فهرست مطالب ghasem rajaei

The purpose of the present study was to determine the acute toxicity (LC50) of HgCl2 and CuSO4 in Caspian roach (Rutilus caspicus) and CuSO4 in Caspian kutum (Rutilus kutum). The Caspian roach LC50 values for HgCl2 at 24, 48, 72, and 96-hrs of exposure, were 0.64, 0.61, 0.42, and 0.28 mg L-1, respectively, and for CuSO4 were 11.55, 5.08, 2.49, and 1.47 mg L-1, respectively. The Caspian roach LC50 values for CuSO4 at 24, 48, 72, and 96-hrs of exposure, were 5.31, 4.17, 3.20, and 2.25 mg L-1, respectively. The results of this study showed that the toxicity of HgCl2 is higher than that of CuSO4 for the studied species. The mortality decreased with time, and most of the deaths were occurred during the first 24 hrs.

Background and The release of metals due to different natural and human activities, bioaccumulation, biological inseparability and toxicity, even in low densities, have caused serious threat to living creatures and human. This study evaluated the concentration of heavy metals including lead, cadmium, zinc and copper in edible tissues of Caspian Kutum (Rutilus frisii kutum) in Miankaleh International Wetland and the health risk resulted from consumption of this fish. During fishing season, 20 White fishes were collected from Miankaleh International Wetland with the permission of Environmental Protection organization. The densities of heavy metals in skin and muscles were determined using atomic absorption (Scientific Equipment GBS). Data was analyzed using SPSS V.16. The mean densities of lead, cadmium, zinc and copper in the skin were 3.4, 0.48, 40.55, and 3.3, respectively and 2.1, 0.39, 16.52, 4.5 microgram per gram of the wet weight in muscle tissues, respectively. A significant difference was seen in the concentration of heavy metals between the skin and the muscle tissue (p<0.01). The observed EDI and EWI were found lower than the guidelines recommended by WHO and FAO. According to this study the concentration of zinc and copper in whitefish were lower than the standard levels, so its consumption is not a threat to the health of consumers. However, the levels of cadmium and lead in edible tissues of whitefish were found higher than international levels. Hence, the pollutants of Miankaleh wetland (i.e. industrial and agricultural wastewater) should be highly controlled.

Background and Lack of awareness of people about the future environmental risks posed by wastes is the most important problem of this sector. Awareness, and then cultural education in this area, can be a breakthrough to this significant environmental problem. This study aimed to assess the degree of awareness of the people of the cities of Gorgan, Gonbad, and Aliabad Katool (Iran) in relation to municipal solid waste management. In this descriptive-periodic study in 2012, a questionnaire with a Cronbach's alpha of 0.78 was used. 550 questionnaires were completed: 200 in different areas of the city of Gorgan, 240 in different areas of the city of Gonbad, and 110 in different areas of the city of Aliabad Katool. Data were analyzed by SPSS software. The awareness of the citizens in the studied cities in the area of waste-related diseases and the waste effect on the environment was satisfactory. The rate of citizen's awareness in the field of recycling and ways of reduction of household waste and the methods of waste disposal was above the average. The awareness in the area of existence of urban recycling organization and its duties was rated weak to average and in the area of compost, it was weak. The performance of citizens in the area of relation of people with urban materials recycling organization and regional municipality regarding solid waste materials was rated very weak to weak and in the area of source waste separation, the performance was rated average. Considering the results obtained, the information of people regarding compost production and existence of urban recycling organization and its duties was low and, it is necessary to provide certain educational programs for increasing public awareness.

During recent years, overpopulation, increase of wastewater, and drop in water tables has led to high concentration of salts in underground water, which is an important environmental pollutant. If concentration of salt in drinking water exceeds the limits, it will be dangerous for health. The aim of this study was to measure physical and chemical parameters in drinking water of rural areas of Birjand and Qaen plains, Iran, and compare them with national and international standards. This was a cross sectional descriptive study carried out during the autumn of 2009 and the spring of 2010. 54 samples from 27 stations (27 samples in spring and 27 samples in autumn) were randomly collected and the concentrations of their physical and chemical parameters were measured. The results were analyzed by descriptive statistical method and Shuler’s diagram. The results showed that the remaining dry solids (37%), hardness (25%), sulfate (33%), Sodium (70%), Chloride (25%), and electrical conductivity (%51) in all samples, were more than national standards. Fluoride concentration in 92% of analyzed samples was less than the minimum recommended level. According to Shuler’s diagram, the parameters of water quality ranged between good and poor situations. Since the recent drought has negative impacts on water quality of rural areas, and the measured parameters have not met the standards, it is necessary to consider a continuous plan for monitoring of water resources.