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Multifractal features of activity concentration and stochastic risk assessment of naturally occurring and technogenic radionuclides in the soil of Yerevan, Armenia
2022
Aruta, Antonio | Sahakyan, Lilitʻ | Tepanosyan, Gevorg | Movsisyan, Nona | Belyaeva, Olga | Albanese, Stefano
Spatial patterns and background ranges of naturally occurring radionuclides (NORs) (i.e. U-238, Th-232, K-40) and Cs-137 were studied in the urban soils of Yerevan, the capital city of Armenia. Multifractal Inverse Distance Weighting (MIDW) was used to generate and analyze distribution patterns of radionuclide activities. Based on Fourier transformation of radioactivity data, a spectral analysis was also applied to separate, where possible, background/baseline patterns from local anomalies: two ranges of background values were found to characterise the Yerevan territory. Specifically, in the south and south-east of Yerevan, the lower background ranges of U-238, Th-232 and K-40 comprised in the intervals 2.60–36.42 Bq/kg, 4.04–30.63 Bq/kg and 147.7–396.7 Bq/kg, respectively, were observed in association with the presence of sedimentary formations. In contrast, the higher ones were found, instead, in the central and northern parts of the city where andesite-basalt lavas and ignimbrite tuffs occur. Here, the background values rise to 142.4 Bq/kg, 138.76 Bq/kg and 1502 Bq/kg, respectively. As for the distribution of artificial Cs-137, its baseline levels in Yerevan seem to depend mostly on the global radioactive fallout and some local technogenic sources. Its distribution patterns partially differ from those of NORs. In the framework of this paper, Radium equivalent activity (RaEq), outdoor absorbed dose rate in air (ODRA) and annual effective dose equivalent (AEDEs) were also determined and mapped. They show a good coincidence of their spatial variations with those of NORs. The Monte Carlo simulation was used to assess excess lifetime cancer risk from a stochastic perspective. The related sensitivity analysis revealed that, among NORs, U-238 and Th-232 give the greatest contribution to the total variance (45.7% 42.8%, respectively). In comparison, K-40 has the lowest share (11.3%). Regarding Cs-137, a highly negligible contribution to the onset of health risks (accounting for 0.02%) was observed.
Afficher plus [+] Moins [-]Combination of compositional data analysis and machine learning approaches to identify sources and geochemical associations of potentially toxic elements in soil and assess the associated human health risk in a mining city
2020
Tepanosyan, Gevorg | Sahakyan, Lilitʻ | Maghakyan, Nairuhi | Saghatelyan, Armen
Mining activities change the chemical composition of the environment and have negative reflection on people’s health and there is no single measure to deal with adverse consequences of mining activities, as each case is specific and needs to be understood and mitigated in a unique way. In this study, the combination of compositional data analysis (CoDA), k-means algorithm, hierarchical cluster analysis applied to reveal the geochemical associations of potentially toxic elements (PTE) in soil of Alaverdi city (Armenia) (Ti, Fe, Ba, Mn, Co, V, Pb, Zn, Cu, Cr, Mo, As). Additionally, to assess PTE-induced health risk, two commonly used approaches were used. The obtained results show that the combination of CoDA and machine learning algorithms allow to identify and describe three geochemical associations of the studied elements: the natural, manmade and hybrid. Moreover, the revealed geochemical associations were linked to the natural pattern of distribution of the element concentrations including the influence of the natural mineralization of the parent rocks, as well as the emission from the copper smelter and urban management related activities. The health risk assessment using the US EPA method demonstrated that the observed contents of studied elements are posing a non-carcinogenic risk to children in the entire territory of the city. In the case of adults, the non-carcinogenic risk was identified in areas situated close to the copper smelter. The Summary pollution index (Zc) values were in line with the results of the US EPA method and indicated that the main residential part of the city was under the hazardous pollution level suggesting the possibility of increase in the overall incidence of diseases among frequently ill individuals, children with chronic diseases and functional disorders of vascular system. The obtained results indicated the need for further in-depth studies with special focus on the synergic effect of PTE.
Afficher plus [+] Moins [-]The prevalence of toxic hotspots in former Soviet countries
2016
Sharov, P. O. (Petr O.) | Dowling, Russell | Gogishvili, Megi | Jones, Barbara | Caravanos, Jack | McCartor, Andrew | Kashdan, Zachary | Fuller, Richard
Using a global database of contaminated sites, toxic hotspots in eight former Soviet countries were analyzed to identify the prevalence, types and sources of toxic pollution, as well as their associated potential public health impacts. For this analysis, polluted sites in Armenia, Azerbaijan, Kazakhstan, Kyrgyzstan, Russia, Tajikistan, Ukraine, and Uzbekistan were compiled and analyzed. The levels of contamination of seven key pollutants were assessed in each country. 424 contaminated sites were identified using data from Blacksmith Institute. Pesticides, lead (Pb), radioactive metals, arsenic (As), mercury (Hg), chromium (Cr), and cadmium (Cd) were the most commonly identified key pollutants. Collectively, these sites pose health risks to an estimated 6.2 million residents. The existing data on toxic hotspots in former Soviet countries likely captures only a small percentage of actual contaminated sites, but suggests potentially severe public health consequences. Additional assessments are needed to understand the risks posed by toxic pollution in the region.
