Spatial distribution and pollution assessment of heavy metals in soil from the Republic of North Macedonia

The Distribution Characteristics and Potential Risk Assessment of Lead in the Soil of Tieguanyin Tea Plantations in Anxi County, China

Assessing the distribution and risks associated with the soil lead content in the Tieguanyin tea plantations of Anxi County is critical, given the county's significance as the primary Tieguanyin tea production area in Fujian Province. This study examined the distribution characteristics of soil lead in Anxi County's tea plantations according to the Kriging spatial interpolation of the parameters of the semivariance function of the exponential model. Moreover, the sources of lead content were analyzed, considering geological backgrounds and anthropogenic influences. Ecological risks and the issuance of early warnings were also assessed. The soil lead content in the rocks of the Tieguanyin tea plantations in Anxi County followed the order: andesite > dacite > rhyolite > granite. The soil lead content gradually decreased from the center toward the east and west, forming four distinct north-south parallel zones. High-lead-content areas were identified at the border of Jiandou, Bailai, and Hushang; in the central part of Lutian; and in the southern part of Huqiu. The high levels of soil lead in the tea plantations possibly originated from industrial and mining activities, automobile exhaust, and agricultural activities. The distribution of single-factor pollution indices and potential risk evaluation based on the Soil Environmental Quality Standard, Environmental Technical Conditions for Tea Production Area, and Environmental Technical Conditions for Organic Tea Production Area indicated that the soil in Tieguanyin tea plantations in Anxi County was clean and safe for tea cultivation.

Lithological distribution of rare earth elements in soils in the As-Sb-Tl Allchar mining area, North Macedonia

Despite the growing interest, the information available on rare earth elements (REEs) in the last two decades is relatively premature and sparse. The importance of these elements as indicators of soil and physiological processes and responses have contributed to the increased interest in these previously less considered elements in the environmental sciences. This study provides an overview of the content and distribution of rare earth elements in the soil in the vicinity of the hydrothermal volcanogenic As-Sb-Tl deposit of Allchar, North Macedonia. Elemental contents were determined by inductively coupled plasma mass spectrometry (ICP-MS). The light rare earth elements (LREEs) content in the study area ranges from 8.92 to 188 mg/kg, while the heavy rare earth elements (HREEs) content ranges from 1.95 to 42.7 mg/kg. It can be concluded that there is some enrichment of light REEs in the volcanic intrusive rocks of the Allchar mine area, including latite, quartz-latite, trachyte and occasionally andesite and dacite. The spatial distribution of HREEs is closely related to the lithology of the region, especially the sandstone and claystone, followed by layered and massive carbonate rocks (limestone, dolomite, marble) that occurred in the Middle and Upper Triassic.

Accumulation and distribution of heavy metals in soil and food crops in the Pb-Zn mine environ. Case study: Region of Probištip, North Macedonia

The aim of the study was to investigate the exploration and distribution of various chemical elements in soils and vegetables from gardens in the region of Probištip, North Macedonia. This region was exposed to heavy metals pollution from Pb-Zn mining and flotation tailings landfill near the town of Probištip for 70 years. A total of 38 samples of various crops and vegetable products from 19 gardens were analyzed. The analyzes were carried out by ICP-AES (Al, Ba, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, Sr, V, and Zn) and by ICP-MS (As, Cd, Co, Cr, and Pb). It was found that the content of some potentially toxic elements (As, Cd, Cu, Pb, and Zn) in the soil samples from the gardens, exceeded the target values. From these results, it is clear that the contamination of the soils in this area is due to mining activities and the distribution of flotation wastes from the nearby flotation dump. It was also found that the contaminated soils lead to elevated levels of these elements in some vegetables from the gardens, especially those near the Zletovska River and the flotation waste landfill, exceeding the nationally permissible food content.

Levels and distribution of chemical elements in house dust from the area of an abandoned Pb-Zn smelter in North Macedonia

The content of 41 chemical elements (Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hf, In, K, La, Li, Mg, Mn, Mo, Na, Nd, Ni, P, Pb, Rb, Sb, Sc, Se, Sm, Sr, Tb, Th, Ti, Tm, U, V, W, and Zn) was determined in attic dust, household dust and soil samples collected from 33 houses in the area of the town of Veles, North Macedonia. Silver, Cd, Cu, Li, P, and, Pb were analyzed by inductively coupled plasma - atomic emission spectrometry while the other elements were analyzed by neutron activation analysis. The study area has been continuously exposed to high amounts of potentially toxic elements due to the emission from an abandoned Pb-Zn smelter plant. In this study, attic and household dust together with soil samples collected from the yards of the houses were used to assess the level of historical and present air contamination by potentially toxic elements. It was found that the contents of Ag, As, Cd, Cu, In, Pb, Sb, Se, and, Zn in dust samples represented an anthropogenic association of elements, with very high contents in samples collected from the town of Veles, which is close to the Pb-Zn smelter, compared with those collected from the mountainous area.

