Reducing risk factors in the workplace of the laser system operator

Publisher Copyright: © 2019 Pavels Narica, Inese Martinsone. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.Laser processing of materials takes an increasing place in production processes. Improving the performance, improving the quality of processing is not a complete list of the positive aspects of the introduction of laser processing, but there are a number of points that need to be paid attention to during the operation of laser systems-these are issues related to safety. The following risk factors are specific to laser systems: firstly, the laser beam itself, effects on the organs of vision, direct thermal effects on the skin and tissues, secondly, harmful products resulting from the interaction of the laser beam and the material being processed. Aerosols, smoke and dust have different effects on the human body, especially on the respiratory system and the publication considers the risks associated with the release of harmful products during laser processing and the existing methods for reducing the concentration of harmful substances in the working area with specific examples.publishersversionPeer reviewe

CHILDREN’S DEPRESSION RATING SCALE-REVISED (CDRS-R) – DEVELOPMENT OF THE LATVIAN VERSION AND PSYCHOMETRIC PROPERTIES IN A CLINICAL AND NON-CLINICAL SAMPLE OF ADOLESCENTS

Depression is one of the most widespread mental disorders worldwide. Adolescence is a vulnerable period for developing depression. It is associated with a number of challenges in biological, psychological and social areas. Valid and reliable measurement instruments are required for assessment of symptoms of depression in clinical samples of adolescents in Latvia. Children's Depression Rating Scale Revised (CDRS-R, Posnanski Mokros, 1996) is a semi-structured, clinician-rated interview for assessment of depression in children and adolescents. While the CDRS-R is the most widely used rating scale for research and clinicians’ practical use worldwide, there's no validated version in Latvian language available yet. The aim of this study is to present the reliability and validity of the Latvian version of CDRS-R in the adolescent age group. Twenty-five adolescents (aged 12-17) with diagnosis of depressive disorder (inpatients and outpatients) and twenty healthy controls were assessed with CDRS-R by clinical psychologist. Reliability and validity were calculated and analyzed: Cronbach’s alpha, Weighted Kappa, Spearman's rank correlation coefficient, Receiver operating characteristic (ROC). The Latvian translation of CDRS-R showed good psychometrical properties. Internal consistency for the CDRS-R was high. CDRS-R total score was significantly correlated with CDI both in nonclinical and clinical sample. There was a significant concordance with the reference standard of ICD-10 diagnosis. 

Wrist hypothermia related to continuous work with a computer mouse : A digital infrared imaging pilot study

Publisher Copyright: © 2015 by the authors; licensee MDPI, Basel, Switzerland. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.Computer work is characterized by sedentary static workload with low-intensity energy metabolism. The aim of our study was to evaluate the dynamics of skin surface temperature in the hand during prolonged computer mouse work under different ergonomic setups. Digital infrared imaging of the right forearm and wrist was performed during three hours of continuous computer work (measured at the start and every 15 minutes thereafter) in a laboratory with controlled ambient conditions. Four people participated in the study. Three different ergonomic computer mouse setups were tested on three different days (horizontal computer mouse without mouse pad; horizontal computer mouse with mouse pad and padded wrist support; vertical computer mouse without mouse pad). The study revealed a significantly strong negative correlation between the temperature of the dorsal surface of the wrist and time spent working with a computer mouse. Hand skin temperature decreased markedly after one hour of continuous computer mouse work. Vertical computer mouse work preserved more stable and higher temperatures of the wrist (>30 °C), while continuous use of a horizontal mouse for more than two hours caused an extremely low temperature (<28 °C) in distal parts of the hand. The preliminary observational findings indicate the significant effect of the duration and ergonomics of computer mouse work on the development of hand hypothermia.publishersversionPeer reviewe

The effect of different workplace nanoparticles on the immune systems of employees

Publisher Copyright: © 2017, The Author(s). Copyright: Copyright 2017 Elsevier B.V., All rights reserved.Currently, nanoparticles are widely present in the environment and are being used in various industrial technologies. Nanoparticles affect immune functions, causing different immune responses. The aim of the current study was to evaluate several cytokines, interleukin (IL)-1b, IL-6, IL-8, tumour necrosis factor-a (TNF-α), interferon-γ, adhesive molecule sICAM-1, macrophage inhibitory protein 1a (MIP1a) and secretory immunoglobulin A, in nasal lavage fluid and in the peripheral blood of healthy subjects exposed to workplace nanoparticles. Thirty-six employees from three different environments were examined: 12 from a metalworking company, 12 from a woodworking company and 12 office workers. The nanoparticles in the different workplaces were detected in the air in the immediate vicinity of the employees. The particle number concentration and surface area values were significantly higher in the workplaces of the metal- and woodworking industries, but concentrations of mass were lower (the measurements were performed by an electrical low-pressure impactor ELPI+). Energy dispersive X-ray spectroscopy (EDS, an attachment to a high-resolution SEM) was used to provide elemental analysis or chemical characterization of the dust particles in a low-vacuum field-free mode operating at a potential of 15 kV spot 3.0. The technique used provided quantitative and spatial analyses of the distribution of elements through mapping (two to three parallel measurements) and point analysis (four to five parallel measurements). Samples from the metal industry contained more ultramicroscopic and nanometric particles, e.g. toxic metals such as Zn, Mn and Cr, and fewer microscopic dust particles. The nasal lavage and peripheral blood were taken at the beginning and the end of the working week, when immune indices were measured. Our data showed a statistically significant increased level of the pro-inflammatory cytokine TNF-α in serum in both exposed groups compared with office workers as well as a higher level of TNF-α in workers from the woodworking company compared with the metalworking employees. We found an elevated level of IL-6 in the exposed groups as well as an elevated level of IL-8 in the nasal lavage in woodworking employees after work.publishersversionPeer reviewe

