Radon measurement and age-independent effective dose attributed to ingestion of bottled water in Iran: sensitivity analysis.

A comprehensive study was made to measure the radon concentration in bottled water available in Iran market. The 222Rn concentration in 70 bottled water samples were measured by the sniffing mode technique and RTM 1688-2 (SARAD, Germany) in immediate sampling time and 3 months later for determination of radon decay. The measured radon concentration ranged from 0.003 to 0.618 Bq L-1 in bottled water samples, which were much lower than the recommended value for radon in drinking water by WHO (100 Bq L-1) and United states environmental protection agency (USEPA) (11.1 Bq L-1). The annual effective dose of 222Rn due to ingestion bottled water was also evaluated in this research. The mean annual effective dose due to ingestion of radon in bottled water for adults, children, and infants were estimated to vary from 5.30 × 10-4 mSv-1, 4.90 × 10-4 mSv-1, and 2.15 × 10-4 mSv-1, respectively. Overall, this study indicated that the Iranian people receive no significant radiological risk due to exposure to radon concentration in bottled water brands common consumed in Iranian market.

A review of novel green adsorbents as a sustainable alternative for the remediation of chromium (VI) from water environments.

The presence of heavy metal, chromium (VI), in water environments leads to various diseases in humans, such as cancer, lung tumors, and allergies. This review comparatively examines the use of several adsorbents, such as biosorbents, activated carbon, nanocomposites, and polyaniline (PANI), in terms of the operational parameters (initial chromium (VI) concentration (Co), temperature (T), pH, contact time (t), and adsorbent dosage) to achieve the Langmuir's maximum adsorption capacity (qm) for chromium (VI) adsorption. The study finds that the use of biosorbents (fruit bio-composite, fungus, leave, and oak bark char), activated carbons (HCl-treated dry fruit waste, polyethyleneimine (PEI) and potassium hydroxide (KOH) PEI-KOH alkali-treated rice waste-derived biochar, and KOH/hydrochloric acid (HCl) acid/base-treated commercial), iron-based nanocomposites, magnetic manganese-multiwalled carbon nanotubes nanocomposites, copper-based nanocomposites, graphene oxide functionalized amino acid, and PANI functionalized transition metal are effective in achieving high Langmuir's maximum adsorption capacity (qm) for chromium (VI) adsorption, and that operational parameters such as initial concentration, temperature, pH, contact time, and adsorbent dosage significantly affect the Langmuir's maximum adsorption capacity (qm). Magnetic graphene oxide functionalized amino acid showed the highest experimental and pseudo-second-order kinetic model equilibrium adsorption capacities. The iron oxide functionalized calcium carbonate (IO@CaCO3) nanocomposites showed the highest heterogeneous adsorption capacity. Additionally, Syzygium cumini bark biosorbent is highly effective in treating tannery industrial wastewater with high levels of chromium (VI).

Prediction models for groundwater quality parameters using a multiple linear regression (MLR): a case study of Kermanshah, Iran.

Groundwater is one of the major sources of exploitation in arid and semiarid regions. Spatial and temporal quality distribution is an important factor in groundwater management. Thus for protecting groundwater quality, data production on spatial and temporal distribution is essential. The present study has applied multiple linear regression (MLR) techniques to predict the fitness of groundwater quality in Kermanshah province, west of Iran. The parameters examined were Total dissolved solids (TDS), Total hardness (TH), Sodium adsorption ratio (SAR). the quality variables were modelled by MLR. Finally, the performance of the models was assessed using the coefficient of determination (R2). The relationship between parameters by MLR showed that TDS and water quality parameters in semi-deep wells and aquifers had a strong positive correlation (r = 0.94, r = 0.98) and there was a strong positive significant correlation between SAR and water quality parameters in deep wells and aquifers (r = 0.98, r = 0.99). Also, TH and water quality parameters in all water sources had a strong positive correlation (r = 1). The MLR model could serve as an alternative and cost-effective tool for groundwater quality prediction where there is limitation in laboratory facilities, trained expertise or time. Consequently, the usefulness of these linear regression equations in predicting the groundwater quality is an approach, which can be applied in any other locations.

