Abstract:
Soil quality assessment plays a critical role in promoting sustainable land management, particularly in fragile steppe ecosystems. This study provides a comprehensive geoecological
evaluation of heavy metal contamination (Pb, Cd, Zn, Cu, Co, Ni, Fe, and Mn) in soils across
five districts of the Akmola region, Kazakhstan. The assessment incorporates multiple
integrated pollution indices, including the geochemical pollution index (Igeo), pollution coefficient (CF), ecological risk index (Er), pollution load index (PLI), and integrated pollution
index (Zc). Spatial analysis combined with multivariate statistical techniques (PCA and
clustering analysis) was used to identify pollutant distribution patterns and differentiate
areas by risk levels. The findings reveal generally low to moderate contamination, with
cadmium (Cd) posing the highest environmental risk due to its elevated toxic response
coefficient, despite its low concentration. The study also explores the connection between
current soil conditions and historical land-use changes, particularly those associated with
the Virgin Lands Campaign of the mid-20th century. The highest PLI values were recorded
in the Yesil and Atbasar districts (7.88 and 7.54, respectively), likely driven by intensive agricultural activity and lithological factors. PCA and cluster analysis revealed distinct spatial
groupings, reflecting heterogeneity in both the sources and distribution of soil pollutants.
