An Evaluation of the Risk of Heavy Metals in Soils Irrigated with afra Thermal Water Springs, Jordan

The present study investigates the concentrations of six heavy metals (Cu, Ni, Co, Zn and Cr) in Afra thermal springs in Tafila, southern Jordan and their accumulations in soils irrigated by this hot spring water. Thermal water samples were collected during two seasons that is at the end of summer and at the end of the winter season, 2012-2013. The results show that the concentrations of heavy metals in the soil were relatively low. This was attributed to their low concentrations in the control samples as well as in the thermal water. The current study investigates water quality in Afra thermal springs in Jordan in terms of heavy metal concentrations. It shows relatively low concentrations and a great variation with seasons. Heavy metal concentrations at the end of winter (in ascending order) were CCu > CNi > CCo > CZn >CCd, whereas at the end of the summer season, they were: CCo > CNi > CCu. All analyzed metals in the thermal spring water were below the WHO guidelines for drinking water except Ni which showed higher concentrations than those set by the WHO guidelines. As for soil analysis, the results showed that most of the detected heavy metals were related to pedogenesis rather than to the accumulation from irrigation with thermal water. However, there is an increase in all metals in soils irrigated with thermal springs compared to the control sample, which indicates that there is an accumulation of heavy metals coming from the thermal springs through successive irrigation.