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Analysis of exposure to radon in Bulgarian rehabilitation hospitals Texto completo
2022
Ivanova, Kremena | Dzhunakova, Desislava | Stojanovska, Zdenka | Djounova, Jana | Kunovska, Bistra | Chobanova, Nina
Mineral springs are used in spa resorts throughout the world. Radon is a natural radioactive source, which can dissolve, accumulate, and be transported by water. This study investigates the radon concentration in air and water in 12 Bulgarian rehabilitation hospitals and presents the assessment of the exposure to radon in them. The measurements were performed at 401 premises within 21 buildings, using two types of passive detectors for a dry and wet environment that were exposed from February, 2019 to June, 2019. The radon concentration varied from 19 to 2550 Bq/m³ with an arithmetic mean and a standard deviation of 102 Bq/m³ and 191 Bq/m³, respectively. The hypothesis that in hospitals the source of radon, besides soil under the buildings, is also the mineral water that is used for treatment was tested. Thermal water samples were procured sequentially from a spring and baths to analyse the reduction of radon concentration in them till reaching the premises. The results show that the concentration of radon decreased by approximately 50%. Further, the correlation analysis applied to the data proved the relation of the levels of indoor radon in the treatment rooms with those in the water. Mineral water used in rehabilitation hospitals have radon transfer coefficients ranging from 4.5·10⁻⁴ to 8.4·10⁻³. In addition, an analysis of the exposure of patients and workers to radon in rehabilitation hospitals based on the indoor radon levels and period of exposure was performed. The doses of workers do not exceed the limit of the annual effective dose for the population from all sources (1 mSv/year).
Mostrar más [+] Menos [-]Soft-template solvent thermal method synthesis of magnetic mesoporous carbon–silica composite for adsorption of methyl orange from aqueous solution Texto completo
2022
Zhu, Bo | Xu, Jiangyan | Xu, Zhihui | Wu, Meisheng | Jiang, Hongmei
A facile soft-template solvent thermal strategy was developed to prepare mesoporous carbon–silica composite (MMCS) by using furfuryl alcohol (FA) as carbon precursor, Pluronic copolymer P123 as template, hydrated iron nitrate as iron source, and teraethylorthosilicate as silicon source and it was applied for the removal of methyl orange (MO). The as-synthesized MMCS with abound of hydrophilic groups processed a high specific surface area, large pore volume, and good magnetic response. With the increased amount of FA, the surface area and functional groups increased, promoting the adsorption effect. The maximum adsorption capacity of MO on MMCS can be high to 113.1 mg g⁻¹ at pH 4 with 150 mg L⁻¹ initial MO concentration. The adsorption isotherm, kinetic, and thermodynamics were all studied and the results showed the adsorption process well fitted Langmuir adsorption isotherm and pseudo-second-order model. Additionally, it was shown that the adsorption process could not be interfered by the co-existence of PO₄³⁻, NO₃⁻, CO₃²⁻, SO₄²⁻, and real water matrix. And the proposed adsorbent can remove MO in three practical water samples with satisfied removal rates ranging from 92.8 to 99.8%. Thus, the MMCS prepared in this study could be utilized as an alternative adsorbent for the removal of methyl orange from practical aqueous solution.
