فصلنامه سلامت و محیط زیست
سال هفتم شماره 1 (پیاپی 23، بهار 1393)

The contamination of agricultural crops with heavy metals due to soil and atmospheric contamination is a potential threat for their quality and their safety. Heavy metals such as Cd and Pb have been reported for their carcinogenic effects. The aim of this study was to investigate the lead and cadmium concentration in some of crops grown in Isfahan province, Iran. During two seasons (spring and summer), 80 samples of four different crops (20 samples from each crop) were randomly harvested from some of the agricultural lands of Isfahan province. After sample preparation, lead and cadmium contents were determined by atomic absorption spectrometry. The average concentration of Pb and Cd were different in different crops. A significant difference (p<0.05) was observed between mean concentration of lead in beetroot with onion and also cabbage whereas no significant difference was observed for lead between beetroot and lettuce (p>0.05). Means comparison showed a significant difference for cadmium between beetroot and cabbage and also beetroot and onion (p<0.001). Results showed that the concentration of Pb and Cd in most of the samples was higher than the standard limits reported by Iran (maximum tolerance of heavy metal in lettuce, cabbage, rootbeet and onion is 0.2, 0.3, 0.1, and 0.1 for lead and 0.1, 0.05, 0.05 and 0.05 UNIT for cadmium respectively) and FAO-WHO. The findings of this study indicated that although most of the sampling plants were contaminated with lead and cadmium, the estimated daily intake of each metal (EDI) showed that except lead in lettuce, other crops have EDI below the provisional tolerable daily intake (PTDI) recommended by the Institute of Standards and Industrial Research of Iran. In order to better management, preventing pollution and also finding the origin of elements, analyzing heavy metals content in soil, water, and dust of this region is recommended.

As a green fuel and environmentally friendly energy, biodiesel has recently attracted much attention and efforts are ongoing to optimizing biodiesel production from microalgae’s. The aim of this study was to determine the appropriate method of dewatering and drying biomass and selecting a suitable organic solvent for extraction lipids from biomass. After culturing Nannochloropsis Oculata in Gillard F/2 medium and reaching at the end of the stationary growth phase, algal biomass was separated from aqueous by centrifuge and drying in three fore, air-dried and lyophilized. Lipid extractions of each sample was performed using soxhlet apparatus and three solvents including diethyl ether, n-hexane and n-pentane. At each stage, the quantity and quality of the extracted lipids was determined by gas chromatography. In all three drying methods, palmitic acid and palmitoleic acid were significantly the main fatty acid composition of microalgae. The fatty acid composition of palmitic acid extracted by diethyl ether was significantly more than the other two solvents. Maximum production of triglyceride was observed in air dried and lyophilized (using diethyl ether solvent) microalgae as 75.03 and 76.72 % of fatty acid respectively. The use of lyophilized method for dewatering and drying of biomass and diethyl ether as solvent for the extraction of lipids from biomass yielded more compared with other methods studied in this paper and would be more efficient in research works related to the production of biodiesel from microalgae’s lipid.

Extreme use of antibiotics and discharging them to the environment lead to serious consequences. Activated carbon is the most commonly adsorbent for these contaminants but its main drawback is difficulty of its separation. The objective of this study was synthesis of magnetic activated carbon by Fe3O4 and investigating its efficiency in adsorption of amoxicillin from synthetic wastewater. Physical and structural characteristics of the adsorbent synthesized were analyzed using SEM, TEM, XRD and BET techniques. The effect of factors like pH, initial concentration of amoxicillin and adsorbent, contact time, and temperature were investigated to determine thermodynamic parameters, equilibrium isotherms, and kinetics of adsorption process. Physical characteristics of the magnetized activated carbon showed that Fe3O4 nanoparticles had the average size of 30-80 nm and BET surface area was 571 m2/g. The optimum conditions of adsorption were: pH=5, contact time=90min, adsorbent dose of 1g/L and temperature 200C. The equilibrium isotherms data showed that the adsorption process fitted both Freundlich and Longmuir models with the maximum capacity of 136.98 mg/g. The kinetic of the adsorption process followed pseudo second-order model. The negative values of ΔH0 and ΔG0 obtained from studying the adsorption thermodynamic suggested that amoxicillin adsorption on magnetic activated carbon was exothermic and spontaneous. The present study showed that the magnetic activated carbon has high potential for adsorption of amoxicillin, in addition to features like simple and rapid separation. Therefore, it can be used for adsorption and separation of such pollutants from aqueous solutions.

