Journal of School of Public Health and

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Visceral leishmaniasis (VL) has been found as an endemic disease in some areas in northwest and south parts of Iran during recent two decades. The species of the Leishmania has been characterized as L.infantum and the main sources of human infection in the endemic areas is dog. The majority of kala-azar cases are found among children in the age group of 1-4 years. As the delay in diagnosis and treatment of kala-azar cause high mortality in the patients, serological surveillance, using direct agglutination test (DAT), and treatment of seropositive cases who have clinical symptoms are carrying out with cooperation of Provincial Health Services in the endemic foci of Ardebil and East Azerbaijan Provinces in the northwest and Bushehr in the south parts of Iran since 1997.
DAT Leishmania antigen is made in the Protozoology Unit of the School of Public Health with the strain of L.infantum isolated from an infected dog in Iran. The finger prick blood samples are collected by trained Health Workers (Behwarz) from suspected kala-azar patients in the Rural Health Houses. The collected samples are transferred to the near district kala-azar laboratory and tested (using DAT) by the trained technicians. The sero -positive patients are referred to pediatricains or trained general physicians in district hospital or health center for clinical examination and treatment of the seropositive cases (DAT titers of 1:3200 or higher) with kala-azar clinical symptos. For the treatment, usually, meglomine antimongtc (Glucantime) is used via intra-muscular in dosss of 20mg/kg/day for 20 days.
In kala-azar case finding in the serological surveyed areas of Ardebil, East-Azerbaijan and Bushehr provinces during 1997-2001, altogether, 19693 blood samples were collected from suspected kala-azar patients and tested by DAT. Totally , 1274 cases (6.74%) were seropositive in titers of 1:3200 or higher. In the clinical examination of seropositive cases 690 patients (54.16% of sero-positive cases and 3.50% of the total samples) had kala-azar clinical symptoms and therefore they were treated.
This seroloeical surveillance of kala-azar in the endemic area as have detected high number of kala-azar patients among children up to 12 years old, who were subsequently treated on time . This ptoject has prevented the mortality of the disease in the studied areas.

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Heavy metal contamination of food products, especially seafood is a major concern because of the bioaccumulation and biomagnification of metal contaminants. Their detection in fish is an indicator of marine pollution. In this study heavy metal concentrations were measured in a sample of commercially obtained canned tuna after digestion and preparation of 21 such samples, levels of mercury and arsenic were determined by the hydride generation technique, while those of lead and cadmium were measured by the graphite furnace system. Tin levels were determined by flame atomic absorption spectrophotometery. The mean contents of heavy metals expressed in ug/g of wet weight were O.U3±0.027 (range 0.082-0.16) for mercury, 0.129±0.082 (0.037-0.262) for arsenic, 0.029±0.019 (0.006-0.088) for cadmium, and 0.33±0.12 (0.016-0.049) for lead. No tin was detected any of the samples. The concentrations of toxic metals in this study were below the WHO/FAO-recommended levels, but further studies are needed to assess the risk associated other types of food.

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The start of this survey, 588 students (294 in either area) were selected randomly but the ultimate size of the sample was increased to 905, allowing for a 35% omission rate. Anthropometric measurements and stool examinations were performed. Questionnaires dealing with socioeconomic status were completed through interviews with mothers. We also carried out blood tests on a subsample of 180 individuals (1/5 of the the original sample).The results of the study were as follows:In Area 1:4.3% and 15% of the subjects showed evidence of anemia and parasites, respectively.Th mean hemoglobin and hematocrit concentrations were 13.46 g/dland40%.Anthropometric assessment revealed rates of 8.6% and 1.3% for severe wasting and obesity, and 11.9% for severe stunting. Gauging the weight-for-age index on standard growth charts, 13.1% of the subjects had severe wasting and 14.4% suffered from severe stunting and based on BMI, 21.3% were severely malnourished.ln Area 2:5.8% and 13% of the subjects suffered from anemia and parasites, respectively.Mean hemoglobin and hematocrit concentrations were 13.05 g/dl and 37.8%.Anthropometric assessment showed that 9% of the subjects had severe wasting, and 1.8% were obese. 11.7% showed severe stunting. On standard growth charts, 12.4% had severe wasting and 15.3% were severely stunted. Judging by the Body Mass Index, 21.6%) of the subject had severe malnutrition.The mean weight, height and BMI in both areas were substandard and the mean weight in Area 1 was lower than in Area 2. Statistical Associations:In Area 1: the following variables showed statistically significant relationships: History of parasite infection in the last year with child's weight for age. Mother's age and history of maternal parasite infection in the fast year with child's height for age.Parasites infection in the last year with BMI.In Area 2: statistically significant relationships were found:Between mother's literacy / mother's job /family income and child's weight for age.Between family income / percentage of income spent on food/ current parasite infection and height for age.Between diseases affecting food intake and BMI.