Mostrar más [+] Menos [-]Influence of Methyl Groups in Triphenylmethane Dyes on Their Adsorption on Biochars from Coffee Husks Texto completo
2022
de Castro, Amanda Eugênio | da Silva Martinho, Felipe | Barbosa, Mylene Lourdes | Franca, José Romão | Ribeiro-Soares, Jenaina | Ferreira, Gabriel Max Dias | Ferreira, Guilherme Max Dias
Biochars (BC), whose properties are highly dependent on the pyrolysis temperature used, have been proposed for the efficient removal of a variety of contaminants from wastewater. In this work, pristine biochars were produced by the pyrolysis of coffee husks at temperatures of 400, 500, 750, and 900 °C, for use in the adsorption of pararosaniline (PRA) and methyl violet 10B (MV10B), which are triphenylmethane dyes with similar structures, but different numbers of methyl groups. The biochars were characterized and the dye adsorption kinetics and equilibria were investigated. FTIR and Raman spectroscopy analyses indicated that a higher pyrolysis temperature increased the aromaticity of the biochar surface structure, while decreasing the number of oxygenate functional groups. Higher adsorption capacities were generally observed at pH 7.5, with the maximum adsorption amounts increasing in the order BC900 ≈ BC750 < BC500 < BC400 for both dyes, being 1.3 times higher for PRA on BC400 (97.22 mmol kg⁻¹), but 1.9 times higher for MV10B on BC900 (5.49 mmol kg⁻¹). The Langmuir model provided the best fit to the adsorption isotherms for BC400 and BC900, while the Dubinin–Radushkevich model satisfactorily fitted the isotherms for the other biochars. These results showed that increase of the pyrolysis temperature resulted in a decrease in the number of adsorption sites with which the dyes interacted more favorably by means of hydrogen bonds. Although hydrophobic interactions were not important driving forces for adsorption of the dyes, the higher number of methyl groups in MV10B favored its adsorption on the more hydrophobic biochar.
Mostrar más [+] Menos [-]Spatial analysis and probabilistic risk assessment of exposure to fluoride in drinking water using GIS and Monte Carlo simulation Texto completo
2022
Ali, Shahjad | Ali, Hamid | Pakdel, Manizhe | Ghale Askari, Sahar | Mohammadi, Ali Akbar | Rezania, Shahabaldin
Prevalence of fluorosis is a worldwide public health problem especially in many states of India. It is necessary to find out the fluoride endemic areas to adopt remedial measures to the people on the risk of fluorosis. The target goals of this research were to assess (a) the exposure of fluoride concentration; (b) probabilistic risk assessment, sensitivity analysis, and uncertainty through intake of groundwater among population of Agra City (infants, children and adults) by Crystal Ball software; and (c) spatial distribution of HQ and fluoride concentration. A total of sixty samples from standing tube wells/hand pumps were gathered from selected and identified fluoride prevalent areas in Agra City. The concentration of fluoride scrutinized was obtained to be ranging from 1.32 to 4.60 mg/L with mean value of 2.36 in Agra City, and more than 91% of samples investigated surpassed the allowable level set for fluoride concentration in potable water 1.5 mg/L, although 9% of the samples were well within the drinking water guidelines (0.5-1.5 mg/L). The hazard quotient (HQ) was obtained to an enormous difference in the exposure dose in infants (1.66–3.91), children (1.87–4.4), and adults (0.92–2.16), correspondingly. The non-carcinogenic HQ values in the group of infants, children, and more than 90% of adults were higher than those of the safety level (i.e., HQ >1). Consequently, the non-carcinogenic risks (HQ level) of fluoride vary from the most to the least: children, infant, and adults, respectively. With 87.41% certainty, the results indicated that the HQ values are between 1 and 3.42. So, infant is the most vulnerable group to fluoride consumption in study area. Uncertainty analysis results indicated that the children group’s HQ level was between 1 and 1.90 with 38.48% certainty. To avoid further worsening of the situation as far as health is concerned, remedial actions like alternate sources of water supply and appropriate treatment of water need to be adopted besides required medical attention to affected people.
