Permissible Exposure Limit Research Articles

Traditional indigenous medicines are an etiologic consideration for NELL1-positive membranous nephropathy

Traditional indigenous medicines are an etiologic consideration for NELL1-positive membranous nephropathy

Computational modeling method to estimate secondhand exposure potential from exhalations during e-vapor product use under various real-world scenarios

Potential secondhand exposure of exhaled constituents from e-vapor product (EVP) use is a public health concern. We present a computational modeling method to predict air levels of exhaled constituents from EVP use. We measured select constituent levels in exhaled breath from adult e-vapor product users, then used a validated computational model to predict constituent levels under three scenarios (car, office, and restaurant) to estimate likely secondhand exposure to non-users. The model was based on physical/thermodynamic interactions between air, vapor, and particulate phase of the aerosol. Input variables included space setting, ventilation rate, total aerosol amount exhaled, and aerosol composition. Exhaled breath samples were analyzed after the use of four different e-liquids in a cartridge-based EVP. Nicotine, propylene glycol, glycerin, menthol, formaldehyde, acetaldehyde, and acrolein levels were measured and reported based on a linear mixed model for analysis of covariance. The ranges of nicotine, propylene glycol, glycerin, and formaldehyde in exhaled breath were 89.44–195.70 µg, 1199.7–3354.5 µg, 5366.8–6484.7 µg, and 0.25–0.34 µg, respectively. Acetaldehyde and acrolein were below detectable limits; thus, no estimated exposure to non-EVP users is reported. The model predicted that nicotine and formaldehyde exposure to non-users was substantially lower during EVPs use compared to cigarettes. The model also predicted that exposure to propylene glycol, glycerin, nicotine and formaldehyde among non-users was below permissible exposure limits.

A systematic comparative study of granular activated carbons and catalysts for ozone removal

Ozone is one of the critical air pollutants having direct and indirect adverse health effects. The occupational safety and health administration (OSHA) set 100 ppb as the ozone's permissible exposure limit, highlighting the need for an ozone removal mechanism in many indoor settings. Activated carbon (AC) and metal oxide catalyst based ozone removal are two widely-used technologies for ozone mitigation; however, currently, little insight exists for choosing the best technology based on the application requirements. AC tests were typically limited to low ozone concentration (e.g., ppb level) making it difficult to obtain a broad picture of the link between their performance and properties. Additionally, the ozone removal by ACs and catalysts lacked a complete assessment of performance degradation over time. To fill this gap, this study involves a systematic evaluation of the ozone removal by various granular ACs and granular manganese oxide-cuprous oxide catalysts. The testing methodology was initially based on ASHRAE 145.1 standard; however, test conditions were later made more challenging to better capture the performance decline. It was surprisingly found that, among ACs, the coconut shell-based one have a substantial capacity to remove ozone at moderate and mild concentration levels (<200 ppm), even higher than catalyst, although all ACs get considerably deactivated at high concentration (>99% efficiency at 1 ppm down to <40% efficiency at 900 ppm). By contrast, catalysts feature a slow steady decrease of active sites over time (99% efficiency at 1 ppm down to >70% efficiency at 900 ppm). Subsequent analysis of the material properties demonstrated a strong link between material's type and its physical and chemical characteristics with its ozone removal capacity. The knowledge is envisioned to be of significant utility for numerous applications where ozone contamination is a challenging problem.

Elevated exposures to respirable crystalline silica among engineered stone fabrication workers in California, January 2019-February 2020.

Workers fabricating engineered stone face high risk for exposure to respirable crystalline silica (RCS) and subsequent development of silicosis. In response, the California Division of Occupational Safety and Health (Cal/OSHA) performed targeted enforcement inspections at engineered stone fabrication worksites. We investigated RCS exposures and employer adherence to Cal/OSHA's RCS and respiratory protection standards from these inspections to assess ongoing risk to stone fabrication workers. We extracted employee personal air sampling results from Cal/OSHA inspection files and calculated RCS exposures. Standards require that employers continue monitoring employee RCS exposures and perform medical surveillance when exposures are at or above the action level (AL; 25 μg/m3 ); exposures above the permissible exposure limit (PEL; 50 μg/m3 ) are prohibited. We obtained RCS and respiratory protection standard violation citations from a federal database. We analyzed RCS exposures for 152 employees at 47 workplaces. Thirty-eight (25%) employees had exposures above the PEL (median = 89.7 μg/m3 ; range = 50.7-670.7 μg/m3 ); 17 (11%) had exposures between the AL and PEL. Twenty-four (51%) workplaces had ≥1 exposure above the PEL; 7 (15%) had ≥1 exposure between the AL and PEL. Thirty-four (72%) workplaces were cited for ≥1 RCS standard violation. Twenty-seven (57%) workplaces were cited for ≥1 respiratory protection standard violation. Our investigation demonstrates widespread RCS overexposure among workers and numerous employer Cal/OSHA standard violation citations. More enforcement and educational efforts could improve employer compliance with Cal/OSHA standards and inform employers and employees of the risks for RCS exposure and strategies for reducing exposure.

