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Environment International Aug 2023The World Health Organization (WHO) and the International Labour Organization (ILO) are developing joint estimates of the work-related burden of disease and injury... (Meta-Analysis)
Meta-Analysis
The prevalences and levels of occupational exposure to dusts and/or fibres (silica, asbestos and coal): A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury.
BACKGROUND
The World Health Organization (WHO) and the International Labour Organization (ILO) are developing joint estimates of the work-related burden of disease and injury (WHO/ILO Joint Estimates), with contributions from a large number of individual experts. Evidence from human, animal and mechanistic data suggests that occupational exposure to dusts and/or fibres (silica, asbestos and coal dust) causes pneumoconiosis. In this paper, we present a systematic review and meta-analysis of the prevalences and levels of occupational exposure to silica, asbestos and coal dust. These estimates of prevalences and levels will serve as input data for estimating (if feasible) the number of deaths and disability-adjusted life years that are attributable to occupational exposure to silica, asbestos and coal dust, for the development of the WHO/ILO Joint Estimates.
OBJECTIVES
We aimed to systematically review and meta-analyse estimates of the prevalences and levels of occupational exposure to silica, asbestos and coal dust among working-age (≥ 15 years) workers.
DATA SOURCES
We searched electronic academic databases for potentially relevant records from published and unpublished studies, including Ovid Medline, PubMed, EMBASE, and CISDOC. We also searched electronic grey literature databases, Internet search engines and organizational websites; hand-searched reference lists of previous systematic reviews and included study records; and consulted additional experts.
STUDY ELIGIBILITY AND CRITERIA
We included working-age (≥ 15 years) workers in the formal and informal economy in any WHO and/or ILO Member State but excluded children (< 15 years) and unpaid domestic workers. We included all study types with objective dust or fibre measurements, published between 1960 and 2018, that directly or indirectly reported an estimate of the prevalence and/or level of occupational exposure to silica, asbestos and/or coal dust.
STUDY APPRAISAL AND SYNTHESIS METHODS
At least two review authors independently screened titles and abstracts against the eligibility criteria at a first stage and full texts of potentially eligible records at a second stage, then data were extracted from qualifying studies. We combined prevalence estimates by industrial sector (ISIC-4 2-digit level with additional merging within Mining, Manufacturing and Construction) using random-effects meta-analysis. Two or more review authors assessed the risk of bias and all available authors assessed the quality of evidence, using the ROB-SPEO tool and QoE-SPEO approach developed specifically for the WHO/ILO Joint Estimates.
RESULTS
Eighty-eight studies (82 cross-sectional studies and 6 longitudinal studies) met the inclusion criteria, comprising > 2.4 million measurements covering 23 countries from all WHO regions (Africa, Americas, Eastern Mediterranean, South-East Asia, Europe, and Western Pacific). The target population in all 88 included studies was from major ISCO groups 3 (Technicians and Associate Professionals), 6 (Skilled Agricultural, Forestry and Fishery Workers), 7 (Craft and Related Trades Workers), 8 (Plant and Machine Operators and Assemblers), and 9 (Elementary Occupations), hereafter called manual workers. Most studies were performed in Construction, Manufacturing and Mining. For occupational exposure to silica, 65 studies (61 cross-sectional studies and 4 longitudinal studies) were included with > 2.3 million measurements collected in 22 countries in all six WHO regions. For occupational exposure to asbestos, 18 studies (17 cross-sectional studies and 1 longitudinal) were included with > 20,000 measurements collected in eight countries in five WHO regions (no data for Africa). For occupational exposure to coal dust, eight studies (all cross-sectional) were included comprising > 100,000 samples in six countries in five WHO regions (no data for Eastern Mediterranean). Occupational exposure to silica, asbestos and coal dust was assessed with personal or stationary active filter sampling; for silica and asbestos, gravimetric assessment was followed by technical analysis. Risk of bias profiles varied between the bodies of evidence looking at asbestos, silica and coal dust, as well as between industrial sectors. However, risk of bias was generally highest for the domain of selection of