Showing 7 results for Lead
A Meshkinian , H Asilian , Sh Nazmara , Jd Shahtaheri ,
Volume 1, Issue 3 (6-2003)
Abstract
The purpose of this study was to measure ambient lead concentrations in Tehran's 12th Municipal District and also Pb concentrations in urine samples from municipal workers assigned to the same region. In this research workers from the 12th District were matched and compared with a control group who were doing the same type of work in another region in northern Tehran with lighter traffic and comparatively clean air.Air samples were analyzed by atomic absorption techniques. Results showed the mean air concentration of lead to be higher than standard (1.5ug/m3) except on Fridays and Thursdays (1.9±0.32). The end-shift urine samples were prepared and analyzed using the HSE method. Lead levels in 77.1% of the urine samples were higher than HSE-recommended limits (643.86±353.73). The independent t-testindicated that the mean urine Pb concentration in the case group was significantly higher than in controls (p<0.001). Mean urine lead levels in smokers were significantly higher than non-smokers in case group (p^0.043). The Pearson Correlation test showed a significant relationship between urine Pb concentration and age, duration of employment, and smoking habit in case workers (r=0.427, p= 0.011, r=0.385, p=0.632 and r=0.632, p=0.009 respectively). Also, the Kruskal-Wallis test indicated that urine lead levels were independent of the workers'education level and work shifts.
M Arab , M Tajvar , F Akbari , H Zerati,
Volume 4, Issue 3 (6-2006)
Abstract
Background and Aim: One of the most important responsibilities of managers is leadership. Leadership styles are the constant behavioral models used by managers when working with others in organizations.
The main purpose in this research was gaining an insight into the leadership styles of hospital managers (manager and chief) and to see if there is relationship between managers and employers' personality traits and the style of leadership adopted by the hospital manager.
Materials and Methods: This was a cross-sectional study involving all the hospital managers and 385 hospital staff in the province of Qom. We gathered data through a questionnaire based on the Likert system. We thus recognized four different styles of leadership: Exploitive-Authoritative, Benevolent – Authoritative, Consultative, and Participative. Data were analyzed using the SPSS software package.
Results: 1-Overall, the managers’ leadership styles were found to be mostly of the consultative type but the staff regarded their managers’ style of leadership as mainly Benevolent – Authoritative, 2- There was no statistically significant relationship between the managers’ personal characteristics and their leadership styles, 3- There is a significant association between the staff members’ characteristics and their perception of the manager’s leadership styles.
Conclusion: The managers’ personal traits do not appear to have an effect on their leadership styles but the same traits in employees can have a bearing on how they perceive leadership in their managers.
R Saeedi , K Naddafi , R Nabizadeh ,
Volume 5, Issue 2 (5-2007)
Abstract
Background and Aim:We studied the biosorption of lead(II) and cadmium(II) from aqueous solutions by the brown algae Sargassum sp. biomass in a batch system.
The heavy metal uptake was quite rapid, reaching 88-96% of the equilibrium capacity of biosorption in 15 minutes.
Material and Methods: Kinetic data were analyzed using the pseudo first-order, pseudo second-order, and saturation and second-order rate equations.
Results: The pseudo second-order and saturation rate equations gave the best fit with the experimental data(R2 > 0.99). The data obtained from experiments of single-component biosorption isotherm were analyzed using the Freundlich, Langmuir, Freundlich-Langmuir and Redlich-Peterson isotherm models. The Redlich-Peterson equation was found to provide the best fit with the experimental data (R2 > 0.99). Also the other models described the isotherm of lead(II) and cadmium(II) biosorption with relatively high correlation coefficients (R2 > 0.93).
Conclusion: Using the Langmuir model, the maximum uptake capacities (qm) of Sargassum sp. for Pb2+ and Cd2+ were 1.70 and 1.02mmolg-1, respectively.
F Kargar, Sj Shahtaheri, F Golbabaie, A Barkhordari, A Rahimi Forushani,
Volume 8, Issue 3 (9-2010)
Abstract
Background and Aim: Lead is a toxic metal used in different industries and occupational and environmental exposure to it is quite likely to occur. Because of its high potential toxicity, serious damages to those exposed to it are common. Since the ceramic industry, in which lead is used, is considered a domestic industry in Iran, in this study occupational exposure of glaze workers to lead was assessed in a ceramic industry.
Materials and Methods: A total of 55 glaze workers (39 tillers and 16 potters) were selected as the case group. Association of lead concentration with several variables, including work shift, work type, ventilation system, and the number of extra work hours during the previous month, was determined. A sampling pump (SKC Co.) and ester cellulose filters with a pore size of 0.8 µm, 37 mm in diameter, were used for sampling. The flow-rate was adjusted at 2 l/min based on the NIOSH 7300 method. After sampling, filters were transferred to the laboratory and digested in a mixture of nitric acid and per chlorate solution (4:1) and analyzed by ICP-AES. To minimize probable errors and pollution during sampling and sample handling, samples were also taken from employees in the administration department to serve as control. Spiro metric tests were performed on both the case and the control groups.
Results: The lead concentrations were higher than the threshold limit value (TLV) (0.17 mg/m). Independent t-test showed that there was a significant relation between concentration of the lead present in the breathing zone air and 2 independent variables, including shifts work (morning and afternoon) and the ventilation system among tillers. Also, based on the one-way ANOVA, there was a significant relation between concentration of the lead present in the breathing zone and the number of extra working hours over the shift.