4-Chlorophenol adsorption from water solutions by activated carbon functionalized with amine groups: response surface method and artificial neural networks.

4-Chlorophenol pollution is a significant environmental concern. In this study, powdered activated carbon modified with amine groups is synthesized and investigated its efficiency in removing 4-chlorophenols from aqueous environments. Response surface methodology (RSM) and central composite design (CCD) were used to investigate the effect of different parameters, including pH, contact time, adsorbent dosage, and initial 4-chlorophenol concentration, on 4-chlorophenol removal efficiency. The RSM-CCD approach was implemented in R software to design and analyze the experiments. The statistical analysis of variance (ANOVA) was used to describe the roles of effecting parameters on response. Isotherm and kinetic studies were done with three Langmuir, Freundlich, and Temkin isotherm models and four pseudo-first-order, pseudo-second-order, Elovich, and intraparticle kinetic models in both linear and non-linear forms. The synthesized adsorbent was characterized using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses. The results showed that the synthesized modified activated carbon had a maximum adsorption capacity of 316.1 mg/g and exhibited high efficiency in removing 4-chlorophenols. The optimal conditions for the highest removal efficiency were an adsorbent dosage of 0.55 g/L, contact time of 35 min, initial concentration of 4-chlorophenol of 110 mg/L, and pH of 3. The thermodynamic study indicated that the adsorption process was exothermic and spontaneous. The synthesized adsorbent also showed excellent reusability even after five successive cycles. These findings demonstrate the potential of modified activated carbon as an effective method for removing 4-chlorophenols from aqueous environments and contributing to developing sustainable and efficient water treatment technologies.

Photocatalytic degradation of bisphenol a from aqueous solution using bismuth ferric magnetic nanoparticle: synthesis, characterization and response surface methodology-central composite design modeling.

Purpose: Bisphenol A (BPA), as endocrine-disrupting compound (EDC), is extensively used as an important chemical in the synthesis of polycarbonate polymers and epoxy resins. BPA absorption into the body can result in the development of metabolic disorders such as low sex-specific neurodevelopment, immune toxicity, neurotoxicity and interference of cellular pathway. Therefore, the presence of BPA in the body and the environment can create hazards that must reach standards before being discharged into the environment. Methods: In this study, bismuth ferric nanomagnetic (BFO NMPs) were successfully synthesized via sol-gel method and developed as photocatalysts for BPA removal under visible light irradiation. FE-SEM, TEM, PL, XRD, UV-Vis DRS, VSM, EDX, and FTIR were used to characterize the BFO NMPs. Results: RSM model (R2 = 0.9745) showed a good correlation between experimental and predicted removal efficiency of BPA. The investigation of four independent variables indicated that pH had the most significant positive effect on the degradation of BPA. Under optimal conditions (pH = 4.042, catalyst dose = 7.617 mg, contact time = 122.742 min and BPA concentration = 15.065 mg/L), maximum degradation was calculated to be 98.7%. After five recycles, the removal of BPA remained >82%, which indicated the proper ability to reuse the catalyst. Conclusion: In conclusion, it can be stated like BPA, the prepared BFO NMPs is a promising photocatalyst for practical application in organic pollutant decomposition.

Evaluation of conventional wastewater treatment plants efficiency to remove microplastics in terms of abundance, size, shape, and type: A systematic review and Meta-analysis.

In the present study Web of Science, Scopus, and PubMed as electronic databases were used to find work published up to October 27, 2020 about microplastics evaluation in conventional wastewater treatment plants. In total, 407 publications were found, of which 77 were eligible for meta-analysis. A comprehensive meta-analysis was undertaken to evaluate the relevant publications regarding microplastics abundance. The average microplastics abundance was within the 1-31,400, 0.2-12,580, 0.002-7863, and 0.003-447 items range per liter wastewater for influent, primary, secondary, and tertiary treatment steps, respectively. The difference between the abundance of microplastics characterization for the different treatment steps was analyzed using ANOVA or Kruskal-Wallis test (depending on the data distribution). According to the pooled data, the average microplastics abundance was 124.04, 20.67, 5.62, and 1.97 (items/l) for influent, primary, secondary, and tertiary treatment. The results of Egger's test (t = 7.49, P ≤ 0.0001) were statistically significant, suggesting the existence of publication bias.

