ORIGINAL PAPER Pb in medicinal plants from Jordan Ahmed Alomary • Eshraq El Jamal • Idrees Al-Momani • Abdulrahman Attiyat • Safwan Obeidat Received: 22 April 2012 / Accepted: 20 July 2012 Ó Springer-Verlag 2012 Abstract This is the first report on Pb in medicinal herbs from Jordan. Medicinal herbs may present a health risk due to the presence of toxic metals. Seventy-nine dry medicinal plant samples were collected from herbalist shops in Jor- dan. The plants were digested with acids and analyzed for total Pb concentration using atomic absorption spectrom- etry. Mean Pb concentration was 15.9 lg/g on a dry weight basis. Our results show that Pb concentrations in Jordan medicinal plants are higher than published data in other countries. The highest level of 33.4 lg Pb/g was deter- mined in Inula viscosa, and the lowest level of 3.0 lg Pb/g was found in Nigella sativa. Calculated daily intakes of Pb of most analyzed herbs were high; most of them are higher than recommended values by the world health organization (WHO). Fortunately, the herbs that contain the highest Pb levels are the less commonly used medicinal herbs in Jordan. The mean Pb levels in the most commonly, com- monly and less commonly used herbs in Jordan are 13.9, 13.1 and 16.9 lg Pb/g, respectively. The average dietary intake of Pb through a mixture of these medicinal herbs consumption, assuming 5.0 g herbs is consumed daily, is 79.5 lg Pb/day, which is higher than the maximum daily limit allowed by WHO. We conclude that most of the medicinal plants consumed in Jordan contain significant amount of Pb, and therefore, people of Jordan should not consume large amounts of these herbs. Keywords Lead Á Acid digestion Á Medicinal plants Á Jordan Á AAS Introduction There is a growing demand for herbal medicine worldwide to meet the primary healthcare needs (Abu-Irmaileh and Afifi 2000; Pei 2001; Hamilton 2004). In developing countries, medicinal plants are easily found in local markets and sold without regulations. One hundred and fifty medicinal plant species are present in the Jordanian market (Abu-Irmaileh and Afifi 2003). These herbs were categorized by the Jor- danian herbalists as most commonly used, commonly used and less commonly used herbs (Afifi and Abu-Irmaileh 2000; Abu-Irmaileh and Afifi 2003). The most commonly used herbs are frequently used in tea and added frequently to food to give a good taste, whereas the less commonly used herbs are not usually used in tea or food. Medicinal herbs may be subjected to several types of contaminants such as microbes, insects, environmental chemicals and metal(loid)s (Abou-Arab et al. 1999; Abou- Arab and Abou Donia 2000; Chizzola et al. 2003; Smol- inske 2005). Many medicinal herbs and their mixtures can present a health risk due to the presence of toxic elements such as Pb, Cd, Hg and Cr; monitoring metals such as Pb in medicinal plants is considered as part of the quality control in the pharmaceutical industry (Chizzola et al. 2003). In addition, medicinal herbs may be easily contaminated during growing and processing. An important link in the transfer of some trace elements from soil to man is plants. Contamination of medicinal herbs with toxic elements can be estimated from surveys of herbs found in the market; for example, in the analysis of herbal products by California Food and Drug Administration (FDA), 24 of 251 products contained lead, in amounts ranging from 10 to 319 lg/g (Smolinske 2005). Lead occurs naturally in the environment. However, most of the high levels found throughout the environment A. Alomary (&) Á E. E. Jamal Á I. Al-Momani Á A. Attiyat Á S. Obeidat Yarmouk University, Irbid, Jordan e-mail: ahmedalomary1000@hotmail.com 123 Environ Chem Lett DOI 10.1007/s10311-012-0378-y