Occupational Pollutants Research Articles

The Impact of Ambient Environmental and Occupational Pollution on Respiratory Diseases.

Ambient pollutants and occupational pollutants may cause and exacerbate various lung and respiratory diseases. This review describes lung and respiratory diseases in relation to ambient pollutants, particularly particulate matter (PM2.5), and occupational air pollutants, excluding communicable diseases and indoor pollutants, including tobacco smoke exposure. PM2.5 produced by combustion is an important ambient pollutant. PM2.5 can cause asthma attacks and exacerbations of chronic obstructive pulmonary disease in the short term. Further, it not only carries a risk of lung cancer and death, but also hinders the development of lung function in children in the long term. It has recently been suggested that air pollution, such as PM2.5, is a risk factor for severe coronavirus disease (COVID-19). Asbestos, which causes asbestosis, lung cancer, and malignant mesothelioma, and crystalline silica, which cause silicosis, are well-known traditional occupational pollutants leading to pneumoconiosis. While work-related asthma (WRA) is the most common occupational lung disease in recent years, many different agents cause WRA, including natural and synthetic chemicals and irritant gases. Primary preventive interventions that increase awareness of pollutants and reduce the development and exacerbation of diseases caused by air pollutants are paramount to addressing ambient and occupational pollution.

Induction of hemolysis and eryptosis by occupational pollutant nickel chloride is mediated through calcium influx and p38 MAP kinase signaling.

Nickel (Ni) is an abundant environmental hazard and an occupational pollutant. Exposure to Ni compounds is prevalent in electroplating workers and in the printing industry, among others. The toxicity of Ni manifests as dermatological, gastrointestinal, respiratory, allergic, and cardiovascular symptoms. In particular, hyperbilirubinemia and reticulocytosis have been detected in intoxicated subjects; an observation possibly implicating selective red blood cell (RBC) toxicity. Herein, the interaction of nickel chloride (NiCl2) with human RBCs and associated molecular mechanisms are described. Cells from healthy donors were incubated for 24 h at 37°C in the presence or absence of 0.5‒10 mM of NiCl2, and cytotoxicity was determined through hemoglobin leakage by colorimetry under different experimental conditions. Eryptotic markers were also identified by flow cytofluorometry using Annexin-V-FITC tagging for phosphatidylserine (PS) exposure, light scatter properties for cellular dimensions, Fluo4/AM labeling for intracellular calcium, and H2DCFDA staining for reactive oxygen species (ROS). Additionally, small molecule inhibitors were used to probe the signaling pathways involved. It was found that NiCl2 at 10 mM caused profound intracellular calcium overload and significant calcium-dependent hemolysis. Also, NiCl2 reduced forward scatter and increased side scatter, Annexin- positive cells, and ROS levels. Importantly, NiCl2-induced hemolysis was significantly attenuated by the exclusion of extracellular calcium, and in the presence of p38 MAP kinase (MAPK) inhibitor SB203580. It is concluded that NiCl2 induces p38 MAPK-dependent hemolysis, and stimulates the canonical features of premature eryptosis. This report presents the first description of the molecular mechanisms underlying the hemolytic and eryptotic potential of NiCl2 and, thus, may explain changes in hematological parameters observed in poisoning victims. Int J Occup Med Environ Health. 2022;35(1):1-11.

Occupational Health and Safety Challenges among small- scale miners in Ghana

Mining is a key bedrock of Ghana’s economy, second only to agriculture. Artisanal and small-scale mining has expanded and become increasingly influential. Unfortunately, small-scale miners encounter a lot of occupational health and safety (OHS) challenges in their mining operations, in part due to the mode of mining. However, very few research studies touch on the OHS challenges small scale miners face in their day-to-day operations. The object of the present study was, therefore, to quantify and examine the OHS challenges among small scale miners in Ghana using Pameng gold mining site as a case study. The study assumed a quantitative research approach. Purposive sampling was used to select 100 small-scale miners. The results of the study revealed that small scale miners considered mining accidents and injuries as the most important OHS challenge, followed by occupational hazards and environmental pollution, with unsafe work practices and behaviour being viewed as the least important as it registered the lowest mean Likert score. It is recommended that the small-scale mining industry with help from government should execute OHS awareness initiatives.