The potential ‘blue light hazard’ from LED headlamps

Many dental personnel use light-emitting diode (LED) headlamps for hours every day. The potential retinal ‘blue light hazard’ from these white light headlamps is unknown. MethodsThe spectral radiant powers received from direct and indirect viewing of an electronic tablet, an LED curing light, a halogen headlamp, and 6 brands of LED headlamps were measured using integrating spheres attached to fiberoptic spectroradiometers. The spectral radiant powers were measured both directly and indirectly at a 35 cm distance, and the maximum daily exposure times (tMAX) were calculated from the blue weighted irradiance values. ResultsThe headlamps emitted very different radiant powers, emission spectra, and color temperatures (K). The total powers emitted at zero distance ranged from 47 mW from the halogen headlamp to 378 mW from the most powerful LED headlamp. The color temperatures from the headlamps ranged from 3098 K to 7253 K. The tMAX exposure times in an 8 h day when the headlamps were viewed directly at a distance of 35 cm were: 810 s from the halogen headlamp, 53 to 220 s from the LED headlamps, and 62 s from the LED curing light. Light from the LED headlamps that was reflected back from a white reference tile 35 cm away did not exceed the maximum permissible exposure time for healthy adults. Using a blue dental dam increased the amount of reflected blue light, but tMAX was still greater than 24 h. ConclusionsWhite light LED headlamps emit very different spectra, and they all increase the retinal ‘blue light hazard’ compared to a halogen source. When the headlamps were viewed directly at a distance of 35 cm, the ‘blue light hazard’ from some headlamps was greater than from the LED curing light (tMAX = 62 s). Depending on the headlamp brand, tMAX could be reached after only 53s. The light from the LED headlamps that was reflected back from a white surface that was 35 cm away did not exceed the maximum permissible ocular exposure limits for healthy adults. Clinical relevanceReflected white light from dental headlamps does not pose a blue light hazard for healthy adults. Direct viewing may be hazardous, but the hazard can be prevented by using the appropriate blue-light blocking glasses.

Evolution of beryllium safety standards over the last 70 years and challenges ahead

Beryllium (Be), its alloys, and ceramics are widely used in high-tech applications such as electronics, space, atomic energy, and other day-to-day items of use. Initially, Be-based phosphors such as ZnBeSiO4 were being used in the lamp industry during the 1930s onward but were soon abandoned due to lung-related diseases and deaths of workers in the phosphor industry which was attributed to the highly toxic nature of Be. Typical effects associated with Be inhalation are chronic and acute Be diseases (CBD and ABD) and the main target organ being affected is the lung although effects on other human body organs are also well documented. Such diseases were observed not only in occupational workers handling Be but also in the members of the public residing in the neighborhood of Be manufacturing and processing facilities, especially in the USA. The CBD in occupational workers may depend on many factors such as individual's sensitivity to Be, amount of Be exposure, nature of Be compound, and types of Be operations and processes being performed. All this led to safety concerns about the toxicity of Be and recommendations regarding Be air concentration in the workplace and public environment were issued by the Department of Energy, USA in 1949 as occupational exposure limit (OEL)/threshold limit values (TLVs) which were 2.0 μg/m3 and 0.01 μg/m3 for occupational Be workers and public environment, respectively. It is worth to mention that these recommendations were adopted by various countries and organizations either as it is or with small changes. Later, different organizations recommended changes in the value of TLV for occupational workplaces, but such changes were never adopted as they were lacking sound epidemiological basis. The OEL/TLV of 2.0 μg/m3 continued for nearly 70 years until Occupational Safety and Health Administration (OSHA) in 2017 reduced the Be air concentration (BeAir-Conc) limit for occupational workers to 0.20 μg/m3 as the value of 2.00 μg/m3 was inadequate to protect occupational workers from CBD. This is a major change in the Be-related safety standards recommended recently and is/being adopted by many countries. The present article provides details about the evolution of Be safety standards over the last 70 years, the notion behind the recent revision of Be permissible exposure limit (PEL) value from 2.0 μg/m3 to 0.20 μg/m3 by OSHA and the associated safety challenges ahead. The information from literature about Be safety and related safety standards adopted in India is also given. The article also provides details about TLVs for BeAir-Conc being followed in various countries in the world and various challenges for the implementation of a revised PEL value of 0.20 μg/m3 as suggested by OSHA i.e., reduction in PEL value by a factor of 10 or recommendation of revised TLV of 0.05 μg/m3 by American Conference of Governmental Industrial Hygienists as compared to the previous value of 2.0 μg/m3. In view of different notations and limits for BeAir-Conc recommended by various agencies and limited information about Be safety-related details, all relevant information regarding Be safety along with the evolution of Be safety standards over the last 70 years is included in the present article. This is an important issue for the safety of individual's at occupational workplaces as well as for environmental safety and its compilation was highly needed for providing comprehensive information on Be safety from the inception of standards to till today.

