Probabilistic risk assessment of heavy metal(loid)s in traditional Chinese medicinal materials and their decoctions:...

The global use of Traditional Chinese medicines (TCMs) is increasing, raising concerns regarding contamination by heavy metal(loid)s. Although decoction is a common method of administration, limited research has investigated the transfer of heavy metal(loid)s from medicinal materials to decoctions, particularly for compound formulas, or has performed probabilistic health risk assessments. In this study, six common TCMs (Persicae Semen, Carthami Flos, Rehmanniae Radix, Angelicae Sinensis Radix, Chuanxiong Rhizoma, and Paeoniae Radix Alba) were collected from various regions across China. Concentrations of Pb, Cd, Hg, Cu, and As were analyzed in the raw medicinal materials, their single-herb decoctions, and the corresponding compound formula decoction (Taohong Siwu Decoction). The results showed that Hg in some batches exceeded safety limits. Transfer rates of heavy metal(loid)s from medicinal materials to the decoctions varied considerably among elements, ranging from 8.67 % to 65.56 %. Compared with single-herb decoctions, the dissolution of Cu, Pb, and Cd increased in the compound decoction, whereas that Hg decreased. Probabilistic risk assessment indicated no significant non-carcinogenic risk; however, Paeoniae Radix Alba showed a 1.12 % probability of carcinogenic risk above the 1 × 10^-4 threshold. Importantly, both heavy metal(loid) levels and the associated health risks were substantially lower in the decoctions than in the raw materials.