RESEARCH OF THE RELATIONSHIP BETWEEN THE CONTENT OF HEAVY METALS IN SEDIMENT DUST AND AGRICULTURAL SOIL IN THE AREA SURROUNDING THE STEELWORKS ZENICA

Sanela Beganovic 1 , Sefket Goletić 2 , Halim Prcanovic 1 , Mirnes Durakovic 1 and Amna Karic 3 . 1. University in Zenica, Institute „Kemal Kapetanović“ of Zenica, Travnička cesta 7, Zenica, Bosnia and Herzegovina. 2. University in Zenica, Faculty of Mechanical Engineering, Fakultetska 1, Zenica, Bosnia and Herzegovina. 3. University in Zenica, Faculty of Metallurgy and Technology, Travnička cesta 1, Zenica, Bosnia and Herzegovina. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

This paper contains analysis of the results after monitoring the content of heavy metals (Pb, Cd, Fe, Zn, Ni, Cr and Mn) in sediment dust and agricultural soil in nine locations surrounding steelworks Zenica from March to August in 2016. The aim of the paper is to analyze and assess connection of the content of heavy metals in sediment dust and in soil surrounding steelworks Zenica in order to rate soil contamination caused by heavy metals that have been emitted from metallurgic plants, and in order to evaluate the industrial emissions effect on the environment and human health. It has been established that the biggest sample number of sediment dust is being loaded by Nickel and Cadmium, and soil samples by Nickel and Manganese. By applying Pearson coefficient, it has been concluded that there is a strong relation between Lead and Zinc, and a medium strong relation between Iron in sediment dust and soil, while other analyzed metals do not show significant correlation in terms of statistics. This shows that Lead, Zinc and Iron in the soil are probably of techno-genic origin, and the other metals are of primarily geological origin. The correlation analysis of metal substance in soil and sediment dust in measuring areas has shown that there is a statistically significant correlation between Zinc in sediment dust and soil in the following areas: Gradišće, Arnauti and Novo Selo, and correlation of Chromium in sediment dust and soil is present in Šerići.

…………………………………………………………………………………………………….... Introduction:-
Soil in industrial areas is often exposed to the influence of increased emissions of different pollutants from industrial machines. Research has registered higher concentrations of heavy metals in the soil than those naturally present, and very often this concentration is even higher than limit, which leads to deterioration of physical, chemical and biological characteristics as well as violations of soil usable values.

ISSN: 2320-5407
Int. J. Adv. Res. 6(7), 969-978 970 Also, the living environment surrounding the steelworks in Zenica, central Bosnia for the past decades has been exposed to the influence of the high emissions of heavy metals and other pollutants emitted from industrial plants. Monitoring results identified a higher content of heavy metals in agricultural soil and in populations of different plants, which is a consequence of more than a couple decades of the environment being loaded by the emissions from industrial plants [1,2,3,4].
Heavy metals from industrial sources are being emitted in the air and they are included into anthropogenic redistribution in the geosphere. The atmospheric deposits of heavy metals reach the soil, where they are accumulated and stored for decades. Heavy metals from the soil are taken out by the harvest and are washed by water and in that way they are included in the geobiocycle and food networks, through which they can cause different consequences for all elements in food networks, including health consequences for the people. Harmful effects of heavy metals on ecosystems, especially on plants, are expected with higher concentration and are being reflected through different changes and disorders, which can reflect on human health [5]. Therefore, knowing all the factors affecting the redistribution of heavy metals in geosphere is of high significance for the protection of the environment, human health, and the stability of the eco-system. [5,6,7]. This paper contains analyzed results of heavy metals monitoring of (Lead-Pb, Cadmium-Cd, Iron-Fe, Zinc-Zn, Nickel-Ni, Chromium-Cr and Manganese-Mn) in sediment dust and agricultural soil surrounding steelworks Zenica. The aim of the analysis is to determine the origin of heavy metals in agricultural soil and the origin of soil contamination caused by heavy metals that have been emitted from industrial plants in order to assess the influence of industrial emissions to the environment and people's health.

