Risk assessment of genotoxic and carcinogenic alkenylbenzenes in botanical containing products present on the Chinese market

In the present study, a risk assessment of plant food supplements (PFS), traditional Chinese medicines (TCM) and herbal teas containing alkenylbenzenes was performed using the Margin of Exposure (MOE) approach. The levels of alkenylbenzenes in botanical preparations collected on the Chinese market were quantified and the combined estimated daily intake (EDI) was determined using dose additivity. The combined EDI values obtained assuming equal potency of all alkenylbenzenes detected in the PFS, TCM and herbal teas were 0.3 to 14.3, 0.05 to 539.4 and 0.04 to 42.5 μg/kg bw/day, respectively. Calculating combined EDI values taking into account the toxic equivalency (TEQ) approach, the values for PFS, TCM and herbal teas were 0.3 to 7.7, 0.05 to 278.0 and 0.02 to 16.5 μg estragole equivalents/kg bw/day, respectively. The MOE values resulting from consumption of these PFS, TCM and one cup of herbal tea per day during life-time were generally lower than 10 000, suggesting a potential priority for risk management. For short-term exposure such as two weeks consumption, applying Haber's rule, only one TCM 6 (四神丸) still had an MOE value below 10 000. It is concluded that selected consumption of Chinese botanical preparations raise a concern because of exposure to alkenylbenzenes, especially when exposure is for longer periods of time.