The negative aspects of using medicinal plants: human health risks assessment of mycotoxins and toxic metal contamination

Medicinal plants (MPs) have been valued for their therapeutic properties and are crucial in traditional and modern medicine. However, contamination with hazardous substances such as mycotoxins and toxic THMs (THMs) poses significant safety concerns. This study quantified the levels of mycotoxins and THMs in ten commonly used MPs in Tehran markets, Iran, and assessed their carcinogenic and non-carcinogenic risks to ensure consumer safety. A total of 210 samples were analyzed. THMs, including arsenic (As), mercury (Hg), cadmium (Cd), and lead (Pb), were detected using atomic absorption spectrometry, while mycotoxins such as aflatoxins (B1, B2, G1, G2) and ochratoxin A (OTA) were measured using high-performance liquid chromatography. Risk assessments used Target Hazard Quotient (THQ), Hazard Index (HI), Incremental Lifetime Cancer Risk (ILCR), and Total Carcinogenic Risk (TCR) methodologies. Results revealed variability in contaminant levels (p < 0.05). While heavy metal concentrations were within safe limits, mycotoxin exposure posed non-carcinogenic risks for children, with a THQ exceeding the acceptable limit. Mycotoxin levels remained below carcinogenic thresholds. To mitigate risks, storing MPs in dry, low-humidity environments is recommended to prevent fungal growth and reduce mycotoxin contamination, emphasizing the need for stricter safety measures.