INTRODUCTION The air around us contains aromatic compounds originated from citizens’ daily activity in residential, trade and industrial areas which create the modern societies. Daily exposure to odor pollution is a part of modern life 1 . Odor is generally defined as the feeling caused by chemical compounds which are called odorants while being perceived by stimulating the sensory receptors of smell 2 . Odor is a combination of one or more volatile chemical compound that humans perceive by the sense of olfaction 3 . According to the EPA definition odorous compounds are pollutants while annoying the human or affect his health or welfare 4 . Current World Environment Vol. 7(2), 191-200 (2012) Assessment of Odor Annoying Impacts on Trade and Serving Centers Close to a Vegetable Oil Manufacturing Plant MOHAMMAD REZA MONAZZAM 1 *, M. AVISHAN 2 , M.ASGHARI 1 and M. BOUBEHREJH 2 1 Department of Occupational Hygiene, School of Public Health and Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran. 2 Air Pollution Bureau, Iran Department of the Environment, Tehran, Iran. (Received: July 12, 2012; Accepted: September 17, 2012) ABSTRACT The environmental odor pollution emitted from different sources has undesirable impacts on communities’ health and welfare in a way that caused increasing public worry and complains around the world. Pars Vegetable Oil Processing Plant (PVOPP) is located near populated residential areas in Tehran; hence, many people are exposed to the plant process annoying odor daily. In order to assess the odor annoying impacts on its nearby business centers a social survey has been applied. In the field area 200 questionnaires were intended to be filled out but 180 of them have been completed by the respondents (90%). Almost 98% of the respondents have perceived the odor from the outdoor source in their working places which is known as the industry by 78% of them. Among the respondents 42% of them have defined the odor as intolerable. Considering that industry has been recognized as the most important external parameter which affect the quality of working environments, the impact of this industrial unit on decreasing the quality level of working conditions is more obvious. The duration of presence in the working place and record of service are related to disorders in working activity and emotion and thus confirm the odor pollution impacts on the employees’ efficiency. Key words: Odor pollution, questionnaire, annoyance, Vegetable Oil Manufacturing. Researches show that environmental irritants like noise and odor can have considerable impacts on the physical and moral condition of the people and their quality of life 5-6 . If this exposure is long or intensive the unpleasantness would be converted to annoyance gradually. Annoyance is described as an unpleasant feeling about a defined factor or condition which adversely affects the individuals or groups 9 . The human perception of odor is the result of a set of physiological and mental reactions which identify the odor quality 7 . Hence, the compatibility of odor perception is widely personal among individuals which their reaction is different due to their age and health status 8 . The unpleasant impacts of odor emitted from different sources have