Afficher plus [+] Moins [-]On the Recovery of the Water Balance
2020
Varotsos, Costas A. | Krapivin, Vladimir F. | Mkrtchyan, Ferdenant A.
Climate scenarios for future global warming expect the enhancement of the hydrological cycle during the twenty-first century. In particular, accurate simulation of water content in the soil depends not only on the correct determination of the percentages of each component in the water balance but also on the measured biophysical properties of the soil available. One of the greatest man-made environmental disasters in history is the destruction of the Aral Sea which is heavily polluted. Possible scenarios have been formulated, to transfer water from the Siberian rivers to Central Asia and to limit the unsustainable extension of irrigation in this region. A new scenario proposed in this paper is partly based on the use of Caspian water evaporators located on the eastern coast of the Caspian Sea. The implementation of this scenario allows the rescue of the Aral Sea and the normalization of water balance in Central Asia. The results of the calculations show that the Aral Sea can be restored over the next 90–240 years depending on these versions. If the anthropogenic outflow of river water is further reduced by 10%, the Aral Sea will be restored for about 90 years. Finally, possible versions of the water recovery scenario are discussed and evaluated and compared with other examples such as Lake Eyre in Australia, Lake Sevan in Armenia, and Lake Chad in central Africa.
Afficher plus [+] Moins [-]Potentially toxic elements contents and the associated potential ecological risk in the bottom sediments of Hrazdan river under the impact of Yerevan city (Armenia)
2022
Tepanosyan, Gevorg | Harutyunyan, Norik | Maghakyan, Nairuhi | Sahakyan, Lilitʻ
This research aims to assess the ecological status of the Hrazdan river (Armenia) section that flows through Yerevan. The distribution of potentially toxic elements (PTE) (Cr, V, As, Zn, Cu, Ni, Co, Mn, Pb, Ti, Mo, Fe, and Ba), the bottom sediments pollution level, and the ecological risk were assessed employing the single pollution index (SPI), the enrichment factor (EF), the geo-accumulation index (Igₑₒ), and the potential ecological risk index (RI). On sampling sites, water quality parameters (turbidity, DO, electrical conductivity (EC), salinity, TDS, pH, temperature °C) were measured as well. The correlation analysis revealed a significant correlation between Zn—Cu, Pb; Cu—Pb, Mo; Co—Fe, Ti pointing out similar sources and origination of these elements. The results indicated that the content of the studied elements in the Hrazdan bottom sediments exceeded the background content in urban soils, which was due to a set of geological and anthropogenic factors. High contents of elements were determined on the sampling sites spatially confined to the residential and industrial areas. According to EF and Igₑₒ data, the priority bottom sediment contaminants are As, Pb, Mo, Zn, V, and Cu. The RI value varies from 196 to 316 with the mean of 246 which corresponds to the moderate-level ecological risk. On the whole, a moderate (77.8%) and a considerable (22.2%) ecological risk was revealed. The major source of Pb, Cu, Zn, and Mo contents was identified as the surface runoffs in the urban environment. This was verified by the cluster analysis results.
Afficher plus [+] Moins [-]A Novel Approach to Monitoring the Quality of Lakes Water by Optical and Modeling Tools: Lake Sevan as a Case Study
2020
Varotsos, Costas A. | Krapivin, Vladimir F. | Mkrtchyan, Ferdenant A. | Gevorkyan, Suren A. | Cui, Tengfei
The geo-ecosystems of the lakes play an important role in their wider geographical areas, such as energy and biological resources, as well as water sources for agriculture, industry, and drinking water. The main goal of the present paper is to develop a new approach to the effective monitoring of lakes water quality. Three new optical decision-making systems (ODMS) are being set up first as components of this new monitoring system. The first ODMS is based on an 8-channel universal spectrophotometer. The second involves a 35-channel spectrophotometer to diagnose water sampling and the third includes a 128-channel spectroellipsometer. All versions of ODMS include special software that incorporates algorithms and models to solve optical inverse tasks and decision making about the quality of lakes water. ODMS provides a spectral image of the water quality of the lakes in wavelengths ranging between 350 and 910 nm depending on the optical device. The recognition of spectral images generated by ODMS allows the detection of adverse changes in water quality and the decision-making on the choice of strategy to deal with this change. In particular, a case study of Lake Sevan in Armenia is being conducted for the ODMS demonstration, and the results of the lakes water diagnosis are being discussed. The ODMS estimate for water quality error does not exceed 18%, while the forecast for water quality for 1 month includes an error not exceeding 10% and 20% for 1 year.