Measurement and Assessment of Exposure to 50 Hz Magnetic Fields from Common Home Electrical Appliances

In this twenty first century, man is exposed to a very high amount of magnetic fields in his environment. This is mainly due to the ubiquitous use of electricity and other technological devices, which are the major sources of magnetic field pollution. The effect of magnetic field exposure on health problems and safety risk of people is continually being investigated. A number of international organizations have formulated guidelines on limits to the value of the generated magnetic field. This work provides information on the amount of 50 Hz magnetic field created by some common home electrical appliances, and compare results obtained with permissible exposure limit by The International Commission on Non-Ionising Radiation Protection (ICNIRP) for the public. The home electrical appliances investigated include electric cooker, hair dryer, toaster, kettle, fan, microwave oven, electric iron, voltage stabilizer, etc. Measurements were carried out with the aid of a magnetic field strength meter, at a distance of 3 cm to 75 cm from the appliances. Results showed that the magnetic field varies with distance from the appliances (by quarter of a meter, most become negligible), the power consumption of the appliance, the age of the appliance, and the product (manufacturer) of the appliance. Also, appliances with electromagnets, coils and electric motors produce more magnetic fields than appliances with heating elements. At a distance of 3 cm from the appliances, the highest value of magnetic field obtained was 85.5 µT and the lowest value of the magnetic field obtained was 4.28 µT. The overall results obtained indicate that the magnetic field strengths are lower than the maximum permissible exposure limit (100 µT) recommended by ICNIRP for members of the public, and therefore, will not lead to any significant exposure risk. In conclusion, in-expensive measures of reducing magnetic field exposure are recommended.

Hybrid Laser-LED Transmitter With Closed-Loop Beam-Steering Control for Indoor Optical Wireless Communication

In this paper, we demonstrate a hybrid Laser-LED transmitter module for indoor optical wireless communication with closed-loop, non-mechanical beam steering capability. The hybrid transmitter module consists of a near infrared laser diode for data communication and white LED array for illumination, combined on a diffuser surface. Dual-axis non-mechanical beam steering of the laser beam is implemented using two off-centered liquid lenses. The diffused laser beam directed towards the receiver is steered over an angular range of −7.6 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> to 7.6 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> (−1.7 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> to 2.6 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> ) along the horizontal (vertical) axes spanning −200 to 200 mm (−44 to 67 mm) at the receiver placed 1.5-meter from the transmitter. M-QAM/OFDM in combination with adaptive bit-and power-loading is utilized to achieve a total data throughput of 5.15 Gbps for the diffused laser beam with steering. Laser intensity levels as measured at the receiver plane are kept below the maximum permissible exposure limit for indoor usage across the entire beam steering range. Closed-loop beam steering is also demonstrated by scanning the transmitted laser beam horizontally, measuring the signal strength using a low bandwidth photodetector and locking the laser beam to the receiver position for data-communication. Such hybrid transmitters offer the benefit of decoupling the data communication and illumination requirements of the indoor optical link, thereby tailoring the individual light emitter's performance to specific use-case.

