Showing 5 results for Nikaeen
E Taheri, M Vahid Dastjerdi, M Hatamzadeh, A Hassanzadeh, F Ghafarian Nabari, M Nikaeen,
Volume 2, Issue 4 (9 2010)
Abstract
Backgrounds and Objectives: Drinking water quality after treatment and before reaching the consumer could be affected by distribution pipes, service lines and Home devices. The structure of water coolers, a home device that are widely used in warm months of the year, could potentially affect the quality of drinking water. The aim of this study was to assess the microbial and chemical quality of water from conventional water coolers.
Materials and Methods : Water samples were collected from 29 water cooler systems at the Isfahan university of medical sciences. 29 control samples also obtained from the nearest drinking water taps. All samples were examined for total heterotrophic bacteria and physicochemical parameters including temperature, ph, turbidity and heavy metals.
Results: All samples from the water cooler systems complied with the EPA guidelines for total heterotrophic bacteria count. There were no significant differences between the levels of heavy metals in water samples from the water cooler systems and taps. There was only a significant difference between the level of Cu in the water samples from cooler systems and taps
Conclusion: The overall results of this study indicated that the use of water cooler systems from hygienic point of view could not cause any problems for consumers
Farzaneh Baghal Asghari, Mahnaz Nikaeen,
Volume 5, Issue 3 (21 2012)
Abstract
Background and Objectives: Legionella are gram-negative bacteria widely dispersed in
natural and man-made water sources. Some Legionella species are pathogenic and
could cause respiratory infections. Cultivation technique is the conventional
method for the detection of Legionella spp. in aquatic samples. However, the
method has low sensitivity and require prolonged incubation period. Therefore,
Polymerase chain reaction (PCR) as a rapid method with extreme sensitivity is
used. The present study was designed to evaluate the feasibility and
sensitivity of PCR method for detection of Legionellas pp. in aquatic samples
using three sets of primers.
Materials and Methods: In this study, 60 water samples were investigated for the presence of
Legionella species using Nested- PCR technique. The sensitivity of this
technique was evaluated for the detection of Legionella species in aquatic
samples using three primer sets, including (LEG225-LEG858), (LEG448-LEG858),
and (LEG448-JRP).
Results: The nested
PCR assay revealed that detection percentage of Legionella in samples was 70
when LEG448-JRP primers were used, whereas this percentage reduced to 50 and 45
when we applied prime sets of LEG225-LEG858 and LEG448 - LEG858, respectively.
Conclusion: The
results of the study showed that contamination of aquatic samples to the
Legionella spp. could be easily and rapidly detected by nested PCR. However,
selecting appropriate method for DNA extraction and choosing the primers are
important factors in efficiency and sensitivity of detection method.
Abdolmotaleb Seid-Mohammadi, Hossein Movahedian Attar, Mahnaz Nikaeen,
Volume 5, Issue 4 (15 2013)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Contamination of drinking water sources with nitrate may
cause adverse effects on human health. Due to operational and maintenance
problems of physicochemical nitrate removal processes, using biological
denitrification processes have been performed. The aim of this study is to
evaluate nitrate removal efficiency from drinking water using autotrophic
denitrifying bacteria immobilized on sulfur impregnated activated carbon in a
fluidized bed bioreactor.
Materials and Methods: After impregnating activated carbon by sulfur as a microorganism carriers and
enrichment and inoculation of denitrifying bacteria, a laboratory-scale
fluidized bed bioreactor was operated. Nitrate removal efficiency, nitrite,
turbidity, hardness and TOC in the effluent were examined during the whole experiment
under various conditions including constant influent nitrate concentration as
90 mg NO3--N/l corresponding to different HRT ranging from 5.53 to 1.5 hr.
Results: We found
that the denitrification rates was
depended on the hydraulic retention time and the nitrate removal efficiency was
up to 98% and nitrite concentration was
lower than 1mg/l at optimum HRT=2.4 hr respectively. Moreover, there was no
difference in hardness between influent and effluent due to supplying sodium
bicarbonate as carbon source for denitrifying bacteria. However pH, TOC, hardness, and turbidity of
the effluent met the W.H.O guidelines for drinking water.
Conclusion: This
study demonstrated that an innovative carrier
as sulfur impregnated activated carbon could be
used as both the biofilm
carrier and energy source for
treating nitrate contaminated drinking water in the
lab-scale fluidized bed bioreactor.
Sepideh Sadeghi, Farzaneh Mohammadi, Amir Hossein Nafez, Sahar Gholipour, Mahnaz Nikaeen,
Volume 16, Issue 2 (9-2023)
Abstract
Background and Objective: The presence of pathogenic microorganisms in compost of solid waste can threat public health. Therefore, it is necessary to evaluate the safety of produced composts before its land application as a soil conditioner. This study was conducted to investigate the presence of pathogenic microorganisms in municipal solid waste (MSW) compost and health risks associated with accidental ingestion of compost by children.
Materials and Methods: In this study, sampling was done from compost piles at different public parks of Isfahan city during the period of compost spreading. Presence and concentration of pathogenic microorganisms including salmonella, campylobacter, cryptosporidium and adenovirus were investigated by culture or real-time PCR methods.
Results: All pathogenic microorganisms were detected in MSW compost in a frequency from 11%-62% with the highest frequency for detection of adenovirus. The health risk assessment showed that the highest risk of daily infection was for Cryptosporidium (7.67 × 10-4 pppy) and the lowest risk was related to adenovirus (8.27 × 10-10 pppy). The annual infection risk from gastrointestinal disease was calculated above guideline infection risk (10-3 pppy).
Conclusion: The results showed contamination of produced compost to pathogenic microorganisms and potential health risks from applying MSW compost in urban green spaces. Therefore, the relevant organizations should pay more attention to the composting process and its microbial quality and application in public access areas.
Soudabeh Ghodsi, Mina Sheikh, Farzaneh Mohammadi, Mahnaz Nikaeen,
Volume 17, Issue 3 (12-2024)
Abstract
Background and Objective: The adverse health effects of polycyclic aromatic hydrocarbons (PAHs) have received significant attention in recent years. This study aimed to measure the concentration of PAHs associated with fine particles and assess the health risks posed by these compounds.
Materials and Methods: A total of 38 air samples were collected from the central part of Isfahan city using a particle sampler equipped with an inlet to capture particles smaller than 2.5 µm (PM2.5). The samples were analyzed using GC-MS, and molecular ratios were used to identify potential sources of PAHs. Additionally, a Monte Carlo simulation was employed to perform a probabilistic risk assessment of carcinogenic and non-carcinogenic effects of PAHs for two groups: children and adults.
Results: Out of the 16 priority PAH compounds, seven compounds were identified, with average concentrations ranging from 0.003 to 17.8 ng/m3. Molecular ratios indicated that pyrogenic sources were the main contributors to PAHs in the air. The median carcinogenic risk for children and adults was estimated to be 3.1×10-8 and 5.99×10-8, respectively. The median non-carcinogenic risk for PAH compounds was estimated at 3.08×10-1.
Conclusion: The probabilistic risk assessment revealed that the PAHs concentrations associated with fine particles do not pose a significant risk to exposed individuals. However, it is important to note that this study focused solely on the risk assessment of PAHs associated with fine particles. A comprehensive risk assessment of all PAHs present in the atmosphere is, therefore, recommended.