Determination of activated carbon fiber adsorption capacity for several common organic vapors: applications for respiratory protection

ABSTRACT In the context of workplace safety, activated carbon in the fiber form (i.e., activated carbon fiber, ACF) represents an alternative adsorbent to granular activated carbon (GAC) for use in organic vapor respiratory protection devices. ACFs are high surface area carbonaceous materials that are often available in a self-supporting non-woven form. The physical form of ACF suggests the potential for a filtration medium that is capable of supporting both organic vapor adsorption and particulate filtration. To study the application of these materials in respiratory protection devices, ACFs (ACFF 1200 m2/g, ACFF 1800 m2/g, and ACFF 2000 m2/g) were challenged with representative organic vapors (toluene, hexane, and methyl ethyl ketone (MEK)) at an occupationally relevant concentration (200 ppm). Breakthrough curves were generated for at least three different bed weights of adsorbent. Pressure drop (i.e., the resistance across the filtration media) was also measured to determine maximum ACF bed depths for use in respiratory protection devices. Breakthrough experiments indicate that ACFF 2000 has the highest adsorption capacity for toluene (381 mg/g), followed by ACFF 1800 and ACFF 1200 (344 mg/g and 239 mg/g, respectively). A similar trend was observed for hexane: 221 mg/g, 196 mg/g, and 146 mg/g for ACFF 2000, ACFF 1800, and ACFF 1200, respectively. ACFF 1200 showed the highest adsorption capacity for the polar adsorbate MEK (168 mg/g), followed by ACFF 1800 and ACFF 2000 (166 mg/g and 147 mg/g, respectively). Based on the constraints of pressure drop, it seems unlikely the exclusive use of ACF in a filtering facepiece respirator can provide an adsorbent mass sufficient for full shift protection against organic vapor contaminants at or above the legally enforceable permissible exposure level (PEL). Nevertheless, the incorporation of ACF into a facepiece respirator appears promising for “nuisance odor” applications; i.e., the further reduction of organic vapor concentrations when workplace exposures are already below PEL concentrations. Implications: This research brings innovation to the field of occupational health and air pollution control technology by investigating the adsorption performance of activated carbon fiber (ACF) media in the context of worker respiratory protection. ACF properties such as high specific surface area (m2/g), high permeability to airflow, and rapid adsorption kinetics make it ideal for use in thin, N95-style respirators for organic vapors. Respiratory protection is an exciting and relevant application for ACF media. A lightweight adsorbent such as ACF, if incorporated into an N95-style respirator, could potentially provide nuisance-level VOC protection in a physical form that is accessible to workers and consistent with OSHA’s voluntary use provisions for facepiece respirators. The research presented in this manuscript represents one of several steps planned in the characterization of ACF media for this particular application.

Effects of Urban Green Space on Cardiovascular and Respiratory Biomarkers in Chinese Adults: Panel Study Using Digital Tracking Devices.

BackgroundThe health benefits of urban green space have been widely reported in the literature; however, the biological mechanisms remain unexplored, and a causal relationship cannot be established between green space exposure and cardiorespiratory health.ObjectiveOur aim was to conduct a panel study using personal tracking devices to continuously collect individual exposure data from healthy Chinese adults aged 50 to 64 years living in Hong Kong.MethodsA panel of cardiorespiratory biomarkers was tested each week for a period of 5 consecutive weeks. Data on weekly exposure to green space, air pollution, and the physical activities of individual participants were collected by personal tracking devices. The effects of green space exposure measured by the normalized difference vegetation index (NDVI) at buffer zones of 100, 250, and 500 meters on a panel of cardiorespiratory biomarkers were estimated by a generalized linear mixed-effects model, with adjustment for confounding variables of sociodemographic characteristics, exposure to air pollutants and noise, exercise, and nutrient intake.ResultsA total of 39 participants (mean age 56.4 years, range 50-63 years) were recruited and followed up for 5 consecutive weeks. After adjustment for sex, income, occupation, physical activities, dietary intake, noise, and air pollution, significant negative associations with the NDVI for the 250-meter buffer zone were found in total cholesterol (–21.6% per IQR increase in NDVI, 95% CI –32.7% to –10.6%), low-density lipoprotein (–14.9%, 95% CI –23.4% to –6.4%), glucose (–11.2%, 95% CI –21.9% to –0.5%), and high-sensitivity C-reactive protein (–41.3%, 95% CI –81.7% to –0.9%). Similar effect estimates were found for the 100-meter and 250-meter buffer zones. After adjustment for multiple testing, the effect estimates of glucose and high-sensitivity C-reactive protein were no longer significant.ConclusionsThe health benefits of green space can be found in some metabolic and inflammatory biomarkers. Further studies are warranted to establish the causal relationship between green space and cardiorespiratory health.

