Journal of Human Environment and Health Promotion
Volume:8 Issue: 4, Autumn 2022

 This study evaluated the effect of varied culture conditions and nutritional requirements in producing antimicrobial metabolite by Streptomyces.

 Streptomyces species were isolated from soil samples using the spread plate method on Streptomyces agar. In addition, the yeast-malt broth was used for fermentation and optimization. The different culture conditions were pH, mineral salt concentrations, and agitation rate. The tested nutritional components were Carbon and Nitrogen sources.

 We observed the maximum production of the antimicrobial metabolite using the medium containing Galactose anhydride showing high inhibition zone of 32 mm (Staphylococcus aureus) and 23 mm (Pseudomonas aeruginosa), respectively. Maximum secondary metabolite productivity was also achieved with the medium containing malt extracts Staphylococcus aureus (30 mm) and Pseudomonas aeruginosa (27 mm). For pH, maximum metabolite production was obtained in the medium adjusted to 10 (30 mm, 33 mm). The best metabolite production was obtained at 0.30 mol/ml (30 mm, 27 mm) with the medium incorporated with additional sodium chloride. Good antimicrobial metabolite production was also observed with a medium and maximum agitation speed of 250 rpm.

 For efficient production of antimicrobial metabolite by Streptomyces species, Galactose anhydride, malt extract, sodium chloride concentration of 0.30 mol/ml, pH of 10, and agitation speed of 250 rpm should be used.

Aflatoxins are classified as definitive or possible human carcinogens. Nuts and nutty products are among the most frequent aflatoxin-contaminated foodstuffs. The aim of this study was to assess the levels of aflatoxins (B1, B2, G1, G2, total) in different nuts, including pistachio, almond, cashew, hazelnut obtained from selected supermarket chains in Tehran city.

A total of 20 nut samples were collected from eight randomly selected chain stores, and the levels of aflatoxins in the samples were evaluated using an immunoaffinity column and quantified by high-performance liquid chromatography technique (HPLC).

Among 20 tested nuts, only one sample (roasted hazelnut) was contaminated with the aflatoxins (AG1) at a level of 0.34 µg/kg, while the tested mycotoxins were not detected in the other samples.

Our findings indicated that different parameters such as climatic conditions, implementing strict regulations, improvement in harvest and post-harvest practices alongside rigorous surveillance by the Department of Public Health and Preventive Medicine (AJA University of Medical Sciences) on the quality of food materials may explain the low incidence of aflatoxins in this study.

Using disinfectants that inactivate microorganisms in various industries, from the pharmaceutical to the food service industry, has been increasing over the last few years. Antimicrobial disinfectants are used as primary treatment options against pathogens on surfaces in healthcare facilities to help prevent healthcare-associated infections. The aim of this study was to determine the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the disinfectants used and study the corrosion of surfaces in contact with these disinfectants.

In this study, MICs and MBCs of the disinfectants against B. cereus, S. cerevisiae, P. aeruginosa, and S. epidermidis were measured by the microdilution method. Ethanol, percidine, benzalkonium chloride, and deconex 50ff were examined for antimicrobial effects.

The findings showed that S. cerevisiae had the lowest level of disinfectant resistance, whereas B. cereus consistently exhibited higher resistance. Additionally, when compared to other disinfectants at lower concentrations, deconex 50ff was the most potent disinfectant that resulted in microbial growth suppression. Deconex 50 FF had MICs of 0.101, 12.939, 3.235, and 1.617mg/L for S. cerevisiae, B. cereus, P. aeruginosa, and S. epidermidis, respectively. In contrast, MBC of S. cerevisiae, B. cereus, P. aeruginosa, and S. epidermidis were 0.404, 25.879, 12.939, and 6.470 mg/L, respectively. Macroscopic analysis of stainless steel and plastic sandwiches treated with the specified disinfectant concentrations revealed no corrosion.

Considering the importance of these microbial strains in healthcare-associated infections, using these effective disinfectants is recommended in the pharmaceutical industry.

We assessed and ranked environmental risks in the mechanized urban waste collection and storage systems in Tehran municipality (Iran) to locate safe areas for the establishment of these systems.

This descriptive-analytical study first identified and classified the effective factors in locating the mechanized systems of the studied district in seven criteria (socioeconomic, physical-spatial, hydrological-climatic, geological, and three passive defenses including dispersion, lifeline, and high-risk facilities). Risk factors were evaluated using the FMEA technique and prioritized using the TOPSIS method.