Photocatalytic removal of diazinon from aqueous solutions: a quantitative systematic review.

Diazinon is a widely used pesticide that can be effectively degraded in aqueous solutions via photocatalytic oxidation. This quantitative systematic review was conducted to shed light on the various aspects of photocatalytic diazinon removal based on evidence. A systematic search was performed in Scopus, PubMed, Web of Science, Embase, and Ovid databases with keywords including diazinon, photocatalysis, and their equivalents. The search was limited to original articles in English published between January 1, 2010, and March 25, 2021. The results were expressed by descriptive statistics including mean, SD, median, and percentiles, among others. The initial electronic and manual search retrieved 777 articles, among which 41 studies comprising 49 trials were qualified for data synthesis. The reported diazinon degradation rate ranged from 2 to 100%, with a mean ± SD of 59.17 ± 28.03%. Besides, ZnO/UV, WO3/UV, TiO2/UV, and TiO2/Vis, in sequence, were the most widely used processes with the highest efficacies. Solution pH in the range of 5-8, catalyst dose below 600 mg/L, diazinon initial concentration below 40 mg/L, and contact time of 20-140 min could be the optimum conditions. Diazinon degradation obeyed the first-order kinetic model with kobs between 0.0042 and 1.86 min-1 and consumed energy of 38.93-350.36 kWh/m3. Diazoxon and IMP were the most detected by-products of diazinon degradation although bioassay data were scarce. Based on the results, photocatalytic processes are very efficient in removing diazinon from aqueous solutions although more elaborate studies are needed to assess the mineralization rate and effluent toxicity.

Isolation, identification and reviewing the health effect of HPC bacteria in household point-of-use (PoU) water treatment devices: a case study, Ahvaz, Iran.

In Ahwaz, a city in west southern Iran, the majority of households are using Point of Use (PoU) water treatment units. The heterotrophic plate count (HPC) bacteria were isolated from these units while they were mounted on water distribution system in order to determine the variations in HPC and diversity of the bacterial population using polymerase chain reaction (PCR). Results showed that bacterial population regrowth in PoU units could increase HPC exceeding the limit of the 500 CFU/mL in outlet water. In around 70% of the input water samples, the HPC was less than 500 CFU/ml with a mean of 226.7 (CI 95%: 28.1-425.3). HPC in output treated water samples had an increasing trend from the start of the unit operation with a mean of 2416.4 (CI 95%: 1074.9-3757.9). Out of 49 detected bacterial strains, 20 strains were Gram-negative and 29 Gram-positive. Bacillus was the most frequent genes detected in inlet and outlet water samples. Most of the identified bacterial strains were opportunistic pathogens potentially dangerous for immunocompromised population. HPC population in PoU units significantly can be increased during a one-month period of operation, so replacement of the filters must be done regularly.

Presence of heavy metals in drinking water resources of Iran: a systematic review and meta-analysis.

Water quality is one of the most important indices for public health especially for drinking water consumptions. This study was conducted to survey the presence of heavy metals in drinking water resources of Iran using a systematic review and meta-analysis. The literature search was conducted in data bases of PubMed, Web of Science, EMBASE, Scopus, Google Scholar, and some Persian databases up to 31 July 2018. Of all the articles reviewed (1151 articles), 61 papers were eligible for systematic review. Results indicated variable heterogeneity between studies for different pollutants (I2 between 0 and 100). A subgroup analysis was performed for three different types of water resources such as drinking water, groundwater, and surface water to find the possible source of the heterogeneity. The pooled mean concentration level of iron was the highest at 255.8 (95% CI = 79.48-432.13 µg/l) and vanadium the lowest at 3.21 (95% CI = 1.45-4.98 µg/l). The sequence of metal concentration (µg/l) in descending order is as follows: Fe (255.8) > B (159.81) > Al (158.5) > Zn (130.73) > As (85.85) > Mn (51.61) > Cu (47.98) > Se (42.68) > Pb (37.22) > Co (22.76) > Mo (18.92) > Ni (16.79) > Cr (13.47) > Hg (4.49) > Cd (4.19) > V (3.21). The mean pooled concentration level of Al, As, Se, Pb, and Cd was higher than the WHO guideline and Iran Standard, and the rest of the metals had lower mean pooled concentration level. Pb and Cd were the common heavy metals that existed in all subgroups. As a recommendation, the relationship assessment of water parameters and heavy metals could be addressed in future studies of Iran's water resources.

