三七及种植土壤重金属污染特征与风险评价

以主产地云南省文山州三七及其种植土壤为研究对象，测定土壤和三七地上和地下部重金属镉（Cd）、砷（As）、铅（Pb）含量，揭示三七对重金属的吸收转运特征，通过分析重金属日摄入量（ADI）和靶标危害商数（THQ），评估三七中Cd、As、Pb的食品安全风险和人体健康风险.结果表明：种植土壤Cd、As含量为0.07~4.1和13.9~310mg/kg，超标率为63.2%和79%，Pb未超标；综合污染指数P>3，均值3.52，表明达重度污染等级；Cd、As单因子污染指数P_Cd/As>1的土壤样品占比为63.2%和84.2%，表明土壤Cd、As达轻度污染等级.三七地上和地下部Cd、As、Pb含量分别为0.05~0.69、0.07~0.73，0.25~1.06、0.09~1.73和0.12~1.13、0.07~0.66mg/kgdw，Cd超标率为26.3%~36.8%，As、Pb无超标，表明三七易吸收Cd且存在超标现象，需重点关注.三七Cd含量与土壤Cd含量呈极显著正相关（p<0.01），As、Pb表现为负相关，生物浓缩因子BCF_Cd=0.03~3.5，BCF_As和BCF_Pb均<1，进一步表明三七对Cd具有较强的富集能力；转运系数表现为：TF_Pb（3.53）>TF_As（2.32）>TF_Cd（0.59），表明三七易将吸收的Cd储存于主要食用部位地下部（主根），其食品安全风险和人体健康风险值得关注.三七Cd、As、Pb每日摄入量均值分别为0.0026~0.0035、0.0043~0.0066和0.0026~0.0059mg/d，每日摄入量占每日允许摄入量ADI标准限值的百分比为3.3%~4.7%、4.3%~5.8%和1.2%~2.7%，表明三七中Cd、As具有较高的食品安全风险（ADI>1%）.三七Cd、As、Pb靶标危害商数THQ>1的占比分别为42.1%~68.4%、84.2%~100%和0~31.6%，表明长期食用三七摄入Cd、As具有潜在人体健康风险.

Heavy metals pollution characteristic in Panax notoginseng and planting soil and the associated risk assessment

Panax notoginseng (P. notoginseng) and its growing soil from the main producing area Wenshan, Yunnan Province, were sampled and analyzed. The uptake and accumulation characteristics of Cd, As, and Pb were analyzed by determining their concentrations in soils and the aboveground and underground parts of P. notoginseng. The food safety risk and human health risk of Cd, As, and Pb in P. notoginseng were evaluated by analyzing their daily intake (ADI) and target hazard quotient (THQ). The results showed that. Cd and As concentrations in soils were 0.07~4.1 and 13.9~310 mg/kg, with standard-exceeding ratios being 63.2% and 79%, while Pb was within the standard values. The comprehensive pollution index P was >3, with an average value of 3.52, indicating that soil pollution reaches heavy pollution level. The proportion of soil samples with single factor pollution index P_Cd and P_As>1were 63.2% and 84.2%, indicating that soil Cd and As are at light pollution level. Cd, As, and Pb concentrations in P. notoginseng aboveground and underground parts were 0.05~0.69, 0.07~0.73; 0.25~1.06, 0.09~1.73; and 0.12~1.13, 0.07~0.66mg/kg dw, respectively. The standard-exceeding ratio of Cd was 26.3%~36.8% while As and Pb were within the standards, indicating P. notoginseng prefers to uptake Cd, thereby should be paid more attention. Cd concentrations in P. notoginseng and soil were significantly positively correlated (p<0.01), while for As and Pb were negatively correlated. Bioconcentration factor BCF_Cd was 0.03~3.5, while BCF_As and BCF_Pb were <1, which further indicated that P. notoginseng has a strong uptake ability for Cd. Translocation factor was in the order of TF_Pb (3.53)>TF_As (2.32)>TF_Cd (0.59), indicating that P. notoginseng prefers to accumulate Cd in the underground edible part, thus its food safety risk and human health risk deserve attention. Cd, As, and Pb daily intake indexes (ADI) of P. notoginseng were 0.0026~0.0035, 0.0043~0.0066, and 0.0026~0.0059mg/d, and the mean ADI percentages were 3.3%~4.7%, 4.3%~5.8%, and 1.2%~2.7%, indicating that Cd and As in P. notoginseng has high food safety risk (ADI>1%). The proportions of target hazard quotients THQ>1of Cd, As and Pb were 42.1%~68.4%, 84.2%~100%, and 0~31.6%, indicating that intaking Cd and As via long-term ingestion of P. notoginseng has potential human health risks.