Assessment of community response to odor annoyance in nearby residents of a vegetable oil processing plant.
Growing population, urbanization and industrialization, have increased complaints about the environmental pollution such as air pollution, water pollution, noise and offensive odors, in most of countries. Today attention to odor as an environmental problem has been developing as a result of increased industrialization and the awareness of people's need for a clean and comfortable environmental condition. 
Odor is described as: "perception of smell" or in scientific terms as "a sensation resulting from the reception of stimulus by the olfactory sensory system".  According to context of EPA, odor causes pollution by making offence to human sense or harm to human health or harm to the quality of the environment..To understand odor, our brains respond to chemicals that present in the air we breathe. People who have a sensitive sense of smell are able to recognize the odors, even in low concentrations. 
"Odor which refers to unpleasant smells emitted from any source; will be regarded as odor pollution when it disperses in the surrounding area. Without any diffusion process odor production will not lead to odor complaints by the nearby residents." 
The most important point about odor is the ability of causing an effect that could be considered 'Objectionable' or 'offensive' resulting in annoyance, nuisance actual harm. Both low and high concentrations are important, although the low concentrations are mostly less than the concentration that could harm physical health. There are a lot of different symptoms for whom exposed to offensive odor such as vomiting, respiratory problems, nausea, drowsiness, fatigue, eye complaints, nose and throat irritation, hoarseness, headache, diarrhea, chest tightness, nasal congestion, palpitations and shortness of breath.
Industries are known as the main odor source. Odors are generated in many different sites, sometimes related to processing of natural products, e.g. oil extract or synthesis of chemical compounds. Industrial facilities with odorous emissions may cause concern within nearby communities.  In this case, more than 30 % of all complaints reported to administrates in Flanders and more than 70% of complaints to EPA are about odor pollution. Also in Germany approximately 5000 cases had to be recorded in North Rhine-Westphalia between 1995 and 1999. 
Many researchers studied odor annoyance in residential areas from different aspects by a social survey. Results of a survey from over 2000 residents near three deferent hazardous waste site showed that there are significant positive relationships between prevalence of several symptoms and both frequency of odor and degree of annoyance.  In a study about the connection between odor annoyance emitted by several industries and subjective health complaints; it was found that people are annoyed when exposed to odorant concentrations with different degrees. Only some of these people report general health complaints. Annoyance is the intervening variable between exposure and general health complaints. People regard malodor as a threat to their health when exposure with a strong predictor annoyance. 
Assessment of both physical and mental health of residents near a large-scale swine operation indicated that this group of people reported higher rates of variety of symptoms including respiratory problems, nausea, headaches, and irritated eyes and weakness..Results from odor annoyance survey in New Zealand show that 5-15% of the community report being 'at least annoyed by industrial odors, even when there are no significant odors.. Reports of study about the prevalence of somatic symptoms in three places near the composting facilities presented that residential place close to site A (exposed to bio-aerosols and odor annoyance) had the highest rates of complaints .
The investigation near industrial odor sources in six German cities has shown that exposure-annoyance as well as exposure-symptom associations are strongly influenced by odor hedonic .
Duke University professor Susan Schiffman recently published a report about the effect of odor annoyance on the mood of nearby residents in the large scale swine operations. The results indicated that a person, who experienced the odors, reported significantly more tension, more depression, more anger, more confusion, more fatigue, and less vigor than control subjects. 
In this research odor annoyance and its impact on the nearby residents in different fields of industry, has been studied from various aspects and the relationship between this characteristic compared with other factors. However, no published research was found in the field of odor annoyance assessment of vegetable oil manufacturing process in literature and internet reviews. This may be due to the various modern technologies being applied in oil extraction, odor management plans developed in these regions or prohibition of this kind of factory establishment near the residential areas around the world. The reasons of choosing Pars Vegetable Oil Processing Plant (PVOPP) in Tehran are a) locating near the residential areas and b) old technology. This manufacturing factory is known as the odor source of the nearby area and so the people complaining.