Occupational exposures and symptoms of hearing loss among traffic police wardens, Karachi Pakistan.

Objective: To assess the frequency and association of symptoms of hearing loss among traffic police wardens. Study Design: Observational (Cross-sectional) study. Setting: Karachi, Pakistan. Period: January to June 2019. Material & Methods: Non-probability purposive sampling technique was used to employ 181 traffic police wardens. A self-administered questionnaire translated into Urdu language was used. Written informed consent was taken from the participants. IBM SPSS Statistics version 22 was used for the data entry and analysis. Frequencies were determined of socio-demographic data. Multivariable logistic regression analysis was done to assess the factors associated with tinnitus. Results: Most of the traffic police wardens were young (mean age: 29.96 years), non-smokers (95%) and having a matriculate degree (49.7%). Around 97.8% documented working in noisy places; 98.3% of the wardens did not use any hearing protection devices during work, while 98.9% stated that they never had a hearing test. Multivariable logistic regression showed strong inverse associations of tinnitus with higher education levels, longer duration of work, working in a noisy area, and experiencing sudden noise exposures in their lifetime. Conclusion: Traffic police wardens are exposed to loud noise during work, exhibiting the deleterious health impacts of occupational exposure. This workforce needs to be educated regarding the adverse health impacts of occupational noise pollution, the importance and use of personal protective equipment. Further research is warranted using more quantitative assessment

Mechanical Properties of Furnace Slag and Coal Gangue Mixtures Stabilized by Cement and Fly Ash.

The mechanical properties and strength formation mechanism of cement–fly-ash-stabilized slag–coal gangue mixture were examined using an unconfined compressive strength test, splitting strength test, triaxial test, and scanning electron microscopy to solve the limitations of land occupation and environmental pollution that is caused by fly ash from the Xixia District thermal power plant in Yinchuan, slag from the Ningdong slag yard, and washed coal gangue. Its performance as a pavement base mixture on the road was investigated. The results demonstrated that as the slag replacement rate increased, the maximum water content increased while the maximum dry density decreased. The addition of slag reduced the unconfined compressive strength and splitting strength of the specimens; furthermore, the higher the slag substitution rate, the lower the unconfined compressive strength and splitting strength of the specimens. As the cement content increased, the specimen’s unconfined compressive strength increased. Based on the principle of considering the mechanical properties and economic concerns, the slag replacement rate in the actual construction should be ~50% and should not exceed 75%. Based on the relationship between the compressive strength and splitting strength of ordinary concrete, the relationship model between the unconfined compressive strength and splitting strength of cement–fly-ash-stabilized slag–coal gangue was established. The failure mode, stress–strain curve, peak stress, and failure criterion of these specimens were analyzed based on the triaxial test results, and the relationship formulas between the slag substitution rate, cement content, peak stress, and confining pressure were fitted. As per the SEM results, the mixture’s hydration products primarily included amorphous colloidal C-S-H, needle rod ettringite AFt, unhydrated cement clinker particles, and fly ash particles. The analysis of the mixture’s strength formation mechanism showed that the mixture’s strength was the comprehensive embodiment of all factors, such as the microaggregate effect, secondary hydration reaction, and material characteristics.

