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Reviews on Environmental Health Mar 2023Inappropriate processing and disposal of electronic waste (e-waste) expose workers and surrounding populations to hazardous chemicals, including clastogens and aneugens.... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Inappropriate processing and disposal of electronic waste (e-waste) expose workers and surrounding populations to hazardous chemicals, including clastogens and aneugens. Recently, considerable literature has grown around e-waste recycling, associated chemical exposures and intermediate health outcomes, including DNA damage. Micronuclei (MN) frequency has been widely used as a biomarker to investigate DNA damage in human populations exposed to genotoxic agents. We conducted a systematic review of published studies to assess DNA damage in e-waste-exposed populations and performed a meta-analysis to evaluate the association between e-waste exposure and DNA damage.
METHODS
This systematic review with meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement checklist. Articles published in English from January 2000 through December 2020 investigating the associations between e-waste exposure and DNA damage were retrieved from the following three major databases: MEDLINE, ProQuest, and Scopus. Studies that reported the use of MN assay as a biomarker of DNA damage were included for meta-analysis. Studies that also reported other DNA damage biomarkers such as chromosomal aberrations, comet assay biomarkers, 8-hydroxy-2'-deoxyguanosine (8-OHdG), telomere length, apoptosis rate were reported using narrative synthesis.
RESULTS
A total of 20 publications were included in this review, of which seven studies were within the occupational setting, and the remaining 13 studies were ecological studies. The review found six biomarkers of DNA damage (micronuclei, comets assay parameters (tail length, % tail DNA, tail moment, and olive tail moment), 8-OHdG, telomere length, apoptosis rate and chromosomal aberrations) which were assessed using seven different biological matrices (buccal cells, blood, umbilical cord blood, placenta, urine and semen). Most studies showed elevated levels of DNA damage biomarkers among e-waste exposed populations than in control populations. The most commonly used biomarkers were micronuclei frequency (n=9) in peripheral blood lymphocytes or buccal cells and 8-OHdG (n=7) in urine. The results of the meta-analysis showed that electronic waste recycling has contributed to an increased risk of DNA damage measured using MN frequency with a pooled estimate of the standardized mean difference (SMD) of 2.30 (95% CI: 1.36, 3.24, p<0.001) based on 865 participants.
CONCLUSIONS
Taken together, evidence from this systematic review with meta-analysis suggest that occupational and non-occupational exposure to e-waste processing is associated with increased risk of DNA damage measured through MN assay and other types of DNA damage biomarkers. However, more studies from other developing countries in Africa, Latin America, and South Asia are needed to confirm and increase these results' generalizability.
Topics: Humans; Electronic Waste; Mouth Mucosa; DNA Damage; Chromosome Aberrations; Biomarkers
PubMed: 34727591
DOI: 10.1515/reveh-2021-0074 -
Radiation Research May 2023The number of people living with dementia is rising globally as life expectancy increases. Dementia is a multifactorial disease. Due to the ubiquity of radiation... (Meta-Analysis)
Meta-Analysis
The number of people living with dementia is rising globally as life expectancy increases. Dementia is a multifactorial disease. Due to the ubiquity of radiation exposure in medical and occupational settings, the potential association between radiation and dementia, and its subtypes (Alzheimer's and Parkinson's disease), is of particular importance. There has also been an increased interest in studying radiation induced dementia risks in connection with the long-term manned space travel proposed by The National Aeronautics and Space Administration (NASA). Our aim was to systematically review the literature on this topic, and use meta-analysis to generate a summary measure of association, assess publication bias and explore sources of heterogeneity across studies. We identified five types of exposed populations for this review: 1. survivors of atomic bombings in Japan; 2. patients treated with radiation therapy for cancer or other diseases; 3. occupationally exposed workers; 4. those exposed to environmental radiation; and 5. patients exposed to radiation from diagnostic radiation imaging procedures. We included studies that considered incident or mortality outcomes for dementia and its subtypes. Following PRISMA guidelines, we systematically searched the published literature indexed in PubMed between 2001 and 2022. We then abstracted the relevant articles, conducted a risk-of-bias assessment, and fit random effects models using the published risk estimates. After we applied our eligibility criteria, 18 studies were identified for review and retained for meta-analysis. For dementia (all subtypes), the summary relative risk was 1.11 (95% CI: 1.04, 1.18; P = 0.001) comparing individuals receiving 100 mSv of radiation to those with no exposure. The corresponding summary relative risk for Parkinson's disease incidence and mortality was 1.12 (95% CI 1.07, 1.17; P <0.001). Our results provide evidence that exposure to ionizing radiation increases the risk of dementia. However, our findings should be interpreted with caution due to the small number of included studies. Longitudinal studies with improved exposure characterization, incident outcomes, larger sample size, and the ability to adjust for effects of potential confounders are needed to better assess the possible causal link between ionizing radiation and dementia.
