed and Web of Science up to November 2022 to identify potentially relevant studies. We graded the evidence into convincing, highly suggestive, suggestive, weak, or not significant according to a standardized classification based on: random-effects p value, number of cancer cases, 95% confidence interval of largest study, heterogeneity between studies, 95% prediction interval, small study effect, excess significance bias and sensitivity analyses with credibility ceilings. The quality of meta-analysis was evaluated by AMSTAR 2. Forty-eight articles yielded 79 meta-analyses were included in current umbrella review. Evidence of associations were convincing (class I) or highly suggeastive (class II) for asbestos exposure and increasing risk of lung cancer among smokers (RR = 8.79, 95%CI: 5.81-13.25 for cohort studies and OR = 8.68, 95%CI: 5.68-13.24 for case-control studies), asbestos exposure and increasing risk of mesothelioma (RR = 4.61, 95%CI: 2.57-8.26), and formaldehyde exposure and increasing risk of sinonasal cancer (RR = 1.68, 95%CI: 1.38-2.05). Fifteen associations were supported by suggestive evidence (class III). In summary, the current umbrella review found strong associations between: asbestos exposure and increasing risk of lung cancer among smokers; asbestos exposure and increasing risk of mesothelioma; and formaldehyde exposure and higher risk of sinonasal cancer. Other associations might be genuine, but substantial uncertainty remains.

Global burden of leukemia attributable to occupational exposure to formaldehyde from 1990 to 2019

The objective of this study was to evaluate the worldwide burden of leukemia owing to occupational exposure to formaldehyde (OEF) from 1990 to 2019. Data on leukemia due to OEF were obtained from the Global Burden of Disease Study (GBD) 2019. By region, age, sex, and disease subtype, the numbers and age-standardized rates (ASRs) associated with deaths, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life years (DALYs) were analyzed. Annual average percentage change (AAPC) was used to estimate disease burden trends from 1990 to 2019. To measure the risk of leukemia due to OEF, the population attributable fraction (PAF) was introduced. From 1990 to 2019, the number of deaths, DALYs, YLLs, and YLDs for leukemia caused by OEF increased by 44%, 34%, 33%, and 124%, respectively. Regarding the change in ASRs, the age-standardized YLDs (ASYLDs) rate of leukemia due to OEF, which was 38.03% (AAPC = 1.17 [95% confidence interval [CI] 1.11, 1.23]), indicated an increased trend. But the age-standardized mortality rate (ASMR), age-standardized DALY (ASDALY) rate, and age-standardized YLL (ASYLL) rate showed decline trends, with - 11.90% (AAPC =  - 0.41 [95% CI - 0.45, - 0.37]), - 14.19% (AAPC =  - 0.5 [95% CI - 0.55, - 0.45]), and - 14.97% (AAPC =  - 0.53 [95% CI - 0.58, - 0.48]), respectively. In terms of PAFs, there were increasing trends in PAFs of age-standardized deaths, ASDALYs, ASYLLs, and ASYLDs for leukemia caused by OEF, with 20.15% (95% uncertainty interval [UI] 11.76%, 30.25%), 36.28% (95% UI 21.46%, 53.42%), 51.91% (95% UI 35.05%, 72.07%), and 36.34% (95% UI 21.58%, 53.63%), respectively. Across the socio-demographic index (SDI) regions, the leukemia burden caused by OEF was concentrated in middle and high-middle SDI regions. Besides, OEF poses a more serious risk for acute leukemia among the leukemia subtype. Globally, leukemia caused by OEF remains a public health burden. Policies must be developed to avoid the burden of leukemia caused by OEF.

Secular trends and attributable risk factors of esophageal cancer deaths among non-elderly adults based on Global Burden of Disease Study

OBJECTIVE

Esophageal cancer (EC) poses a persistent threat to the health of non-elderly adults. This study aims to elucidate the temporal trends of EC-related mortality and investigate the impact of various risk factors on such deaths in the age group of 20-59 years, spanning 3 decades.

METHODS

Data on EC deaths were acquired from the Global Burden of Disease, Injuries, and Risk Factors (GBD) study. We employed estimated average percentage change (EAPC) and linear mixed-effects (LME) models to analyze mortality trends and pertinent risk factors for EC.

