Introduction Today, hookah use is a growing problem throughout the world, especially in the countries of the Eastern Mediterranean, including the Arab countries, Turkey, and Iran (1-3). While most recent studies, policies, and efforts have focused on cigarette smoking, hookah use is increasing, particularly in developing regions (Asia, India, and the Eastern Mediterranean), and has received little attention (4, 5). There has been a significant increase in hookah use according to the results of a study conducted in one of the Arab countries, indicating that 25% of male students and 5% of female students used hookah (5). In recent years, the popularity of hookah has increased among young people in the Middle East, the United States, Canada, France, Russia, the United Kingdom, and Australia (6). The most important factors influencing the increase in hookah smoking are social acceptance, lack of awareness about its health effects, and lack of consistency in prevention programs. Many people believe that hookah smoke is somewhat purified and less dangerous due to passing through water and this misconception has increased the use of hookah in friendly gatherings (7, 8); however, in most cases, hookah use is one of the preventable causes of diseases and deaths due to heart diseases and cancer. Studies have shown that a single hookah smoking session could be associated with endothelial dysfunction, even in young people without cardiovascular disorders or other risk factors. The results of a study showed that there are several toxic substances in hookah smoke, including nicotine (9-11), carbon monoxide (9, 12), carcinogenic polycyclic Relationship between Exposure to Hookah Smoke and Lung Capacity of Hookah Cafe Employees Vali Alipour 1 ID , Hadi Eshaghi 2* ID , Leila Rezaei 3 , Amin Ghanbarnejad 4 , Zahra Hosseini 1 , Hamid Reza Ghaffari 1 , Somayyeh Dehghani 4 1 Tobacco and Health Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran 2 Department of Occupational Medicine, School of Medicine, Shahid Mohammadi Hospital, Hormozgan University of Medical Sciences, Bandar Abbas, Iran 3 Department of Environmental Sciences, Qeshm Branch, Islamic Azad University, Qeshm, Iran 4 Social Determinants of Health Promotion Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran © 2022 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: The aim of the present study was to investigate the effect of exposure to hookah smoke on the respiratory capacity of employees working in hookah cafes in Bandar Abbas. Methods: A total of 75 employees of hookah cafes and 64 people in the control group were the target population. Participants without a history of smoking, diabetes, and hypertension were included in the study. First, the height and weight of subjects were measured and then a respiratory test was performed by an occupational medicine specialist. At the same time, a checklist was completed, which contained demographic characteristics, history of working in hookah cafes, pulmonary diseases, hypertension, smoking, exercising, and a second job. Results: The mean age of the case and control groups was found to be 31.41 and 30.73 years, respectively. The mean values of the indices in the case and the control groups were as follows: forced expiratory volume (FEV1): 84.4% and 89.9%, forced vital capacity (FVC): 91.5% and 91.1%, forced expiratory flow 25-75 (FEF25-75): 78.7% and 75.9%, and peak expiratory flow (PEF): 87.2% and 95.2%, respectively. A significant relationship was found between exposure to hookah smoke and the lung capacity of employees working in hookah cafes (P < 0.001). Conclusion: Based on the findings of the study and in order to reduce passive exposure to hookah smoke and its negative consequences, officials should review and apply strict rules on hookah use and monitor and control the air quality inside hookah cafes. Keywords: Waterpipe, Hookah, Smoke, Employee, Lung capacity *Correspondence to Hadi Eshaghi, Email: hadi.eshaghi@hums. ac.ir Received: June 19, 2022, Accepted: August 27, 2022, ePublished: September 25, 2022 Open Access Scan to access more free content Tobacco and Health Original Article 10.34172/thj.2022.20 Tob Health. 2022; 1(3):127-131 doi