Permissible Levels Research Articles

Ensuring durability and reliability of contact rings of current collection devices when working in elastic-plastic state

The reliability of ring current-collecting devices during a given service life plays a decisive role in the opera- tion of power supply systems of various equipment and largely depends on the strength and reliability of all its components, in particular, contact rings. One of the most important characteristics of ring current collectors is the contact resistance, which is reduced by using non-ferrous and precious materials with low resistance, while increasing the downforce between the rings of the current collector. With an increase in the compression force F of the contact ring, the resistance of the contacts decreases to a certain minimum value and practically does not decrease with further growth of the force. The dependence of the contact resistance on the compression force has the form of a power function, the coefficients of which are determined experimentally. However, the operability of the contact rings in such severe conditions can be ensured in the case of low speeds and a small number of loading cycles by using the low-cycle fatigue area on the Weller curve. Having determined the coefficients of the equation of the inclined section on the Weller curve in the area of low-cycle fatigue, it is possible to determine the number of permissible loading cycles at a given stress level or solve the inverse problem of determining the permissible stress level if the number of loading cycles is known. To substantiate the correctness of the selected compressive force and the corresponding stresses, methods for calculating the fatigue margin coefficient, as well as a method for calculating the reliability of the ring material, are proposed. Reliability is estimated by the Gauss curve and is numerically expressed in the form of the probability of failure-free operation and the probability of failure, for which the corre- sponding theoretical dependencies are obtained. According to the proposed methods, calculations of the rings of the current-collection device used in EX- PRESS-type spacecraft were performed, which showed the operability of the methods and allowed to ensure the required service life of the contact rings and their reliability. A very simple analytical formulation of the methods allows us to solve both verification and design calculations of rings, depending on the task at hand.

PM2.5 and heavy metals in urban and agro-industrial areas: health risk assessment considerations

The study investigated PM2.5 and heavy metal pollutant concentrations in Seoul and Wonju, South Korea, emphasizing the importance of considering PM2.5 chemical constituents for health impact assessments. While PM2.5 concentrations were similar between the two cities with slight variations, heavy metal concentrations differed significantly. Regional sources, PM2.5 composition, and meteorological conditions influenced these variations. Exposure to Fe was highest in all areas, with some heavy metals exceeding permissible levels, stressing the need to consider regional characteristics in assessments. Different heavy metals influence health risks differently in each city. When examining the HI (the summation of the hazard quotient for heavy metals), Seoul remained below an HI value of 1, while Wonju exceeded this threshold when exposed to CTE concentrations. In Seoul, As had a significant health impact of PM2.5, while in Wonju, Mn was more influential. Source apportionment confirmed different pollution sources in Seoul and Wonju, affecting the distribution of PM2.5 constituents in the atmosphere. Effective PM2.5 management requires a comprehensive approach considering chemical constituents and health impacts not just mass-based PM2.5 management, emphasizing regional-specific assessments and policy considerations to mitigate health risks. Therefore, tailored management strategies based on regional characteristics are necessary.Graphical

Sustainability of cool and black roofs with high initial construction moisture

This study examines the sustainability of roofs subjected to hot climate of Phoenix and cold climate of Montréal by using a validated numerical model that simultaneously solves the heat, air, and moisture equations. In many situations, the initial conditions needed to solve these equations are not available. This paper provides a procedure for conducting energy and moisture modelling so that using different initial conditions would result in no effect on the final results of roof performance. Additionally, the study focuses on: (a) assessing the moisture performance of black and cool roofs in case of using material layer with high initial construction moisture content (Fibreboard, FB), (b) identifying the time period needed so that the moisture content would reach acceptable limit by the building codes, and (c) determining the amount of energy savings as a result of using sustainable cool roofs instead of black roofs. The results show that the moisture content in the FB decreases to permissible levels after 92.6 days for black roof and 175.7 days for cool roof in Phoenix, while in Montréal, it takes 238.6 days and 1597 days, respectively. The effect of using different initial condition vanishes after 196 days for Phoenix’s black roof, 583 days for its cool roof, and 1247 days for Montréal’s black roof and 4590 days for its cool roof. Mold is detected in FB. In Phoenix, mold disappears after 379 days for black roof and 479 days for cool roof, whereas in Montréal, it takes 708 days and 3143 days, respectively.