RESULTS

Between 1990 and 2019, EC mortality showed a downward trend, and the global number of deaths from EC among non-elderly adults surged by 24.37%. During this period, mortality rates saw an increase in only two regions-the Caribbean and Western Sub-Saharan Africa (EAPCs > 0). For male deaths, smoking and alcohol use emerged as the primary risk factors, while high body mass index (BMI) stood out as the main risk factor for female deaths. Furthermore, the LME model identified male sex, advancing age, alcohol use, smoking, and chewing tobacco as factors associated with an additional rise in EC deaths.

CONCLUSION

EC continues to exert a substantial toll on mortality among young and middle-aged adults globally. Implementing targeted interventions are significant in alleviating the burden of this disease within this population.

Global burden of tracheal, bronchus, and lung cancer attributable to occupational carcinogens in 204 countries and territories, from 1990 to 2019: results from the global burden of disease study 2019

BACKGROUND

Occupational-related cancers are a substantial global health issue. The largest proportion of occupational-related cancers is tracheal, bronchus, and lung (TBL) cancer. This study aimed to explore the geographical and temporal trends in occupational carcinogens related to TBL cancer.

METHODS

Data on TBL cancer attributable to occupational carcinogens were collected from the Global Burden of Disease Study 2019. Numbers and age-standardized rates (ASRs) of deaths, disability-adjusted life years (DALYs), and corresponding average annual percentage change (AAPC) were evaluated and stratified by geographic location, socio-demographic index (SDI) quintiles, age, and sex.

RESULTS

Globally, ASRs of deaths and DALYs in TBL cancer attributable to occupational carcinogens showed a downward trend (AAPC = - 0.69%, - 1.01%) while increases were observed in the low, low-middle, and middle SDI quintiles. Although males accounted for 82.4% and 81.5% of deaths and DALYs in 2019, respectively, it showed an upward trend of ASRs in females (AAPC = 0.33%, 0.02%). Occupational exposure to asbestos, silica and diesel engine exhaust were the top three causes of age-standardized TBL cancer deaths and DALYs. Over the past three decades, the percentage of age-standardized TBL cancer deaths and DALYs attributable to occupational asbestos and silica exposure decreased by 18.24, 6.71 and 20.52%, 4.00% globally, but increased significantly in lower SDI regions, while the burden attributable to occupational diesel engine exhaust exposure increased by 32.76, 37.23% worldwide.

CONCLUSIONS

Occupational exposure remains an important risk factor for TBL cancer. The burden of TBL cancer attributable to occupational carcinogens showed obvious heterogeneity which decreased in higher SDI but increased in lower SDI regions. The burden of males was significantly higher than females, but the females showed an increasing trend. Occupational exposure to asbestos was the main causes of the burden. Therefore, effective prevention and control measures tailored to local conditions are necessary.

Global burden of neoplasms attributable to specific occupational carcinogens over 30 years: a population-based study

OBJECTIVES

The study aimed to analyze the global burden of occupational neoplasms from various epidemiological perspectives.

STUDY DESIGN

In this cross-sectional study, secondary analyses were conducted to assess the burden of neoplasms attributable to occupational carcinogens and their distribution characteristics using data from GBD 2019 and the World Bank database.

METHODS

Based on the GBD 2019 and the World Bank database, we analyzed the global burden of occupational neoplasms including the age-period-cohort model, decomposition analysis, health inequality analysis, and panel model. All analyses were conducted in R (version 4.0.3) and Joinpoint (version 4.9.1).

RESULTS

The absolute number of neoplasms burden attributable to occupational carcinogens has continued to rise over 30 years. In 2019, occupational neoplasms caused 333,867 [95% uncertainty interval (UI): 263,491 to 404,641] mortalities and 6,964,775 (95% UI: 5,467,884 to 8,580,431) disability-adjusted life years (DALYs) globally. Greenland, Monaco, the Netherlands, and Andorra suffered the highest burden. The burden was higher in countries with a higher sociodemographic index. The age effect was prominent in the elderly, and the 1925 birth cohort had the highest cohort effect. Population growth was the most significant driver of the mortalities (89%) and DALYs (111%) change. Moreover, the proportion of urban population was significantly positively associated with the disease burden, while GDP per capita was negatively correlated with the disease burden.