participants into the studies. The largest bodies of evidence for silica related to the industrial sectors of Construction (ISIC 41-43), Manufacturing (ISIC 20, 23-25, 27, 31-32) and Mining (ISIC 05, 07, 08). For Construction, the pooled prevalence estimate was 0.89 (95% CI 0.84 to 0.93, 17 studies, I 91%, moderate quality of evidence) and the level estimate was rated as of very low quality of evidence. For Manufacturing, the pooled prevalence estimate was 0.85 (95% CI 0.78 to 0.91, 24 studies, I 100%, moderate quality of evidence) and the pooled level estimate was rated as of very low quality of evidence. The pooled prevalence estimate for Mining was 0.75 (95% CI 0.68 to 0.82, 20 studies, I 100%, moderate quality of evidence) and the pooled level estimate was 0.04 mg/m (95% CI 0.03 to 0.05, 17 studies, I 100%, low quality of evidence). Smaller bodies of evidence were identified for Crop and animal production (ISIC 01; very low quality of evidence for both prevalence and level); Professional, scientific and technical activities (ISIC 71, 74; very low quality of evidence for both prevalence and level); and Electricity, gas, steam and air conditioning supply (ISIC 35; very low quality of evidence for both prevalence and level). For asbestos, the pooled prevalence estimate for Construction (ISIC 41, 43, 45,) was 0.77 (95% CI 0.65 to 0.87, six studies, I 99%, low quality of evidence) and the level estimate was rated as of very low quality of evidence. For Manufacturing (ISIC 13, 23-24, 29-30), the pooled prevalence and level estimates were rated as being of very low quality of evidence. Smaller bodies of evidence were identified for Other mining and quarrying (ISIC 08; very low quality of evidence for both prevalence and level); Electricity, gas, steam and air conditioning supply (ISIC 35; very low quality of evidence for both prevalence and level); and Water supply, sewerage, waste management and remediation (ISIC 37; very low quality of evidence for levels). For coal dust, the pooled prevalence estimate for Mining of coal and lignite (ISIC 05), was 1.00 (95% CI 1.00 to 1.00, six studies, I 16%, moderate quality of evidence) and the pooled level estimate was 0.77 mg/m (95% CI 0.68 to 0.86, three studies, I 100%, low quality of evidence). A small body of evidence was identified for Electricity, gas, steam and air conditioning supply (ISIC 35); with very low quality of evidence for prevalence, and the pooled level estimate being 0.60 mg/m (95% CI -6.95 to 8.14, one study, low quality of evidence).
CONCLUSIONS
Overall, we judged the bodies of evidence for occupational exposure to silica to vary by industrial sector between very low and moderate quality of evidence for prevalence, and very low and low for level. For occupational exposure to asbestos, the bodies of evidence varied by industrial sector between very low and low quality of evidence for prevalence and were of very low quality of evidence for level. For occupational exposure to coal dust, the bodies of evidence were of very low or moderate quality of evidence for prevalence, and low for level. None of the included studies were population-based studies (i.e., covered the entire workers' population in the industrial sector), which we judged to present serious concern for indirectness, except for occupational exposure to coal dust within the industrial sector of mining of coal and lignite. Selected estimates of the prevalences and levels of occupational exposure to silica by industrial sector are considered suitable as input data for the WHO/ILO Joint Estimates, and selected estimates of the prevalences and levels of occupational exposure to asbestos and coal dust may perhaps also be suitable for estimation purposes. Protocol identifier: https://doi.org/10.1016/j.envint.2018.06.005. PROSPERO registration number: CRD42018084131.
Topics: Humans; Adolescent; Occupational Diseases; Dust; Prevalence; Silicon Dioxide; Cross-Sectional Studies; Coal; Steam; Asbestos; Occupational Exposure; World Health Organization; Cost of Illness
PubMed: 37487377
DOI: 10.1016/j.envint.2023.107980 -
Human Reproduction Update 2012Fertility problems are an important health issue, as 10-15% of couples have difficulties conceiving. Reproductive function is thought to be compromised by lifestyle... (Review)
Review
BACKGROUND
Fertility problems are an important health issue, as 10-15% of couples have difficulties conceiving. Reproductive function is thought to be compromised by lifestyle behaviours, but environmental contaminants and work-related factors are also thought to play a role. The objective of this review was to systematically summarize the available evidence concerning the influence of occupational exposure to chemicals on time to pregnancy (TTP).