Metal content, bioaccumulation, translocation, and health risk assessment of root vegetables grown in KwaZulu-Natal small-scale farms of South Africa.

Metal uptake by vegetables is becoming a threat to the life of consumers. Therefore, continuous monitoring of metals in vegetables and soils is becoming a necessity. In this study, the occurrence of 18 metals in amadumbe (Colocasia esculenta L.), sweet potatoes (Ipomoea batatas L.), potatoes (Solanum tuberosum L.), and carrots (Daucus carrota L.) grown in small-scale South African agricultural farms was monitored using inductively coupled plasma-optical emission spectroscopy. All the 18 investigated elements were detected in soils and different vegetative plants parts. Bioaccumulation factors indicated the transfer of selected metals from soils into the plant roots. Toxic metals Cd, Cr, and Pb had their concentrations exceeding the maximum permissible levels set by the World Health Organization in the edible parts of all root vegetables. Cd and Pb varied between 18.89 and 19.19mgkg-1 and 10.46 and 11.46mgkg-1, respectively, while Cr remained constant at 16.78mgkg-1. The exact metals together with As and Ni had their total hazard quotients exceeding the threshold value of 1, which indicated that the daily consumption of the investigated root vegetables is likely to pose health risks to both adults and children. Therefore, this study points out to a possibility of toxic health effects that could arise when these vegetables are consumed daily.

Phytoremediation Characterization of Heavy Metals by Some Native Plants at Anthropogenic Polluted Sites in Jeddah, Saudi Arabia

Many anthropogenic activities have lately resulted in soil adulteration by heavy metals (HMs). The assessment of native plant species that grow in the polluted environments is of great importance for using these plants in phytoremediation techniques. This study was conducted in three industrial regions in Jeddah city, Wadi Marik, Bahra, and Khumrah, to assess the HM contamination level in them. This study also evaluated the phytoremediation ability of nine plant species collected from the studied regions. Soil physicochemical properties of the studied sites were investigated. Nine HMs, aluminum (Al), nickel (Ni), zinc (Zn), cobalt (Co), iron (Fe), lead (Pb), manganese (Mn), chromium (Cr), and barium (Ba), have been evaluated in the collected soil, plant shoots, and root samples. Total thiol concentration in the plant shoots and roots was determined. The phytoremediation indexes, such as bioaccumulation factor (BCF) and translocation factor (TF), were estimated. The results show that the soil of all the explored sites was sandy and slightly alkaline. It was found that Ni, Pb, and Cr were above the international permissible limit in all soil samples. The Wadi Marik region recorded the highest HM concentration compared to the other sites. In the Bahra region, Fe, Zn, Co, and Mn in all collected soil samples were below internationally permissible levels. In Khumrah, the highest concentration of Zn was found in the soil sample collected around F. indica plants, while Fe, Co, and Mn in all collected soil samples were below the international permissible limit. Depending on the BCF calculations, most of the investigated species showed phytostabilization ability for most of the studied HMs. Of them, E. indica, T. nubica, and P. divisum recorded the highest BCF values that ranged from 16.1 to 3.4. The BCF values of the studied HMs reduced in the order of Cr > Zn > Mn > Co > Ba > Fe > Al > Pb. Phytoextration of Co and Cr could be achieved by P. oleracea and F. indica, which showed TF values that reached 6.7 and 6.1, respectively. These plants showed high potential for phytoremediation and can be suggested as protective belts close to the contaminated regions of Jeddah.