CONCLUSIONS

The burden of occupational neoplasms was unevenly distributed across locations and populations. The need for rational allocation of healthcare resources was urgent.

Burden of lung cancer and predicted costs of occupational exposure to hexavalent chromium in the EU - The impact of different occupational exposure limits

BACKGROUND

Exposure to hexavalent chromium [Cr(VI)] occurs widely in occupational settings across the EU and is associated with lung cancer. In 2025, the occupational exposure limit is set to change to 5 μg/m³. Current exposure limits are higher, with 10 μg/m³ as a general limit and 25 μg/m³ for the welding industry. We aimed to assess the current burden of lung cancer caused by occupational exposure to Cr(VI) and to evaluate the impact of the recently established EU regulation by analysing different occupational exposure limits.

METHODS

Data were extracted from the literature, the Global Burden of Disease 2019) study, and Eurostat. We estimated the cases of cancer attributable to workplace exposure to Cr(VI) by combining exposure-effect relationships with exposure data, and calculated related DALYs and health costs in scenarios with different occupational exposure limits.

RESULTS

With current EU regulations, 253 cases (95%UI 250.96-255.71) of lung cancer were estimated to be caused by Cr(VI) in 2019, resulting in 4684 DALYs (95%UI 4683.57-4704.08). In case the welding industry adopted 10 μg/m³, a decrease of 43 cases and 797 DALYs from current values is expected. The predicted application of a 5 μg/m³ limit would cause a decrease of 148 cases and 2746 DALYs. Current costs are estimated to amount to 12.47 million euros/year (95%UI 10.19-453.82), corresponding to 39.97 million euros (95%UI 22.75-70.10) when considering costs per DALY. The limits implemented in 2025 would lead to a decrease of 23.35 million euros when considering DALYs, with benefits of introducing a limit value occurring after many decades. Adopting a 1 μg/m³ limit would lower costs to 1.04 million euros (95%UI 0.85-37.67) and to 3.33 million euros for DALYs (95%UI 1.89-5.84).

DISCUSSION

Assessing different scenarios with different Cr(VI) occupational exposure limits allowed to understand the impact of EU regulatory actions. These findings make a strong case for adapting even stricter exposure limits to protect workers' health and avoid associated costs.

Epidemiological and demographic drivers of lung cancer mortality from 1990 to 2019: results from the global burden of disease study 2019

Background

Understanding the effects of demographic drivers on lung cancer mortality trends is critical for lung cancer control. We have examined the drivers of lung cancer mortality at the global, regional, and national levels.

Methods

Data on lung cancer death and mortality were extracted from the Global Burden of Disease (GBD) 2019. Estimated annual percentage change (EAPC) in the age-standardized mortality rate (ASMR) for lung cancer and all-cause mortality were calculated to measure temporal trends in lung cancer from 1990 to 2019. Decomposition analysis was used to analyze the contributions of epidemiological and demographic drivers to lung cancer mortality.

Results

Despite a non-significant decrease in ASMR [EAPC = -0.31, 95% confidence interval (CI): -1.1 to 0.49], the number of deaths from lung cancer increased by 91.8% [95% uncertainty interval (UI): 74.5-109.0%] between 1990 and 2019. This increase was due to the changes in the number of deaths attributable to population aging (59.6%), population growth (56.7%), and non-GBD risks (3.49%) compared with 1990 data. Conversely, the number of lung cancer deaths due to GBD risks decreased by 19.8%, mainly due to tobacco (-12.66%), occupational risks (-3.52%), and air pollution (-3.47%). More lung cancer deaths (1.83%) were observed in most regions, which were due to high fasting plasma glucose levels. The temporal trend of lung cancer ASMR and the patterns of demographic drivers varied by region and gender. Significant associations were observed between the contributions of population growth, GBD risks and non-GBD risks (negative), population aging (positive), and ASMR in 1990, the sociodemographic index (SDI), and the human development index (HDI) in 2019.

Conclusion

Population aging and population growth increased global lung cancer deaths from 1990 to 2019, despite a decrease in age-specific lung cancer death rates due to GBD risks in most regions. A tailored strategy is needed to reduce the increasing burden of lung cancer due to outpacing demographic drivers of epidemiological change globally and in most regions, taking into account region- or gender-specific risk patterns.