Material and methods of work:-
Research has taken place in 9 locations (L) surrounding steelworks Zenica, in the Central Bosnia area. The locations are positioned in a cyclical scheme various distances (1,2 -17,4 linear km) from industrial sources of emissions (Table 1 and Picture 1). Sampling of sediment dust has been done in nine locations surrounding steelworks Zenica in continuously for a 6 months period, starting from March to August 2016. Sampling has been done with Bergerhoff's device for collecting sediment dust, which consists of a sampling bowl for collecting sediment dust and a stool with wire net. The stool is positioned so that the surface of the bowl is in horizontal position 1, 5-2 m above the surface of the soil. Measuring of the sediment dust has been done according to standard method [8,9,10].
Soil sampling has been done on representative surfaces set in the same locations (Table 1). Soil sampling and preparation of the samples have been done according to standard procedure [11]. In each location, average soil samples have been collected (approximately 2 kg) from more (10-20) single samples taken with chrome-plated probe and with hand plastic tools. The samples are taken from the surface layer of 25 cm in depth of agricultural soil, which has been used for food production for humans and cattle.
According to mechanical composition, the researched soil in 5 locations (L-1, L-3, L-4, L-5 and L-9) has a powderclay structure, and in 3 locations (L-2, L-6 and L-7)there are argillaceous soil and in location L-8 there is sandy soil.
The chemical analysis of the content of total shape of heavy metals in sediment dust and soil have been performed in the laboratory for the following elements: Pb, Cd, Fe, Zn, Ni, Cr and Mn according to AAS method (Perkin Elmer Analytical Methods for Atomic Absorption Spectrometry). The content of metal in the soil is expressed in mg/kg, and in sediment dust in %.
The correlation between the content of heavy metals in sediment dust and agricultural soil has been done using statistical tools in the Excel programme.
The Pearason coefficient of correlation is used to determine how close observations are to the regression line which best describes linear connection of heavy metals in sediment dust and the soil. Table 2. Shows the interpretation of linear correlation coefficient, upon which a conclusion on intensity and character of a connection between questioned variables is made.
972 Connection intensity is the same for negative values of the correlation coefficient as well. For the determination of connectivity of chemical elements in sediment dust and agricultural soil, the correlation coefficients between elements (Table 8), and cluster analysis (Picture 2) have been used. The aim of the cluster analysis is to determine the the group of chemical elements (cluster) that shows that the elements inside the cluster are mutually alike more than the elements of the other cluster. Cluster hierarchy technique has been used in this analysis, which is based on correlation coefficient (r).
In order to assess values of total sediment dust and heavy metal concentration in sediment dust (Table 3), measured values are compared with limit values of polluting substance given in Annex XV: Limit and tolerant values for dedicated measuring according to [12].  Table 4, which are determined according to the national standards [13].  Limit values of heavy metals in the soil (Tables 4 and 5) refer to the soil areas with acid reaction. In alkaline and carbonated soil areas, limit values can be increased by 25%.

Content of heavy metal in sediment dust:-
According to the data presented in Table 6, we notice that in locations L-1 and L-3 average values of sediment dust are higher than limit value of 350mg/m 2 /day. The highest maximum value has been recorded in these locations, which was expected since they are exposed to the highest pressures of industrial emissions due to the proximity to anthropogenic sources of the emissions and to the directions of dominant winds.
Average values of Pb concentrations in sediment dust are lower than the limit value of 0,1mg/m 2 /day, but maximum concentrations are exceeding limit values in localities L-1, L2, L-7 and L-9, which are located in the direction of dominant winds. For other heavy metals Fe, Cr and Mn, which are measured in sediment dust as well, the limit values are not prescribed nor does the criteria for their concentration assessment exist.