Materials and Methods
--Study area and odor source:
This research has been conducted in summer 2010 near the odor source (PVOPP) in southern Tehran. As the capital city of Iran, Tehran area is approximately 400 [km.sup.2] and its population is about 8429807. The factory is located in a residential area and its odor emitted from oil extracting process of the oil seeds is smelled most of the time, intensified during summer.
In this research it has been tried to select the areas which have almost the same condition from the odor reception point of view and also the people which are being interviewed. The study area and factory location is shown in figure1.
--Survey strategy /study design:
The strategy planned to determine the odor annoyance included a questionnaire filled out in a direct interview. In designing the questionnaire it has been tried to take all effective parameters into account, so the German VDI Guideline (VDI3883-Part II) published in 1993 and researches about Community Response to Odorous Emissions in other countries have been considered. As it was guided in the guideline in order to decrease the residents' sensitivity to the odor source, other environmental aspects of the region have been also scripted in the questionnaire.
Estimating the number of questionnaires which should be completed, part of the region has been selected as pilot area and 30 questionnaires were filled out by trained questioners and on this basis the number of samples was determined using the common statistical methods by 95% confidence. In the designed sampling network in residential area as illustrated in figure1, 300 families have been stochastically selected and questioners have completed in a direct interview. Attempts have been paid to select the respondents so that they were over 18 years old and spent most of their time at home.
--Structure of the questionnaire:
Many different variables have been considered while designing the questionnaire. Generally the questions could be categorized in 4 different parts:
1- Social-demographic variables including age, gender, educational level, job, length of residence, house status and the number of hours spent in the house daily.
2- Health and living conditions which assess the other environmental issues like air and noise pollution, personal hygienic and health issues (asthma, allergy, sleep disorder, headache, cough, use of drug and smoking).
3- Odor annoyance which have been asked in the figure of the questions about odor source, quality, annoyance and disturbance level, frequency, odor perception, hedonic tone and judgment about acceptance or non-acceptance of the odor. In order to facilitate the collecting and analyzing data, each variable has been categorized in different classes as below:
* Source type: 3 categories (industry, agriculture or vehicle)
* Odor quality (sulfur, burning or sweet smell)
* Degree of disturbance: 11 classes from 0 for no nuisance to 10 for maximum nuisance
* Degree of annoyance: 7 classes from 0 for no annoyance to 7 for maximum annoyance
* Odor frequency: 6 classes from 1 for once or less monthly to 6 for frequently daily
* Odor intensity: 6 classes from 1 for very weak to 6 for unbearable
* Hedonic tone: 9 classes from -4 for extremely unpleasant up to +4 for extremely pleasant.
* Acceptability judgment: 2 classes 0 for acceptable and 1 for unacceptable
4- Social emotional variables which assess the odor impact on social activities and emotional condition of the people in 5 classes from 0 for never up to 4 for always.
[FIGURE 1 OMITTED]
In order to analyze the outcome data the well-known statistical software SPSS (version 18) has been applied.
From the 300 families selected to fill out the questionnaires 282 families have cooperated with the questioners (response rate 94%), 61% of which were male, their mean age is 37 years and 71% were married. 65% of the respondents live in 1-family houses. Data related to the first part of the questionnaire, social demographic variables, are summarized in Table 1.
The general health complains of the respondents according to the questionnaires filled out is summarized in Table 2.
Having headache and waking up during the night have been more common among respondents. 64% have no allergy and 57% of people which have allergic reactions have to take medicine. In this survey odor has been mentioned as the most important environmental issue by 91%. For 56% of the people air pollution and for 35% noise pollution are also considerable environmental problems.
The third part of the questionnaire has focused on the odor characteristics. The results related to this part are summarized separately as below:
--Sensitivity to odor:
95% of the respondents have perceived the odor in their environment and 94% of them introduced the industry as the main source of odor. Chart2 shows the data about odor source determined by the respondents.
