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International Journal of Molecular... Jun 2024Disruption of any stage of iron homeostasis, including uptake, utilization, efflux, and storage, can cause progressive damage to peripheral organs. The health hazards...
Disruption of any stage of iron homeostasis, including uptake, utilization, efflux, and storage, can cause progressive damage to peripheral organs. The health hazards associated with occupational exposure to inhalation anesthetics (IA) in combination with chronic iron overload are not well documented. This study aimed to investigate changes in the concentration of essential metals in the peripheral organs of rats after iron overload in combination with IA. The aim was also to determine how iron overload in combination with IA affects tissue metal homeostasis, hepcidin-ferritin levels, and MMP levels according to physiological, functional, and tissue features. According to the obtained results, iron accumulation was most pronounced in the liver (19×), spleen (6.7×), lungs (3.1×), and kidneys (2.5×) compared to control. Iron accumulation is associated with elevated heavy metal levels and impaired essential metal concentrations due to oxidative stress (OS). Notably, the use of IA increases the iron overload toxicity, especially after Isoflurane exposure. The results show that the regulation of iron homeostasis is based on the interaction of hepcidin, ferritin, and other proteins regulated by inflammation, OS, free iron levels, erythropoiesis, and hypoxia. Long-term exposure to IA and iron leads to the development of numerous adaptation mechanisms in response to toxicity, OS, and inflammation. These adaptive mechanisms of iron regulation lead to the inhibition of MMP activity and reduction of oxidative stress, protecting the organism from possible damage.
Topics: Animals; Rats; Hepcidins; Oxidative Stress; Iron; Male; Anesthetics, Inhalation; Iron-Dextran Complex; Ferritins; Iron Overload; Liver; Lung; Kidney; Spleen; Rats, Wistar; Homeostasis; Isoflurane
PubMed: 38928030
DOI: 10.3390/ijms25126323 -
Biology Jun 2024Understanding speech in noise is particularly difficult for individuals occupationally exposed to noise due to a mix of noise-induced auditory lesions and the energetic...
Understanding speech in noise is particularly difficult for individuals occupationally exposed to noise due to a mix of noise-induced auditory lesions and the energetic masking of speech signals. For years, the monitoring of conventional audiometric thresholds has been the usual method to check and preserve auditory function. Recently, suprathreshold deficits, notably, difficulties in understanding speech in noise, has pointed out the need for new monitoring tools. The present study aims to identify the most important variables that predict speech in noise understanding in order to suggest a new method of hearing status monitoring. Physiological (distortion products of otoacoustic emissions, electrocochleography) and behavioral (amplitude and frequency modulation detection thresholds, conventional and extended high-frequency audiometric thresholds) variables were collected in a population of individuals presenting a relatively homogeneous occupational noise exposure. Those variables were used as predictors in a statistical model (random forest) to predict the scores of three different speech-in-noise tests and a self-report of speech-in-noise ability. The extended high-frequency threshold appears to be the best predictor and therefore an interesting candidate for a new way of monitoring noise-exposed professionals.
PubMed: 38927296
DOI: 10.3390/biology13060416 -
BMC Public Health Jun 2024Global warming has led to an increase in the number and intensity of extreme heat events, posing a significant threat to the health and safety of workers, especially...
PURPOSE
Global warming has led to an increase in the number and intensity of extreme heat events, posing a significant threat to the health and safety of workers, especially those working outdoors, as they often have limited access to cooling strategies. The present systematic literature review (a) summarizes the current knowledge on the impacts of climate change on outdoor workers, (b) provides historical background on this issue, (c) explores factors that reduce and increase thermal stress resilience, (d) discusses the heat mitigation strategies, and (e) provides an overview of existing policy and legal frameworks on occupational heat exposure among outdoor workers.
MATERIALS AND METHODS
In this systematic review, we searched scientific databases including Scopus (N = 855), Web of Science (N = 828), and PubMed (N = 202). Additionally, we identified relevant studies on climate change and heat-stress control measures through Google Scholar (N = 116) using specific search terms. In total, we monitored 2001 articles pertaining to worker populations (men = 2921; women = 627) in various outdoor climate conditions across 14 countries. After full-text assessment, 55 studies were selected for inclusion, and finally, 29 eligible papers were included for data extraction.
RESULTS
Failure to implement effective control strategies for outdoor workers will result in decreased resilience to thermal stress. The findings underscore a lack of awareness regarding certain adaptation strategies and interventions aimed at preventing and enhancing resilience to the impact of climate change on heat stress prevalence among workers in outdoor tropical and subtropical environments. However, attractive alternative solutions from the aspects of economic and ecological sustainability in the overall assessment of heat stress resilience can be referred to acclimatization, shading, optimized clothing properties and planned breaks.
