Determination of toxic element contamination in thyme and thyme-containing products consumed in Lebanon

Abstract

Thyme herbs constitute a major part of the Mediterranean diet and are gaining worldwide popularity. However, their chemical contamination with toxic metals may put consumers at a health risk. Thus, the aim of this study was to assess the incidence of Arsenic (As), Cadmium (Cd), Lead (Pb) and Mercury (Hg) in thyme herbs and thyme-containing products. For this, 180 samples pooled into 36 composite samples of the most consumed types of thyme-containing products and thyme herbs were collected twice at three-month intervals. Samples were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and the four heavy metals were detected in all the samples. Eleven percent, 22%, and 97% of samples had unacceptable levels of As, Hg and Pb respectively according to the international standards set by Codex Alimentarius and all the samples had acceptable limits of Cd. The dried thyme herbs were more contaminated with the four toxic elements than the thyme-containing products including cereal-based products, dairy products, herbal thyme tea and thyme salad. This study highlighted the importance of monitoring and enforcing regulatory actions related to the contamination of the food chain with chemical contaminants such as toxic elements to protect the health of consumers.