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To determine the prevalence of various intestinal parasitic infections, we examined 966randomly collected stool specimens from urban areas and 569 such samples from the ruralregions. These were examined using formalin-ether sedimentation and direct smearmethods. From the total of 1535 specimens, 143 that belonged to 1-6 years old childrenwere examined by scatch tape method.The results indicated that 53.2% of the subjects were infected with intestinal protozoa andhelminths with the following prevalence rates:Entamoeba histolytica 9.6%, E. coli 16%, E.hartmanni 7%, Endolimax nana 2.6%,Iodomoeba biitschlii 1.8%, Dientamoeba fragilis 1.5%, Chi/omastix mesnili 0.4%), Giardialamblia 18.8%, Blastocysts hominis 16.5%, Dicrocoelium dendriticum 0.1%, Taeniasaginata 0.2%, Hymenolopis nana 1.4%, Ascaris lambricodies 0.3%, Enterobiusvermincularis (using scatch tape method) 0.7%, E.vermicularis (using formalin - ethermethod) 28.7%,Trichostrongylusspp.0.1%,Strongyhidessiercorials 0.3% and Trichuristrichiura 0.1%.Rural people were significantly more likely to bear helminthic infections than urbanresidents (4.9% versus 2.1%).E.histofytica wasmore prevalent among men (11% versus 7.1%) and, interestingly,age-specific infection rates for giardiasis and amebiasis showed contrasting patterns in thisstudy

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The Intrauterine device (IUD) is very effective in preventing pregnancy, it is the cheapestform of birth control in the long run, allows almost immediate return to normal life andwork, and it can be used as an alternative to hormonal methods of emergencycontraception.This study was designed to assess factors causing IUD iscontinuation. It is a cross-sectional study among 343 women in Urmia in 2001 who had had lUD'splanted back in 1998.Within 3 years, more than 50 percent had theirlUD's removed. The 1-year IUD survivalrate was 62 percent and the 3-year rate about 42 percent.54.5 percent of users had at least one complication (P=0.000). The main complications were: Bleeding 28.7% , Pain 27.3% and Infection 18.5%.In cases where the device was planted by a midwife, the overall removal rate was 62.5%(p= 0.009). Pregnancy rate was 0.49% per 100 woman - year and the IUD expulsion ratewas 6.5%o.Bleeding is clearly the most common complication. If cases are chosen more carefully, the effective life of device will probably increase.

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A study was carried out to estimate the prevalence of Coagulase – Positive Staphylococcus aureus in milk collected in the milk collecting center in Garmsar city. Ninety-six raw milk samples (84 composite samples and 12 bulk samples) were collected from Garmsar milk collecting center. Raw milk samples were transferred to laboratory in safe conditions. After serial dilution, the appropriate concentrations (10 -2 to 10 -6) were cultured on Baired- Parker agar medium. The plates were incubated at 37 oC for 2 days (48h). After 48 hours' incubation, the colonies with black centers and light areas were used for staphylococcal assay. The coagulase test was done with rabbit plasma and coagulate- positive colonies were then counted. The results showed that mean counts of coagulate-positive Staphylococcus aureus in composite and bulk milk were 5.4 ×10 5 cfu/ml and 3.2 × 105 cfu/ml, respectively. The counts ranged from 8.6 × 10 4 to 2.1 × 10 6 cfu/ml and 1.4 ×10 5to 5.5 × 10 5 cfu/ ml. The standard deviations were 3.5 × 10 5 cfu/ml and 1.4 × 10 5 cfu/ml respectively. It is clear that the milk collected at this facility was rather heavily contaminated with S. aureus. Therefore, it may constitute a health hazard because of the possible production of enterotoxin in the milk consumed by the people. In order to reduce staphylococcal contamination in milk, it is recommended to treat cases of clinical and subclinical staphylococcal mastitis in livestock. Also, it is necessary to use hygienic procedures during the production process as well as transportation and storage.

