Hygienic characteristic of the electromagnetic situation created by the electromagnetic radiation of the antennas of mobile base stations in Cherkasy region before and after the introduction of 4G technology

This work is part of our researches to study the distribution of electromagnetic radiation from mobile base stations in populated areas. The aim of this work was to study and analyze the electromagnetic situation before and after the introduction of fourth generation 4G technology at mobile base stations. We analyzed the maximum and average levels of electromagnetic radiation from mobile base stations located in Cherkasy region. The electromagnetic situation was studied both in urban areas and in rural areas. It was found that after the introduction of the fourth generation 4G technology at the mobile base stations, the levels of electromagnetic radiation in Cherkasy region increased significantly. The median of maximum levels of electromagnetic radiation increased by 155.6% (in particular, in urban areas by 194.1%), and the median of average levels - by 75.2% (in particular, in urban areas by 141.1%). No significant changes in electromagnetic radiation levels were detected before and after the modernization of mobile base stations in rural areas. It has been proven that there are no prerequisites for increasing the maximum permissible level to 100 μW/cm2 when implementing 4G and 5G technologies at mobile base stations.

Safety and quality of feed for piglets

The results of research on the safety and quality of compound feed of domestic producers for piglets have been presented in the article. The materials for the investigation were 4 samples of the starting complete feed for piglets of main domestic producers. Organoleptic characteristics of compound feed for piglets met the requirements of Federal standard 34109-2017. The assessment of the total bacterial contamination showed that sample No. 3 (the feed plant “VEGA”) has the maximum level of contamination, and the lowest level in sample No. 1 - new feeding technologies plant. The content of toxic elements in compound feed did not exceed their maximum permissible level and met the requirements of Federal standard 34141-2017. The level of radionuclides in compound feed did not exceed their maximum permissible level and corresponded to the standards provided for in the instructions on radiological quality control of feed of the Ministry of Justice No. 831 on 14.04.1995. Thus, the analysis of samples of the starting compound feed of domestic producers for piglets on organoleptic, physic and chemical, bacteriological and sanitary-mycological indicators, for the presence of toxic elements and radionuclides showed that all samples meet the requirements of safety and quality.

Compact circular polarized CPW antenna for WLAN and biomedical applications

A compact, circularly polarized, CPW-fed antenna is proposed for wearable applications in ISM Band (5.8 GHz). The antenna is based on DGS, where the ground plane is responsible for impedance matching. The 10 dB impedance of the proposed antenna varies from 5.39 GHz to 5.94 GHz. The circular stub introduced in the ground plane mitigates the surface current and enriches the 3 dB axial ratio from 5.73 GHz to 5.92 GHz. Proposed antenna exhibits the LHCP and RHCP pattern of circular polarization, the antenna can effectively work for biomedical and wearable applications. The antenna is analyzed on the skin phantom model and the SAR value obtained is 1.218 W/kg, which is below the maximum permissible level. The proposed antenna is also used for the detection of breast tumors.

The Secret of the Main Campus Water-Wells, Arba Minch University, Ethiopia

Groundwater is one of the precious water sources for domestic, irrigation, and industrial demands in arid and semiarid regions of the world. The same is true in Ethiopia context. In this study, seven groundwater samples were collected and analyzed for various chemical constituents (pH, TDS, Na+, K+, Ca2+, Mg2+, SO42−, Cl−, HCO3−, and NO3−) to assess the hydrogeochemical characteristics and water types of the groundwater wells. Among the seven sampled groundwater wells, five wells are found and used for domestic water supply in Arba Minch University (AMU) main campus. The remaining two are used for industrial and irrigation demands located at the compound of Textile Factory and Haile Resort, respectively. Results showed that the main campus groundwater wells are saline and harder than the two wells from Textile Factory and Haile Resort. Moreover, elevated concentration of nitrate and potassium (greater than the maximum permissible level allowed in Ethiopia) were obtained in the groundwater sources used mainly in the AMU main campus wells. These elevated concentrations of potassium and nitrate beyond the enriched salt contents in the AMU main campus wells could pose kidney, cardiovascular, and other related health problems. This study, therefore, recommends the AMU to find other groundwater sources for drinking purpose other than the studied water-well field.

Workers’ Health Risk Factors in the Production of Iron Ore Pellets

Introduction. The labor of workers of the main occupations in the mining industry is characterized by a combined effect of occupational risk factors, which can be further aggravated by adverse environmental conditions. Objective: to study working conditions of employees in the mining industry. Materials and methods. We conducted a hygienic assessment of the technological process of manufacturing oxidized fluxed and non-fluxed pellets during the extraction of iron ore by surface mining and its further processing into high-quality raw materials for ferrous metallurgy, and a study of harmful physical and chemical factors of the working environment. Results. We established that a sinter machine operator (Class 3.3 hazard working conditions in the summer time), an operator of the agglomeration and firing furnace (Сlass 3.4), and a bunker operator in the shop for fired pellets (Сlass 3.3) work in hot occupational environment. The average value of the intensity of thermal radiation over the irradiation period (1.35 hours) for agglomeration and firing furnace operators was 356.2 W/m2 or 2–2.5 times higher than the maximum permissible level. Increased noise levels (Class 3.2) were measured at the workplaces of conveyor, sinter and furnace operators (14.8 % and 9.25 %). At individual workplaces of sintering machine operators, we registered elevated dust concentrations (Class 3.1), noise levels (Classes 3.1 and 3.2), sulfur dioxide concentrations (Class 3.1), and the sum of irritant chemicals (Classes 3.1 and 3.2 by excess of the maximum permissible concentration (MPC)) were recorded. At workplaces and in the service area of the furnaces at agglomeration and roasting, the maximum permissible level was exceeded for dust (Class 3.1), noise (Classes 3.1 and 3.2), sulfur dioxide (Class 3.1), and the sum of irritant chemicals (Classes 3.1 and 3.2). Conclusions: The hygienic analysis of the technological process of manufacturing iron ore pellets at the pelletizing plant indicates the presence of sources and conditions forming adverse occupational factors posing health risks for workers. In order to address occupational health and safety issues, it is necessary to introduce comprehensive measures to prevent health disorders in the working population.

