[Elimination of copper and zinc from industrial wastes by mutated bacteria]

Today, toxic effluents have created ecological and health problems in and around the industrial cities resulting in death of nearby living organisms. The aim of this research was to increase the elimination of copper and zinc from copper factory effluents in Kerman/Iran through mutation inducing in metal-resistant bacteria by using Acriflavine, Acridine orange and Ethidium bromide. A total of 20 strains of Pseudomonas spp. were isolated from water and soil of the factory and subjected to microbiological identification. Maximum Inhibitory Concentration [MIC] to Cu and Zn were determined by agar dilution method. Those strains with the highest MIC to these metals [5mM] were subjected to 400-3200mg/L of the above mutagenic agents. After determination of MIC those colonies which were capable to grow on 20mM copper were selected for atomic absorption spectroscopy. According to the atomic absorption spectroscopy of dried biomass obtained from resistant strains after exposure to mutagenic agents, strains 6,7,8,9,10,13 and 16 showed the highest accumulation of CU and Zn [10mM for Cu and 20mM for Zn]. Strain 13 had the highest absorption of Cu [0.35%/mg biomass] and strain 10 showed the highest accumulation of Zn [0.33%/mg biomass]. Elimination of heavy metals by artificially mutated bacteria can be suggested as a cost effective solution to this environmental health issue

Impact of quality control on radiation doses received by patients undergoing abdomen X-ray examination in ten hospitals

The X-ray machines used for radiodiagnosis should meet certain quality assurance [QA] programmes. These are necessary to have good quality radiographs at reasonably low exposure to patients. Dose reduction methods in abdomen X-ray examination were carried out in 10 hospitals in Tehran. This paper presents the work, which was implemented on 200 patients and evaluated using the entrance skin dose [ESD] in the Anterior-Posterior [AP] abdomen projection measured directly at the center of the X-ray field. In addition, the machine room, and dark room parameters, as well as work practices and repeat rates were studied. The quality control [QC] parameters and the ESD were evaluated utilizing an anthropologic phantom to define the optimal exposure condition at all hospitals before and after QC. Results show that after using the QC parameters and optimization of the exposure condition s, the mean of mAs and ESD can be decrease d by 62% and 65% respectively. The quality of the radiograph s generally increased. The reported method is easily implemented in any clinical situation where optimization of abdomen radiography is necessary