METHODS
A structured search on occupational exposure to chemicals and TTP was carried out in PubMed and Embase. Studies were included if TTP was used as outcome measure and exposure to chemicals at the job level was described. In total, 49 studies were included in this review.
RESULTS
Studies varied widely in characterization of exposure, hampering a meta-analytic approach across all studies. For lead, strong indications for adverse effects on TTP were present, supporting the mandatory provisions for pregnant women being exposed to lead in many countries. These indications were also found for pesticide exposure, and one could argue that couples working in agriculture or horticultural trades must be informed about the risks of pesticide exposure. Epidemiologic evidence on other chemicals, such as organic solvents, and other metals remains equivocal, hampering clear counselling of couples who are trying to become pregnant.
CONCLUSIONS
Despite some uncertainties in the evidence base, it may still be prudent to advise against lead and pesticide exposure at the workplace for couples trying to conceive. This review also identifies several priorities for future studies in the field of occupational epidemiology.
Topics: Agriculture; Female; Fertilization; Humans; Lead; Male; Maternal Exposure; Metals; Occupational Exposure; Paternal Exposure; Pesticides; Pregnancy; Solvents; Time-to-Pregnancy
PubMed: 22431564
DOI: 10.1093/humupd/dms005 -
Occupational asbestos exposure and risk of esophageal cancer: A systematic review and meta-analysis.International Journal of Cancer Jun 2024Esophageal cancer (EC), which includes squamous cell carcinoma (ESCC) and adenocarcinoma (EAC), is an important cancer with poor prognosis and high mortality rate.... (Meta-Analysis)
Meta-Analysis
Esophageal cancer (EC), which includes squamous cell carcinoma (ESCC) and adenocarcinoma (EAC), is an important cancer with poor prognosis and high mortality rate. Several occupational exposures have been associated with EC. We aim to investigate the association between occupational asbestos exposure and EC risk, considering types of asbestos and histology of the disease. We included studies mentioned in the list of references in previous reviews and pooled analyses, and we conducted an independent search in PubMed and Scopus. Forest plots of relative risks (RR) were constructed based on the association between occupational asbestos and EC risk. Random-effects models were used to address heterogeneity between 48 independent cohort and case-control studies. We found an association between occupational asbestos exposure and EC (meta-relative risk [RR] = 1.20, 95% confidence interval [CI] = 1.09-1.32; I2 = 58.8%, p-heterogeneity [het] <.001). The results of stratification by job (p-het = .20) indicate an increased RR among asbestos product workers (RR = 1.39, 95% CI = 1.07-1.81), asbestos applicators (RR = 1.41, 95% CI = 1.20-1.67), and construction workers (RR = 1.12, 95% CI = 1.02-1.24). There was no heterogeneity in meta-RR according to outcome (p = .29), geographic region (p = .69), year of publication (p = .59), quality score (p = .73), asbestos type (p = .93), study design (p = .87), and gender (p = .88), control for potential confounders (p = .20), year of first employment (p = .94) and exposure level (p = .43). The stratification analysis by histology type found an increased RR for both ESCC 1.33(1.03-1.71) and EAC 1.45(1.03-2.04) (p-het = .68). We didn't find evidence of publication bias (p = .07). The results of our study suggest that occupational asbestos exposure is associated with an increased risk of EC in both histology types.