Topics: United States; Humans; Parkinson Disease; Radiation, Ionizing; Dementia; Japan
PubMed: 37293601
DOI: 10.1667/rade-22-00153.1 -
Frontiers in Neuroscience 2023The etiology of amyotrophic lateral sclerosis (ALS) remains largely unknown. This study aimed to summarize the relationship between ALS and its genetic and non-genetic...
BACKGROUND
The etiology of amyotrophic lateral sclerosis (ALS) remains largely unknown. This study aimed to summarize the relationship between ALS and its genetic and non-genetic risk factors.
METHOD
A search of relevant literature from PubMed, Embase, and Cochrane Database from inception to December 2022 was performed. Random-effects or fixed-effects models were performed by Stata MP 15.0 to pool multivariate or adjusted ratios (OR). PROSPERO registration number: CRD42022301549.
RESULTS
230 eligible studies were included, of which 67 involved 22 non-genetic factors, and 163 involved genetic factors. Four aspects of non-genetic factors, including lifestyle, environmental and occupational exposures, pre-existing diseases/comorbidity and medical exposures, and others, were analyzed. Exposure to heavy metals (OR = 1.79), pesticides (OR = 1.46), solvents (OR = 1.37), previous head trauma (OR = 1.37), military service (OR = 1.29), stroke (OR = 1.26), magnetic field (OR = 1.22) and hypertension (OR = 1.04) are significant risk factors, but use of antidiabetics (OR = 0.52), high BMI (OR = 0.60 for obese and overweight vs. normal and underweight), living in urban (OR = 0.70), diabetes mellitus (OR = 0.83), and kidney disease (OR = 0.84) decrease the risk for ALS. In addition, eight common ALS-related genes were evaluated, the mutation frequencies of these genes were ranked from highest to lowest as (2.2%), (2.1%), (1.7%), (1.7%), (0.8%), (0.6%), (0.6%) and (0.6%) in all the ALS patients.
CONCLUSIONS
Our findings suggested that effective intervention for risk exposure and timely modification of lifestyle might prevent the occurrence of ALS. Genetic mutations are important risk factors for ALS and it is essential to detect genetic mutations correctly and scientifically.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=301549, identifier: CRD42022301549.
PubMed: 37168926
DOI: 10.3389/fnins.2023.1177431 -
European Respiratory Review : An... Jan 2024Molecular pathways found to be important in pulmonary fibrosis are also involved in cancer pathogenesis, suggesting common pathways in the development of pulmonary... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Molecular pathways found to be important in pulmonary fibrosis are also involved in cancer pathogenesis, suggesting common pathways in the development of pulmonary fibrosis and lung cancer.
RESEARCH QUESTION
Is pulmonary fibrosis from exposure to occupational carcinogens an independent risk factor for lung cancer?
STUDY DESIGN AND METHODS
A comprehensive search of PubMed, Embase, Web of Science and Cochrane databases with over 100 search terms regarding occupational hazards causing pulmonary fibrosis was conducted. After screening and extraction, quality of evidence and eligibility criteria for meta-analysis were assessed. Meta-analysis was performed using a random-effects model.
RESULTS
52 studies were identified for systematic review. Meta-analysis of subgroups identified silicosis as a risk factor for lung cancer when investigating odds ratios for silicosis in autopsy studies (OR 1.47, 95% CI 1.13-1.90) and for lung cancer mortality in patients with silicosis (OR 3.21, 95% CI 2.67-3.87). Only considering studies with an adjustment for smoking as a confounder identified a significant increase in lung cancer risk (OR 1.58, 95% CI 1.34-1.87). However, due to a lack of studies including cumulative exposure, no adjustments could be included. In a qualitative review, no definitive conclusion could be reached for asbestosis and silicosis as independent risk factors for lung cancer, partly because the studies did not take cumulative exposure into account.
INTERPRETATION
This systematic review confirms the current knowledge regarding asbestosis and silicosis, indicating a higher risk of lung cancer in exposed individuals compared to exposed workers without fibrosis. These individuals should be monitored for lung cancer, especially when asbestosis or silicosis is present.