Distribution and statistical analysis of major and trace elements in the bee pollen from the territory of Republic of Kosovo

The objective of this study was the determination of major and trace elements in the bee pollen samples from the whole territory of Republic of Kosovo. Pollen, as a natural plant product, is exposed to different contaminations absorbed by plants from the soil through the root system or with water intake, as well as to pollutants of different origins, including anthropogenic ones, deposited directly on pollen. In total 67 pollen samples were collected in 2019. The samples were analyzed for 27 macro and microelements by using ICP-AES and ICP-MS. The mean content of major elements in bee pollen was 4065, 3455, 1375 and 549 mg/kg for K, P, Ca and Mg, respectively. The range of the contents for some potentially toxic elements was 11.9-139.1, 1.9-16, 0.11-6.25, 0.01-0.329 and 0.001-0.38 mg/kg for Zn, Cu, Pb, Cd and As, respectively. Three groups of elements of mixed origin were identified through factor analysis: the first and the third Factors, are mostly of geogenic origin (Ag, Li, Al, Fe, Ca, Sr, K, Mg and P and Co, Ni, Cr, Cu and Mn) and the second Factor association is related to anthropogenic processes (Sb, As, Pb, Tl, Sn and Cd).

Moss biomonitoring of air pollution with potentially toxic elements in the Kumanovo Region, North Macedonia

A study was carried out to investigate air deposition and to explore the natural distribution and contamination with potentially toxic elements (PTEs) in the Kumanovo Region, North Macedonia, by using moss samples as biomonitors for air pollution. The distribution of 51 elements was detected in 42 moss samples collected from this area. Moss samples were analyzed following microwave digestion by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). It was found that the atmospheric deposition for some PTEs in the moss samples in specific parts of the study area is influenced by anthropogenic and urban activities. R-mode factor analysis was used to identify and characterize element associations, and six associations of elements were determined. Four factors were separated from the group of macroelements determined by ICP-AES: Factor 1 (Al, Cr, Fe, Li, Ni, V, and Zn), F2 (K, Mg, and P), F3 (Ba and Sr), and F4 (Cd, Pb, and Zn); and two associations were separated from the group of trace elements determined by ICP-MS: Factor 1 (As, Co, Cs, Ga, Ge, Sc, Ti, Y, Zr, and rare earth elements-REEs) and Factor 2 (Bi, Br, Hg, I, Sb, Sn, and W).

Assessment of natural and anthropogenic factors on the distribution of chemical elements in soil from the Skopje region, North Macedonia

The main objective of this study is to present the distribution of different chemical elements in soil samples from the Skopje region, North Macedonia. To determine the level of presence of chemical elements, soil samples are collected from a total of 60 locations. From each location, from an area of 5 × 5 km² samples of soil are collected: topsoil (0-5 cm) and subsoil (20-30 cm). The soil samples were analyzed for 69 elements by using two instrumental methods: inductively coupled plasma-atomic emission spectrometry (ICP-AES) for macro-elements and inductively coupled plasma-mass spectrometry (ICP-MS) for trace elements. A factor analysis was applied to analyze the factors affecting the linear combination variables grouped at the same factor. Spatial distribution maps of each factor as well as distribution maps for the analyzed elements were prepared by universal kriging interpolation. It was found that the distribution of most elements follows the lithology of the examined area, except for some elements (Cd, Cu, Fe, Hg, Mn, Pb, and Zn) whose higher contents are found in the area of the city of Skopje as a result of urban and industrial activities (traffic, metal processing, fossil fuel combustion for heating).

Occurrence and enrichment sources of cobalt, chromium, and nickel in soils of Mitrovica Region, Republic of Kosovo

The main purpose of this study is to determine the differences between anthropogenic sources and lithogenic sources of the content of certain potentially toxic elements in the region of Mitrovica, Republic of Kosovo. For that purpose, the results of a study on the spatial distribution and enrichment of cobalt, chromium and nickel in surface soil from Mitrovica and its environ, are reported. The average content of Co, Cr and Ni in soil amounts to 22 mg kg^-1, 60 mg kg^-1 and 96 mg kg^-1, respectively. Spatial distribution maps of Co, Cr and Ni shows their predominance in the area of Triassic serpentinites on the North-eastern and Western parts of study area. The lowest contents are found on the outcropping of Miocene latites, quartz-latites and pyroclastites. It has been established that the increased content of Co, Cr and Ni in soils from this area is of lithogenic origin. It is shown that content of Co, Cr and Ni exceeds the target Dutch value in 173 km², 82 km² and 256 km² (from 302 km² of the study area), respectively, while the content of Cr and Ni exceeds the action Dutch value in 17 km² and 63 km², respectively.