Conclusion: The mean lead concentration in the breathing zone was higher than the respective TLV. Considering the hazardous nature of lead, protective measures─ personal, occupational and environmental─ should be taken. Moreover, clinical examination of job applicants at the time of employment, as well as periodic examinations and Spiro metric tests on the workers, are also strongly recommended.
Abolfazl Askary Sary, Mohammad Velayatzadeh, Mozhgan Khodadadi, Mohammad Kazemian,
Volume 9, Issue 3 (3-2012)
Abstract
Background and Aim: The objective of this study was to determine the contents of heavy metals Hg, Cd and Pb in the muscle, liver and gill tissues of Liza abu fish in the Dez and Bahmanshir Rivers in Khoozestan Province, Iran in winter 2010.
Materials and Methods: The study included 108 samples of Liza abu tissues. The metals were extracted from the tissues using the wet-digestion method and their concentrations were determined by atomic absorption spectrophotometer Perkin Elmer 4100. Analysis of the data was done using the SPSS17 software, the statistical test being the t-test ((p≤0.05).).
Results: The highest concentrations (mg/Kg) of Hg (0.029±0.005), Cd (0.506±0.047) and Pb (1.07±0.096) were found in the gill and their lowest concentrations, 0.023±0.001, 0.346±0.040 and 0.903±0.030, respectively, in the muscle. The concentrations of Cd in the gull, muscle and liver were significantly different (p≤0.05) between the Dez and Bahmanshir River fish samples, but the differences with regard to Hg and Pb concentrations were not different between the 2 rivers (p≥0.05).
Conclusion: The mercury content of Liza abu tissues was lower, while the lead and cadmium contents were higher, than the respective WHO standards (permitted levels).
Eisa Solgi, Raziyeh Yazdanyar , Mina Taghizadeh,
Volume 17, Issue 4 (3-2020)
Abstract
Background and Aim: Phytoremediation is a promising method for improving soils that can easily absorb heavy metals, resulting in decontamination of the soil. The objective of this study was to assess the phytoremediation potential of Alyssum maritimum in the remediation of lead-contaminated soil.
Materials and Methods: A randomized complete block design was used with five levels of lead (Pb) concentration (as lead nitrate) and Alyssum maritimum with six treatments in the research greenhouse of Malayer University, Malayer, Iran. After growth and flowering of the plant, lead concentration in its different organs was measured by atomic absorption spectrometry. The bioaccumulation factor (BCF) and the translocation factor (TF) were used to determine the potential of plant species selected for removing heavy metals from the soil in the environment.
Results: Analysis of the data showed that the highest accumulation of lead nitrate was in the leaf. It could be expected, then, that an increase in the concentration of Pb in the soil would result in the accumulation of Pb in the organs of Alyssum maritimum. Generally the degree of Pb accumulation in various plant organs followed the pattern: leaf > root > stem pattern. The BCF and TF indices of Alyssum maritimum species were greater than 1, which would indicate a high potential for transfer and accumulation of lead in the above-ground parts of the plant.
Conclusion: The selected plant species has, based on defined criteria for a heavy metal hyperaccumulator plant and its bioaccumulation factor and translocation factor values, a high potential for remediation of lead-contaminated soil and can be included in the group of hyperaccumulator plants.
Maryam Samani, Ahmad Golchin, Hosseinali Alikhani, Ahmad Baybordi ,
Volume 18, Issue 3 (11-2020)
Abstract
Background and Aims: Heavy metals in atmospheric dust can enter the human body through ingestion, respiration and skin contact and cause various diseases. The aim of this study was to determine the concentration of lead, a heavy metal, in atmospheric dust and assess its health risk during the period between winter of 1397 and the fall of 1398 in regions 9, 10, 11 and 12 of Tehran Municipality, Tehran, Iran.
Materials and Methods: Atmospheric dusts were collected monthly during one year in the following locations in Tehran: west and east of region 9; east of regions 10, 11 and 12 (the locations in the west of these regions had common borders with the eastern part of the adjacent region). A factorial experiment was performed in a completely randomized design with three replications; the experimental factors included sampling locations and sampling times (seasons). The concentration of lead in the samples was then determined after extraction with hydrochloric acid and concentrated nitric acid (ration 3:1).
Results: The lowest (177.1 mg/kg) and highest (98.476 mg/kg) concentration of lead were found to be in location 9W (Tehransar) in winter and in location 11E (Vahdet-E-eslami Avenue) in autumn, respectively. Further analysis of the data showed that ingestion of the atmospheric dust was the main risk of exposure to lead and that more than 90% of the risk index for non-cancerous diseases caused by lead was related to ingestion hazard quotient (HQ, risk equation).
Conclusion: Based on the findings it can be concluded that in winter the hazard quotient (HQ) and hazard index (HI, non-cancer Risk Index) for lead were lower than the maximum permitted levels for adults and children and, so, did not pose any health risk for these age groups. However, in spring, summer and autumn the risk index for lead was higher than the maximum permitted level for children and, thus, the risk of children developing non-cancerous diseases was high in all the sampling locations.
