Concentrations of Heavy Metals in Vegetables of Farming Lands Irrigated with Water from Karun River in Ahvaz

Heavy metals are very important from environmental aspects due to their toxicity and accumulative properties. The aim of this study was to evaluate concentrations of lead, cadmium, copper and zinc in vegetables of agricultural lands in Ahvaz, capital of Khuzestan province in southwest of Iran.
This descriptive study was done on Ocimumbasilicum, Raphanussativuslongipinatu and Portulacaoleracea samples from 6 farms located in the north and south of Ahvaz city during spring, summer and autumn in 2013. In general, 60 vegetable samples were investigated. Samples were digested by using acidic digestion. Then concentrations of the elements were determined using furnace atomic absorption spectrophotometry according to standard methods. Data were analyzed by SPSS at α=0.05. The results were compared with WHO and FAO guidelines.
Mean concentrations of lead, cadmium, copper and zinc in vegetables were 10.39, 2.51, 7.20 and 31.84 mg/kg, respectively. Comparing the results with permissible levels given by FAO and WHO indicate that lead and cadmium levels in vegetables are above the recommended levels. However, average concentrations of copper and zinc in vegetables were lower than WHO/FAO recommended levels.
According to the results, vegetables cultivated in this area are polluted to heavy metals of Lead and Cadmium. Due to accumulative effects of heavy metals and their harmful effects on human societies and endangering food safety, more precautions are required to reduce such effects.