MULTIPLE PATH PARTICLE DOSIMETRY MODEL CONCEPT AND ITS APPLICATION TO DETERMINE RESPIRATORY TRACT HAZARDS IN THE 3D PRINTING

The Multiple Path Particle Dosimetry (MPPD) model is computer software that estimates and visualizes the deposition, clearance, and retention of particles in the respiratory tract systems of humans, rats, and other species. The mathematical model provides a broad spectrum of settings and input options. This research aims to explore the MPPD model concept and determine the deposition fraction (DF), clearance, and retained mass in the human respiratory tract (HRT) based on the geometric mean diameter (GMD) and mass concentration (MC) of particulate matter (PM) emitted during the 3D printing process. We used the real-time air sample data collected during the 8-hour working shift in the 3D printing office. Ultrafine PM deposits mainly in lungs (56%), fine PM mostly deposits in the upper respiratory tract (URT) (41%) and lungs (39%), but coarse PM mostly deposits in the URT (81%). The biggest DF in lower respiratory tract is ultrafine PM (487 μg), the smaller DF is coarse PM (185 μg) and the smallest DF is fine PM (123 μg). The biggest DF in lung for all PM - lower lobes (fine PM - 60%, ultrafine PM, coarse PM - 61%). In a model, where exposure was 5 hours a day, five days a week, during one month, followed by one year of post-exposure period, it was shown that retained mass in the tracheobronchial (TB) region was 1% for ultrafine and coarse PM each, 2% for fine PM, and 55% for all PM in the pulmonary region. The MPPD software is an easily accessible and valuable tool for assessing the impact of PM on the HRT. Particulate matter decreasing in diameter, tend to deposit mostly in the deeper levels of HRT. Tracheobronchial region clearance is more rapid than pulmonary region clearance. Potentially for persons using the 3D-printer regularly the worst health impact could be associated with smaller size of PM, due to tendency deposit mostly in pulmonary region where the clearance rate is slower

Curcumin effect on copper transport in HepG2 cells

Funding Information: Acknowledgments: The authors appreciate the support and advice of Uldis Berkis. The authors gratefully acknowledge the financial support from EU 7th Framework program project “Unlocking infectious disease research potential at R¯ıga Stradin,š University” (BALTINFECT) (grant agreement No. 316275). Publisher Copyright: © 2018 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.Background and Objective: In Wilson’s disease, copper metabolism is impaired due to defective copper transporting protein ATP7B, resulting in copper accumulation in liver and brain and causing damage to liver and brain tissues. Published data suggest that one of the possible treatments for Wilson’s disease is curcumin—a compound found in the root of Curcuma longa. In this study, we tested whether curcumin affects copper transport and excretion in HepG2 hepatocytes carrying wildtype ATP7B. Materials and Methods: We examined the impact of 5 µM and 25 µM curcumin on the transport of copper in HepG2 cells incubated with 20 µM and 100 µM CuCl2, as well as copper excretion from cells. First, immunofluorescent staining and co-localization analysis were carried out in HepG2 cells using confocal laser scanning microscope and Nikon NIS Elements software. Second, a concentration of copper extracted into cell culture medium was determined using atomic absorption spectrometry. Results: The analysis of the co-localization between Golgi complex and ATP7B revealed that both 5 µM and 25 µM doses of curcumin improve the ability of liver cells to transport copper to plasma membrane at 20 µM CuCl2, but not at 100 µM CuCl2 concentration. However, atomic absorption spectrometry showed that curcumin rather promotes copper absorption into liver cell line HepG2 than excretion of it. Conclusions: Curcumin accelerates the transport of copper within liver cells, but does not promote copper excretion from HepG2 cells.publishersversionPeer reviewe

Indoor Air Radon Concentration in Premises of Public Companies and Workplaces in Latvia