Low-dose blood BTEX are associated with pulmonary function through changes in inflammatory markers among US adults: NHANES 2007-2012

The effects of blood benzene, toluene, ethylbenzene, and xylenes (BTEX) on lung function among general adults remain unknown. We enrolled 5519 adults with measured blood BTEX concentrations and lung function from the US National Health and Nutrition Examination Survey 2007-2012. Weighted linear models were fitted to assess the associations of BTEX with lung function and inflammation parameters (white blood cell five-part differential count and C-reactive protein). The mediating effect of inflammation between BTEX and lung function was also examined. Blood BTEX concentrations decreased yearly from 1999 and were extremely low from 2007 to 2012. Benzene and toluene exerted the greatest influence on lung function in terms of forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), calculated FEV1:FVC ratio, peak expiratory flow rate (PEFR), and forced mid expiratory flow (FEF_25-75%). Both ethylbenzene and all xylene isomers had no effects on FVC but reduced FEV1, FEV1:FVC ratio, PEFR, and FEF_25-75%. Weighted quantile analyses demonstrated that BTEX mixture was associated with decreases in FVC, FEV1, FEV1:FVC ratio, PEFR, and FEF_25-75%, with benzene weighted most heavily for all lung function parameters. BTEX also increased the levels of inflammation indicated by white blood cell five-part differential count and C-reactive protein, and increased levels of inflammation also reduced lung function. From multiple mediation analysis, inflammation mediated the effects of benzene on FEV1 and PEFR, the effects of toluene on FEV1, and the effects of ethylbenzene on FEV1 and PEFR. Low-dose exposure to BTEX was associated with reduced pulmonary function both in large and small airways. Inflammation could be involved in this pathogenesis.

Biochemistry-Not Oncogenes-May Demystify and Defeat Cancer

The presence of mutated genes strongly correlates with the incidence of cancer. Decades of research, however, has not yielded any specific causative gene or set of genes for the vast majority of cancers. The Cancer Genome Atlas program was supposed to provide clarity, but it only gave much more data without any accompanying insight into how the disease begins and progresses. It may be time to notice that epidemiological studies consistently show that the environment, not genes, has the principal role in causing cancer. Since carcinogenic chemicals in our food, drink, air, and water are the primary culprits, we need to look at the biochemistry of cancer, with a focus on enzymes that invariably facilitate transformations in a cell. In particular, attention should be paid to the rate-limiting enzyme in DNA synthesis, ribonucleotide reductase (RnR), whose activity is tightly linked to tumor growth. Besides circumstantial evidence that cancer is induced at this enzyme's vulnerable free-radical-containing active site by various carcinogens, its role in initiating retinoblastoma and human papillomavirus (HPV)-related cervical cancers has been well documented in recent years. Blocking the activity of malignant RnR is a certain way to arrest cancer.

Trichloroethylene: An Invisible Cause of Parkinson's Disease?

The etiologies of Parkinson's disease (PD) remain unclear. Some, such as certain genetic mutations and head trauma, are widely known or easily identified. However, these causes or risk factors do not account for the majority of cases. Other, less visible factors must be at play. Among these is a widely used industrial solvent and common environmental contaminant little recognized for its likely role in PD: trichloroethylene (TCE). TCE is a simple, six-atom molecule that can decaffeinate coffee, degrease metal parts, and dry clean clothes. The colorless chemical was first linked to parkinsonism in 1969. Since then, four case studies involving eight individuals have linked occupational exposure to TCE to PD. In addition, a small epidemiological study found that occupational or hobby exposure to the solvent was associated with a 500% increased risk of developing PD. In multiple animal studies, the chemical reproduces the pathological features of PD.Exposure is not confined to those who work with the chemical. TCE pollutes outdoor air, taints groundwater, and contaminates indoor air. The molecule, like radon, evaporates from underlying soil and groundwater and enters homes, workplaces, or schools, often undetected. Despite widespread contamination and increasing industrial, commercial, and military use, clinical investigations of TCE and PD have been limited. Here, through a literature review and seven illustrative cases, we postulate that this ubiquitous chemical is contributing to the global rise of PD and that TCE is one of its invisible and highly preventable causes. Further research is now necessary to examine this hypothesis.