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Background and Aim: In this study, we compared a latex agglutination test (KatexR) with the direct agglutination test (DAT) for the diagnosis of human visceral leishmaniasis (HVL) in an area with a high prevalence of zoonotic visceral leishmaniasis (ZVL) in Iran.
Materials and Methods: The validity of the KatexR (Kalon Biological Ltd, England) for detection of urinary Leishmania antigens in HVL was compared with standard direct agglutination test on 92 visceral leishmaniasis patients (29 were acute and 65 were chronic phase) and 90 healthy controls over a period of one year.
Results: We detected a sensitivity of 82.7% and a specificity of 98.9% in the acute phase. As for the chronic phase, the test showed a sensitivity of 6.15% and a specificity of 98.9% at a 1:3200 cut-off titer. Concordance between KatexR and DAT was 94 .9% in the acute phase and 59. 3% in the chronic phase. As the rapid, noninvasive Katex does not require much expertise or elaborate equipment.
Conclusion: It can be used for screening and diagnosis of human visceral leishmaniasis in remote endemic foci.

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Background and Aim: Toxoplasma gondii is a protozoan parasite infecting humans and warm-blooded animals. Toxoplasmosis in pregnancy could cause neurologic disorders in the fetus. In immunocompromised hosts, the infection can be reactivated with life-threatening consequences. Detection of the parasite or its components would constitute a better definition of acute infection.

Material and Methods: To detect T. gondii antigen and DNA, twenty serum samples in the acute phase of infection were tested. Polyclonal antibodies were isolated from immunized rabbits and SDS-page and immunoblotting were performed. Also, PCR was done with amplification of the B₁ gene with two primers.

Results: In one patient T. gondii antigen band with a molecular weight of 30 kDa was detected. Parasitemia was detected in the same patient and the 570 bp amplified DNA fragment was isolated. Others had negative results in both immunoblotting and PCR. The patient with positive results had been infected accidentally with a rather virulent C56 strain in the laboratory.

Conclusion: The results indicate that antigen and DNA of T. gondii can be detected during the short acute phase of infection.

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Background and Aim: Exposure to hexavalent chromium in plating operations is associated with skin ulceration, contact dermatitis, respiratory tract irritation, cancer, and kidney damage. We investigated the possibility of using biological monitoring to assess exposure to hexavalent chromium in chrome-plating workers. We compared mean Cr6 concentrations in the breathing zone plus urine chromium, β2 microglobulin (B2M), and N-acetyl-B-D- glucosaminidase (NAG) at the end of the working shift. Then we assessed the correlation between exposure to hexavalent chromium and biological indicators.

Materials and Methods: This study involved 45 chrome platers (Cases) and 40 zinc platers (Controls) in Isfahan. Air and urine samples were collected at the end of the work shift. Measurement of Cr6 concentrations in the workers' breathing zone was performed using the NIOSH Methods 7600. Urine Cr levels were determined by atomic absorption spectrophotometry, with a graphite furnace (Shimadsu, AA680). B2M and NAG were measured by Kits.

Results: Overall, geometric mean of hexavalent chromium concentrations in the breathing zone was significantly higher among chrome platers (14.577 μg/m3) compared to zinc platers (0.862 μg/m3, p<0.001). Moreover, the mean urine Cr concentrations were higher in chrome platers (9.198 vs. 1.811 μg / g creatinine, p<0.001). Similarly, there were significant differences between mean NAG in chrome platers (12.608IU/gr creatinine) and zinc platers (6.824 IU/g creatinine, p<0.001). Differences in B2M concentrations were not significant (p>0.05). A significant correlation was found between Cr6 concentrations in the chrome platers' breathing zone and their urinary chromium levels (r= 0.838, p<0.001). A similar association was found between concentrations of Cr6 and NAG in the breathing zone (r= 0.304, p<0.05).

Conclusion: As urinary B2M concentration did not change significantly, it may not be a sensitive indicator in evaluating exposure to hexavalent chromium. There were significant differences between mean urinary Cr and NAG concentrations in the two groups. The significant correlations between Cr and NAG concentrations indicate that these markers may be suitable indicators of exposure to hexavalent chromium. Our results indicate that NAG is an early indicator of renal dysfunction in chrome platers.