Funding Information: This study was partly financially supported by IAEA Technical Cooperation project RER/9127. Funding to pay the Open Access publication charges for this article was provided by the Institute of Occupational Safety and Environmental Health (Riga Stradins University). Funding Information: Funding: This study was partly financially supported by IAEA Technical Cooperation project RER/9127. Funding to pay the Open Access publication charges for this article was provided by the Institute of Occupational Safety and Environmental Health (Riga Stradins University). Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Considering the multitudes of people who spend their time working indoors in public premises and workplaces, it is worth knowing what their level of exposure is to natural radioactive radon gas, the second most widespread and dangerous carcinogen for lung cancer development after cigarette smoking. This state‐level study covered most of the territory of Latvia and conducted 941 radon measurements with Radtrack2, placed for 4–6 months in the premises of public companies, educational institutions, medical care institutions, etc. The study found that 94.7% of samples did not exceed the national permissible limit (200 Bq/m 3), the level at which preventive measures should be initiated. The median value of average specific radioactivity of radon in these premises was 48 Bq/m 3 (Q1 and Q3 being 27 and 85 Bq/m 3), which is below the average of the European region. Slightly higher concentrations were observed in well‐insulated premises with plastic windows and poorer air exchange, mostly in schools (59 (36, 109) Bq/m 3) and kindergartens (48 (32, 79) Bq/m 3). Industrial workplaces had surprisingly low radon levels (28 (16, 55) Bq/m 3) due to strict requirements for air quality and proper ventilation. Public premises and workplaces in Latvia mostly have low radon concentrations in the air, but more attention should be paid to adequate ventilation and air exchange.publishersversionPeer reviewe

Comparison of biological markers in aerosol-weighed workplaces

Funding Information: Funding information This work was supported by ESF project “The development of up-to-date diagnostic and research methods for the risks caused by nanoparticles and ergonomic factors at workplaces” (Agreement No. 2013/0050/1DP/1.1.1.2.0/13/ APIA/VIAA/025). Publisher Copyright: © 2019, The Author(s). Copyright: Copyright 2019 Elsevier B.V., All rights reserved.Airborne particulates present a potential hazard to health in a variety of indoor workplaces, from offices to the manufacturing floor. Dust and aerosols are two of the most common occupational risk factors in the workplace worldwide. It is very important to understand when it is sufficient to describe dust exposure only by given mass concentration that dust particles could be in the nanosized range in the workplace air even for brief exposures, such as welding aerosols. The main objective was to assess total dust and nanoparticle concentrations in the selected workplaces and to evaluate their impact on workers’ health. This project describes nanoparticle concentrations and their potential impact on workers’ health considering the exposure levels in three workplaces. Industrial and non-industrial environments have been included in the project. The office environment was used as an indicator for the background level of comparison with the metalworking and woodworking industries for measurements of dust particles including the nanoscale particles (> 100 nm). Fraction size of the samples according to a dispersity of > 10 μm, 0.25–10 μm, < 0.25 μm, and 1–100 nm was analysed in order to describe the particles’ chemical composition at the different stages. The worst working conditions (the smallest particles, 12 nm), the highest total dust concentrations, and the lowest difference between total inhalable particle and nanoparticle concentrations were detected among woodworkers. These findings provide a basis on how to evaluate nanoparticle exposure and its impact on workers’ health because the highest immune cell counts and relatively high IL-6 expression were observed among woodworkers compared with the other groups. The data show a negative tendency of nanoparticle exposure concentrations on workers’ health based on the increase of inflammatory processes and damage to airway epithelial cell functionality.Peer reviewe

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

Funding Information: This work was supported by ESF project “Development of up-to-date diagnostic and research methods for the risks caused by nanoparticles and ergonomic factors at workplaces” Agreement No. 2013/0050/1DP/1.1.1.2.0/13/ APIA/VIAA/025. Publisher Copyright: © 2021, The Author(s).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.publishersversionPeer reviewe

Assessment of Occupational Exposures in the 3D Printing: Current Status and Future Prospects

3D (three-dimensional) printing technologies are widespread and rapidly evolving, creating new specific working conditions, and their importance has been highlighted by increasing publications in recent years. The report provides a compilation of current information on 3D technologies, materials, and measurements, considering the determination of the potential actual exposure dose of chemicals through airborne inhalation and dermal exposure, including workers’ exhaled breath condensate and urine data. Noninvasive assessment methods are becoming increasingly popular, as they are painless, easy to perform, and inexpensive. Investigation of biomarkers reflecting pulmonary inflammation and local and systemic oxidative stress in exhaled breath, exhaled breath condensate, and urine are among them. It is also important to consider the occupational health and safety risks associated with the use of various new materials in 3D printing, which are associated with skin irritation and sensitivity risks. Therefore, EDI (estimated daily intake) calculations for assessment of the potential occupational health risk purposes via inhalation and dermal exposure are critical in future. The assessment of occupational exposure and health risks of 3D printing processes is essential for the proper identification, control, and prevention of working conditions, also for the diagnosis and monitoring of occupational diseases among workers to improve public health and well-being in general