Mostrar más [+] Menos [-]An analysis of the asymmetric effects of natural gas consumption on economic growth in Pakistan: A non-linear autoregressive distributed lag approach Texto completo
2022
Sohail, Hafiz M. | Li, Zengfu | Murshed, Muntasir | Alvarado, Rafael | Mahmood, Haider
Natural gas is a vital energy resource that is used to produce the national output of Pakistan. On the other hand, since natural gas is a relatively cleaner energy resource compared to oil and coal, enhancing the level of natural gas consumption can be expected to promote economic growth while somewhat improving environmental quality in the process. Hence, it is pertinent to assess the economic growth effects associated with the consumption of such comparatively cleaner energy resources. Against this background, the main objective of this paper is to explore the asymmetric effects of natural gas consumption, controlling for financial development, on Pakistan’s economic growth figure over the 1965–2019 period. The results from the Augmented Dickey–Fuller, Phillips–Perron, and Zivot–Andrews unit root tests confirm a mixed order of integration among the variables. Besides, the bounds test and the Gregory–Hansen co-integration analysis reveal evidence of long-run associations between economic growth, natural gas consumption, and financial development in the context of Pakistan. Moreover, the outcomes from the nonlinear autoregressive distributed lag model analysis show that in the short-run, positive changes in the natural gas consumption levels increase Pakistan’s economic growth. On the other hand, in the long-run, positive and negative changes in natural gas consumption levels increase and decrease the nation’s economic growth level, respectively. On the other hand, both positive and negative changes in the financial development level are found to reduce Pakistan’s economic growth level in the long run only. Furthermore, the Hacker–Hatemi-J causality analysis verifies that natural gas consumption causally influences the economic growth level in Pakistan; thus, verifying the energy consumption-led growth phenomenon. In line with these key findings, several policy level suggestions are put forward for Pakistan to enhance its natural gas consumption level in order to boost its economic growth rate in the future.
Mostrar más [+] Menos [-]A new record for the presence of microplastics in dominant fish species of the Karasu River Erzurum, Turkey Texto completo
2022
Atamanalp, Muhammed | Köktürk, Mine | Parlak, Veysel | Ucar, Arzu | Arslan, Gökhan | Alak, Gonca
It is known that microplastics (MPs) are increasingly detected in aquatic environments (sea and fresh water), and the presence of these pollutants have worrying potential effects on the biota. This study is the first research to measure and characterize MPs in freshwater ecosystems (inland waters) in Turkey. Accordingly, the identification and characterization of MPs in the gastrointestinal systems of fish by making samples of three species [chub (Squalius cephalus), common carp (Cyprinus carpio), and mossul bleak (Alburnus mossulensis)] of the carp family living in Karasu River in Erzurum. Hydrogen peroxide application and Fourier transform infrared-attenuated total reflectance (ATR-FTIR) analyses were done for this purpose. In the obtained results, 232 microplastics were found in all three fish gastrointestinal systems. While the highest determined color was black (39–58%), the most common shape was fiber (88%), fragment (6%, and pellet (6%); MPs in the range of maximum 1001–2000 mm were detected in size. Plastics are defined as polyethylene, polyester, poly (vinyl stearate), polyethylene terephthalate, polypropylene, and cellulose. Among the studied species, the most common type of plastic pollutants was found in S. cephalus. The findings indicated the presence of microplastics in dominant species. However, these findings will be basic information for future studies on living things and microplastics in inland waters.
Mostrar más [+] Menos [-]New analytical approach to monitoring air quality in historical monuments through the isotopic ratio of CO2 Texto completo
2022
Pironti, Concetta | Ricciardi Ruocco, Maria | Proto, Antonio | Cucciniello, Raffaele | Fiorentino, Antonino | Fiorillo, Rosa | Motta, Oriana
In this study, we evaluated indoor air quality to highlight the effects of environmental pollution in the field of cultural heritage. In particular, two important archeological places in the old part of the city of Salerno, Italy, were analyzed: Fruscione Palace and S. Pietro a Corte. The work focused on the influence of tourists on environmental pollution correlated to indoor air quality during some social and cultural events. Moreover, we focused on the possible use of the carbon isotopic composition of CO₂ as a tool for environmental studies in the field of cultural heritage. The results showed a good relationship between the isotopic composition of CO₂ and the variation of pollutants concentration in the air, demonstrating that it is a valid tool and non-invasive marker to monitor environmental pollution of museums and cultural heritage sites.