Study of Heavy Metals Toxicity Level in Workplace Atmosphere by Alternative Methods

Promoting safety and health at work, as part of the overall improvement of working conditions, is an important strategy, not only to ensure well-being of workers, but also to make a positive contribution to productivity. Health, safety and well-being of workers are therefore prerequisites for improving quality and productivity and are important for equitable and sustainable socio-economic development. Toxicological investigation of an industrial objective involves both knowledge of working conditions and the dynamic establishment of occupational pollutants in the workplace atmosphere, as well as bio-toxicological evaluation, being a synthetic representation of the aggressiveness of pollutants entering the body by various paths (respiratory, cutaneous, digestive, etc.) with reference, at the same time, to the adaptability of respective employees. Evaluation of the toxicological investigation has a role in following the evolution of working conditions and health of employees in time, potential technological changes with possible impact on employees’ health, as well as if new conditions occur, requiring the completion of previous toxicological investigations. Use of heavy metals in different industries has increased the quality of products from different production sectors but on the other hand also led to an increase in the toxicity of workplace atmosphere, which requires an assessment of the negative impact produced. The current paper aims at an alternative analysis of the determination of heavy metals content (Cu, Cd, Pb, Ni, Cr) in workplace atmosphere, using, on one hand, the method of spectroscopy of atomic emissions with inductively coupled plasma and, on the other hand, fluorescence with X rays. Following statistical processing of data gathered by the two alternative methods, the accuracy, reproducibility, relative standard deviation as well as the fidelity of methods expressed by the coefficient of variation will be established.

In vitro impact preliminary assessment of airborne particulate from metalworking and woodworking industries

Inhalation is the main route of exposure to airborne pollutants. To evaluate the safety and assess the risks of occupational hazards different testing approaches are used. 3D airway epithelial tissues allow to mimic exposure conditions in vitro, generates human-relevant toxicology data, allows to elucidate the mode of action of pollutants. Gillian3500 pumps were used to collect the airborne particulate from woodworking and metalworking environments. EpiAirway tissues were used to model half working day (4 h), full working day (8 h), and 3 working day exposures to occupational pollutants. Tissue viability was assessed using an MTT assay. For preliminary assessment, RT-qPCR analyses were performed to analyze the expression of gelsolin, caspase-3, and IL-6. Tissue morphology was assessed by hematoxylin/eosin staining. An effect on the proliferation of lung epithelial cell line A549 was assessed. Acute exposure to workspace pollutants slightly affected tissue viability and did not change the morphology. No inhibiting effect was observed on the proliferation of A549 cells. Preliminary analysis showed that both types of particles suppressed the expression of gelsolin, with the effect of metalworking samples being more pronounced. A slight reduction in caspase-3 expression was observed. Particles from metalworking suppressed IL-6 expression.

Analysis of serum metabolome of workers occupationally exposed to hexavalent chromium: A preliminary study

Hexavalent chromium (Cr(VI)) compound is considered as a common environmental and occupational pollutant due to widespread application in industry and agriculture. Cr(VI) as a carcinogen poses a serious threat to human health and the underlying mechanisms need further investigation. Previous studies had demonstrated the characteristic expression profiling after Cr(VI) treatment in vitro and in vivo at the levels of gene and protein. The comprehensive metabolic signatures were also conducive to discover potential biomarkers for effects assessment of Cr(VI) toxicity. In the current study, Ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS) non-targeted metabolomics was applied to analyze serum metabolic changes in 77 chromate exposure workers and 62 controls. Thirteen metabolites were found significantly decreased and 41 metabolites were increased, which were involved in arginine and proline metabolism, and glycerophospholipid metabolism by bioinformatic analysis. Furthermore, there were significant negative correlations between blood Cr level and Arginine, PC(18:2/24:4) and PC(14:0/16:0), subgroup analyses indicated that these correlations were observed in male-only subgroups, and were not found among chromate workers and controls separately. Diet could be a potential confounder which was not controlled rigorously in this study. These findings provided preliminary clues to investigate the underlying mechanisms of Cr(VI)-induced toxicity and were required to be further verified in future researches.

