Dietary exposure and health risk assessment of heavy metals in <i>hibiscus sabdariffa</i> calyces sold in Ghanaian markets

Hibiscus sabdariffa L. calyces are widely consumed in Ghana as sobolo beverage and as a pot herb, yet systematic heavy metal data and quantitative health risk assessments for market-sourced calyces in the Bono, Bono East, and Ahafo Regions are currently unavailable. This study quantified eight metals (Fe, Zn, Cu, Mn, As, Pb, Cd, Hg) in 15 composite samples from five markets using flame, graphite furnace, and cold vapor atomic absorption spectrophotometry. All mean concentrations fell below Codex Alimentarius and EU maximum permissible limits. Non-carcinogenic hazard indices were well below 1.0 for adults (HI = 0.132) and children (HI = 0.198), with arsenic as the dominant contributor (48.7% of child HI). Adult arsenic incremental lifetime cancer risk (ILCR) values ranged from 8.00 × 10−5 (Techiman) to 2.07 × 10−4 (Berekum), exceeding the USEPA upper acceptable bound of 10−4 under the conservative assumption of complete metal transfer into the beverage. Child ILCR values (1.03 × 10−5 to 2.66 × 10−5) remained within the acceptable range. In vitro bioaccessibility studies, multi-season surveillance, and population-specific consumption surveys are recommended.