afshin maleki

Natural organic matter (NOM) in drinking water sources has always been regarded as a precursor for the formation of trihalomethanes (THMs), haloacetic acids (HAAs), and carcinogenic properties. This study aimed to fabricate and characterize a nanohybrid ultrafiltration membrane (PSF/ZnO) to evaluate its efficiency in NOM removal from water.

Nanohybrid membranes with ratios of 0, 1, 2, 3 and 4% w/w of ZnO nanoparticles (NPs) were fabricated using the phase inversion method and characterized by the contact angle, AFM, FTIR, and SEM analyses. In this study, the effects of initial humic acid (HA) concentration, operating pressure, pH, and filtration time were examined on the HA removal efficiency and pure water flux through the membrane.

The results showed that addition of the ZnO NPs to the PSF membrane reduced the contact angle on the PSF/ZnO nanohybrid membrane’s surface. According to FE-SEM images, increasing the ZnO concentration changed the porous structure of the membranes from a spongy, teardrop shape to a finger-like channel structure. The FTIR analysis revealed an increase in the hydrophilicity of the membrane due to the presence of hydroxyl functional groups in ZnO. AFM images indicated an increase in the surface roughness of nanoparticle-containing membranes. It was found that an increase in the concentration of the ZnO NPs (0-4% w/w) increased HA removal efficiency (43.63-83.4%).

This study demonstrated that the use of the PSF/ZnO nanohybrid membranes increased HA removal efficiency and pure water flux passing through the membrane.

Cadmium is one of the heavy metals and long time exposure to it can cause a lot of health problems in human beings. In this study, we investigated the toxic effects of Cadmium on kidney performance in the smokers and non-smokers and also its relationship with ventilation systems at Maragheh City prison.

This descriptive-analytical study included 90 prisoners. Cadmium of urine samples was measured by using a graphite furnace atomic absorption spectrometer. Parameters of renal function including urine specific gravity, creatinine, protein, albumin, glucose and urea were measured using a Hitachi autoanalyzer.

The highest values of excretion of cadmium, protein, albumin, per gram creatinine and glucose were observed in the smokers without ventilation systems in their living quarters. In this group, ratio of cadmium per creatinine showed significant relationships with protein per creatinine, albumin per creatinine, urea, and glucose (P < 0.05), while in the control group without ventilation, this ratio had significant relationship only with urinary glucose excretion (P < 0.05) and we found no significant relationships between cadmium per creatinine ratio and other variables in this group (P ≥ 0.05).

Exposure to cadmium metal through cigarette smoke can directly and indirectly affect kidney function and lead to increased excretion of protein, albumin, urea and glucose. This effect is also affected by indoor ventilation systems, so that the presence of proper ventilation systems reduces exposure to cigarette smoke and hence cadmium, which results in reduced harmful effects of cadmium on the renal function of the exposed individuals.

People spent most of their time indoors. Therfore, quality of  indoor air ,especially in the therapeutic settings is of particular importance. This study aimed to determine the level of pollutants in indoor and outdoor air of Tohid Hospital in Sanandaj.

In this cross-sectional descriptive study 120 indoor and outdoor air samples were collected by TES-5200 copper counterpart machine made by TES company in Taiwan. Particulate matter samples were collected from 9 wards and also 3 stations in every ward in the hospital. Also air samples were obtained from 3 selected stations outside the hospital. Samples were taken from the selected sites  twice. The results were analyzed by Excel and SPSS software.

According to the results of this study, the highest and lowest concentrations of particulate matter (PM2.5, PM4, PM7, PM10) belonged to the emergency room and the operating room, respectively. The highest level of PM1 concentration was detected in the ICU ward. There was no significant relationship between temperature and particle concentration and also between moisture and particle concentration in the wards of the hospital. In regard to particulate matter, the emergency department was the most contaminated ward and the operating room had the best condition.

The relationship between the concentrations of particles in the outdoor and indoor air indicated the penetration of these particles from outside into the hospital building. Also, outdoor air can affect indoor air quality.

In this study, leaf/flower aqueous extract of medicinal plant species Mentha pulegium was used to synthesize ZnO and CuO nanoparticles (NPs) as a cost-effective, one-step, and eco-friendly method.

Physicochemical properties of both metal oxide NPs (MONPs) were determined by UV-Vis spectroscopy, X-Ray Diffraction (XRD), Fourier-Transform Infra-Red (FTIR) spectroscopy, Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX) techniques.

Phytofabricated ZnONPs and CuNPs illustrated 65.02±7.55 and 26.92±4.7 nm with antibacterial activities against antibiotic-resistant Escherichia coli and Staphylococcus aureus. Higher antibacterial activities were observed for CuONPs compared with ZnONPs.

Large surface area and more reactivity resulted from smaller size as well as higher production of reactive oxygen species (ROS) were considered to antibacterial efficiency of CuONPs against antibiotic-resistant E. coli and S. aureus.

Malachite green (MG) is an organic compound which his used as a dye in textile industry. This compound is applied incorrectly and illegally in aquiculture as an antimicrobial agent. This compound has mutagenic and carcinogenic effects.

In this study we determined the concentrations of MG and leucomalachite green (LMG) in the muscle tissue of 90 rainbow trouts (Oncorhynchus mykiss) collected from the local markets in Sanandaj City within a period of six months in 2018. In order to measure the residues of MG and LMG, we used enzyme-linked immunosorbent assay (ELISA) based on the European Union Decision 2002/657/EC.

The results showed presence of MG and LMG in all 90 samples: The residues of MG in the samples were as follows: 1-2 μg/Kg in 41 (6.45%), more than 2 μg/Kg in 45 (50%) and less than 1 μg/Kg in 4 samples (4.4%). Furthermore, the residues of LMG in the samples were as follows: more than 2 μg/Kg in 13 (45.14%), 1-2 μg/Kg in 67 (44.74%) and less than 1 μg/Kg in 10 samples (11.11%).  Moreover, the limit of detection (LOD) in the method was 0.43 μg/Kg.

 It is concluded that MG is illegally applied in fish farms, which can be a threat to human health and the environment.

 This study was aimed at the evaluation of heavy metals in the drinking water of the rural area of Divandarreh city and the assessment of carcinogenic and non-carcinogenic health risks. 

 In the present work, concentration of four heavy metals in drinking water resource in the rural area of Divandarreh County were evaluated. For these aim, the numbers of 29 samples were collected from rural drinking water resources, and the concentration of heavy metals was determined. In addition, carcinogenic and noncarcinogenic risk assessment was conducted in children and adults as target groups. 

 The level of Cd was higher than the WHO drinking water Standard. The average amount of target hazard quotient for heavy metals through ingestion in children and adults were in the order of Cd > Cr > Pb > Ni. The total hazard quotient hazard quotients (HQ ing + HQ derm) in children group was higher than the limit set by the USEPA (hazard index = 1.68), indicating probable noncarcinogenic risk to this group through consumption of water. 

 Based on the obtained data, the carcinogenic risk for all of the heavy metals were higher than the permissible standard. The obtained data can be useful for managers and the water and wastewater department regarding the improvement of drinking water quality.