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Background and Aim: Dental services in the clinics provides terms of exposure and infection to patients and staff to variety of bioaerosol that often Its origin are the patient's mouth. This study was done with aim of determine the air bacteriological contamination rate in one of the hospital's dentistry centers in Tehran-Iran. Materials and Methods: In this cross sectional study, air sampling from selected parts was done using passive sampling method. Air bacteriological quality was determined with HPC testing, identification and enumeration of Staphylococcus aureus and Pseudomonas aeruginosa. The results were analyzed by SPSS16 software and ttest and ANOVA test. Results and Conclusion: Bacteriological Quality %33/3 of air samples was evaluated at inappropriate status and more than the standard level (25CFU/plate/h). The counts of three air bacteriological indexes include HPC, s.aureus and P. aeruginosa were respectively 43.8, 31.22 and 36.4 in terms of (CFU/plate /h). The highest air contamination was found in periodontal surgery. The mean numbers of bacteria in the air of case and control parts of studied center, shows a significant difference (p<0.05).This study showed that the air bacteriological quality was not acceptable level in dentistry-selected parts and threats the health of dentists and patient's. So pollution load reduction and staff Health promotion, improve the local ventilation system, use of personal protective equipment (PPE) and air bacteriological quality continuous control, is necessary. [ABSTRACT FROM AUTHOR]

The intrinsic hydrophilicity of metal compounds, such as copper ferrite (CuFe 2 O 4 ), and organic compounds, including graphene oxide (GO) and triethylenetetramine (TETA), make them promising adsorbents for heavy metals removal. The presence of lone pairs in these compounds is observed in modified polyethersulfone membranes used for the separation of arsenic (As) and total dissolved solids (TDS), including mono and divalent salts from aqueous solutions. The objective of this study was to investigate the performance of GO-TETA-CuFe 2 O 4 membranes for wastewater treatment applications. The membranes were characterized for their optimal mechanical strength (tensile strength) and high negative charge (zeta potential) on the surface. Separation tests were conducted at different pressures and pH levels to evaluate the membrane's effectiveness in removing contaminants. In addition, the membranes were examined for their antibacterial properties. The modified membrane exhibited superior performance compared with the control membrane, with TDS removal rates of 93.8%, As 3+ removal rates of 81.2%, and As 5+ removal rates of 87.9%. The contact angle of the modified membrane was reduced, resulting in an increase in pure water flux from 13.11 to 27.87 L/m 2 .h. The modified membrane also demonstrated significantly higher resistance to fouling than the control membrane, with a resistance increase from 6.78 × 10 +12 to 2.07 × 10 +12  m -1 . This contributed to the improved separation performance of As and TDS in a cross-flow setup. The results suggest that the GO-TETA-CuFe 2 O 4 modified membrane has great potential for use in water treatment applications. PRACTITIONER POINTS: GO-TETA-CuFe 2 O 4 was successfully used for modification of PES NF membrane structure. The efficiency of blended NF membranes with GO-TETA-CuFe 2 O 4 significantly increased. The modified membranes exhibited significant water flux and antifouling properties. The GO-TETA-CuFe 2 O 4 /PES membranes showed high rejection of heavy metal ions and TDS than PES. The GO-TETA-CuFe 2 O 4 /PES membranes exhibited desirable antibacterial activity., (© 2023 Water Environment Federation.)

Background: The coronavirus disease 2019 (COVID-19) pandemic at the end of 2019 posed a global health concern. It has been found that health education is one of the best methods for health promotion, changing inappropriate personal behaviors, and increasing people's awareness and attitude through major health concerns, including the COVID-19 pandemic. This study aimed to investigate the effect of educational interventions with environmental health approach on the knowledge, attitude, and practice of people in the COVID-19 epidemic era in one residential complex in Tehran., Methods: This cross-sectional study was conducted in Tehran in 2021. The study population was households of a residential complex in Tehran, which was selected by a random sampling method. A researcher-made checklist was used to gather data for this study, and its validity and reliability in the domains of environmental health and knowledge, attitude, and practice in the COVID-19 setting were evaluated before it was used. An intervention was made through social media and the checklist was reevaluated after the intervention., Results: A total number of 306 participants were enrolled in this study. In the assessment of the knowledge, attitude, and practice after the intervention, the mean score of the mentioned values increased significantly ( P < 0.001). However, the influence of intervention was more prominent in the improvement of knowledge and attitude than practice., Conclusion: Public health intervention with an environmental health approach can increase people's knowledge, attitude, and practice against chronic diseases and epidemics such as COVID-19., Competing Interests: The authors declare that they have no competing interests., (© 2023 Iran University of Medical Sciences.)

Nitrate contaminated water resources, a huge environmental problem for countries, including our own. This research aims to evaluate the efficiency of the electrochemical process for the removal of nitrate from the aqueous solution by direct and alternating current. Experiments were done by the Taguchi method, including electrode array, time exposure, voltage, pH, and the initial concentration of nitrate. Minitab 17 and SPSS 18 software were utilized to design and data analysis. In detail, the connection of the electrodes was monopolar, and the direct current (DC) has a greater efficiency as alternating current (AC) in the nitrate removal (p > 0.001). In AC, the nitrate initial concentration, voltage, electrodes material, contact time, and pH have the most effect on the nitrate removal. The optimized conditions for nitrate removal include Al-Al electrode, pH of 7, a voltage of 30 V, and nitrate initial concentration of 100 mg/L with the contact of time 150 min. Selection of appropriate materials for electrodes construction, adequate voltage, and removal of intervention agents from aqueous solution led to greater removal efficiencies. The optimized conditions that can reduce the aqueous solution ORP with high speed and the electrochemical reactor efficiency for nitrate removal were increased. PRACTITIONER POINTS: Electrochemichal (EC) process is evaluated for treatment of nitrate wastewater for the first time. High removal efficiency (over 95%) from nitrate wastewater was obtained. Minimizing energy consumption and maximizing nitrate removal were simultaneously achieved in the integrated single EC process., (© 2021 Water Environment Federation.)

Background: Tremendous amount of researches have investigated the issue of water photodisnfection. The aim of this research is to illustrate the influences of bacterial density, turbidity, exposure time and potassium persulfate (KPS) dosage on the efficacy of associated solar disinfection (SODIS) with KPS for E. coli (ATCC: 25922) eradication as an efficient and inexpensive process., Methods: Desired bacterial density and turbidity was achieved by spiking of 0.5 Mc Farland (1.5×10(8) cell/ml) and sterile soil slurry in 1 liter of the commercially bottled water., Results: The highest value of UVA solar irradiation measured at 13.30 p.m was 5510 μW/Cm(2). Increase of bacterial density from 1000 to 1500 cell/ml led to an increase in disinfection lapse time, except in 2 mMol/l KPS. Spiking of 0.1 mMol/l of KPS was not effective; however, increase of KPS dosage from 0.1 mMol/l to 0.7, 1.5 and 2 mMol/l led to the enhancement of disinfection time from 4 h to 3 h and 1 h, respectively. For bacterial density of 1000 cell/ml, increasing KPS dosage up to 0.7 mMol/l had no improved effect; however, beyond this dosage the disinfection time decreased to 1 h. Without KPS and up to 150 NTU within 4 h exposure time, E. coli disinfection was completed. In 2 mMol/l KPS and 1000 and 1500 cell/ml, the 2 h contact time was sufficient up to 150 and 100 NTU, respectively; moreover, complete disinfection was not achieved at higher turbidity., Conclusion: Association of KPS with SODIS can lead to decreasing of water disinfection time.