Health Scope. 2018 August; 7(3):e12340. Published online 2018 August 20. doi: 10.5812/jhealthscope.12340. Research Article Health Risk Assessment of Heavy Metals in Vegetables in an Endemic Esophageal Cancer Region in Iran Ali Zafarzadeh 1, * , Hadi Rahimzadeh 1 and Amir Hossein Mahvi 2 1 Department of Environmental Health Engineering, Environmental Health Research Center, Faculty of Health, Golestan University of Medical Sciences, Gorgan, Iran 2 Tehran University of Medical Sciences, Environmental Health, Center for Solid Waste Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran * Corresponding author: Department of Environmental Health Engineering, Environmental Health Research Center, Faculty of Health, Golestan University of Medical Sciences, Gorgan, Iran. Tel: +98-9113770889, Email: alizafarzadeh45@gmail.com Received 2017 April 30; Accepted 2017 July 06. Abstract Background: Nowadays, the heavy metals pollution is increasing and the accumulation of these metals in food has posed adverse effects on humans such as inducing various kinds of cancer and non-cancer diseases. The Northeast of Iran, especially Torkman Sahra, has the maximum number of patients with esophageal cancer. Objectives: We investigated the levels of four heavy metals (Zn, Cd, Pb, and Cu) in cucumber and tomato samples in Golestan province, an endemic esophageal cancer region. We evaluated the levels and potential health risks of heavy metals in vegetable samples of Northeastern Iran. Methods: The heavy metal content of the samples was determined by polarography methods. All sample preparation and digestion procedures were carried out according to the Standard Methods for the Examination of Water and Wastewater, 20th Edition. Results: The results showed that Cd and Pb concentrations in cucumber and tomato were estimated to be respectively 2.4 to 14.4 and 1.6 to 7 folds higher whereas Zn and Cu levels were lower than the maximum permissible limit for vegetables. The amounts of Pb intake through the consumption of these vegetables were determined more than the provisional tolerable daily intake. The total non-cancer and cancer risk results indicated that the investigated region was relatively unsuitable for growing the vegetables in the view of the risk of the elevated intakes of heavy metals adversely affecting food safety for consumers. Pb was the heavy metal posing non-cancer risks while Cd caused the greatest cancer risk. Conclusions: It was concluded that due to the toxic effects of cadmium and lead, we should be more serious to reduce pollution levels in this region. Keywords: Risk Assessment, Heavy Metals, Cancer, Vegetables, Iran 1. Background As human beings, we are constantly exposed to dif- ferent toxic substances in our surrounding environment, which may lead to complex diseases such as cancer, car- diovascular, and respiratory diseases (1). Food contamina- tion and presence of hazardous substances such as heavy metals and chemicals in foodstuff have become inevitable problems during the past few years (2). The accumulation of heavy metals in certain tissues of living organisms can have toxic effects that may lead to several disorders (3, 4). Some elements like lead, cadmium, mercury, and arsenic are non-essential and toxic to the body even at low concen- trations while others like copper and zinc are necessary for humans. Nevertheless, even the elements that were men- tioned can cause harm and have toxic effects when their intake exceeds certain levels (5). These heavy metals compete with essential elements due to their chemical similarities and their interaction with several divalent transporters may affect various phys- iologic functions (6). They also have toxic effects on vari- ous systems of the body including cardiovascular, neural, hematopoietic, immunological, and gastrointestinal sys- tems, as well as a possible role in kidney dysfunction, ane- mia, liver toxicity, cancer, and Alzheimer’s disease (6, 7). Some heavy metals such as manganese (Mn), cobalt (Co), molybdenum (Mo), Cu, and Zinc as micronutrients can promote the growth of animals and human beings when present in very small amounts while others such as Cadmium, Arsenic, and Chromium act as carcinogens. Moreover, Hg and Pb are related to the development of anomalies in children (8). Hartwig reported that the long- term intake of Cd caused renal, prostate, and ovarian can- Copyright © 2018, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited