environmental and occupational exposure to nickel in iran: a systematic review

introduction: nickel (ni) is one of the toxic heavy metals that exposure to it has been connected with chronic respiratory complications such as asthma, chronic bronchitis, lung cancer and heart disease. in this research, original studies that investigated occupational or environmental exposure to nickel and  measured nickel levels in human tissues were reviewed. materials and methods: in this study articles were reviewed systematically.  national databases such as sid and magiran  as well as some international databases  including pubmed,  web of knowledge, science direct and google scholar were also searched; to extract studies conducted in iran; until august 19, 2016.  results: based on the results, industrial  professions such as welding and plating who dealt directly with nickel were at a higher risk of contamination. in overall, residents in large polluted cities or taking dental treatments, had more nickel concentrations in their body than others. conclusion: considering the high nickel contamination in some industrial workers, it seems necessary to do regular surveillance in these occupational groups and avoid unnecessary exposure to nickel as much as possible. also, safer dental material should be used in orthodontics.