144 J Contemp Med Sci | Vol. 4, No. 3, Summer 2018: 144–147 Original Evaluation of salivary enzymes and oral lesions among gas station workers compared to nearby shopkeepers in Tehran Arghavan Tonkaboni, a Katayoun Sargaran, b Yalda Ahmadi, c Abdolreza Mohammadnia, d,e Reihaneh Eghbali-Zarch, f Majid Faridpoor, g and Ahmad Reza Shamshiri h a Department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. b Department of Community Oral Health, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. c International Campus, Tehran University of Medical Sciences, Tehran, Iran. d Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. e Department of Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. f Private Clinic, Tehran, Iran. g Private Laboratory, Tehran, Iran. h Research Center for Caries Prevention, Dentistry Research Institute, Department of Community Oral Health, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Correspondence to Katayoun Sargaran (email: k-sargeran@tums.ac.ir). (Submitted: 17 March 2018 – Revised version received: 03 April 2018 – Accepted: 14 May 2018 – Published online: 26 September 2018) Objective Studies on the association of air pollution and oral and dental health status are limited. This study was aimed to evaluate salivary enzymes and oral lesions among gas station workers compared to nearby shopkeepers, in relation to air pollution. Methods In this study, we compared the level of total antioxidant capacity, superoxide dismutase and glutathione peroxidase in the saliva and oral lesions between gas station workers and shopkeepers. Fifty-two participants including 26 gas station workers and 26 shopkeepers were evaluated. These participants had at least 1 year of working experience and worked for 5 days a week. The inclusion criteria for the two groups were as follows: Absence of systemic diseases, no history of using immunosuppressive medications or oral spray, no history of radiotherapy or chemotherapy, absence of xerostomia and age range of 20–60 years. Shopkeepers were recruited from the nearby shops (less than 1 km distance from the gas stations). Saliva samples were collected from all 52 participants and evaluated. Results The mean age was 33.08 ± 8.82 years for the gas station workers and 34.19 ± 12.28 years for the shopkeepers. The mean work experience was 8.38 ± 6.25 years and 8.38 ± 9.17 years for the gas station workers and shopkeepers, respectively. Level of salivary enzymes were not diferent between the two groups. No diference was observed about oral lesions among the two groups. Conclusion This study showed that no diference existed between gas station workers and nearby shopkeepers regarding salivary enzymes and the appearance of oral lesions. Further studies are required to assess the efect of environmental pollutants on the saliva. Keywords Total antioxidant capacity, superoxide dismutase, glutathione peroxidase, oral lesions, air pollution. Introduction Air pollution can have hazardous efects on human health. It negatively afects the nervous, respiratory, cardiovascular, renal, gastrointestinal system, pregnancy and cell function. According to recent statistics, about 3 million people lose their life annually due to air pollution, 90% of which, live in devel- oped countries. 1 Environmental and occupational factors play an impor- tant role in health status of individuals. Occupational and environmental exposures may be related to disease symptoms. Environmental exposures in a specifc patient may necessitate some interventions to prevent future side efects and minimize the risk of occupational diseases. 2 Environmental lead con- tamination is a global health dilemma. Lead is one of the most important environmental pollutants. 3–5 It is mainly produced by the exhaustion of fossil fuels. Extensive use of lead in indus- tries has resulted in air pollution and water and food contam- ination. Tus, the serum and salivary level of lead and its accumulation in diferent tissues in the human body have sig- nifcantly increased in the recent years. 6 As mentioned earlier, long-term deposition of lead in hard tissues is much higher than that in sof tissues. 7 Heavy metals such as lead and cad- mium have no physiological activity and are toxic even in low concentrations. 8 Some studies have shown that dental hard tissue can uptake and store lead and other heavy metals from the environment. Dental hard tissue can become carious or may undergo abrasion, erosion or attrition. In the recent years, many studies have evaluated the efect of heavy metals on dental caries. Moreover, some authors believe that acidic vapors can cause non-carious dental lesions. Extensive dental problems can compromise the quality of mastication, mental power and work quality and result in gastrointestinal and other systemic problems. Tey can also cause serious economic and social problems. 9 Antioxidants play an important role in inhibition of syn- thesis of reactive oxygen species such as O 2 , H 2 O 2 and alkyl peroxyl and repairing the damage caused by their activity. 10 Te oral cavity is the main route of entry of foods, drinks and inhalation substances. Saliva is the frst protective barrier against environmental factors. Saliva possesses many protec- tive mechanisms such as secretory immunoglobulin A, enzy- matic-protein defense system, histatins, lysozyme and lactoferrin. Te salivary antioxidant system is another defense mechanism of the saliva that includes uric acid, superoxide dismutase (SOD), total antioxidant capacity (TAC) and glu- tathione peroxidase (GPX). 10 Antioxidants comprise a great ISSN 2413-0516