The present study was designed to determine total mercury concentrations in sediment and the soft tissues of two bivalve species, Saccostrea cucullata and Callista umbonella, in coastline of Bandar Abbas in 2011. Generally, 67 bivalves and 10 sediment samples were collected from two stations (terminal of Bandar Abbas and tourism park of Soro). We measured total mercury concentrations in each sample using Mercury Analyzer (Leco AMA 254). Means of mercury concentration were 145.58 and 151.13 (ng/g dw) in soft tissues of oyster S. cucullata and 34.5 and 63.95 in the soft tissues of Clam C. umbonella in two stations, terminal of Bandar Abbas and tourism park of Soro respectively. Total mercury concentrations were 30.27 and 20.55 (ng /g dw) in the sediment samples in two stations, terminal of Bandar Abbas and tourism park of Soro respectively. A significant difference was found in mercury concentrations between soft tissue of the two species (p <0.01). Considering higher concentration of mercury in the soft tissues of oyster S. cucullata than clam C. umbonella, lower coefficient of variation in soft tissue of oyster relative to clam C. umbonella, and also significant correlations between mercury levels in the soft tissue of oyster and sediments, it can be concluded that the soft tissues of oyster S. cucullata can be used as biomonitoring agent for mercury in intertidal zone of Bandar Abbas. In comparison with food safety standards (FDA, EU Commission and NHMRC), mercury concentrations in oysters were well within the permissible limits for human consumption.

In this experimental study, we used Analytical Hierarchy Process method to determine the best wastewater treatment process for dairy products factories. That is a multi-criteria decision making techniques and is based on expert knowledge. First, we formed the hierarchical structure and defined the main criteria and indicators. Then, we investigated the current situation of the treatment process through field observations and conducting influent-effluent analysis. Later, we converted the results obtained into quantitative indices. Then we weighted the main criteria, and their related sub criteria, depending on existing conditions; we performed the experiments required and considered the experts ideas. Finally, Evaluation and prioritization of the options was conducted using Expert choice software. Then the sensitivity analysis was performed for main criteria and we evaluated the influence of the parameters weight change on the options. In comparison with the main criteria, environmental criteria were more important followed by engineering criteria, economic and management criteria. Due to the influence of various parameters in choosing optimal wastewater treatment, Multi-criteria decision-making methods are necessary. Finally, “UASB + Aeration” was found to be the first priority followed by “Anaerobic filter + Aeration”, “Anaerobic lagoon + Aeration (2) + Sedimentation (2)”,” Anaerobic filter + Aeration (2) + Sedimentation (2)”. “Septic tank + Trickling filter + Aeration” system was found to be less preferable than other options.

FMEA is one of the best known system safety techniques widely used as an identification tool. The purpose of this study was to apply FMEA method to identify and assess the risks posed by power lines in a residential area is Hasyrabad, Ahwaz. First, we identified the power line process and the equipment involved. Later, we determined the failure modes of equipment, which leads to the risk in the area studied. In order to measure the magnetic field lines, we used 3D EMF TESTER. Risks identified were scored based on the FMEA and for each case we calculated RPN. Then, with the help of SPSS software, we calculated level of risk and the cases identified were prioritized and analyzed based on the risk level. The highest RPN values were associated with health risks and all risks involved in this group are at emergency conditions. It was revealed that wires (loss of privacy) and power transmission line (non-compliance with privacy standards) had highest value (RPN 360) and disconnect switch had lowest value (RPN 60). Due to the high risk in most cases, control measures were proposed based on the expertise in the safety-related equipment, training operators, and regulatory measures in order to reduce the level of risk.

Listeria bacterium resists to the sludge digestion conditions and Listeria monocytogenes is the most important of them. Sludge produced in the north Isfahan wastewater treatment plant is stabilized by anaerobic digesters and is used for fertilizing agricultural lands after drying in the sludge drying beds. Based on the importance of the subject, the objective of this study was evaluation of sludge processing units efficiency, particularly anaerobic sludge digestion for reduction or removal of Listeria. In this descriptive study, samples were collected weekly from sludge processing units 13 times in north Isfahan wastewater treatment plant according to standard methods over three months. Listeria bacteria were enumerated and isolated by triple-tube fermentation method and U.S Department of Agriculture method respectively. Isolated Listeria were confirmed by phenotypic method and then bacterial species were diagnosed differentially by biochemical carbohydrate fermentation and CAMP test. Contamination of raw, stabilized and dried sludge at least to one of L. Monocytogenes, L. Innocua and L. Seeligeri species was 100, 92.3 and 53.8 percent respectively. Anaerobic sludge digesters efficiency to remove L. Monocytogenes, L. Innocua and L. Seeligeri species was determined 64.7, 39.72, and 100 percent while the efficiency of drying sludge beds for L. monocytogenes and L.innocua species removal was 73.4 and 96.68 percent respectively. Listeria monocytogenes is more resistant than other identified species against the sludge processing conditions. Thus, the use of sludge as fertilizer can cause the spread of this bacterium in the environment and agricultural products pollution.

