Explore the vast range of titles available.

Ambient air quality is one of the most critical threats to human health. In this study, the health and economic benefits of reducing PM 2.5 were estimated in the city of Arak during the period of 2017–2019. The concentration data were obtained from the Environmental Protection Organization of Central Province, while the demographic data were obtained from the website of the Iran Statistics Center. The number of premature deaths from all causes, ischemic heart disease, chronic obstructive pulmonary disease, and lung cancer, attributable to PM 2.5 pollution was estimated using the Environmental Benefits Mapping and Analysis Program-Comprehensive Version (BenMAP_CE) to limit the guidelines of the World Health Organization. The results showed that improving air quality in 2017, 2018, and 2019 in Arak could prevent the deaths of 729, 654, and 460 people, respectively. The number of years of life lost (YLL) in 2017, 2018, and 2019 was 11383, 10362, and 7260 years, respectively. The total annual economic benefits of reducing the PM2.5 concentration in Arak under the proposed scenarios in 2017, 2018, and 2019 were estimated to be 309,225,507, 262,868,727, and 182,224,053 USD, respectively, using the statistical life method (VSL). Based on the results of this study, there are significant health and economic benefits to reducing PM 2.5 concentrations in Arak City. Therefore, planning and adopting control policies to reduce air pollution in this city are necessary.

Backgrounds Numerous studies have shown that dental unit water lines (DUWLs) are often contaminated by a wide range of micro-organisms (bacteria, fungi, protozoa) and various prevalence have been reported for it in previous studies. Therefore, this review study aims to describe the prevalence of bacterial biofilm contamination of DUWLs. Methods This is a systematic review and meta-analysis in which the related keywords in different international databases, including Medline (via PubMed ) and Scopus were searched. The retrieved studies were screened and the required data were extracted from the included studies. Three standard methods including American Dental Association (ADA), The Center for Disease Control and Prevention (CDC) and contaminated > 100 CFU/ml( C-100 ) standards were used to assess the bacterial biofilm contamination of DUWLs. All studies that calculated the prevalence of bacterial biofilm contamination of DUWLs, and English full-text studies were included in the meta-analysis. Studies that did not have relevant data or used unusual laboratory methods were excluded. Methodological risk of bias was assessed by a related checklist and finally, the data were pooled by fixed or random-effect models. Results Seven hundred and thirty-six studies were identified and screened and 26 related studies were included in the meta-analysis. The oldest included study was published in 1976 and the most recent study was published in 2020. According to the ADA, CDC and C-100 standards, the prevalence of bacterial contamination was estimated to be 85.0% ( 95% confidence interval (CI) : 66.0–94.0%), 77.0% ( 95%CI : 66.0–85.0%) and 69.0% ( 95%CI : 67.0–71.0%), respectively. The prevalence of Legionella Pneumophila and Pseudomonas Aeruginosa in DUWLs was estimated to be 12.0% ( 95%CI : 10.0–14.0%) and 8.0% ( 95%CI : 2.0–24.0%), respectively. Conclusion The results of this review study suggested a high prevalence of bacterial biofilm in DUWLs; therefore, the use of appropriate disinfecting protocol is recommended to reduce the prevalence of contamination and reduce the probable cross-infection.

Background Antibiotic resistant Acinetobacter baumannii has emerged as one of the most problematic hospital acquired pathogens around the world. This study was designed to investigate the presence of antibiotic resistant A. baumannii in various hospital environments. Methods Air, water and inanimate surface samples were taken in different wards of four hospitals and analyzed for the presence of A. baumannii . Confirmed A. baumannii isolates were analyzed for antimicrobial susceptibility and also screened for the presence of three most common OXA- type carbapenemase-encoding genes. Results A. baumannii was detected in 11% (7/64) of air samples with the highest recovery in intensive care units (ICUs). A. baumannii was also detected in 17% (7/42) and 2% (1/42) of surface and water samples, respectively. A total of 40 A. baumannii isolates were recovered and analysis of antimicrobial susceptibility showed the highest resistance towards ceftazidime (92.5%, 37/40). 85% (34/40) and 80% (32/40) of the isolates were also resistant to imipenem and gentamicin, respectively. Resistance genes analysis showed that 77.5% (31/40) strains contained OXA-23 and 5% (2/40) strains contained OXA-24, but OXA-58 was not detected in any of the strains. Conclusion Detection of antibiotic resistant A. baumannii in various samples revealed that hospital environments could act as a potential source for transmission of A. baumannii infections especially in ICUs. These results emphasize the importance of early detection and implementation of control measures to prevent the spread of A. baumannii in hospital environments.

