Assessment of heavy metals in agricultural soils and their source apportionment

What is it about?

First Online: 07 February 2015 5 Citations Abstract This study aimed at investigating the impact of industrialization on the quality of agricultural soils in the district of Bandırma, Turkey, in terms of soil heavy metal contamination. Many soil and phosphogypsum samples were analyzed, and enrichment factors (EFs) were calculated. The average concentration gradient of metals in the soil (mg/kg) was As < Se < Sb < Pb < Co < Cd < V < Cu < Ni < Zn < Cr < P < Mn < Na < K < Mg < Fe < Ca < Al. According to the Pearson cross-correlation results for the element pairs of Fe-Mg (0.635), Fe-Cu (0.863), Fe-Cd (0.545), Cu-Cd (0.630), Mn-Cr (0.698), Mn-Al (0.523), Cr-Mg (0.543), Al-P (0.508), Na-K (0.616), and C-Zn (0.703), the metal enrichments in the soil were found to be moderately high and significant. In the majority of soil samples, Ni, Cu, Co, Zn, Se, Pb, and Cr were moderately enriched whereas Sb and Cd were extremely highly enriched. A factor analysis (FA) was applied to the cross-correlations of the elements to identify their sources. Six significant factors were extracted with the help of FA, explaining 77.22 % of the total variance, and the elements loaded on these factors were interpreted. The evaluations of the factors showed that the study area has been exposed to heavy metal pollution from anthropogenic sources considering the high levels of Cr, Cd, Cu, P, V, Zn, Ni, Sb, and Pb in the soil and the higher EFs falling in the range of 2.54–372.87. Moreover, the soil concentrations of Mn, Mg, Co, Al, K, and Ca were also high, but they were of lithogenic in origin according to the FA.

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Why is it important?

This study was conducted in the years 2012–2013 in the district of Bandırma in the Balıkesir province of Turkey. During the study, heavy metal pollution in the agricultural soils of the area was examined. Potential environmental problems are present in the study area from a variety of source as it is characterized by industrial facilities as well as intensive agricultural activity. Heavy metal pollution in the area largely arises from a chemical fertilizer factory located at Bandırma due to the emissions from the production of acid, and transportation and deposition of phosphogypsum (PG), that is a by-product, in PG deposition area. The particles of PG containing pollutants are spread great distances away from the deposition area by the wind and cause accumulation of heavy metals in the surrounding soils. There is no previous study about the heavy metal contamination of the agricultural soils in the region caused by that plant. In this study, the heavy metals in soil samples were analyzed and the enrichment factors (EFs) were calculated. The factor analysis (FA) method was applied in order to reveal the source of pollution as lithogenic or anthropogenic.

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