Soil polluted with total petroleum hydrocarbon (TPHs) is a great threat to human health. Phytoremediation, the use of vegetation for treatment of contaminated soils, is an attractive and cost-effective alternative to reduce pollutant from soil. This paper evaluates the effects of the plant and nutrients on the removal of TPHs from soil. Soils were collected at depth of 0-30 cm, and then polluted with 1 and 2.5 % w/w of crude oil. After preparing the experimental pots, Rhizosphere microbial number, plant biomass, and residual TPHs were determined. TPHs and heterotrophic bacterial number were measured by GC and HPC method respectively. Data were analyzed using the Statistical Package for Social Sciences (SPSS 17 for Windows) software and Excel. It was found that the average percent of TPH removal in planted soil (28.42%) was higher than that in unplanted soil (12.2%) (p<0.05). Moreover, the average percent of TPH removal in treatments received nutrient and free nutrient treatments was 35.5and 17.7% respectively. Generally compared with the other studies, high clay and salinity of the experimental soil had a negative effect on phytoremediation efficiency. Finally, regarding to the high clay and salinity of the experimental soil, the phytoremediation efficiency was relatively desirable.

Doogh is considered as one of the traditional drink in Iran and other nations like Eastern Europe, Middle East and Asia. In the past the “doogh” was applied to a product which remained after dilution of full fat yoghurt with water and fat separation using the musk. Nowadays Doogh has have physical, chemical, physico-chemical, microbial and sensory characteristics and standards. In this study the microbial quality of four famous brands produced in Iran was assessed. This is a cross-sectional study. Totally, 126 samples were selected from the foodstuff suppliers using random sampling. In order to determine Staphylococcus aureus, Baird Parker Agar (recognition test) and coagulase test (confirmation test) were used. The results were analyzed using SPSS, and T-Test and one way ANOVA were performed. The results showed that in view of contamination there is Significant differences between the months, the brands and the types of doogh (p<0.05). According to the results and due to probable presence of Entrotoxin, the analyzed brands can be potent risk to consumer’s health.

In the recent years, we confront to harmful effects of toxins such as herbicides on aquatic species due to irregular consumption of these compounds in agricultural operations and drainage of them to water ecosystems. In the present study, the effect of 2,4-D + MCPA “the frequently used herbicide in Kurdistan province” was assessed on the hematological parameters and liver enzymes in rainbow trout as the main aquatic species farmed in this area. After determination of LC50 using Probit model, 60 healthy trout fish with an average weight of 97 g were divided into two groups. The first group was considered as control and in the second treatment group, 1 cc/L herbicide (equivalent to 360 mg/L 2,4-D + 315 mg/L MCPA) was used. After 72 hours, hematology parameters including total number of red and white blood cells, differential count of white blood cells, hematocrit, and serum levels of ALT and AST enzymes were measured. The values of blood tests including leukocytes, monocytes, and eosinophils in the toxin group was significantly increased in comparison with control group, whereas, the values of lymphocytes, erythrocytes and hematocrit were significantly decreased in toxin group compared with the control (p<0.05). There was no difference between the level of neutrophils in the treatment and control groups. The levels of liver enzymes, ALT and AST, in the treatment group increased significantly compared with the control group (P<0.05). The mortality rate after of 72 hours was 25% in the group treated with the toxin. Erythrocytes and hematocrit amounts of blood in rainbow trout were decreased due to exposure to 2,4-D + MCPA herbicide that eventually leads to oxygen deficiency and inefficient blood supply. The contact of red blood cells and hematopoietic tissues to toxin and destruction of them are led to loss of the cells in the blood. On the other hand, liver, kidney and gills autopsy of the wasted fish and the increasing of liver enzymes in the blood and tissues showed that exposure to the toxin lead to damages in fish blood cells and tissues.

Traditional cheese has a special place in the diets of our community because of cultural, favorite taste, odor and its nutritional values as an important protein source. However, its pathogenic infection can endanger the human being health and cause serious economic losses. The aim of this study was measurement and determination of microbial infection in traditional cheese distributed in Markazi province in 2010. Markazi Province was divided into 10 districts; eight sample were chosen from each district at summer, 2011. Samples were transferred to the laboratory under sterile conditions and were analyzed by microbiological tests. The data were analyzed statistically by T-test using SAS software. The results indicated that all of samples had coliform, staphylococcus aurous, mold, and yeast contamination greater than Iranian standards (P<0.001). It was found that 34 percent of the samples had E.coli contamination; moreover, 24 and 8 percent of samples had Coagulase-positive staphylococcal and salmonella contamination respectively. These results indicate a notable contamination of traditional cheese with microbial infection in Markazi province.