Determination of the Presence of Potassium Bromates in Bread Samples Produced in Azare

Introduction/background: To improve bread texture, taste, elasticity of the dough, appearance and sometimes aroma, some ingredients are usually added. However, these ingredients are known to produce adverse health effects over a period of time or if taking in large quantities. One of the commonest food additives is potassium bromate, due to its low cost and being the most efficient oxidizing agent, potassium bromate has been the common choice among bakers and flours millers to raise the dough elasticity and improve texture. Potassium bromate is known to produced reproductive damage, repeated exposure can cause bronchitis, irritability, impaired thinking, personality changes and damage to the kidneys. Larger than recommended quantities should therefore be avoided in processed foods such as bread. Objectives: The aim of this study was to determine the presence and the level of potassium bromate in some selected bread samples produced in Azare. Azare is the headquarter of Katagum Local government area of Bauchi state Nigeria. Methods: Bread samples were collected from nine different bakeries that were sited within Azare. And these are the major breads produced and consumed in Azare town and neighboring villages. The bread samples were subjected to both qualitative and quantitative assay to determine the presence and level of the potassium bromate. The qualitative assay was conducted using simple qualitative method where color change (yellow to purple) produces when potassium bromates react with potassium iodide indicate presence of the potassium bromate. While the concentration of the potassium bromate in the bread samples was determine using spectrophotometric analysis measured at 620 nm. The linear regression curve derived from the standard solutions of Potassium bromate was used to calculate the concentration of potassium bromate levels in the bread samples. Results: The results indicated that bread produced in 5 of the 9 bakeries used in this study contained potassium bromate level within the recommended FDA and NAFDAC permissible level of 0.02ug/g and below. While the remaining four samples contained potassium bromate level higher than the NAFDAC recommended level. Overall, the potassium bromate level across the selected bakeries in this study conducted in Azare town Katagum local government of Bauchi state Nigeria was found in range between -0.91ug/g to 0.40ug/g.

Accumulation of heavy metals and arsenic in plants in the vicinity of the Chadan coal deposit (Republic of Tuva)

The content of copper, zinc, lead, cadmium and cobalt in plant samples from the vicinity of the Severny dump of the Chadansky coal mine in the Republic of Tuva was studied. Heavy metals in plant samples were determined by the Quantum-2mt atomic absorption spectrophotometer. Due to the extra-arid conditions, the studied area belongs to the zone of risky agriculture and there is developed cattle breeding. It was revealed that vegetation typical for steppe communities is developed on the territory of the Chadan coal deposit, represented by wormwood-cereal, grass-grass-wormwood, grass-wormwood-kovyl, wormwood-grass-grass steppes. In the dumps, deposits of different ages with small-scale, wormwood-cereal communities with typically steppe species are developed. For lead, cadmium and cobalt, the concentrations in vegetation samples from the CER and SWZ sites adjacent to the dump turned out to be close to their background values. The Cu content in the vegetation of the dump sites exceeds the natural content by 2–2,2 times, Zn – 2–2,7 times, Pb – 1,5 times. However, a comparison of the content of Cu, Cd, Zn, Pb, Co in vegetation from 2 sites of the Severny dump and the background territory with MDU for plant feeds showed that their concentrations in the studied samples are much lower than the maximum permissible level.

Harnessing the Intrinsic Chemical Reactivity of the Mycotoxin Patulin for Immunosensing.

Mycotoxins are globally pervasive contaminants that threaten food safety worldwide. Regulatory authorities have established maximum permissible levels for certain mycotoxins, and their presence is routinely monitored throughout the food chain to ensure the provision of healthy food and safe feed for humans and animals. While immunoanalytical methods are essential for mycotoxin screening, monoclonal antibodies for the detection of patulin are notably absent. Moreover, leading immunodiagnostic companies currently do not offer rapid tests for patulin in their product portfolios. This deficiency in mycotoxin testing is primarily due to the electrophilic reactivity of patulin. In this study, we exploit this reactivity to develop an innovative strategy that targets the stable adduct formed by the reaction of patulin with aryl-1,2-dithiolates, rather than analyzing the mycotoxin itself. Based on this previously unknown reaction, we present the first collection of monoclonal antibodies, enabling the long-sought goal of sensitive, simple, and user-friendly immunosensing of patulin.