Aim: In dental clinic environment, dental staff and patients are daily exposed to many types of infectious agents transported by aerosols and droplets, promoting an increased risk of cross infection. The aim of this study was to assess the level of bacterial contamination of air and surfaces in different wards of the educational clinic in Arak University of Medical Sciences. Materials and Methods: Samples were obtained from the air and surfaces of five active wards of the dental school clinic. Air sampling was performed actively at ½ and 2 m distances from two random units in each ward. Sampling from surfaces was conducted using a wet sterile swab from the washing sink and handpiece after disinfection. Grown colonies were counted and bacterial phenotyping was based primarily on morphology, Gram-staining, endospore formation, catalase activity, and cytochrome oxidase presence. For statistical analysis, the Kruskal-Wallis test was used at a significance level of P < 0.05. Results: Bacterial contamination was detected in all of 80 samples taken from the surfaces of different sections. Regarding the total number of colonies growing from surface samples, there was no significant difference between the studied wards (P > 0.05). The mean concentration of airborne bacteria in the pediatric ward (488 CFU/m3) at a distance of 0.5 m and the surgical ward (339 CFU/m3) at a distance of 2 m had the highest value compared to other wards. In general, there was no statistically significant difference between the total density of airborne bacteria at distances of 0.5 and 2 m (P > 0.05). Conclusion: Bacterial contamination in the environment of the dentistry clinic increases during the treatment process. The clinic's space, the types of the ward and treatment process, and distance from the unit are among the factors affecting the type and diffusion extent of microbial aerosols.

The presence of airborne bacteria in hospital environments is of great concern because of their potential role as a source of hospital-acquired infections (HAI). The aim of this study was the determination and comparison of the concentration of airborne bacteria in different wards of four educational hospitals, and evaluation of whether particle counting could be predictive of airborne bacterial concentration in different wards of a hospital. The study was performed in an operating theatre (OT), intensive care unit (ICU), surgery ward (SW) and internal medicine (IM) ward of four educational hospitals in Isfahan, Iran. A total of 80 samples were analyzed for the presence of airborne bacteria and particle levels. The average level of bacteria ranged from 75-1194 CFU/m (3) . Mean particle levels were higher than class 100,000 cleanrooms in all wards. A significant correlation was observed between the numbers of 1-5 µm particles and levels of airborne bacteria in operating theatres and ICUs. The results showed that factors which may influence the airborne bacterial level in hospital environments should be properly managed to minimize the risk of HAIs especially in operating theaters. Microbial air contamination of hospital settings should be performed by the monitoring of airborne bacteria, but particle counting could be considered as a good operative method for the continuous monitoring of air quality in operating theaters and ICUs where higher risks of infection are suspected.

Aim: In this study, the levels of indoor and outdoor (I/O) airborne particles and bioaerosols were assessed in two primary schools. Simultaneously, I/O microbial airborne and particle matter (PM) concentrations were analyzed during the autumn of 2018. Materials and Methods: A total of 96 I/O air samples were taken by using a single-stage Andersen sampler from two selected primary schools located in Arak, Iran. Simultaneous with sampling, PM10 and PM2.5 concentrations, temperature, and relative humidity were also measured. Results: The results indicated that the mean levels of indoor airborne bacteria and fungi were 448 and 94 CFU/m3, respectively. The I/O ratios of bacteria and fungi were 2.1 and 0.7, respectively. The airborne bacteria levels showed a weak-positive and moderate-positive association with PM2.5 (r = 0.28, P < 0.05) and PM10 (r = 0.32, P < 0.05), respectively. Further, a moderate-positive association was observed between indoor fungi and the PM2.5 (r = 0.46, P < 0.05) and PM10 (r = 0.30, P < 0.05). In our study, the most fungal species identified were Penicillium, Cladosporium, and Aspergillus, and Staphylococcus spp., Micrococcus spp., and Bacillus spp. were the most frequently founded indoor bacteria. Conclusion: Comparative analysis of classrooms in two schools showed that indoor sources and building conditions have a key role in indoor air quality.

Ambient air quality is one of the most critical threats to human health. In this study, the health and economic benefits of reducing PM.sub.2.5 were estimated in the city of Arak during the period of 2017-2019. The concentration data were obtained from the Environmental Protection Organization of Central Province, while the demographic data were obtained from the website of the Iran Statistics Center. The number of premature deaths from all causes, ischemic heart disease, chronic obstructive pulmonary disease, and lung cancer, attributable to PM.sub.2.5 pollution was estimated using the Environmental Benefits Mapping and Analysis Program-Comprehensive Version (BenMAP_CE) to limit the guidelines of the World Health Organization. The results showed that improving air quality in 2017, 2018, and 2019 in Arak could prevent the deaths of 729, 654, and 460 people, respectively. The number of years of life lost (YLL) in 2017, 2018, and 2019 was 11383, 10362, and 7260 years, respectively. The total annual economic benefits of reducing the PM2.5 concentration in Arak under the proposed scenarios in 2017, 2018, and 2019 were estimated to be 309,225,507, 262,868,727, and 182,224,053 USD, respectively, using the statistical life method (VSL). Based on the results of this study, there are significant health and economic benefits to reducing PM.sub.2.5 concentrations in Arak City. Therefore, planning and adopting control policies to reduce air pollution in this city are necessary.

