Differences in enrichment and soil safety thresholds of five vegetables grown in Cd-polluted soil of Chengdu Plain，China

By analyzing the differences in the enrichment capacity of Cd in several vegetables, the health risks posed by the edible parts of vegetables to human beings under different levels of soil Cd contamination in Chengdu pain were assessed, and the corresponding vegetable-soil Cd safety thresholds were established. We compared and analyzed the enrichment capacity of various vegetable varieties for Cd under various soil Cd contamination levels (0.13, 0.20, 0.32, 0.73, and 1.02 mg kg ^− 1 ) using five commonly grown vegetable varieties ( Lactuca sativa var longifoliaf . Lam(Romaine lettuce), Lactuca sativa var. ramosa Hort. (Cos lettuce), Brassica campestrisL.ssp.chinensis Makino var. communis Tsen et Lee(pakchoi), Raphanus sativus L. (oleander), and Lactuca sativa var. angustata (lettuce)) as research targets. We also assessed potential issues with food safety and health risks associated with Cd in vegetables using the Hazard Quotient ( HQi ) criterion for human health risk assessment. The possible hazards to food safety and health from lead (Cd) in vegetables were assessed using the HQi criteria, and the Cd safety levels for vegetable soil were definited. Results of the assessment of the health risk of food intake indicated that lettuce was more likely to pose a risk than the other four vegetables and that children were more likely to pose a risk than adults with the same intake of vegetables. The enrichment capacity of soil Cd in lettuce was found to be significantly higher than that of Romaine lettuce, Cos lettuce, pakchoi, and oleander(n = 5, P < 0.05). For the Chengdu Plain, the soil Cd safety thresholds were 0.32 mg kg ^− 1 for Romaine lettuce, Cos lettuce, pakchoi and oleander, and 0.20 mg kg ^− 1 for lettuce. These findings offer a scientific foundation for ensuring the quality and safety of vegetables, improving the environmental quality standards of Cd in farmland soils, and attaining the safe utilization of contaminated farmland.