Among the 3 factors presented as the odor quality in the questionnaire, 83% of the people described the odor as sulfuric, 16% burning and 1% sweet.
--Frequency of occurrence:
92% of the respondents have perceived the odor frequently in a day and 8% have chosen the sometimes option.
--Intensity of odor:
For 52% of the respondents intensity of odor is unbearable and 20% have described it as strong. Totally 83% of the people interviewed have classified the intensity of odor unbearable to strong (from 4 to 6). The results related to intensity of odor are as table3.
--Hedonic tone of odor:
Data received about this parameter shows that 74% of the people described the odor as offensive. 99% of the respondents designated the odor hedonic tone from moderately unpleasant to offensive. Table4 shows the related results.
--Degree of odor annoyance:
Among the respondents 72% of them have selected the highest odor annoyance level in their environment which is 6. Degree of odor annoyance average is 5.41 and the standard deviation is 1.13. The confidence interval for degree of odor annoyance in the environment classified from 1 to 6 has been calculated by Percentile Bootstrapping method which is 5.5 and 5.3.
--Degree of odor disturbance:
The average of degree of odor disturbance for the residents is 9.2 and the standard deviation is 1.74. 68% of the respondents have chosen the highest disturbance option. The confidence interval for degree of odor disturbance in the environment measured from 1 to 10 has been calculated by Percentile Bootstrapping method, the result is 8.8 and 9.2.
Almost 93% of the respondents defined the odor as unacceptable; 55.2% of them have complained to authorities. 30% of the people have mentioned it as acceptable. The relationship between adaptation to odor and complaints has been studied applying 2sided Pearson Chi-Square test, the result indicates that there is a significant statistical relationship between these variables(p = 0.30).
The results related to the Socio-emotional effects of odor are summarized in Table5.
Among the respondents 85% of them feel the odor impact on their daily life and emotion always or often. There is a significant relationship between staying in house and showing these effects (p = 0.018 Spearman P = +0/14). The duration of their residence also has a significant relationship with the intensity of odor, hedonic tone and degree of odor disturbance.
Calculating the Spearman's correlation coefficient for odor intensity, socio-emotional effects, hedonic tone, disturbance and annoyance showed that there is a significant relationship between them(p < .001). The value of Spearman's correlation coefficient for their overall relationship is +0.40 to 0.73.
Table 6 shows the relationship between degrees of odor annoyance, odor disturbance and gender status
There is a significant difference between the values males and females gave to both odor disturbance and annoyance. Females show more sensibility to odor disturbance and annoyance, which seems to be related to the more hours spent in the house as an effective parameter.
Mann-Whitney u test computes p-value = 0.044 for degree of odor disturbance and p-value = 0.049 for degree of odor annoyance, the average value given by females is more than males for both parameters.
There is a significant relationship between gender and odor source detection (p = 0.042) calculated by Fisher's Exact test. In the other word, males and females show different sensibility to different odors which seems that odors of industrial sources and vehicles are more annoying than agricultural sources for females.
Data resulted from odor source impacts with some of its characteristics by Kruskal-Wallis test and Bonferroni simultaneous comparisons, applying Mann-Whitney test frequently are summarized in table7.
Intensity of odor has a significant relationship with odor source (p = 0.010) which showed that the intensity of odor of industry is more than vehicle ([alpha] < 0.10). There is also a significant relationship between odor intensity and odor type (p < .001), among which the odor intensity of sulfur type is more than the others ([alpha] < .10).
Negative impact of odor on activity and emotion has a significant relationship with odor source (p = 0.030) but Post Hoc test could not recognize which odor source caused this negative emotion ([alpha] < 0.10). There is also no significant relationship between this impact and odor type (p = 0.106).
Unpleasantness range of odor showed a significant relationship with odor source (p = 0.008) and it is also concluded that unpleasantness of vehicle and industry odor is more than agriculture ([alpha] < 0.10). Unpleasantness range of odor has a significant relationship with odor type too, the sulfur type unpleasantness range is more than the sweet one ([alpha] < 0.10).
