Heavy metal pollution in the soil and water of Sardroud region; an industrial and agricultural area in suburb of Tabriz city
Subject Areas : Optimal management of water and soil resources
Nasrin SabourMoghaddam
1
(Payam Noor University)
Keywords: trace elements, irrigation water, poisoning, atomic absorption,
Abstract :
Background and Aim: Heavy metal pollution is one of the most widespread and serious environmental problems in different regions of the world, including Iran. It is essential to identify the quantity and quality of these pollutants before they reach a critical level, which is a concern for environmental science researchers. In this study, we estimated the concentration of five heavy metals - zinc (Zn), lead (Pb), chromium (Cr), cadmium (Cd), and nickel (Ni) - in the soil and water of agricultural areas surrounded by industrial-agricultural zone in Sardroud which is located in the southwest of Tabriz. This zone has old and diverse gardens and farms, but it is also the industrial hub of Tabriz city, where numerous small and large factories are located. Method: Soil and water samples were randomly collected from forty different vegetable farms in the Sardroud zone in the southwest of Tabriz metropolis, during the crop years of 1400-1401. The samples were transferred to the laboratory and analyzed for the concentration of heavy metals using Atomic Absorption Spectrometry (AAS). On average, two soil samples and two irrigation water samples were collected and tested per hectare of the selected fields during the experiment. Results: A total of 80 soil samples and 80 irrigation water samples were collected and analyzed. The results showed that the concentration of heavy metals in water samples followed the order of Zn > Cr > Pb > Ni > Cd. A similar pattern was observed in soil samples, with the order of Zn > Ni > Cr > Pb > Cd. The metal levels were compared with the standards from various domestic and foreign sources. The average concentration of Zn and Cd in most of the irrigation water samples and the concentration of Cd in almost all soil samples exceeded the recommended acceptable limit. The highest concentration of Cd (11 mg/kg soil) in the soil samples was more than twice the permissible limit. Conclusion: Except for Cadmium in some soil samples, the concentration levels obtained in the soil and irrigation water of Sardroud region for other heavy metals were not at alarming and dangerous levels. Considering the possibility of transferring heavy metal contamination from soil and irrigation water to vegetable, agricultural and garden plants, it is very important to identify the distribution and accumulation of heavy metals in soil and irrigation water of major agricultural areas. Based on the results of this research, it is necessary to identify the sources of cadmium entering the soil and irrigation water of this area and take corrective measures in this regard.