Evaluation of the Acoustic Environment of Urban Recreational Trails

The acoustic environment state of four recreational trails in Taichung was investigated. First, the basic forms, spatial proportions, characteristics of the trail interfaces, and sound sources of the recreational trail spaces were investigated. Second, sound pressure level measurement and a questionnaire survey were conducted in relation to the four trails. The measurements demonstrated that the sound levels of the four trail spaces are lower than the permissible exposure limit 90 dB(A) recommended by the Occupational Safety and Health Administration. Meanwhile, the results of the factor analysis show that the perception of the acoustic environment of recreational trails has five dimensions: likability, intensity, communication, joyfulness, and richness. Compared with the acoustic environments of other cities, the perception of the acoustic environment of the recreational trails in this city was characterized by more dimensions and a more balanced structure.

Determination of Heavy Metals in Some Types of Imported Fish from Local Markets

Heavy metals can be considered in the aquatic environment as natural archaeological components and their quantities have risen as a result of industrial pollution. Heavy metals do not degrade over time and their concentrations can only rise due to bioaccumulation unlike organic contaminants. In the recent period, fish consumption has increased significantly because of its nutritional benefits, as it is a vital source of protein, as well as being high in critical vitamins and minerals. Because of the presence of heavy metals in frozen fish, it is a global public health issue concern but their presence remains essential and important for human physiological activities. However, when concentrations exceed the established allowed limits, they can be detrimental. The aim of this study was to quantify the concentration of heavy metals in frozen fish samples selected from Baghdad’s local markets. Six samples (Cleaned Shrimps, Anchovy Fillets, Captain Fisher Shrimps, Mackerel Fillets, Super Fresh Kalamar Squid and Frozen Rainbow Trout) of common brands of imported fish were selected from Iraqi markets in Baghdad. Acid digestion with a mixture of (65% HNO3 with 37% HCL) was carried out to free heavy metals fromfish samples to prepare solutions for testing in atomic absorption spectroscopy (AAS) device. The results reveal that the element concentrations in the selected samples (Cr, Co, Fe, Cu, Ni, K, Zn and Mg) are within the acceptable levels, and are lower than the permitted exposure limits according to international standards. It is remarkable to mention that the quantities of (Cd and Pb) are lower than permissible exposure limits of cadmium (0.2 mg/Kg) and lead (0.5 mg/Kg), implying that these imported items could be consumed safely.

Electrocautery smoke exposure and smoke evacuation in thoracic surgery: A prospective randomized study

Abstract Objective Worldwide, health care professionals working in operating rooms (ORs) are exposed to electrocautery smoke on a daily basis. Aims of this study were to determine the composition and concentrations of electrocautery smoke in the OR using mass spectrometry and investigate whether smoke evacuation systems, operative technique and distance to the cautery source are effective in reducing exposure. Methods Single-center study at our thoracic surgical unit including 122 surgical procedures. Besides room air measurements away from the operating table (n=35) and direct breath analysis (n=3), 84 minimally invasive and open procedures were in each group 1:1 computer randomized to smoke evacuation system (SES) versus no SES use and hazardous compounds were measured at the height of the operating surgeons respiratory tract. Results Irritating, toxic, carcinogenic and mutagenic volaticle organic compounds (VOCs) were observed in OR air, with some exceeding permissible exposure limits (OSHA/NIOSH). Mean total concentration of harmful compounds at surgeon height without SES was 273ppb (±189ppb) with a maximum total concentration of harmful substances of 8991ppb . Maximum total VOC concentrations were 1.6±1.2 ppm (minimally-invasive surgery) and 2.1±1.5 ppm (open surgery), and total maximum VOC concentrations were 1.8±1.3 ppm at the OR table and 1.4±1.0 ppm in OR air in general. Neither difference was statistically significant. In open surgery, SES significantly reduced maximum concentrations of specific VOCs at surgeon height, including aromatics and aldehydes. Conclusion Our data indicate relevant exposure of health care professionals to volatile organic compounds in the OR. Surgical technique and distance to cautery devices did not significantly reduce exposure. SES reduced exposure to specific harmful VOC's during open surgery.

