Unpleasant odor caused by sewage disposal in rivers, in areas where proper and adequate arrangements have not been made for wastewater treatment, is one of the obvious indicators of air pollution affecting a large population of people living in these areas. This study aimed at investigating the effects of odor-producing gases in the Gohar Rood river in Rasht, as one of the most polluted rivers in northern Iran, on human communities. In this research, the descriptive-analytical method has been used as a comparative analysis based on hierarchical weighting. The statistical population in the communities near and far from this river was 420 and 115 people, respectively. In order to analyze the studied variables, SPSS software, and statistical methods of independent t-test and Levene test were used. The results of a comparative study of the effects of unpleasant odor in communities near and far from this river using t-test of two independent groups and Levene test indicated that clinical symptoms (33.19; 50.86), anxiety symptoms and sleep disturbance (11.89; 17.12), social dysfunction (15.02; 23.13) and depressive symptoms (5.52; 7.16) of communities exposed to the unpleasant smell of this river were significantly higher than other communities (p <0.05). Therefore, people exposed to the unpleasant odor of Gohar Rood river were more dissatisfied with the living conditions in their surroundings and they had a worse quality of life. Manuscript profile