Alipour Darvari H, Zare Mayvan H, Sharifi M. Evaluation of rate of radish proxidase activity and its relationship with heavy metals in soil. Journal of Science-Islamic Republic of Iran, 2009; 35(1): 37-43.
 Wang LK, Chen JP, Hung YT, Shammas NK. Heavy metals in the environment. New York: CRC Press, 2009: 123-4.
 Khalifeh Zadeh R. Survey of some habitat characteristics of medicinal species of Asteraceae family in Ilam. Proceeding of the 2th National Conference on Medicinal Plants and Sustainable Agriculture, 2014 Aug 23; Hamedan, Iran; 15. [in Persian]
 Asghari GR, Palizban AA, Toloo-e-Ghamari Z, Adeli F. Contamination of lead, mercury and cadmium in Iranian herbal medicine. Pharmaceutical Sciences
, 2008; 14(1): 1-8. [in Persian]
 World Health Organization (WHO). Quality Control Methods for Medicinal Plant Materials, Geneva, WHO; 1998.
 Jena V, Gupta S. Study of heavy metal distribution in medicinal plant basil. Journal of Environmental & Analytical Toxicology, 2012; 2(8): 1-3.
 Mozafarian VA. Recognition of medicinal and aromatic plants of Iran. Tehran: Farhang-e-Moaser Publication, 2012: 417-8. [in Persian]
 Selinus O. Essentials of medical geology: impacts of the natural environment on public health. New York: Academic Press, 2005: 316-9.
 Altmann P, Cunningham J, Dhanesha U, Ballard M, Thompson J. Marsh F
. Disturbance of cerebral function in people exposed to drinking water contaminated with aluminium sulphate: retrospective study of the Camelford water incident. British Medical Journal, 1999; 319: 807-11.
 Zeng XW, Ma LQ, Qiu RL, Tang YT. Effects of Zn on plant tolerance and non-protein thiol accumulation in Zn hyperaccumulator Arabis paniculata Franch. Environmental and Experimental Botany, 2011; 70(2-3): 227-32.
 Apau J, Acheampong A, Appiah JA, Ansong E. Levels and health risk assessment of heavy metals in tubers from markets in the Kumasi metropolis, Ghana. International Journal of Science and Technology, 2014; 3(9): 534-9.
 Zhu F, Wang X, Fan W. Assessment of potential health risk for arsenic and heavy metals in some herbal flowers and their infusions consumed in China. Environmental Monitoring and Assessment, 2013; 185: 3909-16.
 Khodadadi M, Malakoutian M, Khosravi R, Dori H. Survey of heavy metals (copper, chromium, cadmium and zinc) concentration in South Khorasan saffron]. Proceeding of the 16th National Congress on Environmental Health, 2013 Oct 1-3. Tabriz, Iran. p. 6. [in Persian]
 Mousavi Z, Ziarati P, Esmaeli Dehaghi M, Qomi M. Heavy metals (lead and cadmium) in some medicinal herbal products in Iranian market. Iranian Journal of Toxicology, 2014; 24: 1004-10.
 Ogunkunle CO. Root-shoot partitioning of copper, chromium and zinc in Lycopersicon esculentum and Amaranthus hybridus grown in cement-polluted soil. Environmental and Experimental Biology, 2013; 11: 131-6.
 Umar A, Adamu GA, Mohammad Y, Faruruwa MD, Garba S. Determination of heavy metals in some medicinal plants commonly used in kura local government area of kano state, Nigeria. Global Advanced Research Journal of Agricultural Science, 2014; 3(8): 256-8.
 Cheraghi M, Mosavinia SM, Lorestani B. Heavy metal contamination in soil and some medicinal plant species in Ahangaran lead-zinc mine, Iran. Journal of Advances in Environment Health Research, 2013; 1(1): 29-34.
 Ahmad T, Abdul Rasheed Naikodi M, Abdul Waheed M, Ahmad SG, Ayub Khan M, Yadav PK, Umar khan M. Determination of heavy metals in some Indian herbs used in Unani system of medicine by using atomic absorption spectroscopy. Journal of Advanced Pharmaceutical Research, 2013; 4(2): 52-5.