Comparative Analysis of Methods for Calculating the Energy Flux Density used in Assessing the Permissible Level of Environmental Pollution by Electromagnetic Radiation

In this article, the results of measurements and calculations of the power flux density in the frequency range 670 MHz-766 MHz (46th and 57th television channels) of digital broadcasting of the DVBT2 standard were presented. Experimental data on the power flux density were obtained by the selective electromagnetic field meters NARDA SRM-3000 with an isotropic antenna. The radiating system consists of 16 panel antennas (four-storey panel antennas) with a circular radiation pattern in the horizontal plane. Calculations were carried out in the ПК АЭМО (Software package for electromagnetic environment analysis) and MMANA programs. The data obtained were compared with the permissible exposure limit (PEL) of energy flux density (EFD) set by health and safety rules and standards (2.1.8/2.2.4.1383-03), which operate on the territory of Russia.The values obtained are significantly less than the acceptable levels. In the USA, Japan, European countries, Canada, China, and the PEL of energy flux density in the frequency range 300 MHz – 300 GHz are higher than in Russia.

Job and demographic risk factors influencing cellular mediated hypersensitivity among Nigerian Laboratory University workers in multiple chemical exposures

Background: Chemicals from laboratories represent a significant risk in cellular mediated hypersensitivity (CMH) and chemo-induced skin injury due to chemical agents present under human skin layers absorbed from the surface. This study aimed to determine the occupational and socio-demographic characteristics of the laboratory workers associated with CMH in multiple chemical exposures. Design: This was a cross-sectional study on a population-based sample of Nigerian laboratory university workers. Methods: Data were collected using the erythema index meter. The study included 287 laboratory workers. Results: The results showed that the number of positive with CMH was 176 (61.3%) with 99 (56.3%) of them were male with AOR 0.31 (95%CI: 0.12, 0.77; p=0.011). Dark-skinned participants with CMH had adjusted odd ration, AOR 0.49 (95%CI: 0.21, 081; p =0.001). Most of the respondents have college education and have been exposed for 4-5hrs in the laboratory with AOR 2.42 (95%CI: 1.10, 5.38; p = 0.049) and 3.11 (95%CI: 1.77, 9.23; p =0.001) respectively. The use of personal protective equipment (PPE) was 60% less likely to be significantly induced with CMH with AOR 0.40 (95%CI: 0.22, 0.77; p =0.011). The Permissible exposure limit (PEL) of chemical was less but have an induced CMH with AOR 4.22 (95%CI: 2.88, 12.11; p =0.004). Conclusion: Results revealed that sex, skin color, working experience, educational level, PPE, PEL, and time of exposure were the probable predictive factors associated with the development of CMH. This study has shown that CMH was significantly associated with occupational and demographic factors. Better educational knowledge and attitude of hazards and safety in the laboratory would lead to a reduced rate of new cases.

General Medical Conditions and Occupational Diseases in Workers Engaged in Crude Nickel and Copper Production

Introduction: Working conditions in the production of crude nickel and copper pose an increased risk of occupational diseases. Objective: To collect new data on health disorders in workers engaged in the production of crude nickel and copper in the Arctic. Materials and methods: We analyzed general medical conditions and occupational diseases in 760 workers engaged in the production of crude nickel and copper in 2008–2020. Results: Nickel compounds, workplace air concentrations of which exceed the permissible exposure limit by 7.6–157.0 times in various unit process areas, represent the main occupational hazard in converter matte processing. According to the regular check-up data for 2008, the most prevalent general medical conditions included diseases of the eye (18.4 %), musculoskeletal (14.7 %) and respiratory (12.5 %) systems. Every 10-year increment in the length of service was associated with an increase in the incidence of diseases of the musculoskeletal, circulatory and endocrine systems (p &lt; 0.001) in the workers. In 2009–2020, 91 occupational diseases were first diagnosed in 50 of 760 employees, among which respiratory diseases prevailed (68.9 %), and the average annual incidence rate was 0.998 cases per 100 workers. Mill and smelter operators (16.7 % and 13.4 % of all workers, respectively) were at higher risk of developing an occupational disease, and their annual incidence rates were 1.389 and 1.122 cases per 100 workers, respectively. We observed a clear dose-response relationship between the exposure and occupational disease rates in the workers concerned: occupational diseases developed in 32.9 % of workers with very high occupational exposure and in 17.6 %, 12.0 %, 2.0 %, and 0.3 % of workers exposed to high, medium, moderate, and low levels of airborne nickel compounds. Conclusion: We have obtained new data on non-occupational and occupational disorders in the crude nickel and copper production workers enabling early and targeted disease prevention.

