Risk evaluation of heavy metal migration behavior during ginseng growth

Ginseng is one of the most valuable herbal remedies and functional foods in the world, which owing global market estimated at 6 billion dollars amid the COVID-19 crisis, and the global market reach up to 12.9 billion dollars in 2027. It is a perennial herb with ginsenosides as its main active components, and potentially at risk for heavy metal contamination. However, the impact of heavy metal migration on the contents and variety of ginsenosides in different parts of ginseng remains unclear. Nine ginsenosides (Re, Rb1, Rc, Rg1, Rb3, Rd, Rb2, Rf and Rg2) and eight heavy metals (Cu, Zn, Ni, Cr, Pb, As, Cd and Hg) were detected. The results demonstrated that the accumulation of ginsenosides varies annually aged 3–6 years with the highest content in fibrous roots, followed by lateral roots and taproots. Concurrently, the average concentrations of heavy metals also increased yearly, with Zn having the highest residual concentration (14.61–53.75 mg/kg) followed by Cu (8.50–12.49 mg/kg). Zn was found to play a crucial role in ginsenoside synthesis, significantly correlating with several ginsenosides, while other metals such as Cu, Cd, and Hg had minimal to negative impacts. Nonetheless, we also found that the accumulation of Ni, Cr, Pb, and As may lead to a reduction in the content of ginsenoside Rg1. Additionally, the dietary risk assessment of heavy metal exposure after consuming ginseng showed that the health risk index for children was generally higher than for adults, highlighting the need to pay special attention to the potential exposure risk for children. These findings underscore the importance of monitoring and controlling heavy metal contamination in ginseng cultivation to ensure safety and optimize medicinal value. • Accumulation of ginsenosides rank as fibrous roots > lateral roots > taproots. • More active substances accumulate in the ginseng roots with cultivation age. • The highest residual concentration in ginseng is Zn, follows by Cu among eight heavy metals. • Zn appears significant positive correlations with dominated ginsenosides Re and Rd. • Dietary risk of ginseng consumption for children is significantly higher than for adults.