Heavy metal content and health risk assessment of commonly patronized herbal medicinal preparations from the Kumasi metropolis of Ghana.

Purpose: To address the question of whether users of herbal products (HPs) are exposed to harmful contaminants, we evaluated six HPs mostly patronized in Kumasi for heavy metal contamination and assessed the health risk associated with their use. This study is one of the first safety evaluation studies on finished multiherbal products in the region.

Method: Three antimalarial, two antidiabetic and one antihypertensive HPs were selected after a mini-survey and coded randomly as HP A-F. The HPs were acid digested for quantitative analysis of heavy metals using Inductively Coupled Plasma Mass Spectrometer. Hg quantification was carried out using cold vapour atomic absorption spectroscopy.

Results: The cancer risk estimation values for the carcinogenic metals ranged between 1.54 × 10 to 3.73 × 10 and were all within acceptable limits. The non-cancer health risk evaluation revealed that, some of the products pose health risk to consumers. The estimated daily intake (EDI) for As in HPF was 2.48 × 10 mg/kg/day compared to the reference limit of 1.67 × 10 mg/kg/day. HPF also had high hazard index (HI) of 5.70 (HI >1) in children as compared to 1.68 (HI >1) in adults showing a 3.4 folds increase in the health risk among the former.

Conclusion: The six polyherbal products exhibited carcinogenic risk within acceptable limits. Although, the non-carcinogenic risk assessment of products HPA to HPE suggests safety, this can only be ascertained after further characterization of their health risks in detailed chronic toxicity studies. The high HI for product HPF suggests health risk for consumers of this product.