In addition, the degree of odor disturbance has a significant relationship with odor source (p = 0.005); the value related to industry is more than agriculture ([alpha] < 0.10). Degree of odor disturbance has also a significant relationship with odor type (p = 0.003); the value related to sulfur type is more than sweet and burning ones ([alpha] < 0.10).
Degree of odor annoyance has a significant relationship with odor source (p = 0.042); the value related to industry is more than agriculture ([alpha] < 0.10). Degree of odor annoyance has a significant relationship with odor type too (p = 0.002); the value related to sulfur type is more than sweet and burning ones ([alpha] < 0.10).
Data analysis has also determined that for workers odor intensity (average = 0.02), hedonic tone (average = 0.026) and annoyance (average = 0.028) are less comparing with other occupations.
The average values for intensity of odor, negative impacts, hedonic tone, degree of disturbance and annoyance are significantly more for people who have disorder while sleeping or awakening time.
The average value of hedonic tone is more for people with headache, cough or respiratory problems. Individuals who have respiratory problems, nose or eyes irritation signs have given higher number for negative impacts on activity or emotion.
Data analysis displays no significant relationship between age effect on annoyance and other odor parameters.
Discussion and Conclusion:
As mentioned before, in this research it has been tried to implement a preliminary study about vegetable oil plants odor annoyance. Despite that odor pollution is not a new issue in urban areas and many countries have started comprehensive researches in this field, no considerable study has been done in Iran.
This research clearly showed that odor annoyance intensity and degree is very high for neighborhoods. Considering that more than half of the people participated in this research describes odor annoyance and disturbance at the maximum level, this can be a very important factor in decreasing welfare and quality of life in the region. Odor from this plant is the first and most effective odor source in the study area which has considerable impact on people's outdoor activities. In many researches including Sakawi et al.  odor source has been mentioned as an effective element on residents' social activity, emotion and health .
It is not easy to discuss the relationship between intensity, frequency and exposure to odor and symptoms but researches confirm the impact of these parameters on human health. In this study also, headache and sleeping disorders relationship with odor intensity and disturbance has been significant.
According to Steinheider, B and Winneke, G,  and Thuerauf et al,  gender has an effect on odor feeling, females describe it more bothersome. The odor found more annoying for females in this research too.
Comparing to other occupations, workers perceive odor less intense and annoying. Some researches concluded that people specifically workers adapt to environmental odor; for instance Schiffman  reason out that workers of an animal husbandry have less sensibility to odor than the individuals who were exposed less frequently. The result of Radon et al.  research also shows that environmental odor is not annoying for most of the farm workers.
On the basis of these researches it could be deduced that the level of people worry (awareness) has a more effective role in determining the odor annoying degree comparing with the real exposure to odor. Studies display that individuals with higher educational level or people who control the quality of their indoor air have more worry and information about odor than the people who are economically rely on odor source. Evans & Jacobs, . Steinheider & Winneke, .
According to the results of this survey the necessity of more comprehensive researches about odor pollution is felt and recommended. The essentiality of odor management of industrial sources (repositioning, applying modern technology and applying instruments to control and decrease odor of the emission sources) as an effective step to decrease the impact and annoyance of odor and increasing the residents' quality of life are also emphasized.
The increase of citizens' sensibility to odor pollution, particularly in industries neighborhoods has led to setting limit level for odor in the world especially in developed countries and so assigning legislations to put these limits into practice. The result of this study could also be a motivating element for authorities in Iran and an opening to develop the odor pollution management plan, we expect.
[1.] Yuwono, A. and P.S. Lammers, 2004. "Odor Pollution in the Environment and the Detection Instrumentation". Agricultural Engineering International: the CIGR Journal of Scientific Research and Development.Invited Overview Paper. Vol. VI. July.