Does urban sprawl exacerbate urban haze pollution?

Is rapid urban sprawl increasing environmental pollution while boosting economic development? This study uses panel data of 30 Chinese provinces during 2002-2018 to investigate the impact of urban sprawl on haze pollution with the use of a spatial lag model. Urban built-up area (ba) and urban public facilities occupation (upfo) are used to measure the differential impact of urban sprawl on haze pollution. The main highlights of the results are as follows: (1) there is a nonlinear relationship between urban sprawl and haze pollution. An inverted U-shaped relationship was found between built-up area and haze pollution, while urban public facility occupation and haze pollution have a U-shaped correlation. (2) The impact of urban sprawl on haze pollution shows a significant time-based difference. The relationship between the two was not significant in 2002-2010, but become significant in 2011-2018. (3) Significant regional differences in the impact of urban sprawl on haze pollution were found. The effects of urban sprawl on urban haze levels are more pronounced in the eastern and western regions than in the central region.

Respirable stone particles differ in their ability to induce cytotoxicity and pro-inflammatory responses in cell models of the human airways

BackgroundRespirable stone- and mineral particles may be a major constituent in occupational and ambient air pollution and represent a possible health hazard. However, with exception of quartz and asbestos, little is known about the toxic properties of mineral particles. In the present study, the pro-inflammatory and cytotoxic responses to six stone particle samples of different composition and with diameter below 10 μm were assessed in human bronchial epithelial cells (HBEC3-KT), THP-1 macrophages and a HBEC3-KT/THP-1 co-culture. Moreover, particle-induced lysis of human erythrocytes was assessed to determine the ability of the particles to lyse biological membranes. Finally, the role of the NLRP3 inflammasome was assessed using a NLRP3-specific inhibitor and detection of ASC oligomers and cleaved caspase-1 and IL-1β. A reference sample of pure α-quartz was included for comparison.ResultsSeveral stone particle samples induced a concentration-dependent increase in cytotoxicity and secretion of the pro-inflammatory cytokines CXCL8, IL-1α, IL-1β and TNFα. In HBEC3-KT, quartzite and anorthosite were the most cytotoxic stone particle samples and induced the highest levels of cytokines. Quartzite and anorthosite were also the most cytotoxic samples in THP-1 macrophages, while anorthosite and hornfels induced the highest cytokine responses. In comparison, few significant differences between particle samples were detected in the co-culture. Adjusting responses for differences in surface area concentrations did not fully account for the differences between particle samples. Moreover, the stone particles had low hemolytic potential, indicating that the effects were not driven by membrane lysis. Pre-incubation with a NLRP3-specific inhibitor reduced stone particle-induced cytokine responses in THP-1 macrophages, but not in HBEC3-KT cells, suggesting that the effects are mediated through different mechanisms in epithelial cells and macrophages. Particle exposure also induced an increase in ASC oligomers and cleaved caspase-1 and IL-1β in THP-1 macrophages, confirming the involvement of the NLRP3 inflammasome.ConclusionsThe present study indicates that stone particles induce cytotoxicity and pro-inflammatory responses in human bronchial epithelial cells and macrophages, acting through NLRP3-independent and -dependent mechanisms, respectively. Moreover, some particle samples induced cytotoxicity and cytokine release to a similar or greater extent than α-quartz. Thus, these minerals warrant further attention in future research.

Regulation of Aβ40 and Aβ42 by formaldehyde exposure in a three‐dimensional (3D) human neural cell culture model for Alzheimer's Disease