Topics: Humans; Occupational Exposure; Asbestos; Esophageal Neoplasms; Adenocarcinoma; Carcinoma, Squamous Cell; Occupational Diseases
PubMed: 38339891
DOI: 10.1002/ijc.34881 -
Journal of Occupational and... Oct 2023Asbestos is a mineral that is carcinogenic to humans. Its use has been banned in many occidental countries yet it is still produced in the United States, and materials... (Meta-Analysis)
Meta-Analysis Review
Asbestos is a mineral that is carcinogenic to humans. Its use has been banned in many occidental countries yet it is still produced in the United States, and materials that contain asbestos remain in many occupational settings and indoor environments. Even though asbestos carcinogenicity is well known, there is scant literature on its specific effects regarding small cell lung cancer (SCLC). We therefore conducted a systematic review and meta-analysis to determine SCLC risk among workers exposed to asbestos. A systematic search of the literature was conducted to identify studies which reported occupational exposure to asbestos and SCLC-related deaths and/or incidence. We identified seven case-control studies that included 3,231 SCLC cases; four studies reported smoking-adjusted risks. A significantly increased risk of SCLC (pooled OR 1.89; 95% CI, 1.25-2.86) was observed on pooling studies on men (six studies) that displayed moderate heterogeneity (I = 46.0%). Overall, our synthesis suggests that occupational exposure to asbestos significantly increases the risk of SCLC on men.
Topics: Male; Humans; United States; Small Cell Lung Carcinoma; Lung Neoplasms; Asbestos; Occupational Exposure; Carcinogens; Occupational Diseases
PubMed: 37405865
DOI: 10.1080/15459624.2023.2232421 -
Annals of Work Exposures and Health Nov 2017Occupational noise exposure has been linked to work-related injuries. Strategies to control occupational hazards often rely on dose-response relationships needed to... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Occupational noise exposure has been linked to work-related injuries. Strategies to control occupational hazards often rely on dose-response relationships needed to inform policy, but quantitative synthesis of the relevant literature has not been done so far. This study aimed to systematically review the epidemiological literature and to perform meta-analysis of the risk for work-related injury due to occupational noise exposure.
METHODS
PRISMA and MOOSE guidelines were followed. PubMed, ScienceDirect, and Google Scholar were searched up until 15 December 2016 in English, Russian, and Spanish. Reference lists, grey literature, and expert archives were searched as well. The risk of bias was assessed for each study and incorporated into the meta-analysis weights using the quality effects model.
RESULTS
Overall, 21 studies were included at the qualitative review stage: 9 cross-sectional, 6 case-control, 4 cohort, 1 case-crossover, and 1 ecological. Noise exposure was assessed objectively in 13 studies. Information on occupational injuries was elicited from medical records/registry in 13 studies. Meta-analyses showed RR = 1.22 (95% CI: 1.15, 1.29) (n = 59028) per 5 dB increase in noise exposure (Cochran's Q = 27.26, P < 0.001, I2 = 67%) and RR = 2.16 (95% CI: 1.61, 2.90) (n = 96023) in the most exposed group (>90-95 dB) compared with the least exposed group (Cochran's Q = 180.46, P < 0.001, I2 = 90%). Subgroup analysis with meta-regression revealed an overall robust pooled risk per 5 dB.
CONCLUSIONS
There is a dose-response association between occupational noise exposure and work-related injury risk. However, the quality of evidence is 'very low'; therefore, the magnitude of this association should be interpreted with caution.
Topics: Cross-Sectional Studies; Humans; Noise, Occupational; Occupational Exposure; Occupational Injuries; Regression Analysis; Risk
PubMed: 29136415
DOI: 10.1093/annweh/wxx078 -
International Journal of Environmental... Apr 2010Exposure to ambient particulate air pollution is a recognized risk factor for cardiovascular disease; however the link between occupational particulate exposures and... (Review)
Review
Exposure to ambient particulate air pollution is a recognized risk factor for cardiovascular disease; however the link between occupational particulate exposures and adverse cardiovascular events is less clear. We conducted a systematic review, including meta-analysis where appropriate, of the epidemiologic association between occupational exposure to particulate matter and cardiovascular disease. Out of 697 articles meeting our initial criteria, 37 articles published from January 1990 to April 2009 (12 mortality; 5 morbidity; and 20 intermediate cardiovascular endpoints) were included. Results suggest a possible association between occupational particulate exposures and ischemic heart disease (IHD) mortality as well as non-fatal myocardial infarction (MI), and stronger evidence of associations with heart rate variability and systemic inflammation, potential intermediates between occupational PM exposure and IHD. In meta-analysis of mortality studies, a significant increase in IHD was observed (meta-IRR = 1.16; 95% CI: 1.06-1.26), however these data were limited by lack of adequate control for smoking and other potential confounders. Further research is needed to better clarify the magnitude of the potential risk of the development and aggravation of IHD associated with short and long-term occupational particulate exposures and to clarify the clinical significance of acute and chronic changes in intermediate cardiovascular outcomes.
