Determination of Heavy Metals Concentration in Traditional Herbs Commonly Consumed in the United Arab Emirates

Herbs are extensively consumed in the United Arab Emirates for their flavoring and medicinal properties. This study aimed at determining the concentration of heavy metals in selected traditional herbs consumed in the United Arab Emirates (UAE). A total of 81 samples of seven herbs, parsley (Petroselinum crispum), basil (Ocimum basilicum), sage (Salvia officinalis), oregano (Origanum vulgare), mint (Mentha spicata), thyme (Thymus vulgaris), and chamomile (Matricaria chamomilla), were purchased from the local market in Dubai and analyzed for their cadmium, lead, copper, iron, and zinc contents. Microwave-assisted digestion was applied for the dissolution of the samples and heavy metals concentration was determined using Atomic Absorption Spectrometry (AAS). Metals were found to be present in varied concentrations in the herb samples. The concentration ranges were found as follows: less than 0.1-1.11 mg·kg(-1) for cadmium, less than 1.0-23.52 mg·kg(-1) for lead, 1.44-156.24 mg·kg(-1) for copper, 12.65-146.67 mg·kg(-1) for zinc, and 81.25-1101.22 mg·kg(-1) for iron. The findings of the study suggest that most of the analyzed herbs contained unsafe levels of heavy metals that exceeded the World Health Organization (WHO) permissible limits (PL).