Determination of Lead and Cadmium on Lettuce and Watercress Planted in Several Areas in Syria

Agricultural soils contamination of heavy metals is a growing concern due to food safety issues and potential health risks. Consuming crops that contain these minerals is one of the main ways elements enter the human body, then, they accumulate in human tissues and cause serious effects on health. This study aimed to monitor the levels of lead and cadmium accumulation in the edible parts of lettuce (Lactuca sativa L.) and watercress (Nasturtium officinale R. Br.) planted in several areas in Damascus and its countryside in accordance with the permissible levels according to FAO 2019. The dried samples were prepared using the open wet oxidation method using concentrated nitric acid HNO₃ 65% and hydrogen peroxide H₂O₂ 50%, noting that the number of samples was (40) samples, finally they were analyzed using the graphite furnace atomic absorption spectrophotometer (GFAAS).The results were compared with the Food and Agriculture Organization standard (FAO) 2019, and the results were as follows: For cadmium: in watercress all samples exceeded the acceptable upper limit of 0.2mg/kg. In lettuce ten samples exceeded the acceptable upper limit of 0.2mg/kg. For lead: in watercress five samples exceeded the acceptable upper limit of 0.3mg /kg. In lettuce the results showed that the lead concentration in all studied samples didn’t exclude normal limits (0.3mg/kg). This study highlights the potential hazard for human health due to the uptake of high concentrations of heavy metals especially Cd and Pb by the studied vegetable crops. Vegetable consumers from these study areas are likely to be more susceptible to cadmium and lead toxicity as mentioned above. To avoid the harmful effects of the heavy metals accumulation on human health, consideration should be given to the constant examination to the edible parts of the vegetables grown in heavy metals contaminated soil.