Digestate from an Agricultural Biogas Plant as a Factor Shaping Soil Properties

In the context of a circular economy, special attention should be paid to the rational management of biodegradable waste. Currently, a potentially valuable waste material, rich in ingredients available to plants, is digestate, obtained as a by-product in agricultural biogas plants. The presented study aimed to determine the impact of digestate (DIG) from an agricultural biogas plant on soil reaction (pH), electrical conductivity (EC), sorption properties (SBC, HAC, CEC, BS), and chemical composition of soil. The research was based on a pot experiment in which increasing doses of liquid (LD) and solid (SD) forms of DIG were used in corn cultivation, balanced in terms of the amount of N introduced into the soil. The composition of DIG varied and depended on the LD or SD form. The LD was characterized by a lower pH value and higher EC compared to the SD form. The LD contained much less TC, fewer macroelements, and fewer trace elements. The application of LD significantly increased in the soil the content of TC, Ntot, available K, P, Fe, and Mn, and exchangeable cations K+. The SD significantly increased the content of available P, Mg, and Mn and exchangeable cations Ca2+ and Mg2+ in the soil. Both forms of digestate increased the total content of heavy metals (Cu, Cr, Pb, and Ni) in the soil. However, they did not pose a threat to the environment concerning their legally permissible levels.

Cadmium Maximum Levels and Residue Situation in the German Wheat and Rye Harvest from 1975 to 2021.

For a better understanding of cadmium (Cd) accumulation over long time periods in cereals, Cd levels of the German wheat and rye harvest from 1975 to 2021 were analyzed. Overall, wheat had higher grain Cd concentrations than rye. Comparing mean values from different time periods showed that Cd levels in winter rye have stabilized, while Cd concentrations in winter wheat have decreased. Furthermore, Cd concentrations in almost all samples were below the newly introduced European Commission limits specifying the maximum permissible contaminant levels in foodstuffs (Cd in grains: rye 50 μg/kg FW; wheat 100 μg/kg FW). However, it is important to note that Cd is still ubiquitous in the German wheat and rye harvest. Although there has been a significant reduction in emissions and imissions for around 30 years, the extraordinarily long biological half-life and carcinogenicity of Cd still make it a relevant substance to food safety and human health.

Parkinson's Disease Progression and Exposure to Contaminated Water at Camp Lejeune.

We recently reported an increased risk of Parkinson's disease (PD) in service members who resided at Marine Base Camp Lejeune, North Carolina, when water supplies were contaminated with trichloroethylene and other volatile organic compounds (VOCs). Prior studies suggest that environmental exposures may affect PD phenotype or progression, but this has not been reported for VOCs. The objective of this study was to test whether PD progression is faster in individuals exposed to VOCs in water at Camp Lejeune. A cohort of 172,128 marines residing at Camp Lejeune between 1975 and 1985 was previously assembled. We identified individuals with PD in Veterans Health Administration and Medicare databases between 2000 and 2021. Using estimates derived by the US Agency for Toxic Substances and Disease Registry, we classified individuals as exposed or unexposed to VOCs in residential water. We used Kaplan-Meier and Cox regression models to test differences between exposed and unexposed groups in the time from PD diagnosis until psychosis, fracture, fall, or death. Among 270 persons with PD, 177 (65.6%) were exposed to VOCs in residential water. Median cumulative exposure was 4970 μg/L-months, >50-fold the permissible level. Time until psychosis, fracture, and fall were all shorter in the exposed group, with adjusted hazard ratios (HRs) exceeding 2: psychosis HR, 2.19 (95% confidence interval [CI]: 0.99-4.83); fracture HR, 2.44 (95% CI: 0.91-6.55); and fall HR, 2.64 (95% CI: 0.97-7.21). A significant dose response was observed for time to fall (P trend, 0.032). No differences were observed for time until death. PD progression may be faster in persons exposed to trichloroethylene and other VOCs in water decades earlier. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Environmental assessment of toxic heavy metals in bottom sediments of the Sharm Obhur, Jeddah, Saudi Arabia