Effect of cadmium on aminotransferases serum activity in European carp

In many densely populated areas of the Earth, there is an excess amount of heavy metals in soil, air and water, a significant part of which comes from industrial pollution. So it is important to evaluate possible effects of heavy metals in biological models.Aim of this study is to asset toxic influence of heavy metals in fish. This research was intended to analyze aminotransferases (ALT, AST) serum activity under the influence of various cadmium concentrations in European carp. Intracellular enzymes activity level elevation in serum is a sign of mass cell destruction and consequently is a sign of pathological process. In this experiment 3 groups of fish (European carp) were formed, 10 fish in each group: control group; 1‐experimental group – fish were contained in water with 0.05 mg/l cadmium acetate concentration (10 times higher than fishery waters permissible exposure limit according to the laws of the Russian Federation); 2‐experimental group – fish were contained in water with 0.5 mg/l cadmium acetate concentration (100 times higher than fishery waters permissible exposure limit according to the laws of the Russian Federation). Exposure time was 4 hours. The blood samplings were taken from heart by syringe and placed in dry test tubes. After samplings centrifugation in non‐hemolysed serum samples ALT and AST activities were assessed. Results presented as mean±standard error of the mean. Student's t‐test was used after proving normal distribution. Level of significance is labeled as p&lt;0.05.The study revealed that there were meaningful elevation of ALT and AST serum activity (p≤0.05) by 44.22% (30,92±1,42 IU/l) and 15.36% (261,5±8,07 IU/l) accordingly in 1‐experimental group in compare with control group (21.44±0.72 IU/l и 226.68±4.35 IU/l). In case where the cadmium acetate concentration were 100 times higher than fishery waters permissible exposure limit were meaningful elevation of ALT and AST serum activity (p≤0.01) by 88.82% (38,34±0,19 IU/l) and 71.53% (388,82±14,57IU/l) accordingly in 2‐experimental group in compare with control group.After analyzing the received data there were established meaningful aminotransferases serum activity elevation under the influence of various cadmium concentrations in European carp. This may be due to the activation of gluconeogenesis, which is necessary to maintain an adequate glucose level in conditions of intoxication, which determines the direction of metabolic flows towards the predominance of catabolic reactions. This data is important to be taken into consideration not only during assessing physiological condition in fish, but also to increase understanding of the damage extent in biological models.

Development of a combinatory filtration system for pollution and virus abatement by optimized nanoparticle deposition.

PM2.5, particulate matter less than 2.5 microns, is the leading contributor to air pollution which results in cardio-vascular and respiratory diseases. Recent studies also indicate a strong correlation between ambient air pollution and COVID-19 cases, which have affected the lives of billions of people globally. Abatement technologies such as ionic and other high efficiency filtration systems are expensive and unaffordable in communities with limited resources. The goal of this study was to develop a mask with an optimized nanoparticle coating which has a dual capability of particulate matter and virus filtration, while being affordable and safe for human use. The nanoparticles were selected for their filtration and virucidal capabilities. Particle filtration efficiency, tested with a wind tunnel and PM2.5 from incense sticks measured by laser particle detectors, improved by ~60% with nanoparticle coatings on KN95 and surgical masks. Virus filtration efficiency, tested using nebulized NaCl particles as a virus surrogate, improved by 95% with coated masks. The nanoparticle retention efficacy, tested by simulating a normal 8-hour workday, was well within the permissible exposure limits. This technology has several applications such as in personal protective equipment for virus protection, and in air-conditioning and car cabin filters for pollution abatement. In conclusion, the chosen combination of nanoparticles provides an effective and safe solution for both particulate matter and viral particle filtration.