Content of heavy metals in soil:-
The content of heavy metals in agricultural soils shown in Table 7, where we can see the increased presence of heavy metals in the area surrounding steelworks Zenica, depending of the distance from the industrial sources, type of the soil and wind rose.
Average concentrations of Pb in the soil in zones up to 3,5 km surrounding steelworks Zenica (locations L-1,L-2 and L-3) were higher than the limit values shown in Table 4. Maximum concentrations of Pb in soil were higher than the limit values in five locations (L-1, L-2, L-3, L-8 and L-9).
Average concentrations of Cd in the soil were higher than the limit values in two of the locations (L-4 and L-7), while maximum concentrations of Cd were higher in most of the researched locations.
Average concentrations of Ni in soil were significantly higher than the limit values in almost all researched locations, which proves that the whole area is loaded with this pollutant.
Average concentrations of Cr in the soil were higher than the limit values in two locations (L-5 and L-7), and the maximum values were higher than the limit values in five locations (L-1,L-2, L-5, L-6 and L-7).
The highest concentrations of Zn in soil were recorded in zones up to 3,5 km surrounding steelworks Zenica (locations L-1, L-2 and L-3), and in location L-8 these were higher than limit values shown in Table 4.
In most locations the content of Mn in the soil was higher than the limit values shown is Table 5. Especially high concentrations have been recorded in location L-9, which is the farthest one from the industrial sources of emission to the air. Table 7, clearly indicates that distribution of concentrations do not show a decreasing trend with moving from industrial sources of heavy metals emission. This is probably because of the origin of certain types of heavy metals, which is primarily geogenic, and secondarily anthropogenic, because of the configuration of the researched area and wind rose [4,13]. The results of this research show increased values of certain heavy metals, especially of Mn, even in the farthest location tested.  Investigation of the relationship between heavy metals content in sediment dust and soil:-In Table 8 there is a survey of the correlation coefficient between heavy metals concentrations in sediment dust and soil.  According to the data presented in Table 8 there is a noticeably strong connection between Pb (r=0,891) and Zn (r=0,804) in sediment dust and soil, while in the connection between Fe in sediment dust and soil is of medium strength (r=0,531). There is a noticeable strong connection between Pb, Fe, Zn, Cr and Mn in sediment dust with Pb and Zn in the soil, as it has been shown in dendrogram in Picture 2. This connection means that these researched chemical elements probably have the same origin and they come from industrial sources of emissions in the air. Ni, Cr, Mn and Cd do not show significant mutual connection in the samples of sediment dust and soil collected in the researched area surrounding steelworks Zenica (Picture 2).

Picture 2:-Dendrogram of cluster analysis-connection of the elements in sediment dust (SD) and soil (S)
Correlation coefficients between heavy metals in sediment dust and soil in researched locations surrounding steelworks Zenica are presented in Table 9. Statistical analysis of data, presented in Table 9, show that the correlation between heavy metal content in sediment dust and soil inside certain locations is weak (negative values are not taken into consideration),except for Zn in locations:L-3 in (Picture 3-d, r=0,78strong connection), L-5 (Picture 3-c, r=0,79middle strong connection) and L-7 (Picture 3-a r=0,82strong connection), and Cr in location L-9 in Picture 3-b, r=0,87strong connection). Therefore, statistically significant connections exist between the heavy metal content in the sediment dust and the soil for Zn in these locations: L-3, L-5 and L7, and for Cr in location L-9.

Conclusion:-
According to the monitoring of in agricultural soil and sediment dust in the area surrounding steelworks Zenica, in central Bosnia, it was found that a large number of the samples of sediment dust were loaded with Ni (25 samples) and Cd (18 samples), with a total number of 54 samples collected. In addition, a large number of the soil samples were loaded with Ni (47 samples) and Mn (42 samples), with a total of 54 samples obtained.
Heavy metal content in sediment dust and agricultural soil in the area surrounding steelworks Zenica shows increase levels compared to the natural state and goes beyond the maximum limit values allowed, which is a consequence of their anthropogenic redistribution caused by present emissions of heavy metals from metallurgic and thermal plants.
Application of Pearson correlation coefficient shows strong connection between Pb and Zn as well as a medium level connection between Fe in sediment dust and soil. Other elements that have been analyzed do not show significant statistical interrelation. This shows that increased content of Pb, Zn and Fe in soil is probably of technogenic origin because of industrial emissions of these elements.
Correlation analysis between the content of metals in soil and sediment dust in these researched locations has shown that there is a statistically significant correlation between Zn in sediment dust and soil in following locations: Gradišće, Arnauti and Novo Selo, and of Cr in sediment dust and soil in location Šerići.
The results of this research of the content and dynamics of heavy metals in agricultural soil of Zenica region show that the soil quality is endangered and is risky for food production because of the heavy metal inclusion in food networks and the potential negative impact on human health.
Since this analysis has shown high variation of the results and high number of negative results, it is necessary, in further research, to lower the number of measuring places, increase the number of elements analyzed, and increase number of samples foe an extend research period. In this way, we would get more representative data, which would provide better correlation between the content of heavy metals in sediment dust and soil. Based on such detailed examination it is possible give recommendations for applying suitable technology and measures for remediation of the contaminated soil (e.g. phytoremediation or calcination or adding humus to the soil, etc.).