 Soylak M, Cihan Z, Yilmaz E. Evaluation of trace element contents of some herbal plants and spices retailed in Kayseri, Turkey. Environmental Monitoring and Assessment, 2012; 184(6): 3455-61.
 Haider S, Naithani V, Barthwal J, Kakkar P. Heavy metal contents in some therapeutically important medicinal plants. Bulletin of Environmental Contamination and Toxicology, 2004; 72(1): 119-27.
 World Health Organization (WHO). Guidelines for assessing quality of herbal medicines withreference to contaminants and residues. World Health Organization, Geneva,Switzerland, 2007.
 Shahbazi A, Soffianian AR, Mirghaffari N, Einghalaei MR. Contamination factor and comprehensive pollution index (A case study in Nahavand City). Environment and Development, 2012; 3(5): 31-8. [in Persian]
 Wyszkowska J, Boros E, Kucharski J. Effect of interactions between nickel and other heavy metals on the soil microbiological properties. Plant, Soil and Environment, 2007; 53(12): 544-52.
 Rahimi M, Farhadi R, Balashahri MS. Effects of heavy metals on the medicinal plant. International Journal of Agronomy and Plant Production, 2012; 3(4): 154-58.
 Kostic D, Mitic S, Zarubica A, Mitic M, Velickovic J, Randjelovic S. Content of trace metals in medicinal plants and their extracts. Hemijska Industrija, 2011; 65(2): 165-70.
 Baye H, Hymete A. Levels of heavy metals in common medicinal plants collected from environmentally different sites. Middle-East Journal of Scientific Research, 2013; 13(7): 938-43.
 Subramanian R, Gayathri S, Rathnavel C, Raj V. Analysis of mineral and heavy metals in some medicinal plants collected from local market. Asian Pacific Journal of Tropical Biomedicine, 2012; 2(1): 74-8.
 Kulhari A, Sheorayan A, Bajar S, Sarkar S, Chaudhury A, Kalia RK. Investigation of heavy metals in frequently utilized medicinal plants collected from environmentally diverse locations of north western India. Springerplus, 2013; 2: 676.
 Meenakshi N, Sarath Babu B, Pavan Kumar S. Analysis of the arsenic in commonly used medicinal plants. International Journal of Ayurveda and Pharma Research, 2014; 2(1): 77-83.
 Krejpcio Z, Krol E, Sionkowski S. Evaluation of heavy metals contents in spices and herbs available on the Polish market. Polish Journal of Environmental Studies, 2007; 16(1): 97-100.
 Okem A, Southway C, Stirk WA, Street RA, Finnie JF, Van Staden J. Heavy metal contamination in South African medicinal plants: A cause for concern. South African Journal of Botany, 2014; 93: 125-30.
 Sarpong K, Dartey E, Dapaah H. Assessing concentrations of hazardous metals in medicinal plants from four selected districts in Ashanti region of Ghana. International Journal of Medicinal Plant Research, 2012; 1(3): 12-9.
 Mahdiyeh Sh, Ghaderian SM, Karimi N. The effect of phosphorus absorption and accumulation of arsenic in two varieties (Triticum aestivum L.) wheat. Journal of Plant Production, 2012; 19(2): 105-21. [in Persian]
 Smith E, Naidu R, Alston AM. Chemistry of inorganic arsenic in soils: II. Effect of phosphorus, sodium and calcium on arsenic sorption. Journal of Environmental Quality, 2002; 31(2): 557-63.
 Nabiollahi K, Haidari A, Tomanian N, Savaghebi GhR. Relationship of soil characteristics in different geomorphicsurfaces with spatial variability of soil arsenic(Case study: Bijar, Kurdistan Province). Journal of Soil Management and sustainable, 2013; 3(2): 1-27. [in Persian]
 Mohammad MJ, Athamneh BM. Changes in soil fertility and plant uptake of nutrients and heavy metals in response to sewage sludge application to calcareous soils. Journal of Agronomy, 2004; 3(3): 229-36.