[2.] Bhawan, P., E.J. Nagar, 2008. " Guidelines on Odor Pollution & Its Control".Ministry of Environment & forests, Govet.of India. Delhi-1100 32, May.
[3.] Scottish Environment protection agency, 2008. "odour Guidance Note". Operational Quality manual. Guidance on Regulating odors Avtivities. External Consultation Draft V3. Page No.3 of 107. June.
[4.] New Zealand Ministry for the Environment, 2003. "Good practice for Assessing and managing Odor in New Zealand". Air Quality Report 36. ISBN:0-478-24092.ME:473.June,2003 www.mefe.govt,nz
[5.] Danish Environmental Protection Agency, 2002. "Industrial Odour Control", Environmental Guidelines. No.9.
[6.] Sucker, K., R. Both, M. Bischoff, R. Guski, G. Winneke, 2008. "Odor frequency and odor annoyance Part I: assessment of frequency, intensity and hedonic tone of environmental odors in the field. Int Arch Occup Environ Health. DOI 10.1007/s00420-007-0259-z. 81: 671-682.
[7.] Shusterman, D., J. Lipscom, R. Neutra, K. Stink, 1991. "Sympotom Prevalence and odor-worry interaction Near Hazardous-waste sites". Environmental Health perspectives, page: 25-30. Aug.
[8.] Cavalini, P.M., 1994. "Industrial odorants: the relationship between modeled exposure concentrations and annoyance".Arch Environ health, 49(5): 344-51. Sep-Oct.
[9.] Tu, K., K. Donham, R. Ziegenhorn, S. Reynolds, P.S. Thorne, P. Subramanian, P. Whitten, J. Stookesberry, 1997. "A Control Study of the Physical and Mental Health of Residents Living Near a Large-scale Swine Operation". Journal of Agricultural Safety and Health, 3(1): 13-26.
[10.] Freeman, T., R. Cudmore, 2002. "Review of Odour Management in New Zealand". New Zealand Ministry for the Environment. Air Quality Technical Report 24. Aug.
[11.] Herr, C.E. A. zur Nieden, R.H. Bodeker, U. Gieler, T.F. Eikmann, 2003. "Ranking and frequency of somatic symptoms in residents near composting sites with odor annoyance."int J Hyg Envoron Health, 206(1): 61-4. Jan.
[12.] Sucker, K., R. Both, V.M. Bischo, R. Guski, U. Kramer, G. Winneke, 2008. "Odor frequency and odor annoyance Part II: dose-response associations and their modification by hedonic tone. Int Arch Occup Environ Health, 81: 683-694.
[13.] Susan, S. Schiffman, Elizabeth A. Sattely Miller, Mark S. Suggs and Brevick G. Graham, 1995. "The effect of environmental odors emanating from commercial swine operations on the mood of nearby residents". Elsevier Science Inc. 37(4): 369-375.
[14.] Sakawi, Z. Sharifah, S.A. Mastura, O. Jaafar and M. Mahmud, 2011. "Community Perception of Odor Pollution from the Landfill", Research Journal of Environmental and Earth Sciences, 3(2): 143-146.
[15.] Steinheider, B., G. Winneke, 1993. "Industrial odours as environmental stressors: Exposure-annoyance associations and their modification by coping, age and perceived health". Journal of Environmental Psychology, 13(4): 353-363.
[16.] Thuerauf, N., U. Reulbacha, C.J. Lunkenheimera, B. Lunkenheimera, R. Spannenbergera, A. Gosslera, C. Maihofnerb, S. Bleicha, D.J. Kornhubera, K. Markovica, 2009. "Emotional reactivity to odors: Olfactory sensitivity and the span of emotional evaluation separate the genders. Neuroscience Letters, 456(2): 74-79.5 June.
[17.] Evans, G.W. and S.V. Jakob, 1982. Air pollution ans Huamn behavior In G.W.Evans.(Eds.)Environmental Stress.New York:Camberidg University Press, pp: 105-132.
