Search published articles


Showing 6 results for Yousefi
Study of the Pollution Condition of Swimming Pools in Sari City for the Staphylococcus aureus 
Z Yousefi,
Volume 2, Issue 3 (25 2009)
Abstract

Backgrounds and Objectives: Swimming pools water if not disinfected properly can be one of the infection sources of different microorganisms such as staphylococcus. This study is to aware the authorities and users about the conditions existed in sheltered swimming pools in Sari and to believe the contamination of the water there, related to the existence of staphylococcus aureus.

Materials and Method: In this descriptive study 32 specimens collected randomly from 15 swimming pools in action during three months from 60 cm deep under specific conditions in sterile containers and taken to the laboratory of health college in 2 hrs and were analyzed for the contamination from staphylococcus aureus and some other parameters like temperature, pH, chlorine residual and opacity on the basis of microbiological and standard methods.

Result: Results showed an average temperature of 27.08 degree Celsius, PH=7.6, average chlorine residual 1 mil/l and opacity average was 77 NTU % and the highest contamination from staphylococcus aureus (29.3 %) in C and the lowest (10.19 %) was observed in D swimming pool. Furthermore this analysis showed that in 90% of specimens there was a direct relationship between the ratio of chlorine residual, times of swimming, water temperature and the number of staphylococcus.

Conclusion: Swimming pools water if not disinfected properly can be one of the infection sources of different microorganisms such as staphylococcus. Some suggestions inorder to optimization of the swimming pools condition presented in this paper.


The Study of the Status of Electromagnetic Waves Resulting from BTS (Base Transceiver Station), 900 Megahertz Frequency in Tehran
P Nasiri, M.r Monazam, S Zare, K Azam, Z Yousefi, R Hematjo,
Volume 4, Issue 3 (1 2011)
Abstract

Background and Objectives: with the developments of technology, contact with various frequencies of electromagnetic fields ( EMF ) has significantly increased, while the abundant benefits of using microwaves in routine life cannot be neglected. During recent years there have been reports of adverse effects caused by contact with electric and magnetic fields of these waves that spread from BTS antennas. The purpose of this study is the measurement of microwaves spreading around BTS antennas in Tehran.
Materials and Methods:  according to the location of BTS antennas in Tehran , power density of electromagnetic waves around 63 antennas in near and distant fields in different distances was measured. The measurements were performed using the standard method of IEEE Std C95.1 by Hi-4333 device .in order to analysis  data we used spss 16 and descriptive and deductive statistical tests.
Results: results of this study show that in the near field, with increase of distance  from the foot of antenna , the  average power density of electromagnetic waves increase in a way that in the distance of 10 meters from the antenna foot , the increase of average power density is hardly conceivable and from 10 to 15 meters distance is perfectly noticeable. But in the distant field, with increase of distance from 20 meters, the average power density of the electromagnetic waves decreases and from 100 meter and further, the gradient of the diagram will get almost linear and the rate of power density reaches the base limit in a way that with the increase of distance there would be no significant decrease.
Conclusion: All the measures of power density of electromagnetic waves caused by BTSs are about 0.06% of recommended measures of environmental standards and 0.0000013% of occupational standards. The results of this study are close to the results of other studies.


Measurement of radon concentration in indoor air of residential and public buildings in Nourabad Mammasani city and estimation of its effective dose
H Hassanvand, N Dehghan, K Naddafi, Ms Hassanvand, R Nabizadeh, S Faridi, Z Yousefi,
Volume 11, Issue 4 (3-2019)
Abstract
Background and Objective: Radon gas is one of the environmental risk factors which can increase the risk of lung cancer and it is well known as the second-leading cause of lung cancer after smoking. The aim of the present study was to investigate indoor radon gas concentration in residential and public environments of Nourabad Mammasani city and to estimate the effective dose due to radon exposure.
Materials and Methods: In this study, 52 homes and 8 public places were investigated to measure the concentration of indoor radon gas. Indoor radon concentrations were measured using passive sampling approach, alpha-track detectors (CR-39) for three months, and after that, detectors were sent to the laboratory to count the number of tracks.
Results: The results of this research showed that the average radon concentration (± SD) in the homes and public places was 42.4(±14.7) and 32.9(±20.1) Bq/m3, respectively. All radon concentration values were lower than the US Environmental Protection Agency standard and WHO guideline. The average of annual effective dose due to the radon exposure in homes was estimated to be 1.07 mSv. The evaluation of the results showed that there was a significant relationship between the room type and the number of floors with radon concentration in the residential buildings.
Conclusion: The results indicated that the indoor radon concentration as an environmental risk factor in the studied places was lower than the WHO guideline levels. Consequently, the indoor radon is not likely a major environmental risk factor in the studied environments.

