Quantitative microbial risk assessment of gastrointestinal illness due to recreational exposure to E. coli and enterococci on the southern coasts of the Caspian Sea.

Background: Gastrointestinal illness refers to a broad range of diseases that affect the digestive system, including infections caused by bacteria, viruses, and parasites. Quantitative Microbial Risk Assessment (QMRA) is a powerful tool used to evaluate the risks associated with microbial pathogens in various environments. The main objective of this study was to conduct a quantitative assessment of gastrointestinal illnesses that occur as a result of exposure to E. coli and enterococci during recreational activities on the southern coasts of the Caspian Sea. Methods: Samples were collected from the recreational beaches along the border line of the Caspian Sea. The samples were analyzed for the presence and enumeration of E. coli and enterococci using the microplate method and membrane filtration techniques. Then, the annual and daily infection risks were computed using the Monte Carlo simulation approach. Results: The results revealed that the risk of daily and annual infections on the coasts of Babolsar was higher than that on the coasts of Sari. Also, in the recreational waters of these beaches, the risk of infection by enterococci was higher than that posed by E. coli. In Babolsar, the average annual infection risk caused by E. coli and enterococci was 0.365 and 1 for children and 0.181 and 0.986 for adults. Also, in Sari, the average annual infection risk caused by E. coli and enterococci was 0.060 and 0.908 for children and 0.027 and 0.815 for adults. In addition, children were more likely than adults to become infected. Conclusion: In light of the study's findings, due to the entry of untreated urban wastewater into the southern part of the Caspian Sea (northern Iran) and the high risk of infectious diseases for children, more control and health measures are necessary for children's swimming.

Impacts of socioeconomic and environmental factors on neoplasms incidence rates using machine learning and GIS: a cross-sectional study in Iran.

Neoplasm is an umbrella term used to describe either benign or malignant conditions. The correlations between socioeconomic and environmental factors and the occurrence of new-onset of neoplasms have already been demonstrated in a body of research. Nevertheless, few studies have specifically dealt with the nature of relationship, significance of risk factors, and geographic variation of them, particularly in low- and middle-income communities. This study, thus, set out to (1) analyze spatiotemporal variations of the age-adjusted incidence rate (AAIR) of neoplasms in Iran throughout five time periods, (2) investigate relationships between a collection of environmental and socioeconomic indicators and the AAIR of neoplasms all over the country, and (3) evaluate geographical alterations in their relative importance. Our cross-sectional study design was based on county-level data from 2010 to 2020. AAIR of neoplasms data was acquired from the Institute for Health Metrics and Evaluation (IHME). HotSpot analyses and Anselin Local Moran's I indices were deployed to precisely identify AAIR of neoplasms high- and low-risk clusters. Multi-scale geographically weight regression (MGWR) analysis was worked out to evaluate the association between each explanatory variable and the AAIR of neoplasms. Utilizing random forests (RF), we also examined the relationships between environmental (e.g., UV index and PM2.5 concentration) and socioeconomic (e.g., Gini coefficient and literacy rate) factors and AAIR of neoplasms. AAIR of neoplasms displayed a significant increasing trend over the study period. According to the MGWR, the only factor that significantly varied spatially and was associated with the AAIR of neoplasms in Iran was the UV index. A good accuracy RF model was confirmed for both training and testing data with correlation coefficients R2 greater than 0.91 and 0.92, respectively. UV index and Gini coefficient ranked the highest variables in the prediction of AAIR of neoplasms, based on the relative influence of each variable. More research using machine learning approaches taking the advantages of considering all possible determinants is required to assess health strategies outcomes and properly formulate policy planning.

Health risk assessment of swimming beaches microbial contamination: a case study - Mahmoudabad, Iran.

Waterborne organisms in marine water generally originate from untreated wastewater discharged into the sea. The presence of numerous leisure beaches in Mahmoudabad city, Iran, annually attracts thousands of tourists from all over the country to participate in recreational swimming activities. This study probabilistically characterized the health risks associated with recreational swimming engendered by waterborne pathogens, such as intestinal enterococci and Escherichia coli (E. coli) at 15 sampling points along the beaches of the study using quantitative microbial risk assessment (QMRA). The mean annual infection risk of E. coli in children and adults was 0.424 and 0.229, respectively. The respective risk in terms of enterococci was 0.999 and 0.997, which were higher than the level recommended by the WHO and EPA. The results show that the risk of infection for children was higher than adults. Related authorities have to consider measures to improve environmental quality to protect tourists' and residents' well-being.

Analyzing the interaction of main components of hidden curriculum in medical education using interpretive structural modeling method.

BACKGROUND: Hidden curriculum (HC) is considered as unintended learning experiences in medical education (ME). This may include values, norms, beliefs, skills, and knowledge which could potentially influence learning outcomes. HC has key components that must be identified and considered properly by individuals and organizations involved in ME. OBJECTIVES: This study aimed to determine the main components of hidden curriculum in medical education (HCME) and the interrelationships among them. METHODS: In this mixed-method study initially we performed a scoping review and determined the main components of HCME using qualitative content analysis approach. Then, the interrelationships among these components were investigated using Interpretive Structural Modeling (ISM). RESULTS: Ten key components for HCME were identified in scoping review. We classified them into four main categories including structural, educational, cultural, and social factors. The ISM analysis revealed that organizational rules and structure, dominant culture of educational environments, teaching and assessment approaches, as well as clinical and educational physical setting were the independent or driving factors. While, social components were dependent and influenced by basic components. CONCLUSION: The ISM model indicated that role modeling behaviors and interpersonal relationships (social factors) are under influence of underlying organizational and educational factors. These results should be considered at all stages of educational management including planning process, implementation of the programs, and development of formal curricula. According to the importance of contextual factors, components of HC must be analyzed and interpreted based on the specific conditions of each educational institution.