[18.] Radon, K., A. Peters, G. Praml, V. Ehrenstein, A. Schulze, O. Hehl, D. Nowak, 2004. "Livestock odors and quality of life of neighboring residents". Annals of Agricultural and Environmental Medicine, 11: 59-62.
[19.] Schifman, S.S., 1998. Livestock odors:implications for human health and well-being. J anim Sci., 76: 1343-1355.
(1) M. Avishan' (2) Mohammad Reza Monazzam, (3) M. Asghari, (1) M. Boubehrejh
(1) Air Pollution Bureau, Iran Department of the Environment, Tehran, Iran
(2) 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
(3) Department of Occupational Hygiene, School of public Health, Tehran University of Medical Sciences, Tehran, Iran
Mohammad Reza Monazzam, 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
Table 1: Social demographic variables. N=282 Mean Range Age( year) 37.5 18-79 Time at home (hours/day) 9.3 1-24 People in family 4.9 2-18 Rooms in houses 2.35 1-10 Length of residence( year) 18.22 2-60 N % Male gender 171 61 Married 199 71 Detached house 183 65 Current smokers 48 17 Table 2: Respondents' general health complaints. Health problem % Difficulties falling asleep 32 Waking up during the night 41 Not getting enough sleep 30 Difficulties falling asleep after Waking up 23 Cough 26 Headache 44 Stomach disorders 18 Breathing difficulties 34 Irritation symptoms 29 Allergies 36 Table 3: Odor intensity. Odor intensity Percent Unbearably strong 52 Very strong 11 Strong 20 Distinct 9 Weak 6 Very weak 1 Not perceptive 1 Table 4: Hedonic tone of odor. Hedonic tone Percent Very pleasant 1 Pleasant Moderately pleasant Mildly pleasant Neutral odor/No odor Mildly unpleasant Moderately unpleasant 7 Unpleasant 18 Offensive 74 Table 5: Frequency of Socio-emotional effects. frequency percent Always 18 Often 49 Sometimes 25 Rarely 5 Never 3 Table 6: Relationships between degrees of odor annoyance, odor disturbance and gender status. Gender N Mean Std. Deviation F odor disturbance 111 9.3694 1.24264 odor annoyance 111 5.5946 0.93787 M odor disturbance 171 8.7953 1.96714 odor annoyance 171 5.2865 1.22944 Table 7: Some statistical analysis findings. Test Variable Industry, Industry & Vehicle & Vehicle (Post Agriculture Hoc [alpha] = ([alpha] = .05) .10/3=.033) Odor intensity .010 * .003 * (Vehicle<Industry) Negative impact .030 * .072 on activity or emotion Unpleasantness .008 * .791 Odor .005 * .044 disturbance Annoyance .042 * .222 Test Variable Vehicle & Industry & Agriculture Agriculture (Post Hoc (Post Hoc [alpha] = [alpha] = .10/3=.033) .10/3=.033) Odor intensity .273 .680 Negative impact .273 .045 on activity or emotion Unpleasantness .030 * .002* (Agriculture (Agriculture < Vehicle) < Industry) Odor .485 .009 * disturbance (Agriculture < Industry) Annoyance .485 .024 * (Agriculture < Industry) Chart 1: illustrates the occupational statues of the respondents. Retire 4% Employee 8% Student 8% Jobless 9% Worker 12% Housewife 23% Self-employed 36% Note: Table made from pie chart. Chart 2: Odor sources. Industry 95% Vehicle 4% Agriculture 1% Note: Table made from pie chart.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||Original Article|
|Author:||Monazzam, M. Avishan Mohammad Reza; Asghari, M.; Boubehrejh, M.|
|Publication:||Advances in Environmental Biology|
|Date:||May 1, 2012|
|Previous Article:||Study of atmospheric pollution emitted rated a plant of fertilizers (Algeria) by the use of bioindicator plants: lichens.|
|Next Article:||The evaluation of critique methods in architecture education: a case study of critiques session in 2nd year design studio of architecture department,...|