Risk Assessment of Heavy Metals Pollution in Urban Environment

This chapter summarizes the results of heavy metal’s human health and ecological risk assessment of multipurpose ecogeochemical studies performed by the Center for Ecological-Noosphere Studies of the National Academy of Sciences of the Republic of Armenia in the young industrial cities of Yerevan and Gyumri and in an old mining region of the city of Kajaran. According to the results children non-carcinogenic risk values were greater than permissible limit of 1 indicating the possibility of an adverse health effect in the whole area of all studied cities. Among all studied elements, the riskiest were those previously identified as primary pollutants. It has also been shown that in biogeochemical provinces, where mining activities and agricultural land of rural communities are spatially juxtaposed, health risk assessment should include all possible exposure pathways. Otherwise, underestimation of possible health risk will take place. Heavy metals in soils of Yerevan and Gyumri are also an ecological risk factor and the riskiest elements having significant contribution to the overall risk and are those (Hg, Cd, and Pb) with the high level of toxicity

Tentative baseline values of less frequently regulated elements in urban park soils of Alcala de Henares, Spain.

Background or baseline concentrations of metals in urban soils are critical to determine risks and establish clean-up decontamination thresholds to protect the public, but these concentrations remain unknown for less frequently regulated and monitored metals in most of the European cities. Iterative 2σ-technique1 and boxplot methods2 were used to establish tentative background values for a variety of metals in soils from urban parks in Alcalá de Henares (Spain), which resulted in the same median values for the elements studied (mg/kg): Ag (0.003), Co (0.8), Mo (0.24), Pt (0.26), Rh (0.15), Sb (0.15) and Y (5.1). The percent differences when comparing these values with the average continental crust3 values were as follows: 47.1, 84.2, 78.8, 83, 34.5, 158, 52.8 and 75.4 for Ag, Co, Mo, Pt, Rh, Sb and Y, respectively. These differences could be explained by the geochemical peculiarities of Alcalá’s soils. Our results are a preliminary step for developing background values following implementation of a further monitoring programme in the urban soils studied

Revealing Soil and Tree Leaves Deposited Particulate Matter PTE Relationship and Potential Sources in Urban Environment

Trees play a pivotal role in improving urban environmental quality and provide several ecosystem services including the removal of pollutants from the air, such as particular matter (PM) and potentially toxic elements (PTE). Therefore, understanding the tree PM and PTE capturing potential, also in connection with plant species, is of great concern, especially in urban areas. This study aims to reveal the link between the elemental composition of PM deposited on tree leaves and soils PTE contents, as well as to rank the PM capturing efficiency of 10 different tree species growing under the impact of urban environments. This also allowed us to test the efficiency of PM deposited on tree leaves as a PTE biomonitoring and pollution source identification tool, in the two biggest urban areas of Armenia. Indeed, high contents of PTE are detected in both soil- and leaf-deposited PM from sites characterized by the presence of localized and active pollution sources (i.e., industrial unites, high traffic, etc.), which are identified by specific tracers (such as Mo, Cu, Zn, Pb, and Cd). Among the studied tree species, the highest PM amount per unit leaf area is observed for Platanus orientalis, but elm species are also identified as promising canditates to be considered for their PM removing potential, and need to be included in future more details studies

Mercury soil contents and associated ecological and health risks in kindergartens and functional areas of the city of Vanadzor (Armenia)

Mercury is a widespread environmental pollutant becoming a crucial health concern as a result of natural and anthropogenic releases. Understanding Hg distribution pattern between different functional urban areas is needed for urban pollution control and health impact assessment. Therefore, in this paper urban soil Hg spatial distribution, pollution level evaluation, and mercury-induced health risks were studied, for different urban functional areas (355 samples) and kindergartens (18 samples) of Vanadzor. Geospatial mapping and the geostatistical analysis suggest that Hg concentration in the entire area of Vanadzor and its kindergartens has a natural origin, besides a certain anthropogenic impact on some urban sites. According to geoaccumulation index (Igeo), uncontaminated or moderately contaminated levels were detected only in 2 samples from industrial area and 5 samples from residential area, the remaining samples were classified as uncontaminated. In all kindergartens and the 22.15 sq.km of the city (270 samples) are characterized by low level potential ecological risk, whereas 3.85 sq.km (85 samples) correspond to moderate and for 1 sampling site high level of potential ecological risk. A non-carcinogenic health risk assessed for children and adults indicates health hazards neither in Vanadzor entire areas nor in kindergartens. The hazard index (HI) in each urban functional area is less than allowable level (HI <1) for children and adults. Obtained results are indicative and offer the ability for better management of urban soil and urban planning in terms of Hg pollution regulation in different functional areas

Multifractal features of activity concentration and stochastic risk assessment of naturally occurring and technogenic radionuclides in the soil of Yerevan, Armenia

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

Relationships between NDVI and climatic factors in mountain ecosystems: A case study of Armenia

In this paper, we study vegetation, temperature, and precipitation dynamics, as well as their correlations and lag-time effects in mountain ecosystems of Armenia using SPOT/VGT NDVI data over the period 1998–2013. Three study sites near the Sisian, Megri and Kajaran meteorological stations were chosen, representing steep, xerophytic and meadow vegetation types, respectively. The results showed a significant increase in NDVI across the growing season during the study period. Meanwhile, a significant increase in mean precipitation and temperature during the growing season was detected for the Kajaran station. A negative correlation was observed between temperature and xerophytic/steep vegetation NDVI and positive correlation between temperature and meadow vegetation NDVI, while correlations between precipitation and NDVI for all vegetation types were positive. Moreover, the response of vegetation to climatic factors exhibited a time-lag effect. In general, the temperature and precipitation in the 2nd and 3rd 10-day intervals of April have a strong impact on the vegetation growth in summer. This study suggests that for a better understanding of the impact and lag-time effect of climatic factors on mountain vegetation growth it is preferable to use 10-day data

A Practice of Useing Remote Sensing Technologies in Geoecological Studies

Рассматриваются основные направления применения дистанционных технологий в Республике Армения. Изложены базовые научно-технологические ресурсы для развития перспективных направлений, которые обеспечат надежную научно-методическую основу для совершенствования и разработки дистанционных методов и создания на этой основе мониторинговой системыThe main areas of the use of remote sensing technologies in Armenia are considered in the article. The basic scientific-technological resources for their perspective development are also discussed. The later will serve a background for the development of remote sensing methods and monitoring system in the futur