Water quality assessment of the most important dam (Latyan dam) in Tehran, Iran.

A pattern of water quality affected by the input regime and site specification is one of the most important issues in water supply resources and demand management. The present study aims to assess the water quality of Latyan dam, the important reservoir that supplies drinking water of Tehran, the capital city of Iran. Monthly water sampling was performed at four depths of the dam. The physical and chemical properties of water including temperature, pH, turbidity, total dissolved solids (TDS), electrical conductivity (EC), hardness, as well as Ca2+, Mg2+, Na+, K+, Cl-, SO42-, silica, ammonium, nitrate, nitrite, and total phosphorus (TP) concentration, were monitored from May 2014 to January 2017. The results of statistical analysis indicated that the quality of water in the dam was affected by the depth in view of five variables of EC, pH, turbidity, SO42-, and TP (p Ë‚ 0.05). Moreover, it was determined that ten out of 17 variables including EC, turbidity, TDS, Ca2+, K, Cl-, SO42-, silica, nitrate, and TP were statistically significant (p Ë‚ 0.05) based on seasonal variation analyses. Comparing the mean values, it could be concluded that EC, TDS, Ca2+, K+, Cl-, and SO42- were slightly higher during the winter probably owing to the diluting effects of seasonal precipitation. Nutrient-like distribution, nitrate, and TP, as well as silica, were much higher during the spring representing a high-diatoms activity and eutrophication. Turbidity was higher in the fall compared to the other seasons, which also demonstrated rainfall effects. Evaluation of the aggressiveness index (AI) suggests that water is moderately corrosive, and noncorrosive in the winter compared to other seasons. Moreover, according to the findings of this research and their comparison with the national and international water quality guidelines/standards, it could be said that the water quality of Latyan dam during the study period was acceptable and thus it was usable as a drinking water supply. However, due to the changes occurred in nitrate and phosphorus and extensive development of eutrophication problem, accurate and continuous evaluation of water quality in this reservoir is deemed necessary.

Correction to: Indoor and outdoor concentrations of BTEX and formaldehyde in Tehran, Iran: effects of building characteristics and health risk assessment.

The original publication of this paper contains a mistake. The correct name and affiliation of the 3rd Author is presented in this paper.

Indoor and outdoor concentrations of BTEX and formaldehyde in Tehran, Iran: effects of building characteristics and health risk assessment.

BTEX (benzene, toluene, ethylbenzene, xylene) and formaldehyde are toxic compounds that can induce adverse health effect in humans. This study measured in-home and ambient concentrations of BTEX and formaldehyde across Tehran, Iran. These pollutants were sampled from the indoor and adjacent outdoor air of 45 houses (9 in each city zone) during the winter of 2015. Sampling was repeated three times for each house. The analyses were performed according to NIOSH procedures. The effect of flooring material, wall covering, ventilation system, heating system, height above ground, presence of attached garages, and distance from highways was evaluated. In addition, carcinogenic and non-carcinogenic risks of these compounds were assessed. The average indoor concentrations of benzene, toluene, ethylbenzene, xylene, and formaldehyde were 53.2, 21.5, 14.4, 21.1, and 17.9 µg/m3, respectively. The average outdoor concentrations of benzene, toluene, ethylbenzene, xylene, and formaldehyde were 43.5, 26.2, 10.0, 19.1, and 6.9 µg/m3, respectively. Separate regression models showed that wall coating, ventilation system, heating system, flat level, and distance from highways explained 29, 60, 16, 60, and 59% of the BTEX concentrations, respectively. Houses with oil painted walls and parquet flooring had higher concentrations of BTEX and formaldehyde, respectively. The health risk assessment found that the carcinogenic risks of benzene and formaldehyde exceeded 1 × 10-4 and represent a definite risk. New buildings can be designed based on the results of this study to use better materials and optimum building designs to reduce exposure to these toxic air pollutants.

Neurobehavioral assessment of rats exposed to pristine polystyrene nanoplastics upon oral exposure.

The increasing use of plastics has raised concerns about pollution of freshwater by these polymeric materials. Knowledge about their potential effects on environmental and public health is limited. Recent publications have suggested that the degradation of plastics will result in the release of nano-sized plastic particles to the environment. Therefore, it is of utmost importance to gain knowledge about whether and how nanoplastics affect living organisms. The present study aimed to analyse potential neurobehavioral effects of polystyrene nanoparticles (PS-NPs) after long-term exposure on rat. Potential effects of PS-NPs were investigated using four test dosages (1, 3, 6, and 10 mg PS-NPs/kg of body weight/day) administrated orally with adult Wistar male rats for five weeks. Neurobehavioral tests were chosen to assess a variety of behavioral domains. Particle diameters in test suspensions were determined through dynamic light scattering and showed an average hydrodynamic diameter of approximately 38.92 nm. No statistically significant behavioral effects were observed in all tests performed (p > 0.05). In the elevated plus maze, PS-NPs-exposed rats showed greater number of entries into open arms compared to controls. Also, PS-NPs had no significant influence on body weight of animals. Taking into account the subtle and transient nature of neurobehavioral consequences, however, these results underline the possibility of even pristine plastic nanoparticles to induce behavioral alteration in the rest of the food web, including for marine biota and humans. Indeed even though studied neurobehavioral effects in our study was not statistically significant, the observed subtle effects may be clinically considerable.