Abdolmajid Fadaei

In the current century, the consumption of cytostatic drugs such as methotrexate, known for their mutagenic and teratogenic properties, has increased due to the rising prevalence of cancer. Given methotrexate’s poor metabolic breakdown in the human body, its residues have been detected in hospital effluents and treated wastewater, underscoring the necessity for its removal from aquatic environments. This study aimed to evaluate the efficacy of the UV/iodide/ZnS process in removing methotrexate from aqueous solutions. Key variables, including pH, catalyst concentrations (iodide and ZnS), initial methotrexate concentration, and contact time, were investigated. Optimized conditions derived from synthetic solutions were compared with real hospital wastewater samples, and methotrexate levels were quantified via high‐performance liquid chromatography (HPLC). Results revealed that optimal methotrexate removal (81%) and mineralization (55%) in synthetic media were achieved using the ZnS/iodide/UV process under the following conditions: pH 7, 2 mM iodide, 0.2 g/L ZnS, and 20‐min contact time. Individual and synergistic analyses of the process demonstrated that the simultaneous application of all three oxidizing agents (ZnS, iodide, and UV) yielded significantly higher efficiency than combined or individual treatments. When applied to hospital wastewater under optimized conditions, methotrexate removal and mineralization efficiencies were reduced to 45.5% and 23%, respectively. These findings highlight the UV/iodide/ZnS process as an environmentally friendly advanced oxidation/reduction technology with promising efficacy for methotrexate removal from aqueous solutions. Under optimized parameters, the method achieves rapid degradation and holds potential for real‐scale implementation in advanced and tertiary wastewater treatment systems.

Aim: This research aimed to evaluate the efficiency of photocatalytic removal of nitrate from aqueous solutions using suspended and immobilized zinc oxide (ZnO). Methods: A comparison was made between the photocatalytic, suspended, and immobilized ZnO nanoparticles (ZnO NPs) for nitrate removal. In addition, the effect of ZnO NPs either suspended or immobilized was evaluated in the presence of ultraviolet irradiation. The transmission electron microscopy, scanning electron microscopy, and X-ray diffraction analyses were applied to survey the physiochemical properties of ZnO. Photocatalytic degradation of nitrate was investigated using a spectrophotometric approach. Results: The ideal function of removing nitrate (90%) was achieved with the concentration of 25 mg/l and in acidic pH. Immobilized catalysts can be used in continuous reactors due to the possibility of elimination of the phase segregation. The rising concentration of NPs to 0.8 g/L was associated with higher efficiency of the removal process. Maximum reduction performance of photocatalytic removal of nitrate (using immobilized and suspended ZnO) was 90% and 81%, respectively. Nevertheless, according to the findings, the immobilized method is highly more efficient for nitrate removal than the suspended method. The optimal time for the photocatalytic process was obtained at 150 min, and after 150 min, the reaction followed the first-order reaction kinetics. Conclusions: The photocatalytic technique is efficient for nitrate removal from water and wastewater.

Background. Prostate cancer is the second most common cancer in men and the fifth leading cause of death worldwide. Our aim in this study was to investigate the relationship between exposure to cadmium and the incidence of prostate cancer through conducting a systematic review and meta-analysis method. Methods. The Studies that investigated the relationship between cadmium and prostate cancer were searched and retrieved from the international databases until May 2022. (x2) and (I2) statistical tests were used respectively to determine the presence and size of heterogeneity; Egger's and Bagg's tests were used to determine the existence of diffusion bias; and meta-regression and sensitivity analysis were used to identify the source of heterogeneity. All analyses were performed by Stata (Version 15) statistical software. Results. It was observed that the relative risk of prostate cancer occurrence compared to the base group, in people exposed/exposed to a dose higher than the base level was equal to 1.05(95% CI:0.94-1.17; P=0.372); Meanwhile, no statistically significant relationship was observed between exposure to cadmium or exposure levels exceeding the baseline and prostate cancer. According to the results of Egger's test (P = 0.989) and Begg's (P= 0.787), diffusion distortion was not observed in this study. Conclusion. Based on the available evidence, although exposure to cadmium leads to an increase in the risk of prostate cancer, this risk increase is not statistically significant. Practical Implications. The World Health Organization should think with a more serious approach to the relationship between environmental health and cancers.

This study aimed to investigate the association between lithium levels in potable water and suicide mortality rates in the total inhabitants. We systematically searched Embase, PubMed/MEDLINE, Scopus, PubMed Central (PMC), Google Scholar databases, as well as medRxiv using the following keywords: drinking water, lithium, standardized mortality ratio (SMR), tap water, suicide, and ground water. Pearson regression analysis was used to test an association between variables with 95% confidence interval (CI). A value of P < 0.05 was considered significant. A total of 16 eligible articles were identified. Lithium concentrations in drinking water range from 0.4 to 32.9 μg/l. Average rates of suicide mortality (per 100 000 capita) range between 0.790 (±0.198) and 123 (±50). About 16 original studies confirmed the inverse relationship between lithium concentrations in potable water and suicide mortality rates (R = −0.576; R ² = 0.3323; 95% CI, −0.820 to −0.325; β = −0.3.2; P = 0.019). High lithium concentrations in potable water were associated with decreased suicide rates. We concluded that lithium concentration in potable water was inversely associated with suicide mortality rates among a total population. However, further research is required to clarify the relationship between lithium concentrations in drinking water and suicide rate.