Investigation of Concentration and Distribution of Elements in Three Environmental Compartments in the Region of Mitrovica, Kosovo: Soil, Honey and Bee Pollen

The abundances of selected elements in different environmental compartments, namely soil, honey, and bee pollen, was determined in this study. For that purpose, sixteen soil and honey samples, and nine pollen samples were taken in the region of Mitrovica, Kosovo. The concentration of elements was measured by ICP-AES and ICP-MS. Pollution level concentrations of Pb, Zn, As, and Cd were observed in soil. The level of soil pollution was estimated by calculating pollution indices. Pb was also observed at high concentrations in honey, as was Cd and Pb in pollen. Pearson’s correlation coefficients revealed mostly weak and moderate correlations of the concentrations of the eight selected elements among the soil, honey, and pollen samples. Several groups of elements with geogenic and anthropogenic origin were identified by hierarchical cluster analysis. The concentrations of selected heavy metals for soil and honey were compared to those in neighboring countries, and those for pollen with samples from Turkey, Serbia, and Jordan.

Atmospheric Mercury Deposition in Macedonia from 2002 to 2015 Determined Using the Moss Biomonitoring Technique

The moss biomonitoring technique was used in 2002, 2005, 2010 and 2015 in a potentially toxic elements study (PTEs) in Macedonia. For that purpose, more than 70 moss samples from two dominant species (Hypnum cupressiforme and Homalothecium lutescens) were collected during the summers of the mentioned years. Total digestion of the samples was done using a microwave digestion system, whilst mercury was analyzed by cold vapour atomic absorption spectrometry (CV–AAS). The content of mercury ranged from 0.018 mg/kg to 0.26 mg/kg in 2002, from 0.010 mg/kg to 0.42 mg/kg in 2005, from 0.010 mg/kg to 0.60 mg/kg in 2010 and from 0.020 mg/kg to 0.25 mg/kg in 2015. Analysis of the median values shows the increase of the content in the period 2002–2010 and a slight reduction of the air pollution with Hg in the period 2010–2015. Mercury distribution maps show that sites with increased concentrations of mercury in moss are likely impacted by anthropogenic pollution. The results were compared to similar studies done during the same years in neighboring countries and in Norway—which is a pristine area and serves as a reference, and it was concluded that mercury air pollution in Macedonia is significant primarily in industrialized regions.

Atmospheric Heavy Metal Deposition in North Macedonia from 2002 to 2010 Studied by Moss Biomonitoring Technique

Moss biomonitoring technique was used for a heavy-metal pollution study in Macedonia in the framework of the International Cooperative Program on Effects of Air Pollution on Natural Vegetation and Crops (UNECE IPC Vegetation). Moss samples (n = 72) were collected during the summers of 2002, 2005, and 2010. The contents of 41 elements were determined by neutron activation analysis, atomic absorption spectrometry, and inductively coupled plasma atomic emission spectrometry. Using factor and cluster analyses, three geogenic factors were determined (Factor 1, including Al, As, Co, Cs, Fe, Hf, Na, Rb, Sc, Ta, Th, Ti, U, V, Zr, and rare-earth elements–RE; Factor 4 with Ba, K, and Sr; and Factor 5 with Br and I), one anthropogenic factor (Factor 2, including Cd, Pb, Sb, and Zn), and one geogenic-anthropogenic factor (Factor 3, including Cr and Ni). The highest anthropogenic impact of heavy metal to the air pollution in the country was from the ferronickel smelter near Kavadraci (Ni and Cr), the lead and zinc mines in the vicinity of Makedonska Kamenica, Probištip, and Kriva Palanka in the eastern part of the country (Cd, Pb, and Zn), and the former lead and zinc smelter plant in Veles. Beside the anthropogenic influences, the lithology and the composition of the soil also play an important role in the distribution of the elements.

Study of nitrogen pollution in the Republic of North Macedonia by moss biomonitoring and Kjeldahl method

In the summer of 2005 and 2010, moss samples were collected from 72 sampling sites evenly distributed all over the territory of Republic of North Macedonia. Kjeldahl method was used to determine the nitrogen content in the samples. Descriptive statistics and distribution maps were prepared. Data obtained from these two surveys were compared, and additional comparison was done with data obtained from similar studies in the South-Eastern European countries and Finland as a clean area. The median value of N content in the samples collected in 2005 is 1.21%, varies from 0.70% to 1.54%, while the content of N in samples collected in 2010 ranges between 0.68% and 1.75% with the median value of 1.06%. High contents of N were found in the Northern and Central parts of the country mainly as a result of agricultural activities, industry and traffic.