Iranian Journal of

Background and Objectives Autoclaving is one of  the methods which sterilizes infectious solid wastes. Since variety of parameters such as temperature, time, and pressure influence autoclave performance, this study was carried out to evaluate the parameters and set optimum condition for the autoclave apparatus  applied in Shahid Beheshti Hospital in Kashan.
Materials and Methods: In this descriptive-analytical study, the performance of subjected autoclave was surveyed based on biological index and through setting 144 tests. Variables were packaging type in two groups (open and wrapped), loading type in three groups (light, medium and heavy), and four temperature-time features in fixed pressure equal to 101 kpa. Biological index was ATCC 7953 which contained Stearotermophilus Geobacillus spores. Finally obtained results were analyzed by Chi-Square test.
Results: The results of statistical test showed that there isn't any meaningful relation between packaging type of waste, system loading, and efficiency of sterilization(P>0.05),while meaningful relation was found between system performance and variety states of temperature-time feature(P<0.05), illustrating temperature and time effects in fixed pressure on sterilization of solid waste.
Conclusion: Based on the results, the best autoclave operational condition for sterilizing infectious solid wastes are: temperature-time equal to 10 min-140°C and 15 min-134°C in fixed pressure of 101 kpa, respectively. It was also revealed that temperature-time condition suggested by manufactory, i.e. 20min-121°C, is not sufficient for complete sterilization of solid waste.

Background and Objectives: Kidney patients in each dialysis cycle are exposed to extremely large volume of water, which is in direct contact with the patient’s blood. Hence, the occurrence of any type of contamination in the water used can be very toxic to patients. Thus, quality of water plays an important role in patient well-being. The aim of our study was to investigate the quality of water used for hemodialysis in Kashan Akhavan hospital.
Materials and Methods: This cross-sectional descriptive study was conducted on water quality used for hemodialysis in Kashan Akhavan hospital during Oct.-Nov., 2011. During the study a total of 26 water samples were taken from the raw water and inlet of hemodialysis instrument. Collected water samples were analysed for Heterotrophic plate count, residual chlorine, pH , K⁺, SO₄^2- , Na⁺, F- ,Ca²⁺ , mg²⁺ ,No^3- , Hg⁺ , Cd²⁺, Cr⁶⁺, Zn²⁺, Cu²⁺, Se²⁺ ,Co²⁺,Ag ⁺and As²⁺ according to the standard methods for water and wastewater examination.
Results: Our results showed that the concentration of copper, zinc, cadmium, lead, chromium, and silver were 0.4, 0.6, 0.07, 0.05, 0.08, and 0.04 µgL^-1 respectively. In addition, concentration of the chemical elements and heavy metals did not exceed the standard level in any cases. Moreover, no microbial contamination was observed in the samples analyzed.
Conclusion: Based on the results obtained, all water quality parameters in hemodialysis ward of Kashan Akhavan Hospital were compatible with AAMI (Association for the Advancement of Medical Instrumentation) water quality Standards and no health risk threatens the kidney patients.

Background and Objective: Street dust is consisting of solid particles with complex compositions which can be an appropriate indicator to determine urban environmental contamination. Therefore, the purpose of this study was to determine spatial patterns and heavy metals contamination in the street dusts of Kashan.   

Materials and Methods: A total of 48 urban street dust samples were collected and total concentrations of Pb, Cu, Zn, Fe, Cr, Ni, and Cd were determined in the dust samples. The geoaccumulation index was applied to assess heavy metals contamination. In addition, the spatial patterns of heavy metals concentrations in the street dust were determined using GIS.

Results: The results showed that the average concentrations of Zn, Cd, Cr, Fe, Ni, Pb and Cu in the street dust samples were 237.21, 0.43, 37.12, 16589.77, 13.62, 45.18 and 45.58 mg/kg, respectively. The average concentrations of Pb, Cu, Zn, and Fe were higher than their local background values. Based on geoaccumulation index, the heavy metals in the street dust were in the following decreasing order: Pb > Zn > Cu > Ni > Cd > Cr.  According to the spatial analysis results, higher concentrations of heavy metals were observed in the city center and Kashan-Qom highway; whereas, lower concentrations were found in the residential regions.

Conclusion: Based on the obtained results, it seems the high concentrations of Pb, Zn and Cu and to a lesser extent Fe and Cd concentrations in the dust samples was derived from anthropogenic activities; whereas the concentration of Cr and Ni has been mostly affected by natural sources. The high concentrations of heavy metals in the street dusts of Kashan could be attributed to vehicle emissions and industrial activities.