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Background and Aim: Intestinal parasites cause significant morbidity and mortality and are considered by the World Health Organization as a public health problem of global importance. These agents are estimated to infect more than three billion people worldwide. In Iran, thanks to long-time efforts by the national health system (including environmental sanitation and public education campaigns), the frequency of the most intestinal parasitic infections has significantly declined in the recent decades. Our study aimed to determine the prevalence of intestinal parasites in a high-risk occupational group, namely the municipal workers in the city of Esfahan.

Materials and Methods: A survey was conducted to determine the prevalence of intestinal parasitic infections among municipal workers in several districts of Esfahan. Specimens were placed into fecal pots, labeled and kept cool before being transported to the Health Research Center Laboratory, affiliated to the School of Public Health & Institute for Public Health Research in Tehran University of Medical Sciences. The technique used for identifying infections was stool concentration by formalin & ether. All the slides were carefully studied using light microscopy with ×10, × 40, and ×100 magnification.

Results: The study results revealed that 24.6% of the workers harbored at least one parasitic species. The highest prevalence (36%) belonged to Giardia lamblia. Ascaris lumbricoides was the most common helminthic parasite (12.4%), followed by Hymenolepis nana (1.2%). The most common non-pathogenic protozoal species was Entamoeba coli (21.7%).

Conclusion: Infection with soil parasites is dependent on environmental conditions that allow parasites to complete their life cycle. Socioeconomic and cultural factors are important for the appearance and spread of intestinal parasites in communities where sanitary conditions and infrastructure are inadequate. However, soil-transmitted helminthiasis (STH) used to be prevalent throughout the country, especially in urban and rural population of the Esfahan Province. We investigated the prevalence of intestinal parasites by fecal examination of workers in Esfahan municipality, a group with a low-sanitation working environment close contact with soil contaminants. The lack of information on prevalence in the general population makes it difficult to arrive at any definite conclusions, but on the basis of unpublished data we can conclude that prevalence is somewhat higher in this occupational group compared to the population at large.

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Background and Aim: Factors determining the health care-seeking behaviors of an individual are social, cultural, and economic (treatment costs). Utilization of a health care system by a person will, on the whole, depend mainly on the socio-economic and demographic factors, cultural beliefs and practices, gender discrimination and women's status, the economic and political systems, environment, patterns of illness, and the health care system itself. The main objective of the present study was to examine current patterns of health care-seeking behavior in residents of Tehran, Iran in 2007.

Methods and Materials: In a cross-sectional study a two-stage cluster sampling method was used to select neighborhoods at the first stage and households at the second. The sample included a total of 1882 individuals over 18 years old in the households. The data were collected using a questionnaire. For analysis of the data the exact fisher test, X2, and multivariate logistic regression were used the software used was SPAA.3

Results: About 22/9% (431 persons) of the participants reported 1-2 illnesses during the previous month. Multivariate logistic regression indicated that age, sex, perceived severity of the illness, educational level, and marital status were all statistically associated with an attempt to seeking care, whether self-treatment or consulting a health center. The effects of different variables on decisions related to seeking care from a health care center versus self-care were also examined. The data showed that age, sex, perceived severity of the illness, income, educational level, household size, and method of payment were statistically the most significant variables affecting seeking care from a health center.

Conclusion: Based on these findings, it may be concluded that increasing social awareness about side effects of medicines, potential dangers of self-treatment, continuous education and training of physicians and pharmacists, improving health insurance systems and universal insurance coverage will be appropriate strategies for better utilization of health care services by the people.

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Background and Aim: The most common cancer in Iran is digestive system cancer, the highest incidence of which is reported from the Caspian Sea littoral. This study aimed to determine factors affecting the survival of patients with gastrointestinal cancer using the Cox and parametric models the 2 models were compared.

Materials and Methods: This survey was a prospective study conducted between 1990 and 1991. Data were collected through the Cancer Registry Center in Babol, which functions under supervision of the School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences. We tried to identify cases of gastrointestinal cancers. The individual characteristics of 484 patients, namely, age, sex, family history, marital status, smoking status, occupation, ethnicity, medication status, education, residence (urban, rural), and type of cancer were recorded. The patients were followed up for a period of 15 years, i.e., until 2006 year. To determine the effective factors on survival of patients, the Cox model and parametric models such as exponential, weibull, log-normal, log-logistic, and the AIC criteria and residuals were used to compare the effectiveness of the models. The SAS and STATA software were used for data analysis, with a significant level of 0.05.