The concentrations, spatial distributions, pollution level, and health risks of heavy metals in sediments of the Sharm Obhur, Northern Jeddah, Saudi Arabia were evaluated. Average concentrations were found to be: Cr > Zn > Ni > Cu > As>Pb with the highest concentrations found near the head of the sharm, and decreasing towards the mouth. Environmental indices, together with the statistical analyses, showed that the sharm experiences a low to moderate degree of pollution. Sampling sites with heavy metal contamination are concentrated near the head and the southern coast of the sharm, where intensive human activities associated with a boat dock, construction, and recreation are common. The mean carcinogenic risk (CR) values of As, Cr and Ni are at permissible level suggesting unlikely adverse impacts of heavy metals on human health. Despite acceptable CR values; however, serious non-carcinogenic and carcinogenic health threats from metals may yet be an issue particularly for sensitive populations such as children.

Personal Exposure to Sulfuric Acid in the Electroplating Industry: Development and Validation of a Predictive Model.

This study aimed to measure personal exposure to sulfuric acid in the electroplating industry to establish a predictive model and test its validation. We collected indoor air parameters and related information from four electroplating plants. Silica gel sorbents were used to collect air samples using high-performance ion chromatography. We collected air samples from three plants (i.e., Plant B, Plant C, and Plant D) and applied multiple linear regressions to build a predictive model. Eight samples collected from the fourth plant (i.e., Plant A) were used to validate the model. A total of 41 samples were collected with a mean of 25.0 ± 9.8 μg/m3 (range 12.1-51.7 μg/m3) in this study, including Plant A (8 samples, 17.5 ± 2.8 μg/m3, 13.0-22.0 μg/m3), Plant B (11 samples, 36.5 ± 9.7 μg/m3, 23.1-51.7 μg/m3), Plant C (11 samples, 16.4 ± 1.7 μg/m3, 12.1-17.8 μg/m3), and Plant D (11 samples, 27.4 ± 1.7 μg/m3, 24.1-29.9 μg/m3). Plant B was significantly higher in sulfuric acid than the other plants. Workers from the electroplating process plants were exposed to sulfuric acid at 29.0 ± 11.5 μg/m3. The predictive model for personal exposure to sulfuric acid fit the data well (r2 = 0.853; adjusted r2 = 0.837) and had an accuracy of 5.52 μg/m3 (bias ± precision; 4.98 ± 2.38 μg/m3), validated by the personal sampling of the fourth plant. This study observed that sulfuric acid exposure was lower than the permissible exposure level of 1000 μg/m3 in Taiwan and the United States, and only two samples were lower than the European Union standard of 50 μg/m3. The developed model can be applied in epidemiological studies to predict personal exposure to sulfuric acid in plants using electroplating.

EFFECTS OF FERTILIZATION REGIMENS ON THE FRUIT YIELD AND QUALITY OF CUCUMBER CULTIVAR ‘DZHERELO’

