نشریه مهندسی بهداشت محیط
سال یازدهم شماره 1 (پیاپی 42، پاییز 1402)

Antibiotics are among the environmental pollutants with stable effects during consumption, they are rarely completely metabolized in the body and 30-90% of them are excreted through urine and feces and enter into the environment. The present study was conducted to evaluate the degradation of cefixime pollutant by photocatalyst Fe3O4@SiO2@TiO2@rGO + UV in the presence of persulfate (PS) from synthetic wastewater.

Fe3O4@SiO2@TiO2 (F@ST) photocatalyst was synthesized by co-precipitation method, and then fixed on reduced graphene oxide (rGO). The structural properties of magnetic photocatalyst were evaluated using FESEM, XRD, TEM, VSM techniques. The effect of variables such as solution pH, catalyst dosage, persulfate concentration and initial pollutant concentration on the performance of the FS@T/rGO/PS/UV process in the degradation of cefixime pollutant was investigated. After determining the optimal conditions, the influence of interfering ions and scavengers on the process, as well as the amount of recovery and reuse of the catalyst were investigated.

The synthesized photocatalyst had features such as excellent magnetic properties, crystalline and relatively spherical structure in nano size, high purity, photocatalytic properties in both ultraviolet and visible ranges. Under optimal conditions (pH=6.5-7, PS= 2mM and photocatalyst dosage= 0.1 g/L), after 60 min of oxidation time, cefixime antibiotic with a concentration of 50 mg/L and TOC, respectively, with efficiency > 98% and 55.7% were removed. The performance of the process was affected by the presence of organic scavengers (TBA, NaN3, KI and CH3OH) and interfering ions (Cl-, SO4-2, NO3- and CO3-2); so that the pollutant degradation efficiency decreased in the presence of organic scavengers and interfering ions. The effective reaction species were included h⁺, 1O2, OH• and SO4•⁻ in the degradation of cefixime by photocatalytic process in the presence of PS. The synthesized photocatalyst could be used for 4 consecutive steps, and in the fourth step, cefixime was degraded with an efficiency of 70.1%. The behavior of the photocatalytic degradation of cefixime antibiotic per unit time was a function of the pseudo-first-order kinetic model.

: FS@T/rGO/UV/PS photocatalytic process with features such as high efficiency in antibiotic degradation, easy and fast separation, pollutant mineralization, production of side products with simple molecular structure and good performance on the real wastewater sample could be used as a suitable method for industrial wastewater post-treatment as well as pre-treatment in order to reduce organic load and increase biodegradability.

Climate change and declining rainfall have significantly reduced access to surface water in Iran, particularly in Hamedan Province. This has led to increased reliance on groundwater resources, consequently altering their quality for various uses. Therefore, this study was conducted to develope a qualitative model for assess of groundwater resources in Kabudarahang Plain, Hamedan Province, using an Artificial Neural Network (ANN) and the Gray Wolf Optimizer (GWO) algorithm.

Qualitative data of groundwater resources in Kabudarahang Plain were collected and analyzed over a decade (2012-2022). ANN modeling was employed to predict groundwater quality changes. Additionally, the GWO algorithm was integrated to enhance prediction accuracy. The model utilized three output or dependent variables (TDS, EC, and pH) and six input or independent variables (calcium, magnesium, chloride, sulfate, sodium, and turbidity).

The ANN model demonstrated that over 99% of water quality variations can be attributed to the six input variables. Moreover, the GWO algorithm effectively reduced average prediction errors from 0.0015 to 0.0008.

The ANN algorithm exhibited high prediction accuracy, low prediction error, and model optimality, which were further enhanced by the GWO algorithm. This suggests that while the ANN model successfully predicted groundwater quality changes in the study area, the GWO algorithm refined the predictions, and improving the model's overall performance. Considering the complementary nature and effectiveness of ANN and GWO algorithms for prediction, their application to predict qualitative changes in groundwater resources in other regions is recommended.

Antibiotics are a type of medicine that are found in different concentrations from nanograms to micrograms in water sources, and their high resistance to decomposition makes it difficult to remove them from aquatic environments. The aim of this study is to investigate the removal of tetracycline antibiotic from water environments.

In this study, modified y-type nano zeolite was synthesized for tetracycline adsorption. The properties of modified y type nano zeolite adsorbent were determined by FESEM, EDS, FTIR and XRD analysis. Then the absorption process of tetracycline was investigated.

The highest removal rate of tetracycline antibiotic was achieved at a concentration equal to 50 mg/L and a contact time of 30 min, at pH=7 and a modified nano zeolite concentration of 0.4 g/L, 97.4%. The adsorption process of tetracycline through modified nano-zeolite y was compatible with the Langmuir isotherm model (R = 0.991) and pseudo-second-order kinetics (K2 = 0.002).

The results showed that the nano adsorbent is significantly able to remove tetracycline from aqueous solutions in a short period of time. Therefore, it can be used as an effective adsorbent to remove antibiotics.

Due to the increasing spread of musculoskeletal problems (MSDs), it is necessary to examine and compare the ergonomic risk factors of the workplace with general and specific methods. The present study was conducted to evaluate the ergonomics of the office work environment using two specific and general evaluation techniques in two universities of medical sciences in the country.

The prevalence of MSDs was evaluated using the Nordic standard questionnaire and the ergonomic assessment of employees in the workplace using ROSA's quick assessment of administrative stress and REBA's quick assessment of the whole body. Descriptive statistics and chi-score, independent t-tests, and logistic regression tests were used to describe and analyze the data.

