مجله تحقیقات نظام سلامت
سال هشتم شماره 6 (بهمن و اسفند 1391)

The growing number of people with diabetes mellitus and its complications shows the need to focus on ways to control diabetes mellitus through improving lifestyle، dietary patterns and physical activity. This systematic review assesses the effects of healthy dietary patterns on managing hyperglycemia، insulin resistance and diabetes mellitus type 2.

The main keywords used in this study were: Healthy dietary pattern، prudent، Mediterranean، DASH (Dietary Approach to Stop Hypertension)، diabetes mellitus، insulin resistance and metabolic syndrome. The search was performed in ISI، Cochrane Central Register of Controlled Trials Databases، PubMed، Iran Medex and MagIran. Journals، E-books، seminars، symposiums and articles (prospective cohort studies، randomized clinical trials and cross sectional studies) which were published during 1992 to 2011 were reviewed. The materials were selected based on the title، abstract and full text.

Dietary patterns rich in whole grains، nuts، seeds، vegetables، fruits and in general high-fiber foods and white meat sources، containing less red and processed meat and less refined grains had a protective role in controlling hyperglycemia. Healthy، Mediterranean، prudent or DASH dietary patterns were associated with lower risk of type 2 diabetes mellitus.

Following healthy dietary patterns rich in fiber and unprocessed foods lowers the probability of insulin resistance، hyperglycemia and risk of type 2diabetes.

Plagiarism is a serious debate in scientific community and in recent years has been in the center of interest in academic and scientific communities. Plagiarism is considered as an unethical and improper act، because it constitutes theft from an intellectual work. Self-plagiarism is considered as a sort of plagiarism and is defined as an improper release of information as a new idea، or using main or a part of self article which previously has been published. There are still doubts in definition of self-plagiarism as theft، fraud and abuse or plagiarism and whether or not such penalties are required، it has been introduced as plagiarism in several studies but in some cases، this view was rejected. Multiple and different definitions are presented for plagiarism، such as republishing articles in other journals or publishing with changes and introducing it as a new article. Sometimes it has been introduced as using phrases، sentences and a part of a previously published article without reference. However، it is clear that self plagiarism is not acceptable to the scientific community، and the authors of this paper believed that using ones own previous works، without proper citation is an instance of plagiarism. Therefore، it is necessary that researchers do not summarize this subject merely as the improper use of words and sentences، and in addition to proper referencing of their works، avoid publishing previous articles as new ideas and dividing data into several articles. This study aimed to present and summarize the views of the authors and editors in published papers in national and international journals for students and scholars، especially for young scholars.

Physical symptoms are often associated with poor quality of life (QOL) in patients with heart failure (HF). Progressive impairment in the ability ofperforming routine physical activities of daily lifeand decrease inexercise tolerance is thought to lead to the worsening of physical symptoms. Exercise and physical activity can improve functional capacity، and improve the symptoms associated with HF. For these reasons، exercis is recommended as an adjunct to the medication therapy in patients with HF. Additionally، studies that have applied the efficacy-based interventions to improve exercise participation have beendiscussed. The aimof this review wasto summarize the literature on role of self-efficacy as a leading construct of social cognitive theory (SCT) in physical activity of patients with heart failure. We searched five relevant electronic databases using the terms based on the diagnosis of self-efficacy، chronic heart failure، heart failure،congestive heart failure،rehabilitation، physical activity andexerciseduringAugust1992 to 2012. We also used the gray literature and review to ensure that all the relevant papers were included in the review. Out of 34 collected papers،less than half (n = 12) were found relevant tothis review. Thisstudyhas identified self-efficacyas the most prominent factoraffecting on exercise and regular physical activityin heart failure patients. Beyond the role of self-efficacy as a predictor، exercise adherence in CHF patients is of high importance. It has also identified dominant strategies through which patients with CHF improve their self-efficacy exercise and following adherence such as performance accomplishments، vicarious experience، verbal persuasion and emotional arousal. A number of studies have recognized that exercise self-efficacy wasstrongly associated with the amount of physical activity undertaken in heart failure patients. Evidence from some trials supportedthe view that incorporating the theory of self-efficacy into the design of an exercise intervention is beneficial. Moreover، exercise interventions aimed toimprovethe self-perception of exercise self-efficacy which can have positive effects on confidence and the ability to initiate and recover heart failure symptoms. Finally، it is important to test these self-efficacy interventions more widely، especially to leadpatients to the behavioral modifications.