A comparative study of the disease burden attributable to asbestos in Brazil, China, Kazakhstan, and Russia between 1990 and 2019

Background

Brazil, China, Kazakhstan, and Russia are the main asbestos-producing countries, and all forms of asbestos are carcinogenic to humans. The objective of this study was to estimate the disease burden attributable to asbestos between 1990 and 2019 in major producing countries, including Brazil, China, Kazakhstan, and Russia.

Methods

Age-standardized mortality rates (ASMR) and age-standardized disability-adjusted life year (DALY) rates (ASDR) of disease burden attributable to asbestos by country, age, and sex were extracted from the Global Burden of Disease 2019. Percentage change and estimated annual percentage change (EAPC) were used to assess the trends of ASDR and ASMR of disease burden attributable to asbestos between 1990 and 2019.

Results

Asbestos-related diseases were highly heterogeneous across Global, Brazil, China, Kazakhstan, and Russia. There was a downward trend in ASMR and ASDR of diseases burden related to asbestos globally. The age-specific mortality rate of disease attributable to asbestos increased in men and women, although it decreased in women aged 85–89, the highest age-specific mortality rate were observed in age 95 + group in men [162.14 (95% UI: 103.76–215.45)] and women [30.58 (95% UI: 14.83–44.33)] per 100 000 population, respectively. Tracheal, bronchus, and lung (TBL) cancer was the leading cause of death and DALYS attributable to asbestos between 1990 and 2019 globally and in Brazil, China, Kazakhstan, and Russia. China had the highest percentage change (73.31%) and EAPC [3.41 (95% CI: 2.75–4.08)] in ASMR related to exposure to asbestos in men, with the highest percentage change (73.31%) and EAPC [3.41 (95% CI: 2.75–4.08)] in ASDR in men.

Conclusions

The ASMR and ASDR of disease burden attributable to asbestos decreased between 1990 and 2019 globally. TBL cancer was the leading cause of death and DALYs attributable to asbestos between 1990 and 2019. There has been an increasing trend in mortality and DALYs globally, especially in older men. The burden of disease attributable to asbestos is increasing in China, especially in men.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14437-6.

Burden of Lung Cancer Attributable to Occupational Carcinogens from 1990 to 2019 and Projections until 2044 in China

Simple Summary

The disease burden trend of lung cancer that is attributable to occupational carcinogens in China remains unclear. We used the data from the Global Burden of Disease (GBD) study in 2019 to investigate the related disease burden from 1990 to 2019 and to project the disease burden for the next 25 years. The results indicate that the disease burden of lung cancer that can be attributed to occupational carcinogens significantly increased from 1990 to 2019 in China, and the absolute burden will continue to increase in the next 25 years.

Abstract

Background: Little is known about trends in the lung cancer burden from the disease that can be attributed to occupational carcinogens in China. Methods: Data regarding the lung cancer burden that can be attributed to occupational carcinogens in China were extracted from the Global Burden of Disease (GBD) study in 2019. Joinpoint regression analysis and an age-period-cohort (APC) analysis were conducted to estimate the trend of lung cancer burden as a result of occupational carcinogens from 1990 to 2019. A Bayesian APC model was used to predict the disease burden until 2044. Results: The average annual percentage changes of age-standardized summary exposure values (SEVs) of occupational lung carcinogens, as well as the age-standardized population attributable fraction (PAF) of lung cancer due to occupational carcinogens, were 0.5% (95% confidence interval (CI): 0.4–0.5%) and 0.1% (95% CI: 0–0.2%), respectively. In addition, both the joinpoint regression analysis and APC analysis demonstrated significantly increased trends of age-standardized lung cancer mortality (ASMR) and age-standardized disability-adjusted life years (ASDR) as a result of occupational carcinogens. Asbestos and silica accounted for the two most important occupational lung carcinogens in China. The absolute burden is expected to increase, mainly due to population aging and the age-specific rate of illness. Conclusions: The lung cancer burden that could be attributed to occupational carcinogens significantly increased from 1990 to 2019 in China, and the absolute burden will continue to increase in the next 25 years.

The Burden of Trachea, Bronchus, and Lung Cancer Attributable to Occupational Exposure From 1990 to 2019

Objectives

Occupational exposure to carcinogens is associated with trachea, bronchus, and lung (TBL) cancer. The objective of this study was to provide global and regional estimates of the burden of TBL cancer associated with occupational carcinogens (OCs) between 1990 and 2019.