Investigating the treatment and mineralization of olive oil mill wastewater by using electrocoagulation and novel various advanced oxidations: a kinetic study
Mr Khani, Ah Mahvi, Ma Zazouli, Z Yousefi, Y Dadban Shahamat,
Volume 12, Issue 1 (5-2019)
Abstract
Background and Objective: Olive Mill Wastewater (OMWW) is one of the most polluted sanitary wastewaters that its ineffective treatment will cause severe pollution of the environment. In this study, OMWW treatment wasinvestigated using combined electrocoagulation and novel advanced oxidation process.
Materials and Methods: Biodegradability, efficiency and kinetics of removal of turbidity and organic matter from the OMWW by applying the operational parameters of electrocoagulation such as current density (0-0.77 A/dm2), type of anode electrode, reaction time (0-45 min) were investigated. Various types of advanced oxidation processes were performed to determine the the efficiency of removal of TOC and kinetics and biobegradability.
Results: The optimum condition for removing turbidity, BOD, TOC and consumed Iron anode electrod in electrocoagulation were 78%, 57%, 72% and 583 mg/ per liter of wastewater, respectively. Thus, the kinetic of TOC removal was first-order and was 0.027 min-1. The TOC removal efficiency of pretreated OMWW in oxidation processes of US, H2O2, SOP, O3 / H2O2, COP, COP/US and H2O2/COP/US were measured as 8%, 15%, 20%, 25%, 61%, 68% and 75%, respectively. The highest biodegradability index (BOD/TOC) in the COP/US/H2O2 process was increased 1.5 times.
Conclusion: The advenced oxidation process of COP/US/H2O2 follwed by electrocagulation demonstrated an effective treatment of OMWW and improved its biodegradability. Therefore, this process can be used for efficient treatment of OMWW in olive and similar industries.
 

Removal of nickel from paddy soil by electrokinetic reclamation process, a case study of Silakhor plain (Lorestan)
Mohsen Shaban, Daryoush Yousefi Kebria, Marzie Razavi,
Volume 14, Issue 1 (5-2021)
Abstract
Background and Objective: Application of chemical fertilizers in agricultural industry is known as one of the methods of crop enhancement. However, chemical fertilizers application can lead to an increased risk of chemical pollutants entering the human food cycle.  The aim of current research was feasibility study and evaluation of nickel from paddy soils in Lorestan province.
Materials and Methods: Sampling was done from 15 stations and randomly from rice cultivation areas in Silakhor plain of Lorestan province. Then, electrokinetic modification method was carried out in three reactors with lengths of 5, 10 and 15cm. After sample preparation, the initial and final concentration of nickel were measured and calculated using inductively coupled plasma - optical emission spectrometry (ICP-OES).
Results: The results showed that electrokinetic modification method was effective in reducing the concentration of heavy metals in agricultural soil samples and reduced the amount of nickel in soil to the permissible limits of the Iranian soil national standards (50 mg/kg). The initial values of nickel in paddy soil of composite samples were 108 mg/kg. Nickel maximum removal efficiency of 90.84% and 93.75% were observed in cathode and anode regions, respectively.
Conclusion: The health and quality of agricultural products depend on the use of safe soil within the limits of environmental standards. The results of this study showed that the EKR process is able to remove nickel from soil. As a result of the present process, nickel concentration has reached the permissible amount and even lower than the soil quality standard set by the Iranian Environmental Protection Agency.

Evaluation of environmental health measures related to corona disease in dental offices of Sari in 2021
Zabihollah Yousefi, Adel Naderi, Seyed Noureddin Mousavi Nasab, Samaneh Dehghan,
Volume 16, Issue 3 (12-2023)
Abstract
Background and Objective: The high risk of Sars-CoV-2 infection in dental centers is a serious problem for doctors and patients. The main purpose of this study was to investigate the environmental health measures related to corona disease in the dental offices of Sari city during the COVID-19 epidemic in 2021.
Materials and Methods: The present study is descriptive and cross-sectional, and the tool used in it is a researcher-made questionnaire collected with the cooperation of the personnel working in 100 active dental service centers in Sari. to determine content validity, two qualitative and quantitative -qualitative methods were used. The qualitative content validity of this questionnaire was confirmed by 8 environmental health experts. Cronbach's alpha was used to determine the reliability of the questionnaire. Data analysis was done using SPSS software V. 25.
Results: Based on the results of this study, personal protective equipment was used continuously in 100% of the centers. In 93% of the centers, sodium hypochlorite and formaldehyde were used to disinfect the equipment, and in 94% of the cases, the frequency of disinfection of the equipment was after each patient. Disinfection of toilets was done daily in 62% of the centers and every two days in the rest. In 72% of the examined dental centers, had no local hood installed or turned on above the units, but in 92% of the offices, there was proper ventilation of public spaces. In addition, according to the results, in 99% of clinics, waste management was carried out in accordance with national laws and regulations and based on the rules and methods of the executive management of medical waste and related waste and related instructions, and also in 100% of clinics, water consumption was healthy and desirable.
Conclusion: Overall, environmental health measures in dental offices were at an optimal level in most cases and in accordance with the instructions of the Ministry of Health. Not installing a hood or not turning it on above the units and improper ventilation of the dentist's office were the most critical problems of the centers, which need to be given more attention and corrective measures should be taken according to the instructions of the Ministry of Health.
 

Page 1 from 1     

© 2024 , Tehran University of Medical Sciences, CC BY-NC 4.0

Designed & Developed by: Yektaweb