Background: Airborne transmission of pathogenic resistant bacteria is well recognized as an important route for the acquisition of a wide range of nosocomial infections in hospitals. The aim of this study was to determine the prevalence of airborne vancomycin and gentamicin (VM and GM) resistant bacteria in different wards of four educational hospitals. Materials and Methods: A total of 64 air samples were collected from operating theater (OT), Intensive Care Unit (ICU), surgery ward, and internal medicine ward of four educational hospitals in Isfahan, Iran. Airborne culturable bacteria were collected using all glass impingers. Samples were analyzed for the detection of VM- and GM-resistant bacteria. Results: The average level of bacteria ranged from 99 to 1079 CFU/m3. The highest level of airborne bacteria was observed in hospital 4 (628 CFU/m3) and the highest average concentration of GM- and VM-resistant airborne bacteria were found in hospital 3 (22 CFU/m3). The mean concentration of airborne bacteria was the lowest in OT wards and GM- and VM-resistant airborne bacteria were not detected in this ward of hospitals. The highest prevalence of antibiotic-resistant airborne bacteria was observed in ICU ward. There was a statistically significant difference for the prevalence of VM-resistant bacteria between hospital wards (P = 0.012). Conclusion: Our finding showed that the relatively high prevalence of VM- and GM-resistant airborne bacteria in ICUs could be a great concern from the point of view of patients' health. These results confirm the necessity of application of effective control measures which significantly decrease the exposure of high-risk patients to potentially airborne nosocomial infections.

Ambient air quality is one of the most critical threats to human health. In this study, the health and economic benefits of reducing PM 2.5 were estimated in the city of Arak during the period of 2017–2019. The concentration data were obtained from the Environmental Protection Organization of Central Province, while the demographic data were obtained from the website of the Iran Statistics Center. The number of premature deaths from all causes, ischemic heart disease, chronic obstructive pulmonary disease, and lung cancer, attributable to PM 2.5 pollution was estimated using the Environmental Benefits Mapping and Analysis Program-Comprehensive Version (BenMAP_CE) to limit the guidelines of the World Health Organization. The results showed that improving air quality in 2017, 2018, and 2019 in Arak could prevent the deaths of 729, 654, and 460 people, respectively. The number of years of life lost (YLL) in 2017, 2018, and 2019 was 11383, 10362, and 7260 years, respectively. The total annual economic benefits of reducing the PM2.5 concentration in Arak under the proposed scenarios in 2017, 2018, and 2019 were estimated to be 309,225,507, 262,868,727, and 182,224,053 USD, respectively, using the statistical life method (VSL). Based on the results of this study, there are significant health and economic benefits to reducing PM 2.5 concentrations in Arak City. Therefore, planning and adopting control policies to reduce air pollution in this city are necessary.

Background: Airborne transmission of pathogenic resistant bacteria is well recognized as an important route for the acquisition of a wide range of nosocomial infections in hospitals. The aim of this study was to determine the prevalence of airborne vancomycin and gentamicin (VM and GM) resistant bacteria in different wards of four educational hospitals. Materials and Methods: A total of 64 air samples were collected from operating theater (OT), Intensive Care Unit (ICU), surgery ward, and internal medicine ward of four educational hospitals in Isfahan, Iran. Airborne culturable bacteria were collected using all glass impingers. Samples were analyzed for the detection of VM- and GM-resistant bacteria. Results: The average level of bacteria ranged from 99 to 1079 CFU/m3. The highest level of airborne bacteria was observed in hospital 4 (628 CFU/m3) and the highest average concentration of GM- and VM-resistant airborne bacteria were found in hospital 3 (22 CFU/m3). The mean concentration of airborne bacteria was the lowest in OT wards and GM- and VM-resistant airborne bacteria were not detected in this ward of hospitals. The highest prevalence of antibiotic-resistant airborne bacteria was observed in ICU ward. There was a statistically significant difference for the prevalence of VM-resistant bacteria between hospital wards (P = 0.012). Conclusion: Our finding showed that the relatively high prevalence of VM- and GM-resistant airborne bacteria in ICUs could be a great concern from the point of view of patients' health. These results confirm the necessity of application of effective control measures which significantly decrease the exposure of high-risk patients to potentially airborne nosocomial infections.