There is no doubt that education has an important role in developing and promoting student''s creative ability. Creativity is an equivalent for divergent production based on Guilford''s theory. He was the first one to propose the concept of creativity in psychology. He believed divergent production is the main characteristic of creativity. Divergent production is one of the basic concepts of operation in Guilford''s cognitive abilities structure and was used in evaluating the educational training by Meeker. Meeker provided subscales for assessing divergent production abilities. She also designed educational packages to strengthen and improve those abilities. These packages are used in institution of Meeker''s cognitive abilities structure located in Los Angeles، USA. The purpose of this study was to investigate the effect of creativity training based on Meeker''s method on the divergent production rate of junior high school students of Ilam، Iran.

Statistical population consisted of boys and girls in first and second grade of junior high school of Ilam، Iran in 2010-2011. Subjects were selected from 402 first and second grade junior high school students from two gifted and governmental schools. Semi-experimental study، pre-test and posttest with control group were conducted. From each school four classes were randomly selected and assigned to control and experimental group. Experimental group received 36 hours training and posttest was performed for both groups to compare the differences. The data gathering tool was Meeker''s divergent production subscales.

There was a significant difference between experimental and control groups regarding divergent production subscales، semantic units and symbolic relationships. The results also indicated that there was no significant difference between gifted and ordinary students regarding creativity.

The results of this study emphasized the importance of improving creativity among students based on Meeker''s educational packages.

All humans are searching ways to promote mental health. Mental health is vital for having a healthy life. Some believe that mental health means lack of mental disorders. Positive psychology emphasizes on issues such as hope، wisdom، creativity، spirituality، thinking about future and having purpose in life instead of psychopathology aspects. The purpose of this study was to investigate the relationship between having purpose in life and mental health among university students.

Based on classified sampling from the target population of Ilam University، Iran، 520 students (boys and girls) were randomly selected. Instruments used in this study were Coping Strategies Questionnaire، purpose in life test (PIL) and Goldberg’s General Health Questionnaire. The reliability of these instruments was acceptable in different studies. Pearson correlation coefficient، one way analysis of variance، Turkey test and t-test were used for data analysis.

There was a negative significant relationship between emotion oriented coping style and mental health. Moreover، there was a positive significant relationship between task oriented coping style and purpose of life with mental health. The analysis of variance showed that there were significant difference among purpose of life in different courses، mental health in different courses، emotion and task oriented coping styles in different courses. There was no significant difference between boys and girls regarding purpose of life. But there was a significant difference between them using task oriented coping style. Boys make use of task oriented coping style.

The study showed that there was a significant relationship between purpose of life and mental health. Thus having purpose in life has an important role in preventing mental disorders. Task oriented coping strategy has an important role in maintaining mental health، therefore these strategies can be taught to create a healthy lifestyle and promoted satisfaction.

The detrimental effects of partially hydrogenated vegetable oils (PHVOs) on apolipoproteins have been reported from several parts of the world; however، few data are available in this regard from the understudied region of the Middle East. The present study aimed to evaluate the association between type of vegetable oils، serum lipids and apolipoprotein levels among Iranians. In this cross-sectional study، data of 1772 people (795 men and 977 women) aged 19 to 81 years were used. Participants were selected through multistage cluster random sampling method from three counties of Isfahan، Najafabad and Arak، Iran in Isfahan Healthy Heart Program (IHHP). To assess participants'' usual dietary intakes، a validated food frequency questionnaire was used. Consumption of hydrogenated vegetable oil (commonly consumed for cooking in Iran) and margarine was considered as the category of PHVOs. Consumption of soy، sunflower، corn، olive and canola oils was considered as non-HVOs category. After an overnight fasting، serum colestrol (total، LDL، and HDL) and triglyceride as well as apolipoproteins A and B were measured using standard methods. Participants with the highest intake of non-HVOs and PHVOs were younger and had lower weight than those with the lowest intake. High consumption of non-HVOs and PHVOs was associated with lower intake of energy، carbohydrate، dietary fiber، and higher intake of fruits، vegetables، meat، milk and grains. No overall significant differences were found in serum lipids and apolipoprotein levels across quartiles of non-HVOs as well as PHVOs after controlling for potential confounding. There was no significant association between hydrogenated or non-hydrogenated vegetable oil and serum lipid and apolipoprotein levels. Further studies are needed to explore this association.