The FMEA results classified the identified passive defense and environmental risks into three levels (high, medium, low), with 69% of the risks at the low level, 17% at the medium level, and 14% at the high level. The TOPSIS ranking results identified "Distance to nearest fire station", "Distance to a fault" and "Distance to power substation" as the highest risk factors with the similarity to ideal solution (cli)values of 0.861, 0.774 and 0.771, respectively, as well as "Distance to gas pressure-reducing stations" (cli = 0.134) as the least important risk factor.

New urban waste collection and storage stations in the studied district should be established according to the population of the areas and at a suitable distance to the nearest fire stations. Further, locating and designing these systems in wide open spaces is highly essential.

Falling is one of the most common and serious health problems, especially at home among the elderly. The purpose of this research is to investigate the effect of education in reducing environmental hazards at home for the elderly.

In this quasi-experimental study, 200 elderly people were equally divided into intervention and control groups in 2018. The educational intervention was performed in 4 sessions of 45 mins. Data were collected through a standardized home safety checklist during interviews and home visits before and after six months of the training intervention. SPSS software (v19) analyzed the collected data. Chi-squared, Mann Whitney, Wilcoxon, and Exact Tests were used in this study.

The results showed that the mean score of all dimensions of home safety increased in the intervention group compared to the control group after the intervention. Except for the safety dimensions of external stairs and kitchen, this difference was statistically significant (P <0.05). The findings also showed a significant decrease in the percentage of falls in the intervention group compared to the control group after educational interventions (P <0.05).

Educational intervention is useful in reducing home environmental hazards in the elderly and makes the elderly less likely to fall during their daily activities.

Nowadays, colored water and, remarkably, wastewaters from dyeing industries are one of the most significant sources of toxic compounds in the environment. On the other hand, waste management and reduction are the most main obstacles governments encounter. Therefore, this study aimed to use waste materials to remove contaminants.

First, we pyrolyzed onion peels, added distilled water, and then sonicated the solution. AFM (Atomic force microscopy) analysis determined the characteristics of produced carbon nanosheets. Batch experiments on the synthesized carbon nanosheets implemented adsorption studies. The effects of adsorbent dose, pH, dye concentration, and temperature were also evaluated.

The isotherm assessments indicated that the data significantly matches the Langmuir model; moreover, the kinetic modeling results showed that the experimental data perfectly matched the pseudo-second-order kinetic model.

Synthesized carbon nanosheets from onion peel as a low-cost adsorbent with good properties; not only are eco-friendly materials that can significantly reduce solid waste generation, but they are efficient adsorbents for methylene blue removal from aquatic solution.

Considering the increased demand for cars in different countries during recent years, using car washes for washing vehicles has received a lot of attention. This study aimed to assess removing chemical oxygen demand (COD) from car wash effluent using the electrocoagulation method.

A reactor with dimensions of 40 cm * 50 cm * 50 cm of Plexiglas with a volume of 90 L equipped with an electric current generator and an electrode was used connected to the DC current generator in the form of Al-Al. The response surface method (RSM) was applied to optimize the factors affecting COD removal in the electrocoagulation process. For this purpose, D-optimal was utilized to optimize the experiments. The effects of measurable factors such as electrolysis time (X1), current density (X2), and aeration time (X3) were examined to check COD removal.

According to the results, the optimal operating conditions for COD removal during electrolysis (30 min) were as follow: the current density was 18.75 A/m2, and the aeration time of 30 min was 48.51%.

In conclusion, electrocoagulation is, to some extent, a reliable and environmentally compatible technique for car wash wastewater treatment.

 The present study aimed to evaluate antimicrobial properties of corn starch edible films prepared with Bunium persicum essential-oil nanoemulsions (BPEOne) and BPEOne fortified with cinnamaldehyde (Fortified BPEOne with CIN) against some common food-borne pathogens.  

 Treatments (films containing BPEO, CIN, BPEOne, BPEO+CIN, BPEOne+CIN, Fortified BPEOne with CIN in 0.5, 1, 2, and 4 % concentrations) were prepared using starch solutions. In vitro antimicrobial activity of BPEOne films was evaluated using agar disk diffusion and plate count assay methods against Salmonella enteritidis, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus.

 The inhibitory effect of each treatment against some food-borne pathogen bacteria increased significantly with the enhancement of concentrations (P<0.05). The highest bacterial inhibitory effect was achieved in higher concentrations (2%, 4%). The antimicrobial activity of BPEO nanoemulsion was higher than pure BPEO-containing films. S. aureus and S. enteritidis were more susceptible and resistant bacteria to BPEO, BPEO nanoemulsion-containing films, respectively.

 The films containing a combination of the BPEO (or its nanoemulsion) with CIN have better antimicrobial activity, however the fortification of nanoemulsions with other antimicrobial agents may not show the same results.