Topics: Humans; Silicon Dioxide; Lung Neoplasms; Pulmonary Fibrosis; Asbestosis; Silicosis; Occupational Exposure
PubMed: 38355151
DOI: 10.1183/16000617.0224-2023 -
European Journal of Epidemiology Sep 2021Limited information is available on carcinogenicity of asbestos on non-respiratory organs. We aimed at conducted an updated systematic review and meta-analysis of cohort... (Meta-Analysis)
Meta-Analysis Review
Limited information is available on carcinogenicity of asbestos on non-respiratory organs. We aimed at conducted an updated systematic review and meta-analysis of cohort studies on occupational exposure to asbestos and risk of kidney cancer. We searched through three databases, PubMed, Embase and Scopus for article published after 2000, and after eliminating duplicates and non-relevant studies, we identified 13 studies. We combined their results with those of 31 non-overlapping studies included in a previous review up to 2000. We conducted a meta-analysis based on random-effects models. The pooled relative risk of kidney cancer for asbestos exposure was 0.94 (95% confidence interval, 0.84-1.04), with no differences according to type of asbestos fiber, geographic region, period of exposure, or estimated quality of the study. Our results showed a lack of association between occupational asbestos exposure and risk of kidney cancer.
Topics: Asbestos; Carcinogens; Humans; Kidney Neoplasms; Occupational Exposure; Risk Assessment; Risk Factors
PubMed: 34195879
DOI: 10.1007/s10654-021-00769-x -
Particle and Fibre Toxicology Jan 2022Autoimmunity can result from the interplay between genetic background and effects of environmental and/or occupational exposure to hazardous materials. Several... (Review)
Review
BACKGROUND
Autoimmunity can result from the interplay between genetic background and effects of environmental and/or occupational exposure to hazardous materials. Several compounds, including silica dust, have been linked with systemic autoimmunity and systemic autoimmune diseases, based on epidemiological evidence. For asbestos, a strong link with systemic autoimmune diseases does not yet exist, however, several studies have documented features of autoimmunity following asbestos exposure. Even so, human studies are limited in their ability to identify and examine isolated exposures, making it difficult to demonstrate causation or to assess pathogenic mechanisms. Therefore, this systematic review examines the existing animal evidence regarding autoimmunity and exposure to silicates (silica and asbestos).
METHODS
PubMed and EMBASE were systematically searched for peer-reviewed studies examining systemic autoimmune disease-related outcomes after silicate exposure in rodents. Literature databases were searched up to September 2021 for studies written in English and where the full text was available. Search strings were established based on a PECO (Population, Exposure, Comparator, Outcome) format. After title, abstract, and full-text screening, thirty-four studies were identified for further analysis. Quality assessment through ToxR tool and qualitative analysis of the results was performed.
RESULTS
Although there was significant heterogeneity in the included studies in terms of exposure protocol and genetic background of the rodent models used, it was noted that both genetic background and exposure to silicates [(crystalline) silica and asbestos] are highly relevant to the development of (sub-) clinical systemic autoimmune disease.
CONCLUSION
Parallels were observed between the findings from the animal (this review) and human (epidemiological) studies, arguing that experimental animal models are valuable tools for examining exacerbation or development of autoimmune disease after silicate exposure. However, genetic background and synergism between exposures should be considered in future studies.
Topics: Animals; Autoimmunity; Dust; Occupational Exposure; Rodentia; Silicates
PubMed: 34996462
DOI: 10.1186/s12989-021-00439-6 -
International Journal of Molecular... Dec 2022A significant part of adult-onset asthma is caused by occupational exposure to both high- and low-molecular-mass agents. Insects are occasionally described to cause... (Review)
Review
A significant part of adult-onset asthma is caused by occupational exposure to both high- and low-molecular-mass agents. Insects are occasionally described to cause occupational allergy in professions including anglers and fishers, laboratory workers, employees of aquaculture companies, farmers, bakers, sericulture workers and pet shop workers. Occupational insect allergies are often respiratory, causing asthma or rhinoconjunctivitis, but can be cutaneous as well. The European Union recently approved three insect species for human consumption, enabling an industry to develop where more employees could be exposed to insect products. This review overviews knowledge on occupational insect allergy risks and the tools used to diagnose employees. Despite the limited availability of commercial occupational insect allergy diagnostics, 60.9% of 164 included reports used skin prick tests and 63.4% of reports used specific IgE tests. In 21.9% of reports, a more elaborate diagnosis of occupational asthma was made by specific inhalation challenges or peak expiratory flow measurements at the workplace. In some work environments, 57% of employees were sensitized, and no less than 60% of employees reported work-related symptoms. Further development and optimization of specific diagnostics, together with strong primary prevention, may be vital to the health conditions of workers in the developing insect industry.