Alzheimer's disease (AD), a chronic neurodegenerative disorder characterized by rapidly progressive cognitive dysfunction and behavior impairment, is the most common form of dementia which accounts for 60 to 70 percent of cases. Pathologically, AD is characterized by severe atrophy and neuronal loss, extracellular neuritic plaques composed mainly of aggregated amyloid-b (Ab), and intracellular neurofibrillary tangles consisting of hyperphosphorylated tau protein. Multilevel complex interactions between genetic, epigenetic, and environmental factors contribute to the occurrence and progression of AD. Formaldehyde (FA) is the simplest saturated aldehyde which is one of the most typical environmental and occupational aldehyde pollutants. Recent studies suggested that elevation of FA in the brain, blood or urine by endogenous and/or exogenous exposure may play important roles in AD development. A three-dimensional (3D) human neural cell culture model for AD which can recapitulate key events of AD pathology including β-amyloid plaques and neurofibrillary tangles was used to investigate the effect of FA exposure in AD development and progression in human cells. Immortalized human neural progenitor cells (ReNcell VM (ReN)) were virally transfected with AD-related mutant genes including mutant APP and/or PSEN1 and enriched based on GFP and/or mCherry signals by Fluorescence-activated cell sorting (FACS). In order to mimic the restrictive environment of human brain and allow Aβ deposition and aggregation, the FACS-sorted ReN cells were differentiated into neurons and maintained in a 3D Matrigel culture system. The AD Model and primary ReN cells were treated with different concentrations of FA as well as vehicle controls for 16 weeks. Expression of Aβ40 and Aβ42 were measured in 4, 6, 12 16 weeks by ELISA and cytotoxicity was evaluated by LDH activity assay. The results revealed that FA significantly elevates expression of Aβ40 and Aβ42 in a concentration-dependent manner both in AD model and ReN cells. It indicated that FA exposure may play a critical role in AD development and progression.

A Narrative Review of Occupational Air Pollution and Respiratory Health in Farmworkers.

The agricultural crop sector in the United States depends on migrant, seasonal, and immigrant farmworkers. As an ethnic minority group in the U.S. with little access to health care and a high level of poverty, farmworkers face a combination of adverse living and workplace conditions, such as exposure to high levels of air pollution, that can place them at a higher risk for adverse health outcomes including respiratory infections. This narrative review summarizes peer-reviewed original epidemiology research articles (2000–2020) focused on respirable dust exposures in the workplace and respiratory illnesses among farmworkers. We found studies (n = 12) that assessed both air pollution and respiratory illnesses in farmworkers. Results showed that various air pollutants and respiratory illnesses have been assessed using appropriate methods (e.g., personal filter samplers and spirometry) and a consistent pattern of increased respiratory illness in relation to agricultural dust exposure. There were several gaps in the literature; most notably, no study coupled occupational air exposure and respiratory infection among migrant, seasonal and immigrant farmworkers in the United States. This review provides an important update to the literature regarding recent epidemiological findings on the links between occupational air pollution exposures and respiratory health among vulnerable farmworker populations.

Kefir milk alleviates benzene-induced immunotoxicity and hematotoxicity in rats.

The adverse health effects of benzene occupational and circumstance pollution exposure are an increasing concern. It leads to damage to various human tissues including bone marrow and ovarian tissues and many vital physiological processes. Previous studies showed that kefir is a rich probiotic, having protective effect, thanks to its antioxidant, anti-inflammatory, and immunomodulatory capacity. The purpose of this study was to evaluate the potential efficacy of kefir to remediate benzene toxicity in rat. Thirty-two female rats were randomly allocated and administered orally with benzene and/or kefir during a period of 21 consecutive days. At the end of the experiment, hematological and bone marrow cell changes were estimated. The animals exposed to benzene exhibited anemia and a significant decrease in the levels of white blood cell. Moreover, benzene led to the activation of gene expression of the pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-6 (IL-6), a myelotoxicity in bone marrow cells. Our data showed that kefir treatment alleviated benzene-associated weight loss and increased the number of whole blood cells in peripheral blood and nucleated cells in the bone marrow. Furthermore, these physiological results were observed with animals showing high concentrations of lactic acid bacteria (LAB) determined from fecal samples, which are considered an indicator of kefir-associated microorganisms. Our study suggests that kefir is a potential nutritional supplement target to attenuate hematotoxicity induced by benzene.