Up to today، the most complete risk assessment tool for repetitive movements of upper limbs has been the Occupational Repetitive Actions (OCRA) method. The index of the analysis is relatively accurate. Several risk factors such as repeated motion، force، body condition، additional effective factors and return period can be useful for future preventive measures. The present study evaluated the risk factors for upper limb repetitive movements with OCRA index and was conducted in Isfahan’s handicraft jobs، Iran. In this cross-sectional study، a compilation of four methods of data collection including observation، interviews، Nordic questionnaire and repetitive job activity index (OCRA) was used. The crafts in Isfahan included relief etching، etching mesh، simple etching، calico work، enamels، tile work، gilding، inlay، coppersmith، and miniature. The study included 94 men who were randomly selected. Nordic questionnaire for risk identification and OCRA index for risk assessment and management of repetitive movements were used. In total، for right and left hand 94 tasks were investigated. Significant differences between the OCRA index averages in 10 jobs were observed (P < 0. 001). This indicated that the significant correlation between the level and type of job was the ORCA index. In these jobs the risk level in the right hand was significantly higher compared to the left hand (P < 0. 001)، which indicated the inequality of OCRA index in left and right hand (P < 0. 001). The incidence of skeletal-muscle disorder symptoms in workers of craft jobs was high. Furthermore، the corrective action level that was obtained based on OCRA method indicates harmful conditions and working environment in these professions. The highest scores of OCRA index were related to inlay simple etching task (P < 0. 001) and inlay، etching bold، coppersmith، etching mesh، enamel، tile، miniature، illumination، working pens were in lower risk levels respectively.

Today، lifestyle changes have lead to increasing fast food consumption. Preparing healthy food and addressing nutritional deficiencies during school age help children and adolescents to spend academic time successfully. In addition، it promotes their educational performance by affecting on intellectual activities. Thus، regarding importance of nutrition in adolescence، the present study was done for assessing fast food consumption and its related factors among students of guidance schools in Tehran، Iran. This cross-sectional study was carried out using self-administered questionnaire among 768 (384 boys and 384 girls) students of grades 1، 2 and 3 in regions 2، 9 and 18 of Tehran that was selected bymulti-stagerandomsampling method. Finally، participants were selected from 10 schools. Participation of students in this study was voluntary and with informed consent. Resultsshowed that 98. 7% of all students consume fast food، that 36. 8% and 14. 7% of them eat fast food 2-3 times a week and every day، respectively. There was a significant difference between boys and girls in terms of fast food consumption. This study revealed a high intake of fast foods in school children ofTehran. Therefore، educational interventions to reduce the consumption of fast foods in the adolescent population are absolutely necessary and recommended.

Today sedentary life style in Iranian society is known as a serious problem. Increasing physical activity in women’s health promotion and prevention of cardiovascular disease are essential. The purpose of this study was to explore the relationship between psychological factors (body satisfaction and self-efficacy) and physical activity in female employees. An analytical cross-sectional study was conducted among 408 female employees of University of Isfahan and Isfahan University of Medical Sciences (Iran) who were selected by stratified random sampling method in 2012. Data collection tool was a multidimensional questionnaire which comprised of 4 sections as following: Demographics، body satisfaction tool، self-efficacy and physical activity. 71. 6% of women participated in this study had a sedentary life، and only 28. 4% had an active lifestyle. The mean body satisfaction score in the studied women was 63. 2 ± 16. 2 (from 100). Maximum score of body satisfaction belonged to height. On average، there was no significant relationship between physical activity and BMI (body mass index)، but the relationship between physical activity and body satisfaction and self-efficacy was significant (P = 0. 01). The highest correlation was observed between body satisfaction and participation in aerobic classes (P < 0. 001). A significant relationship was found between marital status and physical activity. It seems that despite the awareness of our society about physical activity، women have a sedentary lifestyle. Focus on psychological factors and providing more facilities for physical activity can improve health promoting behaviors of female employees in family and community.

