نشریه مهندسی بهداشت محیط
سال دوازدهم شماره 1 (پیاپی 46، پاییز 1403)

Due to the advantages of organic metal hybrids in the destruction of various environmental pollutants, the aim of this study is to modify the structure of the carbon substrate and improve the properties of organic metal hybrids in order to photocatalytically destroy organophosphorus toxins (malathion) and the antibiotic tetracycline.

In this research, an easy and effective ultrasonic method was used to synthesize carbon-based metal oxide / graphene oxide / metal organic framework (UiO-66) nanocomposite and various metal oxides including zinx oxide, titanium oxide, tungsten oxide and cobalt oxide in nanocomposite structure were used to compare their photocatalytic activity. The products were identified by X-Ray diffraction (XRD), fourier transform spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis spectroscopy. Photocatalytic activity of synthetic nanocomposites was investigated by degradation of tetracycline and malathion under visible light.

The results showed that the presence of graphene oxide and UiO-66 improved the photocatalytic properties of metal oxide and the removal efficiency increased to 100%. In this study, the effect of metal oxide, dosage of metal oxide / graphene, initial pH of the solution and the presence of various scavengers on photocatalytic properties was investigated. Using LC-MASS analyzes, the formed intermediates during degradation of pollutants were identified.

The results showed that metal oxide / graphene oxide / UiO-66 has the highest efficiency in photocatalytic degradation of organophosphorus toxins (malathion) and the antibiotic tetracyclin

In recent years, the extent and intensity of dust storms in southwestern Iran have made this phenomenon one of the environmental hazards of in these areas. Considering the importance of particulate matter (PM10) in air pollution and its consequences, this study investigated changes in air quality based on PM10 concentration in Ilam City.

In this cross-sectional descriptive study, PM10 concentration values were obtained from the Environmental Protection Organization of Ilam City from 2019 to 2023. The data were categorized and analyzed using Excel software.

The results showed that the highest and lowest average monthly concentrations of PM10 in different years were, respectively, related to April 2022, with a concentration of 271.95 µg/m3, and October 2019, with a concentration of 34.67 µg/m3. In 1812 studied days, the air quality condition was outside the National Ambient Air Quality Standards (150 µg/m3) on 95 days (5.13%). The highest seasonal pollution in terms of PM10 concentration was occurring in the spring season, and while the lowest air pollution was observed in the autumn season.  

The results showed that the concentration of PM10 decreased from summer to autumn and increased from autumn to winter and spring. Which this information can be used utilized by policymakers to design and implement effective personal protection and control measures in  during this period of time

Rivers of the main natural resources for humans and very important role in human life. This research was carried out with the aim of investigating the physical and chemical parameters caused by entry of bitumen layers in the springs of Mamatin on the water of Alla River in Ramhormoz city.

In this research, the study area of Alla River starts from the exit of the river from the Chuvil River and ends at the connection point of the Alla River with the Maron River, and 5 study stations were selected. Water samples were prepared according to the standard method of american environmental health association. Water samples were collected systematically and planned from each station with 3 repetitions in summer (July) and winter (February) of 2023. In other words, a total of 30 water samples were prepared from 5 stations with 3 repetitions in two seasons.

The mean square and sum of square analysis of variance (ANOVA) of the data showed a significant difference in pH concentration (P=0.873), electrical conductivity (P=0.943), BOD (P=0.297), COD (P= 0.928), DO (P= 0.893), TSS (P= 0.739), phosphate (P= 0.355), total hardness (P= 0.212) and turbidity (P= 0.540) were not observed (P>0.05). In winter, electrical conductivity (2163.35 µs/cm) and TDS (980.16 ppm) in station 4 were higher than other stations (P<0.05) and COD (63.56 ppm) and TSS (41 ppm) in Station 1 were obtained higher than the studied stations of Ala River (P<0.05). In the summer season, electrical conductivity (1941.44 µs/cm), salinity (352.56 ppm), COD (43 ppm), BOD (19.63 ppm) and TDS (1242.67 ppm) in the fifth station compared to other stations The studied values ​​of Ala River were higher (P<0.05).

According to the comparison of water quality parameters with the standards of Iran and World Health Organization, it can be said that the water of Ala River is suitable for agricultural, horticultural, aquaculture and household purposes, but it is suitable for drinking

This study aims to investigate the dispersion of pollutant gases emitted from the Sahand thermal power plant's chimney and determine the maximum concentration of these pollutants in the surrounding areas.

The emission of exhaust gases from the chimney was simulated using SCREEN View software. This software calculates the maximum concentration of pollutants at specific distances from the chimney for all air stability classes, using input data such as the mass emission rate of pollutants, the temperature and velocity of the exhaust gases, the ambient temperature, the chimney's dimensions, and the height in the direction of emission. This research calculated the concentrations of nitrogen dioxide, carbon monoxide, and sulfur dioxide in eight directions: north, northeast, east, southeast, south, southwest, west, and northwest of the power plant chimney.

The modeling results indicate that at a distance of 1218 meters from the power plant chimney, the maximum 1-hour concentrations of sulfur dioxide, nitrogen dioxide, and carbon monoxide are 915.9, 54.14, and 1.305 micrograms per cubic meter, respectively. Moreover, for areas with higher elevations relative to the chimney, the maximum 24-hour concentrations for sulfur dioxide, nitrogen dioxide, and carbon monoxide are 680.5, 40.22, and 0.97 micrograms per cubic meter, respectively.