Abstract. This is research relevant because the effects of different fertilization regimens on the fruit yield and quality of cucumber cv. ‘Dzherelo’ grown in an irrigated vegetable–forage rotation in the Left–Bank Forest–Steppe of Ukraine have been studied. Purpose: to evaluate the effects of different ways of optimizing nutrition regimens on the fruit yield and quality of cucumber cv. ‘Dzherelo’. Methods. Field, computational and statistical. Results. The effects of different fertilization regimens have been studied: mineral, organic, organic–mineral, resource–saving (local mineral fertilization), and complex with a calculated dose of mineral fertilizers and trace elements (foliar fertilizing with Reakom – R – cucumbers). The most effective fertilization regimens increasing the fruit yield and quality of cucumber cv. ‘Dzherelo’ grown in an irrigated vegetable–forage rotation have been selected. The nitrate content in cucumbers was shown to increase to 89.0–93.4 mg/kg of fresh weight after mineral fertilization, which was higher than the nitrate content after the other tested fertilization regimens but did not exceed the maximum permissible level of nitrates in outdoor–grown fresh cucumbers (MPL = 150 mg/kg). Conclusions. It was found that N, P and K from fertilizers were the most effectively absorbed by cucumber plants with broadcast mineral fertilizer at N90P60K60. In this variant, the utilization coefficients were as follows: nitrogen – 54%, phosphorus – 18.8%, and potassium – 51.8%. High yields (20.3 and 18.3 t/ha), marketability (87.7 and 88.0%) and fruit quality (dry matter content = 4.32–4.66%; total sugar content = 2.28–2 .35%; vitamin C content = 11.93–12.47 mg/100 g; nitrate content = 82.6–89.0 mg/kg) were recorded when cucumber cv. ‘Dzherelo’ was fertilized with broadcast mineral fertilizers at N200P210K200 with additional foliar fertilization with Reakom – R – cucumbers complex fertilizer or fertilized with organic–mineral fertilizers (66 t/ha of manure + broadcast N90P60K60), respectively.

Evaluation of Ambient Air Quality Levels at Various Locations Within Lead City University, Ibadan

BACKGROUND: Air quality in university environment is strongly affected by the student population explosion, climatic conditions and industrial activity within the institution. Monitoring the main air pollutants such as carbon dioxides, carbon monoxide and particulate matter may help control the most polluted areas of the institution and take measures to reduce the pollution.Universities are big metropolitan institutions with sizable populations of students, employees, and visitors. However, university settings can contribute to air pollution, with diverse activities such as lab work, cooking in dorms, and vehicle traffic, among others, causing interior and ambient air pollution. It is impossible to estimate how much air pollution affects the health and happiness of students without embarking on this type of research work. PURPOSE/AIM: Evaluation of meteorology parameters (i.e. temperature and relative humidity (RH)) and ambient air quality (CO, CO2 and particulate matter (PM2.5)) level at various locations within Lead City University, Ibadan is essential. METHODOLOGY: Ambient concentrations of carbon monoxide (CO), carbon dioxide (CO2), Relative humidity (RH), Temperature (TEMP), and Particulate Matter (PM2.5) were measured in 15 locations across Lead City University over a two-week period (between 25th of June 2023 and 3rd of August 2023) with Bosean air quality detector -T-201. RESULTS: Morning temperatures in all the locations measured ranging from 23.7°C to 29.2°C while afternoon temperature fluctuates more significantly, with the lowest recorded at 27.2°C and the highest at a notably warmer 35.8°C in all the locations measured. The morning RH levels ranging from 63.8% to 74.7% while afternoon RH values, ranging from 58.2% to 63.4%. The finding also shows that afternoon CO2 levels range from 468.5 ppm to 971.6 ppm, with Location 13 having an unusually high average. Morning CO levels ranging from 4.1 ppm to 49 ppm, with location 13 showing the most highest figure of 184.2 ppm. CO2 and CO levels are mostly within acceptable ranges as recommended by World Health Organization (WHO) that CO2 concentration levels in school buildings should kept below 1000 ppm and CO be below an average of nine parts per million (ppm) for any eight-hour period, and below 25 ppm for any one-hour period as an indicative benchmark of good indoor air quality (IAQ). Morning RH values range from 63.8% to 74.7%, with Location 1 having the highest average while afternoon RH values are between 58.9% and 67.7%, with Location 6 having the highest average. The relatively narrow variance in RH indicates that the dataset predominantly represents conditions with moderate humidity levels. Morning PM levels vary from 8.9 to 17.1µg/m³, suggesting diverse air quality conditions across the samples. In the afternoon, PM concentrations display a broader range, from 8.9 to an exceptionally high 436.1 in Location 13. Interestingly, all the air pollutants measured are still within the USA EPA permissible level of the National Ambient Air Quality Standard for PM2.5, which is 35 μg/m3, and CO, which is 40 mg/m3 and CO2 between 400 - 1,000ppm CONCLUSION: Variability in these parameters has implications for human health therefore, adequate ventilation and pollution control measures is thereby recommended for the university management in order to improve indoor air quality.