Results: Sixty-six percent of the patients (total n=484) were males and 34% females, with a mean age of 59 and 55 years, respectively. Their distribution according to type of cancer was as follows: esophageal cancer, 359 (74.2%) stomach cancer, 110 (22.7%) colorectal cancer, 15(3.1%). Estimated one-, three-, and five-year survival rates were 24%, 16% and 15%, respectively.

Conclusion: The results of this study reveal that gender and family history can be strong risk factors for GI cancer. Log-normal and log-logistic models in multivariate and univariate analyses gave almost similar results. However, based on AIC criteria and residuals analysis, the log-logistic model gives the best fit as compared to other parametric models and can be used instead of the Cox model for determining factors affecting survival of patients with gastrointestinal tract cancer.

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Background and Aim: Length of stay (LOS) in a hospital is one of the best hospital indicators that can be used for various purposes. In this survey, we studied the hospital LOS and its associated factors in Tehran University of Medical Sciences Women's Hospital (a teaching hospital) in Tehran using the Cox proportional hazards semi parametric model and compared the results with the results obtained using the multiple linear regression.

Materials and Methods: This was a descriptive-analytical study in which we reviewed 3421 files of inpatients hospitalized in, and those discharged from, the oncology, surgery and obstetrics units in 2008. The required data were collected using a data collection sheet and inpatient interviews. A P<0.05 was considered statistically significant.

Results: The median of patients' LOS in the hospital was 50.8 hours, that in the obstetrics, surgical and oncology units being 48.5, 54.4 and 94.2 hours, respectively. Of all the patients, 2632 (76.9%) had been discharged with a recovery status and the rest (23.1%) with a no-recovery status. Results of the Cox proportional hazards model showed that the following variables had increased LOS: a distance longer than 200 km between a patent's residence and the hospital, hospitalization in the surgery and oncology units, admission on a Thursday, admission by an internist, hospitalization for neoplastic, endocrine, nutritional, or genitourinary system diseases (P<0.005), as well as a high number of diagnostic laboratory tests, radiographies or sonographies (P<0.001). Patients admitted and hospitalized as an emergency case had a shorter LOS (P<0.001) than others. On the other hand, based on the multiple linear regression model results, some occupations (being a worker, a farmer, a stockbreeder, or a retired spouse) admission on a Thursday, (The first day of the weekend in Iran), suffering from a neoplastic disease, and a high number of diagnostic tests or radiographies or sonographies increased, and admission by a resident decreased, patients' LOS (P<0.05).

Conclusion: Considering having censored data, the Cox proportional hazards model is a more suitable model than the multiple linear regression models for identifying factors influencing patients' LOS in a hospital. From among the LOS Cox model's associated factors as identified in this study, policy-makers and managers can only change admission days and the number of diagnostic tests. That is to say, they should try to prevent admission on a Thursday (unless emergency cases) and also perform the required primary diagnostic tests before admitting a patient into the hospital, which would lead to a more effective utilization of hospital beds and other resources.

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Background and Aim: Many researchers have studied survival (time to death) of gastric cancer patients. Although gastric cancer diagnosed in early stages can be cured by surgery, chance of relapse still exists after operation. Hence, we should consider both events, that is, relapse of the disease and death, in order to be able to make a more precise estimation for survival of the patients. The purpose of this study was to use the competing risks method to estimate the cumulative incidence functions (CIF) of the relapse of disease and death and consequently to estimate the postoperative disease-free survival.
Materials and Methods: A total of 330 patients admitted to Iran Cancer Institute and operated between March 1995 and March 1999 were enrolled in the study. They were followed up for at least 5 years to estimate their 5-year disease-free survival. Information on their demographic, clinical, and therapeutic characteristics, as well as on the type and time of occurrence of the first event (relapse of disease or death) after surgery was collected from their medical records. The direct parametric method was applied to estimate CIFs of relapse of the disease and death, while to adjust the effects of some covariates the parametric regression model was used. Data analysis was done using the R software and a p-value <0.05 was considered statistically significant. The findings were compared with the results obtained on the basis of data analysis in which the competing events were not considered.
Results: The median follow-up time was 37.9 months. Of all the patients 13% experienced relapse and 60.9% death as the first event after surgery. The CIFs of relapse of disease and death 5 years after operation, with due consideration of covariates, were estimated at 11.0% and 68.6%, respectively. Age, stage of disease, and complementary treatment were statistically associated with the CIF of death, while only complementary treatment was related to the CIF of relapse. Older patients and those in more advanced stages of disease were more likely to die after operation. Moreover, while complementary treatment after operation decreased the CIF of relapse of disease, it increased the CIF of death. The disease-free survival of patients 5 years after surgery was 20.(consideringtheeffectsofsomecovariates).
Conclusion: The competing risks method is recommended for analyzing survival data because of its capability in considering different events and, therefore, making it possible to make more precise estimations. By using this method, considering smaller variance estimates for model parameters and also narrow confidence intervals for the cumulative incidence functions of competing events, it is expected to obtain more precise results. Unfortunately, the results have revealed that the disease-free survival of gastric cancer patients is low in Iran.