The presence of SARS-CoV-2 in raw and treated wastewater in 3 cities of Iran: Tehran, Qom and Anzali during coronavirus disease 2019 (COVID-19) outbreak.

This study aimed to identifying the presence of SARS-CoV-2 RNA in raw and treated wastewater during the COVID-19 outbreak in Tehran, Qom and Anzali cities (Iran). From three wastewater treatment plants (WWTPs), 28 treated and untreated wastewater composite samples were collected from April 4 to May 2, 2020. In this study, polyethylene glycol 6000 (PEG 6000) was used through one-step real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) for identification of RNA viruses. SARS-CoV-2 RNA was elicited from wastewater composite samples in all inlet samples taken from the three above mentioned cities. The results of outlet samples were as follows: 1) Results from Qom and East Anzali outlets showed no trace of SARS-CoV-2 RNA despite the difference in treatment disinfection method used (chlorine vs. ultraviolet (UV) disinfection). 2. In Tehran, SARS-CoV-2 RNA was not detected in any of the outlet samples taken from the modules disinfected by UV. Out of the four samples taken from the modules disinfected by chlorine, two were positive for the SARS-CoV-2 RNA which could have been caused by deficiencies in operation and maintenance. It can be concluded that meeting the standards of operation and maintenance (O&M) in WWTPs can considerably ensure that wastewater does not act as one of the roots of transmission for the disease.

Assessment of hydrogeochemical characteristics and quality of groundwater resources in relation to risk of gastric cancer: comparative analysis of high- and low-risk areas in Iran.

The chemical quality of groundwater supplies in two high-risk area (HRA) and low-risk area (LRA) for gastric cancer in Iran was assessed through hydrogeochemical analysis and water quality indices. For this aim, Piper and Schoeller diagrams and water quality index (WQI) were applied. In addition, exposure to nitrate via drinking water and its corresponding risk were also assessed using Monte Carlo simulation technique. Data on physicochemical properties of groundwater resources were obtained from Iran Water Resources Management Company. Sampling and analysis of tap water for nitrate concentration were conducted in two cities of Shiraz (as a representative of LRA) and Ardabil (as a representative of HRA). According to Piper diagrams, the dominant hydrogeochemical facies of groundwater supplies in HRA and LRA were Na-HCO3 (43.75%) and Ca-HCO3 (41.77%), respectively. The predominant cations in groundwater resources of HRA were found to be Na+ (68.06%) and Ca2+ (31.94%). For LRA, the typical cations were in decreasing trend: Ca2+ (39.64%) > Mg2+ (18.35%) > Na+ (17.26%). For two areas, HCO3-, SO42- and Cl- were, respectively, the most frequent anions. Two-sample Wilcoxon test showed that there were statistically significant difference between two areas in terms of anions and cations concentrations (p value < 0.05). The mean of total hardness (Ca2+ + Mg2+) concentration of water supplies in LRA (528.1 mg/L) was higher than HRA (263.1 mg/L), whereas the mean of Na+ concentration was found to be lower in LRA (90.6 mg/L) compared with HRA (108.1 mg/L). The sum of nitrate intake and its risk in LRA was higher than HRA. WQI results showed that drinking water quality in HRA and LRA ranged from excellent to poor and most water resources were of a good quality class. Further studies are suggested to investigate the role of drinking water in the etiology of gastric cancer in Iran.

