Insights into the accumulation and potential risks of metal(loid)s in Flos Sophorae Immaturus in a typical non-ferrous metal smelting region in the North China Plain

To investigate the accumulation and potential risks of metal(loid)s in Flos Sophorae Immaturus (FSI) in a typical non-ferrous metal smelting region, fifty pairs of soil and FSI samples were collected from Jiyuan City to determine the metal(loid)s contents and evaluate their potential health risks to local FSI consumers. Results showed that the average contents of Pb, Cd, and As in the soil samples were 309.07, 5.33, and 54.37 mg/kg, with 2%, 10%, 16%, and 72% of these soils were unpolluted, slightly, moderately, and heavily polluted, respectively. Meanwhile, the contents of Pb, Cd, and As in FSI ranged from 0.75 to 41.90 mg/kg, 0.04 to 0.79 mg/kg, and 0.35 to 15.80 mg/kg, and had average contents of 4.62, 0.18, and 1.89 mg/kg, respectively. Approximately 85.8% of metal(loid)s in FSI were accumulated from soil, and the proportion of As accumulated from soil was the highest (95%), followed by Pb (84%) and Cd (79%). In addition, soil organic matter and available phosphorus were the main factors influencing metal(loid)s accumulation in FSI. Health risk assessment revealed that the average and 95% percentile non-carcinogenic risk index (for Cd and As) and total carcinogenic risk were all higher than the reference value. The margin of exposure analysis for Pb further revealed that merely exposure to Pb via FSI can also pose adverse effects on the health of children. These results indicate that the metal(loid)s in FSI pose serious potential health risks to local consumers. • Long-term non-ferrous metal smelting resulted serious metal(loid)s pollution in soil • Metal(loid)s contents in almost all FSI exceeded the national standard of China • The metal(loid)s in FSI mainly originated from the contaminated soil • FSI posed serious health risk to local FSI consumers, and the major contributor was As