Cadmium disrupts mitochondrial distribution and activates excessive mitochondrial fission by elevating cytosolic calcium independent of MCU-mediated mitochondrial calcium uptake in its neurotoxicity

Cadmium (Cd) is a ubiquitous environmental and occupational pollutant that is considered as a high-risk factor for neurodegenerative diseases. However, the mechanism underlying Cd-induced neurotoxicity has not been fully elucidated. Abnormal mitochondrial distribution and excessive mitochondrial fission are increasingly implicated in various neurological pathologies. Herein, by exposing primary cortical neurons to Cd (10 and 100 μM) for various times (0, 6, 12, and 24 h), we observed that the rapid motility of the mitochondria in neurons progressively slowed. Many more mitochondria were transported and distributed to the somas of Cd-treated neurons. Coupled with abnormal mitochondrial distribution, Cd exposure triggered excessive mitochondrial fragmentation, followed by mitochondrial membrane potential loss and neuronal damage. However, BAPTA-AM, a chelator of cytosolic calcium ([Ca2+]c), significantly attenuated Cd-induced abnormal mitochondrial distribution and excessive mitochondrial fission, which protected against Cd-induced mitochondrial damage and neuronal toxicity. In contrast to the increase in [Ca2+]c, Cd exposure had no effect on the level of mitochondrial calcium ([Ca2+]m). Inhibiting [Ca2+]m uptake, either by ruthenium 360 (Ru360) or by knock-out of mitochondrial calcium uniporter (MCU), failed to alleviate Cd-induced mitochondrial damage and neuronal toxicity. Additionally, in MCU knock-out neurons, BAPTA-AM effectively prevented Cd-induced abnormal mitochondrial distribution and excessive mitochondrial fission. Taken together, Cd exposure disrupts mitochondrial distribution and activates excessive mitochondrial fission by elevating [Ca2+]c independent of MCU-mediated mitochondrial calcium uptake, thereby leading to neurotoxicity. Chelating overloaded [Ca2+]c is a promising strategy to prevent the neurotoxicity of Cd.

Acute acrylonitrile exposure inhibits endogenous H2S biosynthesis in rat brain and liver: The role of CBS/3-MPST-H2S pathway in its astrocytic toxicity

Hydrogen sulfide (H2S) as the third gasotransmitter molecule serves various biological regulatory roles in health and disease. Acrylonitrile (AN) is a common occupational toxicant and environmental pollutant, causing brain and liver damage in mammals. The biotransformation of AN is dependent-upon reduced glutathione (GSH), cysteine and other sulfur-containing compounds. However, the effects of AN on the endogenous H2S biosynthesis pathway have yet to be determined. Herein, we demonstrated that a single exposure to AN (at 25, 50, or 75 mg/kg for 1, 6 or 24 h) decreased the endogenous H2S content and H2S-producing capacity in a dose-dependent manner, both in the cerebral cortex and liver of rats in vivo. In addition, the inhibitory effects of AN (1, 2.5, 5, 10 mM for 12 h) on the H2S content and/or the expression of H2S-producing enzymes were also found both in primary rat astrocytes and rat liver cell line (BRL cells). Impairment in the H2S biosynthesis pathway was also assessed in primary rat astrocytes treated with AN. It was found that inhibition of the cystathionine-β-synthase (CBS)/3-mercaptopyruvate sulfurtransferase (3-MPST)-H2S pathway with the CBS inhibitor or 3-MPST-targeted siRNA significantly increased the AN-induced (5 mM for 12 h) cytotoxicity in astrocytes. In turn, CBS activation or 3-MPST overexpression as well as exogenous NaHS supplementation significantly attenuated AN-induced cytotoxicity. Taken together, endogenous H2S biosynthesis pathway was disrupted in rats acutely exposed to AN, which contributes to acute AN neurotoxicity in primary rat astrocytes.