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Background and Aim: Considering the acute and chronic effects of organic solvents to which vehicle painters are exposed for long periods of time, their evaluation and control is crucial for protection of health of the employees. This study aimed to find the most influential factors on exposure to, and spreading pollution with, benzene, toluene, xylem, and etylebenzene (BTEX) in order to be able to choose the best control measures.
Materials and Methods: In a motor-vehicle company the vehicle painting process was studied in detail and the solvents used in paints and in spreading organic solvent stations were identified. Based on the types and concentrations of the variables being studied, using the NIOSH method a total of 240 air samples were collected (5 samples for each variable and the respective controls) and analyzed. The SPSS version 11.5 was used for data analysis, the statistical tests being multi-regression and analysis of variance.
Results: Exposure to benzene in all occupational tasks, as well as to toluene in top coating and undercoating stations exceeded, while exposure to etylebenzene and xylene did not reach, the respective permitted exposure limits (p<0.05). The most effective factors on exposure to all the four solvents were, in order of effectiveness, occupational task, gun type, and the type of paint sued (p<0.05).
Conclusion: The effects of the variables studies – occupational task, gun and paint types – on exposure to BTEX relate to differences in occupational task work load, the type of gun used, and the paint organic solvent formulation. The reason for the potentially high exposure to benzene is its presence as an impurity in the paint solvents. Thus, it is highly recommended that in the process of control and evaluation special attention be paid to these factors.

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Background and Aim: Visceral leishmaniasis is a systemic parasitic disease with a high fatality rate in under-5-year-old children. The disease is endemic in some parts of Iran, particularly in the north-west region. In 2001 a visceral leishmaniasis (VL) surveillance system was established for children aged ≤ 12 years in the primary health system in Meshkin-Shahr District, Ardebil Province, situated in the north-west of Islamic Republic of Iran.

Materials and Methods: All cases with clinical signs and symptoms of VL and confirmed positive by the direct agglutination test (DAT) were referred for physical examination and treatment.

Results: The mean annual incidence of VL decreased significantly from 1.88 per 1000 children before (1985-2000), to 0.77 per 1000 child population after (2001-07), the intervention. In the control area with no surveillance, it increased from 0.11 to 0.23 per 1000.

Conclusion: Early detection of VL using serological tests and timely treatment of cases can decrease the mortality and morbidity rates of VL in endemic areas.

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Background and Aim: In social marketing, the common techniques of commercial marketing are used to increase the chances of acceptability of an idea or action by the target group. In this study, we determined the impact of an intervention based on social marketing to reduce risky driving behaviors among taxi drivers in Tehran.

Materials and Methods: This was a quasi-experimental study, consisting of a quantitative and a qualitative part, on taxi-drivers in 2 regions (an intervention and a control groups) in the City of Tehran. Based on a formative research approach, the components of social marketing, namely, the product (reminder message for concentrating on avoidance of two target behaviors, tailgating and not driving between lines), price, place and promotion were determined. An 8-week educational program was implemented, the components being installation of stickers before the driver's eyes, distributing a pamphlet, and transferring messages through taxi route supervisors as opinion leaders. After six weeks, risky driving behaviors were assessed by checklists and compared.

Results: The intervention resulted in statistically significant reductions in the two target behaviors in the intervention group as compared with the control group. Furthermore, logistic regression showed that the odds ratio for avoiding both behaviors increased significantly in the intervention group. 