Afficher plus [+] Moins [-]Panel estimation for renewable and non-renewable energy consumption, economic growth, CO2 emissions, the composite trade intensity, and financial openness of the commonwealth of independent states
2018
Rasoulinezhad, Ehsan | Saboori, Behnaz
This article investigates the long-run and causal linkages between economic growth, CO₂ emissions, renewable and non-renewable (fossil fuels) energy consumption, the Composite Trade Intensity (CTI) as a proxy for trade openness, and the Chinn-Ito index as a proxy for financial openness for a panel of the Commonwealth of Independent States (CIS) region including Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine, and Uzbekistan over the period of 1992–2015. It is the first time that CTI and the Chinn-Ito indexes are used in an economic-pollution model. Employing three panel unit root tests, panel cointegration estimation methods (DOLS and FMOLS), and two panel causality tests, the main empirical results provided evidence for the bidirectional long-run relationship between all the variables in all 12 sampled countries except for economic growth-renewable energy use linkage. The findings of causality tests indicated that there is a unidirectional short-run panel causality running from economic growth, financial openness, and trade openness to CO₂ emissions and from fossil fuel energy consumption to renewable energy use.
Afficher plus [+] Moins [-]Obsolete pesticide storage sites and their POP release into the environment—an Armenian case study
2012
Dvorská, A. | Šír, M. | Honzajková, Z. | Komprda, J. | Čupr, P. | Petrlík, J. | Anakhasyan, E. | Simonyan, L. | Kubal, M.
Organochlorinated pesticides were widely applied in Armenia until the 1980s, like in all former Soviet Union republics. Subsequently, the problem of areas contaminated by organochlorinated pesticides emerged. Environmental, waste and food samples at one pesticide burial site (Nubarashen) and three former pesticide storage sites (Jrarat, Echmiadzin and Masis) were taken and analysed on the content of organochlorinated pesticides, polychlorinated dibenzo-p-dioxins and furans and dioxin-like polychlorinated biphenyls. Gradient sampling and diffusivity-based calculations provided information on the contamination release from the hot spots on a local scale. A risk analysis based on samples of locally produced food items characterised the impact of storage sites on the health of nearby residents. All four sites were found to be seriously contaminated. High pesticide levels and soil and air contamination gradients of several orders of magnitude were confirmed outside the fence of the Nubarashen burial site, confirming pesticide release. A storage in Jrarat, which was completely demolished in 1996 and contained numerous damaged bags with pure pesticides until 2011, was found to have polluted surrounding soils by wind dispersion of pesticide powders and air by significant evaporation of lindane and β-endosulfan during this period. Dichlorodiphenyltrichloroethane-contaminated eggs, sampled from hens roaming freely in the immediate surroundings of the Echmiadzin storage site, revealed a significant health risk for egg consumers above 1E−5. Although small in size and previously almost unknown to the public, storage sites like Echmiadzin, Masis and Jrarat were found to stock considerable amounts of obsolete pesticides and have a significant negative influence on the environment and human health. Multi-stakeholder cooperation proved to be successful in identifying such sites suspected to be significant sources of persistent organic pollutants.
Afficher plus [+] Moins [-]An integrative evaluation of suitability of a river for natural reproduction of trout of Lake Sevan (Armenia)
2020
Asatryan, Vardan | Dallakyan, Marine | Vardanyan, Tigran | Barseghyan, Nelli | Gabrieli︠a︡n, Bardukh
Endemic fish species of Armenian ichthyofauna—Sevan trout (Salmo ischchan Kessler, 1877)—is registered in the Red Book of Animals of the Republic of Armenia as “Critically Endangered” (corresponds to IUCN category: CR A2cd). Its natural reproduction hardly occurs as a result of numerous problems related to the use and management of water and bio-resources in the Lake Sevan drainage basin. Masrik River is formerly known as a spawning river for two ecological races of the Sevan trout, but there is no up-to-date and in-depth studies of its potential to support natural reproduction. Thus, a set of spawning criteria was arranged as matrix and state of Masrik River as spawning area for the Sevan trout was assessed. The results showed that the potential of different parts of Masrik River to support natural reproduction of Sevan trout varied from quite appropriate to inappropriate. The main limiting factors revealed were water temperature, velocity and substrate conditions.
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