Measurement of the occupational risk level specific to workplaces

Any workplace implies a greater or lesser number of occupational hazards, respectively workers are exposed to occupational risks, putting their health in danger. If we talk about industrial environments (construction, energy, metallurgy, textiles, wood, etc.), these hazards are found to a greater extent, often exceeding the allowable limit, but occupational pollutants such as dust in suspension and microclimate parameters can also be found in offices, whether they are open space or not. In this sense, the current paper reviews some workplaces and quantifies the level of risk to which workers are exposed to show and demonstrate the importance of occupational health prevention in order not to reach further measures, in time, when these occupational diseases occur. The research conducted led to the conclusion that the determined pollutants (dust, gas, microclimate) exceeded the maximum allowable concentration required by national legislation, both at workplaces in various technological flows and in offices. The high concentrations found in offices are caused by staff traffic, large number of employees, as well as the lack of natural ventilation.

Emissions from 3D Printers as Occupational Environmental Pollutants

Abstract While many people work remotely during the pandemic, three-dimensional (3D) printers are working to ensure the medical personnel and general public with the necessary specific materials. Ease of use, low cost, fast prototyping, and a wide range of materials are the advantages of 3D technology that can quickly adapt to specific needs in different application areas and result in increased popularity. The aim was to analyse the concentrations of particulate matter (PM) and volatile organic compounds (VOCs) emitted in 3D printing zone where printers are located throughout the room around the perimeter and where orthopaedics and designers develop models during their full shift. The average ultrafine particles (UFP) concentration level fluctuates from 4×103 to 26×103 particles/cm3 that exceed the background level (<3×103 particles/cm3) during 8 h-shift. Microclimate was evaluated as unsatisfied regarding permissible values for air quality at workplaces: air temperature exceeds permissible upper level +25 °C, relative humidity was 21.5 % and air velocity ≤0.05 m/s. The highest particles’ number concentrations in the nano-scale range (<0.1 μm) and significantly higher mass concentrations in the coarse particle range (>2.5 μm) were detected. The median diameters of particle number (0.019, 0.014, 0.015 μm) and mass concentrations (4.394, 4.433, and 4.677 μm) were similar in all observed premises. Total VOC concentration was increased and specific substances such as toluene and formaldehyde (0.56±0.1 and 0.23±0.034 mg/m3) were found at high concentration in comparison with indoor air quality recommendations.

Is Environmental and Occupational Particulate Air Pollution Exposure Related to Type-2 Diabetes and Dementia? A Cross-Sectional Analysis of the UK Biobank.

Human exposure to particulate air pollution (e.g., PM2.5) can lead to adverse health effects, with compelling evidence that it can increase morbidity and mortality from respiratory and cardiovascular disease. More recently, there has also been evidence that long-term environmental exposure to particulate air pollution is associated with type-2 diabetes mellitus (T2DM) and dementia. There are many occupations that may expose workers to airborne particles and that some exposures in the workplace are very similar to environmental particulate pollution. We conducted a cross-sectional analysis of the UK Biobank cohort to verify the association between environmental particulate air pollution (PM2.5) exposure and T2DM and dementia, and to investigate if occupational exposure to particulates that are similar to those found in environmental air pollution could increase the odds of developing these diseases. The UK Biobank dataset comprises of over 500,000 participants from all over the UK. Environmental exposure variables were used from the UK Biobank. To estimate occupational exposure both the UK Biobank’s data and information from a job exposure matrix, specifically developed for UK Biobank (Airborne Chemical Exposure–Job Exposure Matrix (ACE JEM)), were used. The outcome measures were participants with T2DM and dementia. In appropriately adjusted models, environmental exposure to PM2.5 was associated with an odds ratio (OR) of 1.02 (95% CI 1.00 to 1.03) per unit exposure for developing T2DM, while PM2.5 was associated with an odds ratio of 1.06 (95% CI 0.96 to 1.16) per unit exposure for developing dementia. These environmental results align with existing findings in the published literature. Five occupational exposures (dust, fumes, diesel, mineral, and biological dust in the most recent job estimated with the ACE JEM) were investigated and the risks for most exposures for T2DM and for all the exposures for dementia were not significantly increased in the adjusted models. This was confirmed in a subgroup of participants where a full occupational history was available allowed an estimate of workplace exposures. However, when not adjusting for gender, some of the associations become significant, which suggests that there might be a bias between the occupational assessments for men and women. The results of the present study do not provide clear evidence of an association between occupational exposure to particulate matter and T2DM or dementia.