Assessment of Heavy Metal Accumulation in Soils and Euphorbia rigida Along a Roadside–Urban Gradient in Amasya (Türkiye) and Evaluation of the Species’ Biomonitoring Potential

Authors : Dudu Duygu Kılıç
Pages : 923-931
Doi:10.35229/jaes.1777922
View : 46 | Download : 148
Publication Date : 2025-11-30
Article Type : Research Paper
Abstract :Traffic is a major source of heavy metals, particularly Pb, Cd, Zn, Cu, and Cr, and the accumulation of these elements in soil and plants poses a serious risk to ecosystem health and human health. Therefore, the use of reliable biomonitor species for the regular monitoring of traffic-related pollution is of great importance. In this study, heavy metal accumulation in soil and Euphorbia rigida individuals and the species\\\' biomonitoring potential were investigated at six locations (motorway edge, city centre, 300 m, 500 m, 1000 m, control) representing traffic and urban pressure in Amasya. Cd, Cr, Cu, Pb, and Zn were measured using ICP-OES analysis; the Geo-accumulation Index (Igeo) and Enrichment Factor (EF) were calculated for soil, while the Bioconcentration Factor (BCF) and Transfer Factor (TF) were calculated for plants. Zn and Cd decreased with distance from traffic, while Cu, Cr, and Pb values were highest within the city. Soil analyses indicated moderate anthropogenic contamination for Cd (Igeo = 1.813 at the roadside); Zn (EF = 3.814) and Pb (EF = 3.357) showed significant enrichment in the city and at the roadside. The order of accumulation in plant tissues was Zn > Pb > Cu > Cr > Cd. E. rigida exhibited hyperaccumulator behaviour for Zn with a BCF > 1 value in all localities, with the highest concentration measured in washed roots at 573.90 mg kg⁻¹ exceeding the toxicity threshold. For Pb and Cd, TF ≤ 1 indicated a tendency towards phytostabilisation by retaining the metal in its roots. The results confirm that E. rigida is an effective biomonitor, particularly for Zn and, to a lesser extent, Pb contamination.
Keywords : Amasya, ağır metaller (Cd, Cr, Cu, Pb, Zn), biyomonitörlük, Euphorbia rigida, trafik kirliliği.

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