Topics: Air Pollutants; Humans; Myocardial Infarction; Occupational Exposure
PubMed: 20617059
DOI: 10.3390/ijerph7041773 -
International Journal of Environmental... Jan 2022The characterization of human microbiota and the impact of its modifications on the health of individuals represent a current topic of great interest for the world... (Review)
Review
The characterization of human microbiota and the impact of its modifications on the health of individuals represent a current topic of great interest for the world scientific community. Scientific evidence is emerging regarding the role that microbiota has in the onset of important chronic illnesses. Since individuals spend most of their life at work, occupational exposures may have an impact on the organism's microbiota. The purpose of this review is to explore the influence that different occupational exposures have on human microbiota in order to set a new basis for workers' health protection and disease prevention. The literature search was performed in PubMed, Cochrane, and Scopus. A total of 5818 references emerged from the online search, and 31 articles were included in the systematic review (26 original articles and 5 reviews). Exposure to biological agents (in particular direct contact with animals) was the most occupational risk factor studied, and it was found involved in modifications of the microbiota of workers. Changes in microbiota were also found in workers exposed to chemical agents or subjected to work-related stress and altered dietary habits caused by specific microclimate characteristics or long trips. Two studies evaluated the role of microbiota changes on the development of occupational lung diseases. Occupational factors can interface with the biological rhythms of the bacteria of the microbiota and can contribute to its modifications and to the possible development of diseases. Future studies are needed to better understand the role of the microbiota and its connection with occupational exposure to promote projects for the prevention and protection of global health.
Topics: Humans; Microbiota; Occupational Diseases; Occupational Exposure; Occupational Health; Risk Factors
PubMed: 35162072
DOI: 10.3390/ijerph19031043 -
American Journal of Industrial Medicine Apr 2020Formaldehyde exposure is associated with nasopharyngeal cancer and leukemia. Previously-described links between formaldehyde exposure and lung cancer have been weak and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Formaldehyde exposure is associated with nasopharyngeal cancer and leukemia. Previously-described links between formaldehyde exposure and lung cancer have been weak and inconsistent. We performed a systematic review and meta-analysis to evaluate quantitatively the association between formaldehyde exposure and lung cancer.
METHODS
We searched for articles on occupational formaldehyde exposure and lung cancer in PubMed, EMBASE, Web of Science, and CINAHL databases. In total, 32 articles were selected and 31 studies were included in a meta-analysis. Subgroup analyses and quality assessments were also performed.
RESULTS
The risk of lung cancer among workers exposed to formaldehyde was not significantly increased, with an overall pooled risk estimate of 1.04 (95% confidence interval [CI], 0.97-1.12). The pooled risk estimate of lung cancer was increased when higher exposure studies were considered (1.19; 95% CI, 0.96-1.46). More statistically robust results were obtained when high quality (1.13; 95% CI, 1.08-1.19) and recent (1.13; 95% CI, 1.07-1.19) studies were used in deriving pooled risk estimates.
CONCLUSIONS
No significant increase in the risk of lung cancer was evident in the overall pooled risk estimate; even in higher formaldehyde exposure groups. Our findings do not provide strong evidence in favor of formaldehyde as a risk factor for lung cancer. However, since risk estimates were significantly increased for high-quality and recent studies, the possibility that exposure to formaldehyde can increase the risk of lung cancer might still be considered.