The health promoting effects of green tea including anti-obesity and anti-inflammatory effects، decreasing heart attack risk and oxidative stress status has been widely demonstrated during the past decade. The purpose of this study was to determine the possible effects of green tea on the anthropometric indices، systolic and diastolic blood pressure in overweight and obese women. A before-after، randomized clinical trial was conducted during 45 days on 41 overweight and obese women. The randomly selected participants forming a treatment group consumed 3 to 5 cups of green tea (125 cc) daily for 45 days. Demographic information، anthropometric indices including height، weight، body mass index (BMI)، waist hip ratio (WHR)، percent body fat and systolic/diastolic blood pressure were recorded at the beginning and the end of the study. Mean of age، BMI and body fat were 38. 1 ± 1. 7 years، 28. 8 ± 3. 5 Kg/m2 and 35. 8 ± 3. 51 percent، respectively. The mean of systolic and diastolic blood pressure were 84. 8 ± 12. 9 mmHg and 130. 1 ± 20 mmHg، respectively. There was a non-significant reduction in anthropometric indices such as weight، BMI، and body fat percent; and a significant reduction in systolic blood pressure (P = 0. 009); however، reduction in diastolic blood pressure was not statistically significant (P = 0. 05). Daily intake of green tea was associated with a significant reduction in systolic blood pressure; however، reduction in anthropometric indices and diastolic blood pressure was not significant.

Substance abuse is as a health-related behavioral problem، which more or less all countries have to deal with it. This behavior has broad effects on the individual and societal level، thereforeidentifying factors associated with this behavior is necessary. This study compared rates of depression، anxiety and stress between drug abusers and non-abusers. This was a descriptive-analytic research withcomparative design. The population included the youths of ages 18 to 29 years (with and without drug abuse behavior). The sample size in drug abuser group and non-abusers were 183 and 207subjects، respectively andwere selected by random sampling method. The data collection instrument was aquestionnaire of personal information containing 6 questions and the standard questionnaire wasDepression Anxiety Stress Scales-21 (DASS-21). The data were analyzed using independent t-test، chi-square، Mann-Whitney، and logistic regression analysis. The average age of the drug abusers was 25. 9±2. 96 years and in the comparison group it was 24. 2±3. 36 years. The most consumed drug was methamphetamine (75. 9%). There was asignificant differencebetween the levels of educationof the two groups (P<0. 001). The score of the depression، anxiety and stress in drug abusers wasmore than the comparison group and this relationship was significant (P<0. 001). Based on the logistic regression analysis، anxiety had the highest associationwith drug abuse behavior. According to the relationship between psychological factors and behavior of substance abuse، it is necessary to suggest social plans forprevention and mental disorderstreatment.

Given the high prevalence of addiction in Iran and its social and health problems، addiction is considered as one of the few national health priority. This study compared the views of addicts and their families about the causes of drug abuse that referred to addiction centers in Khorramabad، Iran.

This cross-sectional study was conducted on addicts and their families who referred to the Khoramabad government withdrawal centers in the age range of 15 to 65 years old. The survey tool was a questionnaire consisted of two parts: demographic characteristics and causes of drug abuse in five dimensions including individual، family، social، economic and psychological factors. Collected data was analyzed with SPSS software version 16، using chi-square، Mann-Whitney and Kruskal-Wallis tests.

48. 3% of addicts and 63. 3% of families said that low confidence has an important role in addiction. Half of the subjects in both groups believed that successive failures in life and observational learning from addicted family members have a strong role in addiction. From the perspective of family members، the two factors of economic inequality، unemployment and lack of job opportunities، had significantly greater role in addiction in comparison with the addicts viewpoint. Greater percentage of addicts believed that the role of insistence of friends and peers، relieving pain and physical illness، pleasure and positive attitude to drugs، were more important from other items and the differences of view between the two groups was statistically significant (P < 0. 05).

To prevent and reduce the tendency toward addiction، major steps is essential in reducing anxiety and social concerns، increasing security and social welfare، culturing، especially in the areas of mental health and improving employment and the social economy.

Given the decisive role of youth in spreading the risk of AIDS infection، education and increasing knowledge isone of the most important waysof controlling the disease. Thus، the present study aimed to assessthe effect of aneducational pamphleton knowledge and attitude of non-medical students aboutAIDS in University of Zabol، Iran. This pre-testpost-test quasi-experimental study was performedon 80 non-medical University students that were selected using the randomsamplingmethod. Data were collected through a researcher-madequestionnaire based onthe study objectives، thatcontentreliability had been approved by a number of expertfacultymembers. The questionnaire was filled out before the educational intervention and 40 days later. Mean score of knowledge and attitude after the intervention increased from 7. 76 to 15 and from 6. 45 to 10. 06، respectively (P <0. 005). Since the effect of educational pamphlet on promotion of students’knowledge and attitude was approved and given the low mean score of knowledge in non-medical students، it is recommended that education programs becontinuouslypresented to other non-medical students regarding prevention and control of AIDS.

