ENVIRONMENTAL EARTH SCIENCES, vol.75, no.4, 2016 (SCI-Expanded)
The primary objective of this study was to identify possible heavy metal pollution risks in greenhouse soils. Collected soil samples were subjected to heavy metal analysis to determine Cd, Cr, Cu, Ni, Pb and Zn concentrations. Binding forms of the metals were determined by following a sequential extraction procedure. The wet digestion method with aqua regia procedure was employed to find the pseudo total heavy metal concentrations of soil samples. BCR-701 and NIM-GBW07425 certified reference materials were used to validate the reliability of the methods. Contamination factor, potential ecological risk index and risk assessment code were used to assess the environmental impacts of heavy metals in greenhouse and field samples. Results of extractable amounts of heavy metals from greenhouse samples revealed that mobile fractions of Cd, Pb and Ni were higher than immobile fractions and mobile fractions of Cr and Zn were closer to immobile fractions. Human-induced effects were considered the primary reason for this. Soil pH and organic matter content were found to be highly correlated with heavy metals of soil samples from greenhouses. With regard to environmental impacts of heavy metals, Cd was much more mobile in greenhouse samples than in field samples, retained less in ambient soil and had high environmental risks. It was observed that Cd was highly mobile, less retained and exerted higher environmental risks. With regard to environmental risks, Cd was followed respectively by Pb, Cr and Zn in greenhouse soils. Sequential extraction yielded significant information about mobility, behavior and environmental impacts of heavy metals.