ackground and Aims: Chromium (Cr), as a metallic pollutant, enters to the body through drinking water. Due to the toxic and dangerous characteristic of hexavalent chromium, its removal is necessary. In this research, titanium dioxide nanoparticles were used as an adsorbents to remove Cr from water. Materials and Methods: The characteristic of TiO2 nanoparticles were determined using XRD and FTIR analyses. Batch adsorption experiments were performed using synthetic aqueous solutions containing chromium. The optimal conditions of adsorption were investigated at various pHs, initial concentration of metal ion, contact time and the adsorbent dosage on Cr adsorption capacity. Also, the study was carried out ethically and there was no bias and confinement on the part of the researcher during the research process. Results: The results showed that the removal percentage at pH=3 (88.50%) was significantly more than the other studied pHs. The lowest removal percentage was observed at pH = 9 (38.03%). at the highest Cr adsorption was noticed in concentration of 0.5 g/L (61.52%), which was statistically significant as compared to other concentrations Accordingly, the lowest adsorption was observed at 5 g / L concentration (6.75%). Adsorption performance was not significantly different at different times, and the amount of adsorption was almost constant after 30 minutes. Cr adsorption by TiO2 nanoparticles increased with increase in adsorbent dose and the maximum amount of adsorption occurred at 4 g/L (68.31%) which again was significantly higher than other studied dosages. The lowest removal percentage was observed at 1 g/L (18.57%). The sorption isotherm studies showed that adsorption of chromium by titanium dioxide was fitted well to Freundlich isotherm model (R2 = 0.78). Conclusion: Titanium dioxide demonstrate high efficiency in adsorbing chromium from wastewater and thus can be a promising sorbent for the treatment of industrial wastewaters.

ackground and Aims: Incorporation of health literacy (HL) into health belief model (HBM) assist in strengthening the performance of this model in predicting smoking preventive behavior. However, the type of such an effect and the way in which the HL works in this hybrid model has not yet been determined. Therefore, this study was aimed to determine the influencing ways of HL on adoption of smoking preventive behavior in HBM incorporated with HL. Materials and Methods: In this cross-sectional study, 340 dormitory students of Shahid Beheshti University of Medical Sciences in Tehran were enrolled using single-stage cluster sampling. The data collection tool was a valid and reliable questionnaire based on HBM on smoking prevention and HL questionnaire (HELIA). Data were analyzed using SPSS version 16 and path analysis method based on single-variable and multiple regressions. All stages of the study were conducted ethically. Results: HL had a direct and statistically significant effect on all structures of the model and adoption of behavior. Also, it indirectly influenced adoption of behavior by influencing the structures of the model. Only perceived susceptibility and self-efficacy variables significantly affect adoption of behavior. In addition, the indirect effect of HL on the adoption of behavior was greater than its direct effect. Conclusion: It is possible to improve the degree of HL and, therefore, the adoption of smoking preventive behavior among students through the use of HBM incorporated with HL, which emphasizes on perceived susceptibility and self-efficacy variables.

Background and Aims: The leakage of hazardous materials in industries threatens the workers and residents around these industries and also severely damages the environment. This study thus aimed to predict the emissions and the probable effects of carbon disulfide using ALOHA software in order to performing the appropriate safety measures and consequently to reduce the adverse effects. Materials and Methods: The results of HAZOP studies were used to identify the hazards in one of the refinery units. The plausible worst scenario was also chosen. ALOHA software was then used to model the probable scenarios of carbon disulfide emissions from the tank. All stages of this research were conducted ethically. Results: Based on the results obtained, the concentration of carbon disulfide reaching to the control room would be fatal in the event of an incident. This result is supported by carbon disulfide concentrations of 480 ppm in an area of up to 600 meters around the tank, which is in the range of AGEL-3. In the event of full leakage, the concentration of carbon disulfide would be 7800 ppm 150 m around the tank, which is about 60% of the minimum flammable concentration of this gas. The explosion wave pressure in a distance of up to 190 m around the tank is anticipated to be about 3 psi, which may cause serious injuries to workers. Conclusion: The consequences of carbon disulfide toxicity in the studied refinery are one of the most serious threats to the personnel. Therefore, preparing a reaction plan for emergency conditions will have an effective role in limiting the harmful effects of the toxic and dangerous materials emissions.

Background and Aims: Falls in the elderly has been known as a common and serious problem. Each year about one third of old adults experience a fall. The injuries resulted from fall results in hospitalization, prolong pain, decreased functional performance, disability, and death. The purpose of this study is to investigate the fall and some of its related individual factors among the elderly attending to health centers affiliated to the health network of Rey city. Materials and Methods: This cross-sectional study was conducted on 368 older adults aged 60 and over who referred to health centers. A “multi-stage” sampling method was considered. The data was collected using a questionnaire completed through interview. The questionnaire included demographic characteristics, number of falls during the past year and individual factors. The standard balance test was also conducted to assess the balance. The data were analyzed by SPSS software (version 16) through the related statistical tests. Correlations were considered significant at a = 0.05. All ethical issues were considered throughout the study. Results: About 62.8% out of the total study group were female and the remaining 37.2% were male with median age of 68.41 ± 6.6. By the use of one-variable logistic regression test, it was found that age, gender, marital status, literacy status, postural hypotension, balance disorder, urine disorders, visual impairment, history of heart attack and sleep disorder all had significant relation with fall in the elderly (P < 0/05). Conclusions: The results of this research showed that one in every four elderly participated in health centers of the health network of Ray city has experienced a fall per year. Thus, in addition to proper assessment of the elderly at risk with individual and environmental factors, to prevent and decrease the rate of falling, they need to be educated. A safe environment should also be provided for them.