Methods

Age-standardized mortality rates (ASMR) and age-standardized disability-adjusted life years (DALYs) rates (ASDR) of TBL cancer related to exposure to OCs at the global and regional levels were extracted for 1990–2019 from the Global Burden of Disease 2019. Joinpoint regression was used to analyze trends in the ASMR and ASDR of TBL cancer burden related to OCs, and the annual percent change and the average annual percent change (AAPC) were recorded.

Results

The mortality from TBL cancer related to exposure to OCs increased globally. The ASMR and ASDR decreased in both sexes and in men between 1990 and 2019. The AAPC of ASMR and ASDR decreased in men between 1990 and 2019, but increased in women. Asbestos accounted for the highest death number and beryllium accounted for the lowest; diesel engine exhaust caused the largest percentage change in death number (145.3%), in ASDR (14.9%), and in all ages DALY rates (57.6%). Asbestos accounted for the largest death number in high social development index (SDI) countries, whereas low-middle SDI countries had the largest percent change (321.4%). Asbestos was associated with decreased ASDR in high SDI countries and increased ASDR in low-middle SDI countries, and similar changes were observed for other OCs.

Conclusions

The overall mortality and DALYs of TBL cancer burden related to OCs showed a decreasing trend between 1990 and 2019, whereas death number increased. Asbestos accounted for the highest death number. TBL cancer burden related to OCs decreased to different degrees in high, low, low-middle, and middle SDI countries, which showed variable levels of TBL cancer burden related to exposure to OCs (except asbestos).

Global, regional, and national burden of age-related hearing loss from 1990 to 2019

The global distribution and temporal trend of age-related hearing loss (ARHL) are unknown, and we aimed to investigate magnitudes and temporal trends of ARHL burden and its influencing factors at the national, regional, and global levels. Based on the information of Global Burden of Disease Study 2019, we calculated the estimated annual percentage change to quantify the global, regional, and national temporal trends of age-standardized rates (ASRs) of ARHL by gender, age, and severity. The number of prevalent cases and disability-adjusted life years (DALYs) of ARHL increased from 751.50 million and 22.01 million in 1990 to 1456.66 million and 40.24 million in 2019, respectively. Except for a few countries such as Niger and Burkina Faso, the age-standardized prevalence rate and age-standardized DALYs rate showed a downward trend in most countries and regions. Mild ARHL accounted for the largest proportion in all ARHL, and only mild ARHL showed an upward trend in ASRs. In most regions, the proportion of ARHL disease burden attributable to occupational noise showed a downward trend in the past 30 years. In 2019, ARHL disease burden attributable to occupational noise declined with the increase of socio-demographic index in countries. Although the ASR of ARHL in most parts of the world is declining, the absolute disease burden of ARHL is still heavy. Understanding the real-time disease burden of ARHL and its temporal trend is of great significance for formulating more effective preventive measures and reducing the ARHL burden.

Malignant transformation of oral leukoplakia: Systematic review and meta-analysis of the last 5 years

OBJECTIVE

Oral leukoplakia (OL) is the most frequently encountered oral potentially malignant disorder. The aims of this systematic review are to estimate the overall malignant transformation of OL and to assess the risk factors associated with malignant transformation of OL published in the last 5 years (2015-2020).

MATERIALS AND METHODS

We performed a bibliographic search in PubMed, Scopus, Web of Science, Embase, and Cochrane databases with keywords "oral leukoplakia", "oral cancer", "oral carcinoma" and "oral squamous cell carcinoma". Meta-analysis was conducted using a random-effects model.

RESULTS

Twenty-four studies were selected, that reported a total of 16,604 patients. Malignant transformation proportion varied between 1.1% and 40.8%. Female gender, non-homogeneous clinical type, and presence of epithelial dysplasia were significantly related to MT. Other risk factors previously suggested did not show significant results.

CONCLUSIONS

The pooled proportion of malignant transformation MT was 9.8% (95% CI: 7.9-11.7). It is necessary to continue to conduct well-designed prospective clinicopathological studies on OL, using a uniform definition for OL to reduce the risk of bias for evaluating various factors associated with the MT.