Mostrar más [+] Menos [-]A change is gonna come: will traditional meat production end? Texto completo
2022
Simdi, Halil | Seker, Ayberk
Recently, the world has faced environmental disasters mainly due to global warming. One of the main reasons for global temperature imbalances is the greenhouse gases (GHG) that soar the atmosphere’s heat. The major aim of the current study is to explore whether the livestock population is the main contributor to GHG emission through econometric estimations. In this study, we examine the impact of livestock population with other explanatory variables—GDP per capita, Economic Complexity Index (ECI), ecological balance, and total patent applications—over GHG emission of 25 countries responsible for 76% of GHG emission between 1990 and 2017. To investigate the relationship of variables, Fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS) are used, as well as panel causality. Also, the relationship is examined by using the responsiveness scores (RS) approach. The empirical results reveal that all variables have a causal relationship with GHG emission. GDP per capita, ECI, and livestock population enhance the GHG emission whereas square of GDP per capita and ecological balance decline the environmental degradation. The paper demonstrates that the environmental Kuznets curve is valid and supports the literature. Lastly, the RS estimation results reveal that the livestock population is causing higher GHG emissions for all countries in the analysis, contrary to other independent variables. Governments should promote carbon–neutral meat production facilities instead of traditional beef farms to live in a more sustainable world. In the future, countries that invest in research and development (R&D) for less emission meat production will have a comparative advantage in the sustainable international meat market.
Mostrar más [+] Menos [-]Pollution-driven morphological plasticity in a running water ecosystem Texto completo
2022
Chen, Xingyu | Guo, Xiaoyu | Xiong, Wei | Zhan, Aibin
Various types of pollutants derived from rapid industrialization and urbanization have largely threaten biodiversity and functioning of freshwater ecosystems globally. Morphological plasticity, especially body size–associated traits, is considered a functional response to water pollution in species, as such changes are often directly related to functioning of freshwater ecosystems through dynamics of food webs. However, detailed dynamics of pollution impacts on morphological plasticity remain largely unknown, particularly in the wild. Here, we used the model planktonic rotifer Brachionus calyciflorus to assess morphological response to chemical pollution in a river reach disturbed by sewage discharges. Multiple analyses showed dynamic morphological response to water pollution in wild B. calyciflorus populations. The distance between anterior lateral spines, lorica length, and egg short diameter were the most sensitive morphological indicators to water pollution, while spine length was stable in varied pollution conditions. Interestingly, body size and egg size were increased with accentuated water pollution, suggesting that wild populations maintain fitness by increasing feeding efficiency and reducing vulnerability to predation and ensure survival by producing large newborns in polluted environments. Total ammonia nitrogen was the leading nitrogen pollutant affecting body size, while total phosphorus and elements of Mn and As were the key factors relating to egg size. The results obtained here provide new sights into biological consequences of environmental pollution in the wild, thus advancing our understanding of pollution impacts on structure and functioning of freshwater ecosystems.
Mostrar más [+] Menos [-]Effect of climate change to solar energy potential: a case study in the Eastern Anatolia Region of Turkey Texto completo
2022
Bakirci, Kadir | Kirtiloglu, Yusuf
Architects, hydrologists, agriculturists, and solar engineers require the data of solar radiation for solar technologies such as solar drying, cooking, heating, and building illuminations. The aim of this study is to evaluate the effect of climate change on the potential of solar energy in the Eastern Anatolia Region (EAR) of Turkey. The global warming problem caused by greenhouse gases is increasing due to the increase in the use of fossil origin fuels in our world, and climate change is coming out. In this content, the values of monthly sunshine duration and global solar radiation are provided by the Meteorological Service in Turkish for the EAR of Turkey in the periods between 1987 and 2010. Thus, in a period of 24 years, it is investigated how much change took place in meteorological data. These changes are examined in the two different periods. In conclusion, it is observed that important changes occur in some meteorological data. The highest decrease in the variation amount of yearly average global solar radiation is seen in Erzurum, while the highest increase is seen in Erzincan. The highest increase in the variation amount of yearly average sunshine duration is seen in Erzincan, while the highest decrease is seen in Bitlis. In addition, the statistical analysis (t-test) is made to determine whether the difference between two periods is statistically significant for a considered region.
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