Tehran environmental and neurodevelopmental disorders (TEND) cohort study: Phase I, feasibility assessment.

PURPOSE: To advance knowledge about childhood neurodevelopmental disorders and study their environmental determinants, we conducted a study in Tehran, Iran to assess the feasibility of prospective birth cohort study. METHODS: We evaluated participation of pregnant women, feasibility of sampling biological material, and health care services availability in Tehran in four steps: (1) first trimester of pregnancy; (2) third trimester of pregnancy; (3) at delivery; and (4) two to three months after delivery. We collected related data through questionnaires, also various biological samples were obtained from mothers (blood, urine, milk and nails-hands and feet) and newborns (umbilical cord blood, meconium, and urine samples) from February 2016 to October 2017. RESULTS: overall 838 eligible pregnant women were approached. The participation rate was 206(25%) in our study and about 185(90%) of subjects were recruited in hospitals. Out of 206 participants in the first trimester, blood, urine, hand nail, and foot nail samples were collected from 206(100%),193(93%), 205(99%), and 205(99%), respectively. These values dropped to 65(54%), 83(69%), 84(70%), and 84(70%) for the remaining participants 120(58%) in the third trimester, respectively. Also, we gathered milk samples from 125(60%) of mothers at two to three months after delivery. CONCLUSION: Our findings suggest that hospitals were better places for recruitment of subjects in a birth cohort in Tehran. We further concluded that birth cohort study recruitment can be improved by choosing appropriate gestational ages. Obtaining the newborn's urine, meconium, and umbilical cord blood were challenging procedures and require good collaboration between hospital staff and researchers.

Optimization of free chlorine, electric and current efficiency in an electrochemical reactor for water disinfection purposes by RSM.

This study surveys the possibility to optimally produce active chlorine from synthetic saline solutions using electrolysis by Response Surface Methodology (RSM). Various operating parameters, such as sodium chloride concentration, electrical potential and electrolysis time were evaluated. Central composite design (CCD) was applied to determine the optimal experimental factors for chlorine production. The experimental design, statistical analysis of the data and optimization were performed using R 3.5.3 software. The results showed that the optimum value of electrical efficiency (42 mg Cl2/kj) was obtained at the electrical voltage of 15.73 V during 15.63 min in the presence of 63.42 g/l of sodium chloride. The optimum point for current efficiency was 38.40%, which was obtained at the electrical voltage of 10.76 V during 6.70 min in the presence of 34.65 g/l of sodium chloride. Moreover, generated active chlorine was optimized based on energy consumption, which was 77 mg/l for the energy consumption of 0.2 kWh/l at a current density of 2000 mA/cm2. The electrochemical production of the chlorine gas from saline or brine water can be extensively used for water disinfection.

Comprehensive Risk Assessment of Health-Related Hazardous Events in the Drinking Water Supply System from Source to Tap in Gaza Strip, Palestine.

Background: The traditional approach in the management of the quality drinking water, and relying on end-product testing, has proven ineffective in protecting public health. Therefore, the transition to a systematic approach in drinking water supply systems management from the source to the consumer tap was taken as a water safety plan (WSP). Objective: The study aims to investigate the health-related hazardous events in order to decide on the best risk-reduction strategies in the supply of drinking water in the Gaza strip. Methods: A semiquantitative matrix method for risk assessment was applied. Also, chlorine residual, electrical conductivity, and nitrate concentration further tested in 109 water wells, 109 small-scale water desalination plants, 197 tanker trucks, and 384 households distributed over five governorates of the Gaza strip. Results: The mean of the measured chlorine residual values was less than the recommended national and international limits (0.2-1 mg/liter). The mean of electrical conductivity at catchment points and household municipal water taps was 2165.1 µS·cm-1 and 2000 µS·cm-1, respectively. Furthermore, zero percent of water samples met the recommended criteria, indicating that the groundwater in the Gaza strip is nonpotable. Only 12.8% and 8.8% of water samples met the permissible levels at catchment areas and municipal water at household, respectively, indicating sever health impacts on the public. Moreover, the most hazardous events were related to high levels of groundwater salinity, the low level of disinfection, the effect of electricity outages on the efficiency of the desalination process, and leakage of water from the tanker truck tank reservoirs. Therefore, urgent interventions are required to improve the quality of water and to mitigate the possible health effects. Conclusion: The prioritization of hazardous events that are proportional to the degree of their attributed risk could help guide in making the right risk-reduction decisions. Urgent interventions are required to improve the quality of water and to mitigate the possible health effects.