The need for self-esteem is one of the natural human psychological needs. In lifeskills trainingit is aimed to help women for better understanding and properly being able to cope with violent behavioragainst them. This study examinedthe impact of life skills training on self-esteem of women for the prevention of domestic violence. This was a semi-experimental study with pre-test and post-test design. Itwas performed on 91 women coveredby Imam Khomeini Relief Committee in Gorgan، Iran، in 2011. The subjectswere randomly selected. The data collection toolsincludeddemographic data and Rosenberg’s self-esteem questionnaires. Educational intervention was designedas three educational sessions lasting120 minutes each. 45 days after the intervention، the secondary test was done. Before the intervention، mean scores of self-esteem was 5. 29، whichsignificantly increasedto 6. 64 after the intervention (P<0. 001). The linear regression test showed a significant relationship between life skills training and self-esteem after the educational program. There was a significant relationship between the level of violence before the intervention and after the intervention (P <0. 001). Self-esteem can be increased with life skills training،which leads to problem solving and effective communication in women. Itcan prevent negative behaviors at home and will increase confidence and reduce violence.

Clinical researches indicate the increase of stress in the society and the number of patients with psychological disorders، especially depression. This study was performed to assess the effectiveness of an educational intervention based on cognitive-behavioral methods on stress and depression among women with depressive disorder. Forty patients with depressive disorder who visited psychiatry and consultation clinics of Isfahan were randomly divided into intervention and control group (n = 20 in each group). The subjects were recruited by multistage sampling method. Stress management training was conducted for the intervention group in 8 sessions (90 minutes) through cognitive-behavioral techniques. Data collection tools included stress questionnaire and Hamilton Depression Inventory which was completed before and one month after the intervention in both groups. Data were analyzed using covariance analysis. In the intervention group، there was a significant difference between pre-test and post-test scores on stress levels and depression (P < 0. 001). In the intervention group، adjusted mean difference of the stress score (F = 12. 45، P < 0. 001) and depression score (F = 5. 36، P = 0. 02) were statistically significant. Findings of this study showed that patients learned how to cope with stressful situations and act efficiently through these programs. This، in turn، will prevent depression recurrence or deterioration of the patients'' condition.

Benzene is a volatile compound in petroleum products and the major concern about this is carcinogenic effects. This study aimed to review benzene removal ability ofmulti-walled carbon nanotubesby surface modified with calcium hypochlorite and sodium hypochlorite from aqueous solution. The removal of benzene from aqueous solution by multi-walled carbon nanotubes (MWCNT) and its modified surface by calcium hypochlorite [MWCNT (Ca(OCl) 2)]and sodium hypochlorite[MWCNT (NaOCl)]were evaluated. Synthetic samples were analyzed by Gas Chromatography.. Inthis study، nano-materials with dosageof 0. 5 g/l، contact time (1-hr and 2-hr) with benzene concentration of 100 mg/l and pH 7 werechosen. The equilibrium amount (qe) and removal efficiency (R) for benzene were 188. 6 mg/g and 94. 3%، respectively andby MWCNT (Ca(OCl) 2)werehigher than MWCNT (NaOCl) (qe=187. 7; R=93. 9%) and MWCNT (qe =182. 6; R=91. 3%). The MWCNT (Ca(OCl) 2) can effectively adsorb benzene from water and can thus be used as efficient adsorbents to purify waters and wastewaters polluted by the petrochemicals.

Type II diabetes is the most prevalent disease with numerous complications. Adherence to treatment is an effective role on promoting health outcomes. This study aimed to assess the cognitive adaptation in treatment adherence and its relative factors in coping with disease among type II diabetic patients.

This was a cross-sectional study which was conducted in 2012. Study population composed of 480 type II diabetic patients which were selected through convenience sampling method. In this study، the questionnaire included some socio-demographic and economic data and cognitive adaptation scale was also employed. All the items were scored on a scale of 1 to 5. SPSS software was employed and chi-square test and logistic model were used.

Findings revealed that sex (P = 0. 001)، marital status (P < 0. 001)، disease duration (P < 0. 001)، occupation (P < 0. 001)، diabetes history (P = 0. 001)، age group (P < 0. 001)، annual income (P < 0. 001)، comorbidity (P = 0. 002) and hemoglobin A1c (P < 0. 001) had a statistically significant relationship with cognitive adaptation score. Logistic regression model showed that age، marital status، annual income، diabetes history، comorbidity، disease duration and hemoglobin A1c had a significant relationship with adaptation in type II diabetes disease.