Electrocautery smoke exposure and efficacy of smoke evacuation systems in minimally invasive and open surgery: a prospective randomized study

Worldwide, health care professionals working in operating rooms (ORs) are exposed to electrocautery smoke on a daily basis. Aims of this study were to determine composition and concentrations of electrocautery smoke in the OR using mass spectrometry. Prospective observational study at a tertiary care academic center, involving 122 surgical procedures of which 84 were 1:1 computer randomized to smoke evacuation system (SES) versus no SES use. Irritating, toxic, carcinogenic and mutagenic VOCs were observed in OR air, with some exceeding permissible exposure limits (OSHA/NIOSH). Mean total concentration of harmful compounds was 272.69 ppb (± 189 ppb) with a maximum total concentration of harmful substances of 8991 ppb (at surgeon level, no SES). Maximum total VOC concentrations were 1.6 ± 1.2 ppm (minimally-invasive surgery) and 2.1 ± 1.5 ppm (open surgery), and total maximum VOC concentrations were 1.8 ± 1.3 ppm at the OR table ‘at surgeon level’ and 1.4 ± 1.0 ppm ‘in OR room air’ away from the operating table. Neither difference was statistically significant. In open surgery, SES significantly reduced maximum concentrations of specific VOCs at surgeon level, including aromatics and aldehydes. Our data indicate relevant exposure of health care professionals to volatile organic compounds in the OR. Surgical technique and distance to cautery devices did not significantly reduce exposure. SES reduced exposure to specific harmful VOC’s during open surgery.Trial Registration Number: NCT03924206 (clinicaltrials.gov).

Predicting Low Toxicity and Scalable Solvent Systems for High‐Speed Roll‐to‐Roll Perovskite Manufacturing

Safer Ink Systems In article number 2100567, Richard Swartwout and co-workers demonstrated the coating performance of their new, safer solvent ink mixture with an effective permissible exposure limit 10x higher than traditional DMF/DMSO ink systems. Regulatory requirements limit exposure to solvent vapors generated from ink-based coating processes. For perovskite photovoltaics, this requires new ink formulations that exclude traditionally hazardous solvents while simultaneously coating uniformly at scale.

Medical Staff at Sanatorium-Resort Organizations: Working Conditions and Health Risk Factors

Medical staff working conditions are characterized by a range of adverse workplace factors investigated primarily at hospital organizations. However, sanitary audit of working conditions and health risk factors for medical workers in the sanatorium-resort industry is also a task that needs attention. Aim. To analyze the results of the working conditions special assessment and identify the main work-related factors affecting health state of medical staff at sanatorium-resort organizations. Material and methods. Scientific search and analysis of publications on the safety of working conditions and health protection of medical workers. Systematization of research materials, statistical and comparative analysis of the results of working conditions special assessment carried out at branches of the Medical Research Center and data provided in publications. Results. Medical staff are exposed to a wide range of hazards. Work-related factors that do not meet established hygiene standards cause the greatest concern among medical workers. These are microclimate, lighting and working equipment (47.0%, 37.8% and 24.0%, respectively). A number of devices inspected in the physiotherapy room exceeded hygienic standards for alternating electric and magnetic field intensity. Analysis of air pollution in the physiotherapy department working area showed that some of the harmful chemicals exceeded permissible exposure limits. The results of the special assessment of working conditions performed at branches of the Medical Research Center showed that a high percentage of medical workers was exposed to harmful biological factors and high severity of the labor process. Conclusion. Physical and chemical factors are the greatest workplace hazards for healthcare workers at health resorts. However, a special assessment of working conditions showed that the biological factor was the most significant one across all professional groups.

Temporal and spatial variations in the levels of prominent airborne disinfection by-products at four indoor swimming pools

Exposure to airborne disinfection by-products, especially trichloramine and trichloromethane, may cause various adverse health effects for the workers and users of indoor swimming pools. This study aims to evaluate the spatial and temporal variations in trichloramine and trichloromethane concentrations within and between swimming pools. Workplace measurements were carried out at four indoor swimming pools in Quebec (Canada) during the cold season. To fully represent daily operating conditions, sampling started 2 hr before the swimming pool opened and continued until 2 hr after closing. To quantify trichloramine and trichloromethane concentrations, 304 air samples have been collected. Temperature, humidity, and CO2 were measured—simultaneously every 2 hr. The results showed that both trichloramine and trichloromethane concentrations varied significantly in time. The observed daily variations in trichloramine and trichloromethane concentrations suggest that the common practice of collecting a single 2-hr air sample does not represent daily pool trichloramine and trichloromethane contamination levels and, consequently, does not represent the true exposure and health risks for workers that are present for a full 8-hr shift. This study recommends a new 8-hr sampling strategy or a full-shift strategy using a cassette with three impregnated filters as a valid and cost-effective solution for comparing time-weighted average (TWA) concentrations to permissible trichloramine exposure limits.