The difference in mean ROSA score and mean monitor height between two groups of employees who have experienced MSDs during the last 12 months and the group who have not experienced them is significant. For one unit increase in ROSA score and one centimeter of monitor height, considering other intervening variables, the chance of MSDs increases by 45% and 13%, respectively.

The ROSA tool is a more reliable method to evaluate the ergonomics of the office work environment than REBA. The overall score of the ROSA method and workstation parameters such as monitor height can be used in office jobs to design interventions to reduce MSDs. More studies on the reliability of ROSA are needed to increase the validity of ergonomic interventions based on this method.

Aflatoxin M1 is one of mycotoxins which is produced by metabolism of Aflatoxin B1 and enters to the human body through animal milk. It has very strong hepatotoxic, carcinogenic and mutagenic effects and is potentially dangerous for human health. As milk is one of the most important foods for humans, it is essential to protect the health risk of Aflatoxin M1 in different age groups. In the present study, raw and pasteurized milk samples of Zanjan, East Azerbaijan, Gilan and Kermanshah provinces have been evaluated then contamination of the samples with aflatoxin M1 and also the status of this contamination in different seasons have been investigated.

180 samples (93 samples of raw milk and 87 samples of pasteurized milk) In the autumn and winter of 1997 and the spring and summer of 1998 were collected from stores in Zanjan, East Azarbaijan, Gilan and Kermanshah provinces. The samples were centrifuged, the surface fat removed, and competitive ELISA assessed for aflatoxin M1.

In this study, 180 samples were collected from 4 cities of Tabriz, Kermanshah, Zanjan and Rasht, where the level of aflatoxin M1 was measured by ELISA method. The results showed that 100% of the examined samples were infected with aflatoxin M1 and the average concentration aflatoxin M1 in Tabriz, Kermanshah, Zanjan and Rasht are 31.9±6.5, 30.7±16.9, 29.9±2.2 and 25.4±3.8 ng/L,that was observed in the range of <1-134.2 ng/liter.

The results of our study showed that in all samples taken from four cities of Tabriz, Kermanshah, Zanjan and Rasht, there is aflatoxin M1 contamination that the level of this contamination was different from season to season. In such a way, the highest contamination was observed in the autumn and in the traditional type of production. Considering the harmfulness of aflatoxin M1 for human health, it is very important to continuously control animal feed in terms of aflatoxin B1 and control milk and its products for the absence of aflatoxin M1.

Oil and gas terminals are considered key facilities in every country. The present study aimed to provide a combined model to assess the health and safety of the oil and gas working environment and other similar industries and services.

In this qualitative study, data were collected and produced by the methods of field survey, document review, individual interview, focus group interview and focus group discussion. A combination model of techniques including task analysis, effect, and failure mode analysis, event tree analysis, fault tree analysis, and fishbone diagram, was introduced and used to evaluate the health and safety of the work environment.

Oil and gas terminal jobs have both many tasks and hazards. Among the studied jobs, liquid gas loaders (RPN1=158), general mechanics (RPN1=156), and lab technicians (RPN1=158) had the highest levels of risk that were over upper control while oil material masters had the lowest level of risk that was under lower control. Other jobs were under control.

Applying the corrective and preventive suggestions presented in the cause-control fishbone diagram and safe work procedures for each job, the risk level of the studied workplace can be reduced below the control limit and the negligible risk range. Other industries and services can use the combined model in workplace risk management.

One of the most important issues in today's expanding world is the issue of the environment and its protection. This study was conducted to investigate environmental literacy (knowledge, attitude, and performance of environmental protection) in nursing students of Chabehar City.

This descriptive and analytical research was conducted on 200 nursing students. The research sample was obtained using Simple random sampling. The data collection tool was a demographic questionnaire and an environmental literacy questionnaire. Data were entered into SPSS version 18 statistical software and analyzed using ANOVA and Pearson correlation tests.

The results showed that 69.8% of students had good knowledge about environmental protection behaviors. And 66% of students had good environmental attitudes and 50.8% of students had poor environmental protection behavior. Also, students' environmental behavior had a statistically significant relationship with parents' education level, and gender (p < 0.05). Finally, the results showed that there is a strong positive correlation between environmental awareness, attitude, and behavior variables.

To promote environmental protection behaviors in students, it is possible to hold educational classes in the field of environment, and environmental activities, and use indirect education to develop environmental culture.

Regarding to the role of trees in reduction and absorption air pollutants, assessing the tolerance of different tree species to environmental pollutants is very much important in order to select suitable species around any polluted place. Therefore, the aim of this study was to evaluate the tolerance of P. orientalis, M. nigra and A. altissima species to air pollution using biophysical and biochemical leaf biomarkers.

For this purpose, sampling of the leaves from all three species was carried out at six stations in Isfahan, after being transferred to the laboratory, the Stomatal density, total protein content, soluble sugars and anthocyanin were calculated.

The results showed that M. nigra and A. altissima species responded to air pollution by increasing and P. orientalis by reducing the density of stomata. The amount of total protein content of M. nigra, P. orientalis and A. altissima leaves were 48.93, 55.76 and 23.53% higher in polluted areas than in unpolluted areas. The value of soluble sugars and anthocyanins in M. nigra, P. orientalis and A. altissima leaves were found (90.22, 38.65 and 88.88) and (19.64, 88.8 and 80.05%) in polluted areas compared to non-polluted areas.

According to the findings, it can be concluded that trees have differently respond to air pollution in relation to stomata density, which can be done in two ways, increasing or decreasing stomata density. Increasing the amount of total protein, soluble sugars and anthocyanins in the leaves of trees in the polluted area indicates that these trees are tolerant to pollutants and they applied these useful strategies to adapt and deal with pollutants.