Topics: Adult; Female; Formaldehyde; Humans; Lung Neoplasms; Male; Occupational Diseases; Occupational Exposure; Respiratory Hypersensitivity; Risk Factors
PubMed: 32003024
DOI: 10.1002/ajim.23093 -
Occupational benzene exposure and the risk of genetic damage: a systematic review and meta-analysis.BMC Public Health Jul 2020Benzene, an important component of organic solvents, is commonly used in industry. Meanwhile, benzene is a human carcinogen leading to leukemia. Although the links... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Benzene, an important component of organic solvents, is commonly used in industry. Meanwhile, benzene is a human carcinogen leading to leukemia. Although the links between benzene and various types of genetic damage indicators have been evaluated in several studies, but their results remain inconsistent. So we conducted a meta-analysis, and to explore the influence of low concentration benzene exposure on workers' genetic damage indicators using 3.25 mg/m as the boundary value, in order to provide a basis for improved prevention and control of the harm from benzene exposure to the occupational population.
METHODS
We conducted a search of five databases, including Pub Med, Web of Science, China National Knowledge Infrastructure (CNKI), Wan Fang Data and Chongqing VIP, to identify relevant articles up to December 25, 2018. Two researchers independently extracted and evaluated the data according to the inclusion and exclusion criteria of the literature. The imported articles were managed by Endnote X7, and the data were extracted and sorted by Excel 2013. We utilized Stata 12.0 software to perform the meta-analysis in the present study.
RESULTS
A total of 68 eligible articles were finally included for the synthetic analyses. The meta-analysis results showed that occupational benzene exposure led to significantly increased Micronucleus (MN) frequency, Sister chromatid exchange (SCE) frequency, Chromosome aberration (CA) frequency, Olive Tail moment (OTM), Tail moment (TM), Tail length (TL), and Tail DNA% (T DNA%) compared to the control group (P < 0.05), and the pooled effect value estimates were 1.36, 0.98, 0.76, 1.06, 0.96, 1.78, and 1.42, respectively. Subsequent analysis of the effect of low concentration benzene exposure on genetic damage found significantly increased MN frequency increased compared with the control group (P < 0.05).
CONCLUSIONS
Occupational benzene exposure can affect multiple genetic damage indicators. Even at an exposure concentration lower than 3.25 mg/m, benzene exposure has genotoxicity. These data provide an important scientific basis for the further revision of occupational disease prevention strategies. At the same time, increased attention should be focused on the health monitoring of the occupational population exposed to benzene, and health management should be strengthened to improve the health of the occupational population.
Topics: Adult; Benzene; Carcinogens; Case-Control Studies; Chromosome Aberrations; DNA Damage; Female; Humans; Industry; Male; Occupational Diseases; Occupational Exposure; Recombination, Genetic; Risk Factors
PubMed: 32669091
DOI: 10.1186/s12889-020-09215-1 -
International Journal of Environmental... Dec 2021Isocyanate, whose disease-inducing mechanism is poorly understood, with poor prognosis, is widely used. Asthma is the most frequent manifestation of prolonged exposure....
Isocyanate, whose disease-inducing mechanism is poorly understood, with poor prognosis, is widely used. Asthma is the most frequent manifestation of prolonged exposure. We assessed the evolution of the incidence of isocyanate-induced occupational asthma over time. PubMed and Cochrane databases were systematically searched for studies published since 1990 that assessed the relationship between occupational exposure to isocyanates and asthma. We identified 39 studies: five retrospective cohort studies, seven prospective cohort studies, three of which were inception cohorts), seven observational cross-sectional studies, five literature reviews, two case series, and 13 registry studies. The incidence of occupational asthma secondary to isocyanate exposure has decreased from more than 5% in the early 1990s to 0.9% in 2017 in the United States. Despite the wide use of optimal collective and individual protection measures, the risk of occupational asthma has stabilized. Occupational asthma risk can be assessed with good sensitivity using self-questionnaires and pulmonary function tests. Occupational avoidance should be implemented as soon as possible after the first symptoms appear because the prognosis becomes increasingly poor with the persistence of exposure. It is now necessary to study specifically cutaneous sensitization to isocyanates and to define what protective equipment is effective against this mode of exposure.
Topics: Asthma, Occupational; Cross-Sectional Studies; Humans; Isocyanates; Occupational Diseases; Occupational Exposure; Occupational Health; Prospective Studies; Retrospective Studies
PubMed: 34948791
DOI: 10.3390/ijerph182413181