Uptake of Cd, Pb, and Ni by Origanum syriacum produced in Lebanon
Trace metals are found naturally in soil. However, the increase in industrial and agricultural polluting activities has increased trace metal contamination and raised high concerns in the public health sector. The study was conducted on Origanum syriacum, one of the most consumed herbs in the Middle East, and was divided into three parts. (1) Pot experiment: to study the effect of Cd, Pb, or Ni levels in soil on their uptake by O. syriacum. (2) Field samples: collected from major agricultural regions in Lebanon to analyze Cd, Pb, and Ni concentrations in soil and leaves. (3) Sale outlets samples: to measure the levels of Cd, Pb, and Ni in O. syriacum tissues in the market. Results showed that there was a positive correlation between levels of Cd, Pb, and Ni in soil and those in O. syriacum tissues. None of the field samples contained Pb or Ni that exceeded the maximum allowable limits (MAL). Three samples collected from heavily poultry-manured soil contained Cd higher than the MAL. Samples collected from sale outlets did not exceed the MAL for Ni but two exceeded the MAL for Cd and one for Pb. Trace metal contamination is not a major concern in O. syriacum produced in Lebanon. Only one mixture sample from a sale outlet was higher in Pb than the MAL and three samples from heavily manured fields exceeded the MAL for Cd.
KeywordsZaatar Thyme Trace metal Heavy metal Environmental pollutants
American Herbal Products Association
Agency for Toxic Substances and Disease Registry
American University of Beirut
European Food Safety Authority
Environmental Protection Agency
Food and Agricultural Organization
Food and Drug Administration
Joint Expert Committee for Food Additives
Maximum allowable limits
Middle East and North Africa
World Health Organization
Thanks go to Ms. Rania Shatila, Laboratory Manager, and the KAS CRSL staff for their assistance in using the atomic absorption spectrophotometer (AAS) for elemental analysis.
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