m rezazadeh azari safety promotion and injury prevention research center and school of public health, shahid beheshti university of medical sciences, tehran z naghavi konjin school of public health, alborz university of medical sciences, karaj f zayeri department of biostatistics, school of paramedical sciences, shahid beheshti university of medical sciences, tehran s salehpour national research institute of tuberculosis and lung disease, shahid beheshti university of medical sciences, tehran md seyedi national iranian oil production and distribution company, industrial health department, tehran