Bioaccumulation of Cadmium in Muscle and Liver Tissues of Juvenile Yellowfin Tuna (Thunnus albacares) from the Indian Ocean.

The present study evaluated the cadmium (Cd) levels and temporal variation of Cd in dark muscle, white muscle, and liver of juvenile Thunnus albacares. 72 individuals (Standard length: 50-67 cm; weight: 0.8-2.5 kg) were collected from Indian Oceanic water around Sri Lanka during the period between April 2021 to May 2022. Total Cd levels were analyzed using an Inductively Coupled Plasma Mass Spectrophotometer. The mean Cd levels (mean ± SD mg kg-1 dry weight) in different tissues varied with significantly higher levels in the liver (13.62 ± 0.98, p < 0.05), compared to dark muscle (0.52 ± 0.05), and white muscle (0.42 ± 0.04). Cd levels in liver tissues were positively correlated (p < 0.05) with the fish weight. The Cd levels reported in dark muscles, white muscles, and liver tissues were significantly higher (p < 0.05) during 2nd inter-monsoon than in the other monsoonal regimes and exceeded the maximum permissible level (0.1 mg kg-1 wet weight) set by the European Union (EU). However, the measured Cd levels in white and dark muscles were below the maximum permissible level (0.2 mg kg-1 wet weight) set by FAO/WHO. The Cd levels in all the liver tissues were above the levels set by the EU and FAO/WHO. Accordingly, people should avoid the consumption of liver tissues of T. albacares from the Indian Ocean. A human with a body weight of 60 kg can consume white muscles up to 4.667 kg per week without exceeding the Provisional Tolerable Weekly Intake.

Assessing the physicochemical properties of surface/groundwater of Sudhnoti district, Azad Jammu and Kashmir: Impacts on lindane degradation by photocatalysis

Since polluted water deteriorates the health of human beings and other animals, healthy society and environmental sustainability demand for clean and safe water. The presence of contaminants, and imbalance of common physicochemical parameters significantly disturb the quality of water. Taking the importance of clean and safe water into account, this study investigated fourteen physicochemical parameters of hand pump and open well water (main drinking water sources) from fifteen places of district Sudhnoti, Azad Jammu and Kashmir (AJK). The mean values of pH, electrical conductivity (EC), alkalinity, hardness and total dissolved solids (TDS) were 7.6, 349.9 μS/cm, 144, 152 and 190 mg/L, respectively. The mean concentration of Na+, K+, Ca2+, Mg2+, HCO3−, Cl−, SO42− and NO3− was found to be 9.5, 0.96, 9.9, 44.2, 144, 16.8, 8.1 and 6.67 mg/L, respectively. The turbidity as well as the concentration of CO32− was found below the detectable level in all water samples tested. Interestingly, all the studied physicochemical parameters had lower values than the maximum permissible level recommended by the world health organization (WHO) for drinking water. Eventually, the impacts of the studied physicochemical parameters, particularly anions and cation, on the efficiency of water treatment technology for real field application were discussed. The results revealed that physicochemical parameters of the groundwater of Sudhnoti, AJK had a slight effect on the degradation efficiency of one of the most widely used pesticides, lindane, in water by using ultraviolet–visible titanium oxide/hydrogen peroxide (UV–Vis)/TiO2/H2O2) and ultraviolet–visible/titanium oxide persulfate photocatalysis. Of note, the quality of hand pump and open well water which are the main drinking water sources of district Sudhnoti, AJK was found to be fit for drinking and other domestic purposes as well as for the ecosystem.

