Chromium Contamination and Health Risk Assessment of Soil and Agricultural Products in a Rural Area in Southern China.

With the rapid development of industry, chromium (Cr) pollutants accumulate constantly in the soil, causing severe soil Cr pollution problems. Farmland Cr pollution hurts the safety of agricultural production and indirectly affects human health and safety. However, the current situation of Cr pollution in farmland soil and crops has not been detailed enough. In this study, the evaluation of Cr potential risk in soil-crop systems was conducted in a rural area that was affected by industry and historic sewage irrigation. Ten different crops and rhizosphere soils were sampled from four fields. The results showed that Cr contents in farmland soil exceeded the national standard threshold in China (>21.85%), and the Cr content in edible parts of some agricultural products exceeded that too. According to the PCA and relation analysis, the Cr accumulation in edible parts showed a significant correlation with soil Cr contents and available potassium contents. Except for water spinach, the target hazard quotient (THQ) of the other crops was lower than 1.0 but the carcinogenic health risks all exceeded the limits. The carcinogenic risks (CR) of different types of crops are food crops > legume crops > leafy vegetable crops and root-tuber crops. A comprehensive assessment revealed that planting water spinach in this area had the highest potential risk of Cr pollution. This study provided a scientific and reliable approach by integrating soil environmental quality and agricultural product security, which helps evaluate the potential risk of Cr in arable land more efficiently and lays technical guidelines for local agricultural production safety.

The effects and health risk assessment of cauliflower co-cropping with Sedum alfredii in cadmium contaminated vegetable field.

Phytoremediation coupled with co-cropping is assumed to be good for safety utilization and remediation of heavy metal contaminated farmland, which can ensure farmers' income without increasing health risks for human. In this study, the effects on plant cadmium (Cd) accumulation and health risk of consuming the vegetable plant were compared between monoculture and co-cropping of cauliflower (Brassica oleracea) with two ecotypes of Sedum alfredii in a moderately (0.82 mg kg-1) Cd contaminated greenhouse vegetable field. The results showed that co-cropping with S. alfredii raised Cd concentration in edible part of cauliflower with slightly growth promotion. The health risk of consuming cauliflower to different groups of people have been evaluated by calculating Hazard Quotient (HQ) and all HQ value were less than 1.0, which indicated that eating co-cropped cauliflower would not cause health risks to adults and children. Besides, the Cd concentration of hyperaccumulating ecotype (HE) of S. alfredii was 27.3 mg kg-1 in monoculture and it increased to 51.2 mg kg-1 after co-cropping with cauliflower, suggesting that the co-cropping system promoted HE Cd absorption capacity. Therefore, the "Phytoextraction Coupled with Agro-safe-production" (PCA) model of cauliflower and HE can serve as an alternative sustainable strategy in the Cd moderate polluted greenhouse.