The levels of nitrogen dioxide and sulfur dioxide in some areas near the power plant exceed the permissible limits set by the environmental standards of Iran and the World Health Organization, posing a health risk to the residents of these areas.

With the industrialization of societies, the use of fossil fuels has increased. To address the issues arising from this, the "waste-to-energy" approach using a type of fuel production process known as microbial fuel cells can be utilized. Therefore, the aim of this study was to describe and investigate the use of microbial fuel cells for the production of bioelectricity from organic waste.

In the initial search for articles, a total of 214 articles from 2009 to 2024 were found. After removing duplicates, 101 articles remained. At the end of the screening stage, 62 articles remained. To access relevant articles, the full texts were reviewed, and finally, 29 articles were used in the present study.

In microbial fuel cells, waste is considered as organic substrates, and microorganisms oxidize them to ultimately produce electrical energy without generating toxic by-products. Acetate is commonly used as an organic substrate due to its higher output power in fuel cells. For evaluating the performance of the fuel cells, electrodes are crucial as their material affects electron transfer and chemical efficiency.

Despite the advantages of microbial fuel cell technology in waste management and reducing air pollution, it faces challenges such as relatively high investment costs and low efficiency when applied on a large scale, which has delayed its commercialization. However, it is necessary to examine and control the factors reducing the efficiency of this technology on the large scale to expand its application scope and justify the high investment cost.

The primary goal of the Hazard Communication System (HCS) is to enhance people's safety performance when exposed to hazardous chemicals. This study examined the effects of implementing the HCS program on safety awareness and performance in educational and research laboratories at medical sciences universities.

The HCS program involved inventorying, preparing chemical safety data sheets, and providing training for educational and research laboratories at two selected medical sciences universities. General and specific safety training was conducted for 75 individuals who work with chemicals. Safety awareness and performance were assessed using the program's standard questionnaire before and after the intervention. Descriptive statistical methods and paired t-tests were utilized to analyze the data.

The awareness level of HCS before the intervention was 49.68, which increased to 58.70 after the intervention (P=0.066). The perception level of Globally Harmonized System (GHS) labels before the intervention was 24.70 which increased to 88.98 (P<0.001). The perception level of  UN labels before the intervention was 4.16 which increased to 20.06 (P<0.001). The perception level of EU labels before the intervention was 19.64 which increased to 73.80 (P<0.001). The safety performance level before the intervention was 31.56 which increased to 48.10 after the intervention (P=0.001).

Implementing HCS following GHS principles can enhance chemical safety awareness and performance in research and educational laboratories.

In case of non-supply or monitoring of water hygiene and resulting a direct damage to consumers, the need for compensation will be considered based on the theory of civil liability. Therefore, the purpose of this research is to survey the civil liability of the Ministry of Health for water hygiene.

This research is a qualitative study based on the framework of the theory of civil liability, which by using the library research tool by collecting the laws and regulations of the country and using the thematic analysis method and matching the laws with the framework of the conceptual model, civil liability of the Ministry of Health in the field of water hygiene was identified.

Based on the findings, in Iran since 1949 and with the approval of the Urban Health Law, the Ministry of Health has been obliged to monitor and control the quality of non-piped water in cities. After the enactment of this law, 10 other laws and regulations until 2014, a total of 13 tasks for this ministry were identified in the issue of water hygiene.

The findings suggest that existing laws and regulations adequately address the Ministry of Health's civil liability for water hygiene issues. Therefore, if consumers unknowingly suffer health damage directly from water pollution due to the Ministry's unintentional neglect, equipment defects, or mismanagement, the Ministry holds civil liability and must compensate for any losses incurred.

Since air pollution has always been one of the significant human problems and the effects of dust on human communities are evident, this study aimed to determine the concentration of heavy metals in dust in the urban area of Borazjan and to evaluate the health risk for the residents of this city.

This research was conducted in the summer of 2021, with the collection of dust from the main streets of Borazjan city randomly. The samples were dried and sieved after collection from the street surface and were prepared using a digestion method with four acids (HCl: HNO3: HF: HClO4, 3:1:3:1). They were then analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). After determining the concentrations of heavy metals, the health risk assessment was carried out for children and adults through three exposure pathways: ingestion, inhalation, and dermal contact.

In this study, the average concentrations of metals were determined as follows: Cu (58.4), Zn (178.06), Fe (14694.86), Ni (30.03), Cr (55.73), Cd (0.23), Pb (60.53), and As (3.88) mg/kg. Additionally, the results of the health risk assessment showed that the health risk for non-carcinogenic effects (HI) in children ranged from 10-1 to 10-3, and in adults, it ranged from 10-2 to 10-4 (HI > 1). The carcinogenicity (CR) of these metals was in the range of 10-5 to 10-11.

Overall, the levels of non-carcinogenic health risk as well as the assessment of carcinogenic risk for both children and adults are within the safe range. Moreover, the carcinogenicity of chromium and nickel is within the controlled pollution range (10-4 to 10-6) and does not pose a significant risk to the health of residents regarding cancer diseases.