According to the effects of socio-demographic and clinical factors in cognitive adaptation in treatment adherence in type II diabetes، educational intervention is necessary using health education and promotion focusing on cognitive adaptation theory.

Benzene is one of the most widely used volatile organic compounds showing severely adverse effects on human health. Removing benzene from the airflow or controlling its amounts، is one of the issues put to discussion in the field of environmental engineering. The objective of this study was to examine the efficacy of the Ultraviolet-C (UV-C) radiations on removing benzene from the airflow under conditions of varying humidity and reaction time in the UV/O3 process.

This was an experimental study which was performed on a laboratory scale. The testing and measurement system included an air pump، an injection pump، a mixing chamber، a rotameter، an ozone generator، a heater، an impinger، and a steel reactor with 45 cm long، and with a net volume of 1. 35 L in which a 15-watt UV-C lamp with a wavelength of 254 nm was placed. Different concentrations of benzene were continuously exposed to the UV/O3 process under varying conditions of reaction time and humidity. The concentrations of benzene before and after exposure to the treatment process were measured taking aforementioned factors into account. The data were analyzed using descriptive and inferential statistics and three-way ANOVA test.

The results demonstrated that increasing the humidity levels up to 60% led to an increase in the efficacy of UV-C in the removal of benzene، while this efficacy decreased at humidity levels above 60%. Additionally، the findings indicated that increasing the reaction time can lead to the highest benzene removal rates in the presence of humidity (13. 2%، P < 0. 001).

Given the improvement in the efficacy of benzene removal as a result of the simultaneous use of UV and humidity، and the effects of increased reaction times in a process involving the simultaneous use of the UV rays and relative humidity، it can be concluded that the use of UV-C rays in an airflow containing humidity levels of 50% to 60% can have a positive potentiating effect on the efficacy.

Psychological and behavioral domains are important in coping with type II diabetes. This study was conducted to assess supportive and coping obstacles in living with type II diabetes among patients who visited hospitals affiliated to Tehran University of Medical Sciences (TUMS). This was a cross-sectional study with 600 subjects who participated in the study. Data collection tools included two sections of demographics، health related variables and hemoglobin A1c (10 items) as well as questionnaire of supportive (8 items) and coping (8 items) obstacles which was measured by Likert scale [from completely agree (5) to completely disagree (1)]. Validity and reliability were also assessed. Interview was performed to collect the data. Mean and standard deviation (SD) of supportive and coping obstacles were 22. 7 ± 3. 8 and 24. 8 ± 5. 6، respectively. Study findings revealed that sex (P = 0. 01)، disease duration (P < 0. 001)، educational level (P < 0. 001)، type of treatment (P < 0. 001)، occupation (P < 0. 001)، age groups (P < 0. 001)، income level (P < 0. 001) and familial history (P < 0. 001) had a significant correlation with supportive obstacles. On the other hand، study findings showed that disease duration (P < 0. 001)، educational level (P < 0. 001)، type of treatment (P < 0. 001)، occupation (P < 0. 001)، age groups (P < 0. 001)، income level (P < 0. 001)، familial history (P < 0. 001) and hemoglobin A1c (P < 0. 001) had a significant association with coping obstacle. Findings revealed that several factors related with supportive and coping obstacles in diabetic patients. Disease duration and social class had a relationship with supportive obstacles. Income، disease duration and hemoglobin A1c related to coping obstacles. These can be improved by planning health promotion interventions.

Long-term extraction and production of various oil derivatives causes contamination of soil adjacent to production and refining area. The main important issue is the ecological hazard of these pollutants. The main aim of the study was to identify and separate native bacteria that are responsible for degradation of oil contaminated fields. We prepared a compound sample of contaminated soil in the vicinity of oil wells drilled in Marun oil field of Ahwaz، Iran. Moreover، an uncontaminated sample was picked from the same area and deliberately contaminated with crude oil in a 5 wt% rate. The number of oil degrading bacteria was counted by MPN (Most probable number) method. Then، the bacteria was cultured and isolated in a rich agar medium and late discrimination test was done by gram staining and biochemical tests at the level of family or genus. The number of bacteria in naturally contaminated and artificially soil was 6. 8 × 105 and 3. 5 × 107، respectively. The majority of bacteria responsible for oil degradation were Staphylococcus، Acinetobacter and Flavobacterium genus in naturally contaminated soil; however، Acinetobacter، Pseudomonas and Moraxella genus were the main bacteria in artificially-contaminated soil samples. It is recommended to be used for bioremediation of native organisms and bio-power and robust.