CONCLUSION
The integration of climate change adaptation strategies into occupational health programs can enhance occupational heat resilience among outdoor workers. Conducting cost-benefit evaluations of health and safety measures for thermal stress adaptation strategies among outdoor workers is crucial for professionals and policymakers in low- and middle-income tropical and subtropical countries. In this respect, complementary measures targeting hydration, work-rest regimes, ventilated garments, self-pacing, and mechanization can be adopted to protect outdoor workers. Risk management strategies, adaptive measures, heat risk awareness, practical interventions, training programs, and protective policies should be implemented in hot-dry and hot-humid climates to boost the tolerance and resilience of outdoor workers.
Topics: Humans; Climate Change; Heat Stress Disorders; Occupational Exposure; Hot Temperature; Female; Male
PubMed: 38926816
DOI: 10.1186/s12889-024-19212-3 -
Scientific Reports Jun 2024Occupational radiation protection should be applied to the design of treatment rooms for various radiation therapy techniques, including BNCT, where escaping particles...
Occupational radiation protection should be applied to the design of treatment rooms for various radiation therapy techniques, including BNCT, where escaping particles from the beam port of the beam shaping assembly (BSA) may reach the walls or penetrate through the entrance door. The focus of the present study is to design an alternative shielding material, other than the conventional material of lead, that can be considered as the material used in the door and be able to effectively absorb the BSA neutrons which have slowed down to the thermal energy range of eV after passing through the walls and the maze of the room. To this aim, a thermal neutron shield, composed of polymer composite and polyethylene, has been simulated using the Geant4 Monte Carlo code. The neutron flux and dose values were predicted using an artificial neural network (ANN), eliminating the need for time-consuming Monte Carlo simulations in all possible suggestions. Additionally, this technique enables simultaneous optimization of the parameters involved, which is more effective than the traditional sequential and separate optimization process. The results indicated that the optimized shielding material, chosen through ANN calculations that determined the appropriate thickness and weight percent of its compositions, can decrease the dose behind the door to lower than the allowable limit for occupational exposure. The stability of ANN was tested by considering uncertainties with the Gaussian distributions of random numbers to the testing data. The results are promising as they indicate that ANNs could be used as a reliable tool for accurately predicting the dosimetric results, providing a drastically powerful alternative approach to the time-consuming Monte Carlo simulations.
PubMed: 38926477
DOI: 10.1038/s41598-024-65207-w -
Scientific Reports Jun 2024Human health is becoming concerned about exposure to endocrine disrupting chemicals (EDCs) emanating from plastic, such as phthalates, which are industrially employed as...
Human health is becoming concerned about exposure to endocrine disrupting chemicals (EDCs) emanating from plastic, such as phthalates, which are industrially employed as plasticizers in the manufacturing of plastic products. Due to some toxicity concerns, di(2-ethylhexyl) phthalate (DEHP) was replaced by diisononyl phthalate (DiNP). Recent data, however, highlights the potential of DiNP to interfere with the endocrine system and influence allergic responses. Asthma affects brain function through hypoxia, systemic inflammation, oxidative stress, and sleep disturbances and its effective management is crucial for maintaining respiratory and brain health. Therefore, in DiNP-induced asthmatic mice, this study investigated possible crosstalk between the lungs and the brain inducing perturbations in neural mitochondrial antioxidant status, inflammation biomarkers, energy metabolizing enzymes, and apoptotic indicators. To achieve this, twelve (n = 12, 20-30 g) male BALB/c mice were divided into two (2) experimental groups, each with five (6) mice. Mice in group II were subjected to 50 mg/kg body weight (BW) DiNP (Intraperitoneal and intranasal), while group I served as the control group for 24 days. The effects of DiNP on neural energy metabolizing enzymes (Hexokinase, Aldolase, NADase, Lactate dehydrogenase, Complex I, II, II & IV), biomarkers of inflammation (Nitric oxide, Myeloperoxidase), oxidative stress (malondialdehyde), antioxidants (catalase, glutathione-S-transferase, and reduced glutathione), oncogenic and apoptotic factors (p53, K-ras, Bcl, etc.), and brain histopathology were investigated. DiNP-induced asthmatic mice have significantly (p < 0.05) altered neural energy metabolizing capacities due to disruption of activities of enzymes of glycolytic and oxidative phosphorylation. Other responses include significant inflammation, oxidative distress, decreased antioxidant status, altered oncogenic-apoptotic factors level and neural degeneration (as shown in hematoxylin and eosin-stained brain sections) relative to control. Current findings suggest that neural histoarchitecture, energy metabolizing potentials, inflammation, oncogenic and apoptotic factors, and mitochondrial antioxidant status may be impaired and altered in DiNP-induced asthmatic mice suggesting a pivotal crosstalk between the two intricate organs (lungs and brain).