Conclusion: Determining specific target groups, designing interventions based on actual needs and wants of the target group, and focusing on the factors influencing the behavior market are the basic elements of social marketing. Due consideration of these elements when designing behavioral interventions would lead to reductions in risky driving behaviors.

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Background and Aim: Problems related to conventional Fenton oxidation, including neccesity of having a low pH and production of considerable amounts of sludge, have prompted researchers to consider chelating agents to improve the pH operating range and iron nano-oxide particles to reduce excess sludge. The main objective of this study was to remove pyrene from contaminated soils by a modified Fenton oxidation method  at neutral pH.

Materials and Methods: Experiments were conducted using various concentrations of H2O2 (0-500 mM), iron nano-oxides (0-60 mM), reaction times (0.5-24 hours) and several chelating agents, namely, sodium pyrophosphate, ethylene diamine tetra-acetic acid, sodium citrate, fulvic and humic acids, to eliminate pyrene from soil (concentrations of 100-500 mg/kg).

Results: The efficiency of removal of pyrene at an initial concentration of 100 mg/kg was 99 % at the following reaction conditions: H2O2 and iron nano-oxide concentrations of 300 mM and 30 mM, respectively pH=3 and a reaction time of 6 hours. The initial pyrene concentration of 100 mg/kg decreased to 7 mg/kg at optimum conditions using sodium pyrophosphate as the chelating agent at pH 7.    

Conclusion: The modified Fenton oxidation method, using iron nano-oxide at optimum conditions as defined in this research, is an efficient alternative for chemical remediation or pre-treatment of soils contaminated wih pyrene at neutral pH. 

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  Background and Aim: Current traditional research methods for solving social problems were challenged due to limited participation of community . The health companion project was carried out with the aim of determining effective model of community participation for solving health problems in Boyerahmad and Dena township. .

  Materials and Methods : This study is a community based participatory research performed in Kohgiloyeh and Boyerahmad province 2005-2009.The study population was the entire rural and urban households of Boyerahmad and Dena county.The strategic committee of project including academic researchers, managers of health and health related sectors was formed and this committee selected six regions for research activities. In each region local directing group "health companion " was established with participation of stakeholders: academic researchers, local leaders, health providers and public representatives to guide all aspects of project. The members of the group empowered and enabled by attending training workshops for need assessment, priority setting, research methodology that through these activities the health problem priorities of the regions were recognized, the research area determined and intervention programs were designed and implemented according to these research area.

  Results: The most important achievement of this project is the methods of activities to reaching goals. Implementation of six participatory interventional proposal for solving health problems and needs are the other achievement. The frequency and means of health problems and their risk factors significantly reduced after the completion of intervention program in each region.

  Conclusion: Establishing and activities of health companion groups followed model of Planned Approach to Community Health (PATCH) that help community to form health promotion team, collecting and organizing of data, choosing health priorities, developing a comprehensive intervention plan and evaluation .

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  Background and Aim: In many diagnostic studies, including surveying the survival of patients with gastric cancer where each individual after surgery can experience more than one type of event, and the occurrence of one type of event hinders the occurrence of other types of events, the question of competing risk is raised. For checking the effect of each covariate on the occurrence of any event and estimating the hazard function, Cox and Fine and Gray models are used. In the event that the assumptions of two models do not hold, using them will be an incorrect course of action. One way to overcome this problem is to use models that have higher flexibility.

  Materials and Methods: In this study, the demographic, clinical and therapeutic characteristics of 330 patients with gastric cancer who referred from January 1996 to April 2000 to the Cancer Institute of Iran Imam Khomeini Hospital and underwent surgery, including their type, and the time of occurrence of the first event (locoreginal replace/death) for each patient from medical records were collected and evaluated. Using this information, the cumulative hazard function of relapse of disease was plotted by means of three models Cox, Fine and Gray and the flexible one, and was checked against the observed cumulative incidence function of recurrence of disease and, finally, their performance was evaluated.

  Results: Nearly, for each event, the proportionality assumption holds for all the variables . According to the graph of cumulative incidence function for the event of interest (recurrence), it can be seen that the Cox model, has overestimated the cumulative incidence function and the curves of two other models are very similar and also similar to the observed curve. However, the cumulative incidence function of the flexible model is smoother than the others.

  Conclusion: In the competing risk framework, Cox model is not very useful in practice while it seems that the flexible model is not only a good alternative to the Fine and Gray model but will also be superior to it when the assumption of proportionality does not hold.