Gold Nanoparticles Functionalized with Mercaptosuccinic Acid as a Means for Detecting Fe(III) Ions

The application of mercaptosuccinic acid-capped gold nanoparticles as a sensing probe for the colorimetric detection of Fe(III) is reported. The well-dispersed gold nanoparticles (AuNPs) with a diameter of around 20 nm were obtained by a one-step reaction of tetrachloroauratic acid with mercaptosuccinic acid (MSA) as a reducing and capping agent, respectively. Fe(III) reportedly causes the aggregation of prepared MSA-capped AuNPs followed by a change in color and a shift to long wavelengths in the absorbance spectra. The resulting method allows for a visual and spectrophotometric Fe(III) determination with detection limits of 30 ng/mL and 23 ng/mL, respectively. MSA-capped AuNPs have been used as sensing probes for the detection of Fe(III) in drinking water samples with a detection limit that is much lower than the maximum permissible level of Fe(III) specified by official regulations (300 ng/mL).

Determination of Zinc Content in Commercial Toothpaste Samples in Nigeria by Atomic Absorption Spectrophotometric Method

Zinc as its citrate or sulphate salt is added to some toothpaste as a bactericide to reduce the presence of bacteria in the mouth. These bacteria can form plaque or produce acids which cause dental decay and halitosis. Zinc salt is added at amounts which are enough to show activity against oral bacteria without causing toxicity to the user. Five commercial samples of different brands of toothpaste (TP-A, TP-B, TP-C, TP-D and TP-E) were purchased from different pharmacy stores in Ogige and Eko markets, Nigeria and analysed for the presence of zinc using atomic absorption spectrophotometric method. The samples were digested with deionized water and HNO3, centrifuged and filtered. The absorbance of the supernatants obtained was read with a spectrophotometer. Calibration curves for zinc sulphate and zinc citrate were obtained with regression (R2) values of 0.9992 and 0.9973, respectively. The equation obtained from the curves used in determining the content of zinc in the samples. The zinc content (% w/w) of samples was determined to be 0.8467%, 0.8127%, 0.0119%, 0.0188% and 0.0305%, respectively. These values were well below the maximum permissible level of zinc in toothpaste samples but were within the upper limit for daily zinc intake.

Occupational risks in the aviation industry

The Russian aviation industry is one of the most important high-tech and science-intensive branches of machine building. The aircraft building enterprises employ about 150 thousand workers, whose conditions do not meet sanitary and hygienic requirements. The purpose of the article is to analyze working conditions and assess occupational health risks for aviation workers on the example of an aircraft plant. The object of research is Ulan-Ude Aviation Plant, which is the largest enterprise in the Republic of Buryatia and part of Russian Helicopters JSC. It was found that the risk of occupational diseases is determined by harmful physical (industrial noise) and chemical (harmful substances) factors, as well as severity of the labor process. The largest deviations of the levels of professional risk from the maximum permissible level were revealed for the follwoing professions "screenman", "assembler" and "assembler of hydraulic units". The risks are "high" and "medium". For upholsterer and regulators of electromechanical and radio-technical equipment, the risks are within the permissible working conditions. It is necessary to reduce professional risks by modernizing production and its technological processes: replacing obsolete equipment with modern one, introducing the best available technologies, and automating processes.

Comparative Assessment of Nitrate Concentrations in Vegetables Grown on Commercial and Subsistence Farms in the Saratov Region

Background: Food safety is one of the prerequisites for a healthy diet of the population of the Russian Federation. At the same time, successful functioning of modern agricultural complexes is almost impossible without a widespread use of various agrochemicals, including nitrogen-containing fertilizers. The objective of our study was to conduct a comparative assessment of the nitrate content of vegetables grown on commercial and subsistence farms located in industrially contaminated areas of the region and used as local food. Materials and methods: The research was carried out in the summer and autumn periods of 2017–2019 in a number of polluted areas of the Saratov Region. Nitrate concentrations in local vegetables were measured by a potentiometric method. Results: We established that the nitrate content of vegetables grown in most environmentally disadvantaged areas varied greatly. Concentrations of this contaminant depended on the type of vegetables, growing conditions and region; yet, they did not exceed the maximum permissible level in any vegetable sample tested. At the same time, the level of nitrates in crops grown on commercial farms was significantly higher than that in vegetables grown in private gardens (p < 0.05) due to a more extensive application of nitrate fertilizers in the form of commercially produced ammonium nitrate. Private gardeners, on the opposite, use biomass species, usually legumes, contributing to a better conversion of nitrates into proteins and preventing their excessive accumulation in the produce.

Environmental Assessment of the Impact of Meteorological Parameters on Man-Made Pollution by Carcinogenicly Dangerous Chemicals in the Voronezh Air Basin

Based on the analysis of official statistics from the Voronezh Hydrometeorological Service, the patterns of the dynamics of pollutants (formaldehyde and soot) are investigated depending on the combination of various meteorological parameters — air temperature, wind speed, relative air humidity. A positive relationship has been established between the increase in atmospheric pollution with formaldehyde and air temperature. With increasing wind speed and relative humidity, the concentration of formaldehyde and soot in the atmosphere of the city, as a rule, decrease. The maximum permissible level of carcinogenic risk to public health has been established, causing concern. The obtained patterns can be used to predict the level of technogenic pollution of the city’s atmosphere, depending on meteorological conditions.