The aim of this study is to investigate the prevalence of addictive substance use among workers and employees in industrial workplaces across the country.



The study population comprises all workers and employees employed in industrial settings nationwide (workplaces with 10 or more employees). A total of 16,000 participants will be selected using a multistage cluster sampling method based on the workforce population of industrial centers in each province.



The sample of 16,000 participants will be selected through 609 workplaces, in accordance with a previous similar study conducted in 2014.



The workplaces will be categorized into three groups according to the vulnerability of the area (based on the findings of previous research and the criteria established by the expert panel): low-, medium-, and high-vulnerability. Within each workplace, participants will be randomly selected in proportion to the population of workers and employees and included in the study.



To select participants, a list of eligible individuals will first be prepared, and participants will then be selected using a random number table. Throughout the research process, informed consent will be obtained from all participants.



Data collection instruments will include questionnaires, urine sample testing, and interviews with informants. Data will be collected by trained interviewers. The collected data will be entered into SPSS software and analyzed using descriptive and inferential statistical methods.