Topics: Animals; Apoptosis; Asthma; Oxidative Stress; Mitochondria; Mice; Male; Mice, Inbred BALB C; Lung; Phthalic Acids; Cell Respiration; Signal Transduction; Brain
PubMed: 38926453
DOI: 10.1038/s41598-024-65356-y -
Occupational and Environmental Medicine Jun 2024The aim of this study was to confirm the relationship between several parameters of exposure to asbestos and pleural plaques (PP) using data from a large cohort of...
OBJECTIVE
The aim of this study was to confirm the relationship between several parameters of exposure to asbestos and pleural plaques (PP) using data from a large cohort of retired workers occupationally exposed to asbestos in France.
METHOD
A large screening programme, including high-resolution CT (HRCT) examinations at inclusion and two other HRCT campaigns, was organised from 2003 to 2016 in four regions of France for voluntary, formerly asbestos-exposed workers. Exposure to asbestos has been evaluated by industrial hygienists based on the complete work history. The time since first exposure, the time since last exposure, Cumulative Exposure Index and maximum level of exposure to asbestos, were used in logistic regression using fractional polynomials to model the relationship with PP.
RESULTS
The study included 5392 subjects with at least one HRCT available. There was a significant non-linear effect of time since first exposure, time since last exposure and Cumulative Exposure Index to asbestos on the presence of PP. The risk of PP increased with increasing Cumulative Exposure Index to asbestos adjusted for time since first exposure, age and smoking status. Models also show that PP odds rise with increasing time since first exposure adjusted for cumulative index exposure, age and smoking status. PP odds decrease when time since last exposure increases.
CONCLUSION
The study provides new data on the link between asbestos exposure and the presence of PP using fractional polynomials with non-linear relationships for time exposure parameters and asbestos exposure parameters.
PubMed: 38925963
DOI: 10.1136/oemed-2023-108975 -
Physiological Reports Jun 2024Pro-inflammatory fungal β-d-glucan (BDG) polysaccharides cause respiratory pathology. However, specific immunological effects of unique BDG structures on pulmonary...
Pro-inflammatory fungal β-d-glucan (BDG) polysaccharides cause respiratory pathology. However, specific immunological effects of unique BDG structures on pulmonary inflammation are understudied. We characterized the effect of four unique fungal BDGs with unique branching patterns, solubility, and molecular weights in murine airways. Scleroglucan (1 → 3)(1 → 6)-highly branched BDG, laminarin (1 → 3)(1 → 6)-branched BDG, curdlan (1 → 3)-linear BDG, and pustulan (1 → 6)-linear BDG were assessed by nuclear magnetic resonance spectroscopy. Each BDG was tested by inhalation model with C3HeB/FeJ mice and compared to saline-exposed control mice and unexposed sentinels (n = 3-19). Studies were performed ±heat-inactivation (1 h autoclave) to increase BDG solubility. Outcomes included bronchoalveolar lavage (BAL) differential cell counts (macrophages, neutrophils, lymphocytes, eosinophils), cytokines, serum IgE, and IgG2a (multiplex and ELISA). Ex vivo primary cells removed from lungs and plated at monolayer were stimulated (BDG, lipopolysaccharide (LPS), anti-CD3), and cytokines compared to unstimulated cells. Right lung histology was performed. Inhalation of BDGs with distinct branching patterns exhibited varying inflammatory potency and immunogenicity. Lichen-derived (1 → 6)-linear pustulan was the most pro-inflammatory BDG, increasing inflammatory infiltrate (BAL), serum IgE and IgG2a, and cytokine production. Primed lung cells responded to secondary LPS stimulation with a T-cell-specific response to pustulan. Glucan source and solubility should be considered in exposure and toxicological studies.
Topics: Animals; Male; Mice; beta-Glucans; Lung; Pneumonia; Cytokines; Bronchoalveolar Lavage Fluid; Mice, Inbred C3H; Glucans
PubMed: 38923221
DOI: 10.14814/phy2.16115 -
La Medicina Del Lavoro Jun 2024This study aimed to explore the association between occupational exposure to diesel exhaust (DE) and gynaecological and breast cancers. (Meta-Analysis)
Meta-Analysis
BACKGROUND
This study aimed to explore the association between occupational exposure to diesel exhaust (DE) and gynaecological and breast cancers.