Topics: Adult; Humans; Occupational Diseases; Asthma; Allergens; Occupational Exposure; Skin; Skin Tests
PubMed: 36613529
DOI: 10.3390/ijms24010086 -
GeoHealth Jun 2023Noise is a common harmful factor in our work and the environment. Most studies have investigated the auditory effects of noise exposure; however, few studies have... (Review)
Review
Noise is a common harmful factor in our work and the environment. Most studies have investigated the auditory effects of noise exposure; however, few studies have focused on the extra-auditory effects of exposure to occupational or environmental noise. This study aimed to systematically review published studies on the extra-auditory effects of noise exposure. We reviewed literature from PubMed and Google Scholar databases up to July 2022, using the Patient, Intervention, Comparison, and Outcome criteria and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify studies that reported extra-auditory effects of occupational or environmental noise exposure. Studies were evaluated utilizing validated reporting tools (CONSORT, STROBE) appropriate to study design. A total of 263 articles were identified, of which 36 were finally selected and reviewed. Upon conducting a review of the articles, exposure to noise can elicit a variety of extra-auditory effects on humans. These effects include circulatory effects linked to higher risk of cardiovascular disease and decreased endothelial function, nervous system effects correlated with sleep disturbance, cognitive impairment, and mental health problems, immunological and endocrinal effects connected to increased physiological stress response and metabolic disorders, oncological and respiratory effects associated with an elevated risk of acoustic neuroma and respiratory disorders, gastrointestinal effects linked to an increased risk of gastric or duodenal ulcer, and obstetric effects connected to the risk of preterm birth. Our review suggests that there are numerous extra-auditory effects of noise exposure on human, and further investigations are needed to fully understand these effects.
PubMed: 37303697
DOI: 10.1029/2023GH000805 -
Safety and Health At Work Jun 2023In many industrial sectors, workers are exposed to manufactured or unintentionally emitted airborne nanoparticles (NPs). To develop prevention and enhance knowledge... (Review)
Review
In many industrial sectors, workers are exposed to manufactured or unintentionally emitted airborne nanoparticles (NPs). To develop prevention and enhance knowledge surrounding exposure, it has become crucial to achieve a consensus on how to assess exposure to airborne NPs by inhalation in the workplace. Here, we review the literature presenting recommendations on assessing occupational exposure to NPs. The 23 distinct strategies retained were analyzed in terms of the following points: target NPs, objectives, steps, "measurement strategy" (instruments, physicochemical analysis, and data processing), "contextual information" presented, and "work activity" analysis. The robustness (consistency of information) and practical aspects (detailed methodology) of each strategy were estimated. The objectives and methodological steps varied, as did the measurement techniques. Strategies were essentially based on NPs measurement, but improvements could be made to better account for "contextual information" and "work activity". Based on this review, recommendations for an operational strategy were formulated, integrating the work activity with the measurement to provide a more complete assessment of situations leading to airborne NP exposure. These recommendations can be used with the objective of producing homogeneous exposure data for epidemiological purposes and to help improve prevention strategies.
PubMed: 37389309
DOI: 10.1016/j.shaw.2023.02.002 -
The British Journal of Dermatology Feb 2021Individual studies have suggested that the association between occupational exposure to solar ultraviolet radiation (UVR) and the development of keratinocyte cancers... (Review)
Review
Individual studies have suggested that the association between occupational exposure to solar ultraviolet radiation (UVR) and the development of keratinocyte cancers (KCs) may only be valid in populations of European ancestry living in certain geographical regions. Comparative global data are scarce and so this review aimed to summarize current evidence on the association between occupational exposure to solar UVR and the development of KCs, with a specific focus on geographical location and skin colour. Ovid MEDLINE, PubMed, Embase and Web of Science were searched for potentially relevant records. Extracted data were summarized by study, country and region. We included one prospective cohort study and 18 case-control studies (n = 15 233) from 12 countries in regions where the majority of the population is white skinned (Americas, Europe and Oceania). Eighteen of the 19 studies reported effect estimates suggesting an increased risk of basal cell carcinoma (BCC) and/or squamous cell carcinoma (SCC) among outdoor workers. Only 11 studies found a significantly increased risk and many had imprecise estimates. There was a significantly increased risk of BCC and SCC in individual studies in North America, Latin America and the Caribbean, Western Europe and Southern Europe, but not across regions or countries. Overall, 95% of studies reported higher risks among outdoor workers, although the increases in risk were statistically significant in just over half of the studies. Well-designed and sufficiently powered occupational case-control and cohort studies with adequate adjustment for confounding factors and other risk factors are required to provide more accurate risk estimates for occupational KC.
Topics: Carcinoma, Basal Cell; Caribbean Region; Europe; Humans; Keratinocytes; North America; Occupational Diseases; Occupational Exposure; Prospective Studies; Skin Neoplasms; Sunlight; Ultraviolet Rays
PubMed: 32320481
DOI: 10.1111/bjd.19152