Contamination by heavy metals and toxic elements in children’s toys and jewelry is an ongoing challenge in different countries. These contaminants can enter the children’s body via oral, dermal, and respiratory routes, leading to adverse health effects. This study aimed to investigate the present levels of contamination in children’s toys and jewelry in 15 countries, including UK, Saudi Arabia, Cambodia, China, Kosovo, Nigeria, North American, Kazakhstan, UAE, Pakistan, Iraq, Israel, West Bank/Palestine, Czech Republic, and Turkey. In this review, the legislation and recommendation of the United States (U.S.), the Bureau of Indian Standards (BIS), Turkish Standards Institute (TSE), Canada, and the European Union (E.U.) on toxic elements in toys and jewelry are introduced. Plastic or metallic toys and children’s jewelry still have the most severe toxic elements pollution and the existence of lead (Pb), nickel (Ni), cadmium (Cd), arsenic (As), mercury (Hg), chromium (Cr), copper (Cu), selenium (Se), barium (Ba), Zinc (Zn), cobalt (Co), manganese (Mn), bisphenol A, phthalates, parabens, azo dyes, and flame retardants has been regarded as an ongoing challenge in these articles. Finally, this review offers benchmarking of the concentrations of toxic elements in all types of children’s toys and jewelry in different nations.

Medical waste status is a severe public health problem worldwide. Proper medical waste management is of paramount importance. However, there is insufficient information about medical waste management and lack of management in different countries. The aim of this research was to investigate and evaluate the present status of medical waste management in different countries. We systematically searched Embase, PubMed/MEDLINE, Scopus, PubMed Central, Google Scholar databases, as well as medRxiv using the following keywords: medical waste, waste management, disposal, healthcare per-capita generation, gross domestic product (GDP), and hospital. A total of 38 eligible articles were identified. Correlations were calculated between the amount of medical waste generated (kg bed.day⁻¹) vs. GDP per capita ($) and ranking of healthcare system performance. A negative correlation was found between medical waste generation rate and ranking of healthcare system performance. According to the findings of this study, the medical waste generation rate in different countries ranged from 0.14 to 6.10 kg bed.day⁻¹. About 25% of countries segregated medical waste, and about 17% used standard storage for all medical waste. Shortcomings were also found in waste collection, storage, transportation and transfer, and disposal of medical waste management activities in different countries. Only about 25% of countries simultaneously used three techniques, such as autoclaving, incineration, and landfill for disposal and treatment of medical waste, and 91% used incineration method. This study highlights an essential need for particular medical waste management guidelines and regulations, technologies, knowledge and financing to upgrade medical waste management worldwide. This study can be considered to be a good guide for further research on medical waste management in developing and developed countries.

In this study, the degradability of the antibiotic Ceftriaxone was investigated with the help of genetically engineered Pseudomonas putida, in which the gene producing the enzyme catechol 2 and 3 dioxygenase was designed and then inserted into the pUC18 plasmid and replicated by E. coli. It was purified and extracted and transformed into Pseudomonas putida. Finally, the degradation rate of Ceftriaxone by this bacterium in spiked soil was evaluated using the HPLC measurement technique. Finally, the kinetics of Ceftriaxone degradation by genetically engineered Pseudomonas putida was investigated using zero, first, and second –order kinetic models for all factors. The results of HPLC measurement showed that the biodegradation of ceftriaxone in spiked soil was significant by genetically engineered P. putida compared to autoclaved soil inoculated by wild P. putida and normal soil with normal microbial flora (p < 0.001) and this bacterium was able to degrade ceftriaxone by 69.53% and kinetic modeling showed that the rate of removal by genetically engineered Pseudomonas putida follows the zero-degree reaction model. These findings indicate that Pseudomonas putida, which produces Catechol 2,3-dioxygenase, can be useful and practical in the biological treatment of environment from cephalosporins.

The 2019 novel coronavirus (COVID-19) pandemic has enormously affected the world and become a worldwide problem. To control the spread of COVID-19, human behaviors are generally controlled in most countries. However, exposure to air pollution causes increased susceptibility to COVID-19. The goal of this review research was to investigate the outdoor/indoor air quality during the outbreak of COVID-19. A review search was carried out from the databases Scopus, PubMed, Web of Knowledge, and Embase using the key words: “air quality” and “COVID-19 pandemic”. Twenty-four released articles were ultimately identified as eligible candidates for review study. The type of environment, country and city, type of study, goal of study, and study findings were analyzed. The results demonstrated the significant relationship between air pollution (PM2.5, PM10, SO2, NO2, CO, and O3) and the COVID-19 event. Indoor pollutant concentrations were typically higher during COVID-19 lockdown. There is also a relationship between meteorological parameters (rainfall, relative humidity, temperature, wind speed, and sunlight) and COVID-19 spread. The air quality index (AQI) of most countries improved to varying grades of quality under the COVID-19 infection control. It is crucial that policy makers and decision makers adopt more valuable methods to assist betterment of air pollution, particularly in developing nations, or control contact with pollutants so as to preserve public wellbeing.

Fluoride pollution in subsurface water is a significant problem for different nations across the world because of the intake of excessive fluoride caused by the drinking of the contaminated subsurface. Water pollution by flouride can be attributed to the natural and human-made agents. Increased levels of fluoride in drinking water may result in the irretrievable demineralization of bone and tooth tissues, a situation called fluorosis, and other disorders. There has long been a need for fluoride removal from drinking water to make it safe for human use. Among the various fluoride removal methods, adsorption is the method most popularly used due to its cheap cost, ease of utilization, and being a scalable and simple physical technique. According to the findings of this study, the highest concentration of fluoride (0.1–15.0 mg/L) was found in Sweden and the lowest (0.03–1.14 mg/L) in Italy. We collected the values of adsorption capacities and fluoride removal efficiencies of various types of adsorbents from valuable released data accessible in the literature and exhibited tables. There is still a need to find the actual possibility of using biosorbents and adsorbents on a commercial scale and to define the reusability of adsorbents to decrease price and the waste generated from the adsorption method. This article reviews the currently available methods and approaches to fluoride removal of water.