METHODS
A systematic review was performed to identify cohort studies reporting results on the association between occupational exposure to DE and risk of gynaecological and breast cancers. STROBE guidelines and PECOS criteria were followed. We identified 6 studies for breast cancer (BC), 4 for cervical cancer (CC), 4 for endometrial cancer (EC) and 7 for ovarian cancer (OC). Random-effects meta-analyses were conducted on the relationship between DE exposure and BC, CC, EC, and OC risk; 95% confidence intervals (CI) and prediction intervals (PI) were reported. We investigated between-study heterogeneity and potential publication bias using Egger's test.
RESULTS
No associations were observed between occupational DE exposure and risk of BC [RR=0.93; CI: 0.77-1.13; PI:0.50-1.73, I2=80.31%], EC [RR=0.89; CI: 0.75-1.05; PI:0.61-1.30, I2=0.78%], and OC [RR=1.08; CI: 0.89-1.32, PI: 0.76-1.56, I2=11.87%]. A weak association was observed for CC [RR=1.41; CI: 1.17-1.17; PI:0.85-2.30, I2=6.44%]. No between-study heterogeneity or publication bias was detected.
CONCLUSIONS
This study identified an association between DE exposure and CC, which was not adjusted for potential confounders. No evidence of an association was found with BC, EC, and OC.
Topics: Humans; Vehicle Emissions; Female; Occupational Exposure; Breast Neoplasms; Occupational Diseases; Cohort Studies; Genital Neoplasms, Female; Risk Factors; Risk Assessment
PubMed: 38922840
DOI: 10.23749/mdl.v115i3.15568 -
La Medicina Del Lavoro Jun 2024In the regeneration of waste oil, a strategical technological process for the European Union circular economy action plan, exhausted oils are regenerated to produce high...
BACKGROUND
In the regeneration of waste oil, a strategical technological process for the European Union circular economy action plan, exhausted oils are regenerated to produce high performing oil bases. Aim of this work was to assess the exposure to benzene in plant workers during ordinary activities.
METHODS
59 workers, potentially exposed to benzene, and 9 administrative workers from an Italian plant were monitored for the whole work shift with personal air samplers; urinary benzene (BEN-U) and S-phenyl mercapturic acid (SPMA) were measured by mass spectrometry methods in end-shift urine samples. Different job tasks were identified among workers.
RESULTS
Median (minimum-maximum) airborne exposures to benzene were <0.9 (<0.9-6.3) and <0.9 (<0.9-0.9) µg/m3, BEN-U and SPMA levels were 0.094 (<0.015-3.095) µg/L and 0.15 (<0.10-9.67) µg/g crt and 0.086 (0.034-0.712) µg/L and <0.10 (<0.10-3.19) µg/g creatinine in workers and administrative workers, respectively. No differences were found among job tasks and between workers and administrative workers, while higher levels were found in smokers than in non-smokers. For all job tasks, the exposure to benzene was always below occupational limit values.
CONCLUSIONS
This study has investigated for the first time the exposure to benzene of workers employed in the re-refining of exhaust oil. The results showed that normal production activities in regenerating used oils do not pose a risk of exposure to benzene in workers.
Topics: Humans; Benzene; Occupational Exposure; Adult; Male; Biological Monitoring; Middle Aged; Air Pollutants, Occupational; Italy; Female; Oil and Gas Industry; Acetylcysteine
PubMed: 38922839
DOI: 10.23749/mdl.v115i3.15863 -
La Medicina Del Lavoro Jun 2024Contact dermatitis is a common cutaneous inflammatory condition, triggered by exposure to irritant substances or allergens. Nickel is the most prevalent allergen, a...
Contact dermatitis is a common cutaneous inflammatory condition, triggered by exposure to irritant substances or allergens. Nickel is the most prevalent allergen, a metal widely used in accessories, furniture, office materials, food and in industry, with multiple exposure pathways, making it difficult to assess which exposure is causing allergic dermatitis. Here, we report a case of an administrative worker with chronic hand eczema, limited to the radial metacarpophalangeal region of the left hand, caused by occupational exposure to nickel, confirmed by nickel deposition test on the hand and a positive test with a metallic stapler used at her workplace.
Topics: Humans; Nickel; Dermatitis, Allergic Contact; Dermatitis, Occupational; Female; Hand Dermatoses; Adult; Occupational Exposure; Middle Aged
PubMed: 38922838
DOI: 10.23749/mdl.v115i3.15931