Impact of Aircraft Noise and Compliance with the Use of Personal Protective Equipment on Hearing Impairment in Pilot Cadets at Indonesian Civil Pilot Academy - Banyuwangi

Noise in the workplace is a health issue in several countries. Similarly, in the aerospace industry, advanced aircraft, whether for civilian transportation or military purposes, pose risks due to exposure to aircraft noise, which passengers are continuously subjected to at relatively higher intensities and for prolonged periods. The problem of this research is to identify, reduce, and prevent the impact of aircraft noise and compliance with the use of personal protective equipment (PPE) on hearing impairment among cadet pilots at the Indonesian Aviation Academy in Banyuwangi. The research objective includes collecting medical records of 57 cadets, measuring aircraft noise levels, and conducting a questionnaire survey. The method used in this study is descriptive quantitative, with 57 respondents. Data analysis was performed to determine the compliance of cadets with PPE usage at the Indonesian Aviation Academy in Banyuwangi. The results show that the noise produced by the aircraft operated by the academy exceeds the permissible noise level (PNL), and the questionnaire results indicate low compliance with PPE usage. However, medical record data reveal that the majority of cadets still have normal hearing, with only 12.3% or 7 respondents categorized as having mild hearing impairment. These findings imply a positive and significant influence of aircraft noise level and PPE compliance on hearing impairment among trainees.

PROGRAM AND ANALYTICAL COMPLEX OF THE INDUSTRIAL SAFETY AND HEALTH ANALYSIS SYSTEM

Aim. To investigate the quantitative characteristics of magnetic fields created during electric contact welding by various methods: contact point, arc-contact, capacitor point, contact-contact continuous and pulsating reflow. The problem being solved is the lack of necessary information on the electromagnetic safety of the specified welding methods. Methodology. A description of the proposed methodical approaches to determining the levels of magnetic fields, means of measuring them, and methods of assessing their impact on the welder's body is provided. Based on the analysis and processing of the received oscillograms and spectrograms of magnetic fields, measurements of their quantitative characteristics were performed. To determine the general level of the multifrequency magnetic field that occurs during contact welding, the proposed generalized indicator of the level of the magnetic field was used. Implications of research. It was established that during contact spot welding with a stationary machine, the magnetic field level exceeds the maximum permissible value at the workplace in the range of 50-1000 Hz at a distance of 0.3 m from the welding electrodes. During manual welding by this method, the level of the magnetic field exceeds the permissible level in the frequency ranges of 5-50, 50-1000 Hz directly near the electric cable. Condenser spot welding with direct current is characterized by exceeding the maximum allowable MP at the workplace in the high-frequency range of 1000–10000 Hz. During arc-joint welding at the workplace, exceeding the maximum allowable levels of the magnetic field was not detected. Practical implications. It is shown that the spectral composition and magnitude of the magnetic field signal is determined by the welding method itself and the initial parameters of the power sources. The obtained results can be used in the field of welding production and labor protection for the improvement of contact welding technologies and the development of measures to protect welders from the magnetic field.

Effects of Heavy Metal Pollution on the Element Distribution in Hydrobios.

At a time when heavy metal pollution is increasing, assessing the levels of contamination and associated health risks is crucial. Samples of water, aquatic plants, and fish were collected from four key areas of heavy metal pollution prevention and control in Zhejiang Province. The levels of elements were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES). A human health risk model was also developed. The study revealed that heavy metal pollution in the five industrial zones exceeded the national standard for Class V water. Elements like arsenic (As), cadmium (Cd), and chromium (Cr) exceeded permissible levels in aquatic plants across all industrial zones; the exception was lead (Pb). Moreover, the heavy metal concentrations in subject fish tissues collected from each industrial area exceeded safe limits, especially in the gut. According to the human health risk evaluation model, the health risk (1.12 × 10-3) and children's health risk (1.10 × 10-3) in these prevention and control zones surpassed the maximum acceptable human risk values. In conclusion, heavy metal elements, along with other pollutants, accumulate and become concentrated in the examined aquatic plants and fish. These pollutants move through the food chain, impacting the entire aquatic ecosystem and posing a health risk to nearby populations.