The effect of gas versus charcoal open flames on the induction of polycyclic aromatic hydrocarbons in cooked meat: a systematic review and meta-analysis.

PURPOSE: Open flames of gas and charcoal can induce polycyclic aromatic hydrocarbons (PAHs) in cooked meat. The current study aimed to compare the effect of gas and charcoal open flames on the induction of PAHs in cooked meat using a meta-analysis approach. METHODS: A systematic review of the literature was conducted electronically based on the PRISMA guidelines. Experimental studies comparing the PAHs content of cooked meat over open flames of gas and charcoal were searched using the appropriate keywords until June 2018. RESULTS: Of 1137 papers retrieved, 7 with a total sample size of 474 meat samples were used in the meta-analysis. The mean difference (MD) between the gas and charcoal cooking methods in the induction of each PAH was 2.053 µg/Kg. (95%CI: 1.022-3.085 µg/Kg; P < 0.001). The subgroup analysis of 17 trials indicated the difference between the two cooking methods increases when red meat rather than white meat is cooked (MD in red meat: 3.499 µg/Kg; 95%CI: 2.030-4.967; P < 0.0001 vs. MD in white meat: 3.319 µg/Kg; 95% CI: 1.689-4.950; P < 0.0001). Interestingly, studies that analyzed meat samples for fewer PAHs (cut-off ≤7) found a much wider difference between gas and charcoal-cooked meat (MD: 5.106 µg/Kg; (95% CI: 2.162-8.049; P < 0.001 in studies with ≤7 PAHs vs. MD: 1.447 µg/Kg; 95% CI: 0.628-2.266; P < 0.001 in studies with >7 PAHs). CONCLUSIONS: It is necessary to avoid open flames of charcoal as the heat source or change the geometry of charcoal-fired cookstoves to prevent fat dripping on the fire and thus, excessive PAHs induction.

Prenatal urinary concentrations of environmental phenols and birth outcomes in the mother-infant pairs of Tehran Environment and Neurodevelopmental Disorders (TEND) cohort study.

Daily exposure to environmental phenols can lead to potential undesirable effects on the health of pregnant women and fetuses. The present study is aimed to evaluate the relationship between maternal urinary concentrations of phenols in pregnancy and anthropometric birth outcomes. The studied population comprised of 189 pregnant women participating in the Tehran Environment and Neurodevelopmental Disorders (TEND) prospective cohort study, which had been ongoing since March 2016 in some hospitals and health care delivery centers in Tehran, Iran. Concentrations of bisphenol-A, triclosan, 4-nonylphenol, and parabens were determined in spot urine samples of pregnant mothers in the first trimester. Weight, length, and head circumference at birth were also extracted from the mothers' delivery files. Multivariable linear regression was used to examine the relationship between log-concentrations of phenols and birth outcomes. When we analyzed all samples regardless of neonates' gender, none of the urinary concentrations of phenols were associated with weight and length at birth. Indeed, in sex-stratified adjusted models, one log-unit increase of butylparaben was related to a 283.6 g (95% CI: 23, 544) increase in boys' birth weight. Prenatal urinary concentration of triclosan and propylparaben was respectively related to a decrease of 4.8 cm (95% C: -8.5, -1.1) in boys' length and 0.9 cm (95%CI: -1.8, -0.04) in girls' length. In the adjusted models for estimating the changes in head circumference, one log-unit increase of triclosan, methylparaben, and butylparaben led to a reduction of 1.6 cm (95% CI: -3.17, 0.03), increase of 0.8 cm (95% CI: -0.01, 1.6) and 0.7 cm (95% CI: 0.08, 1.4) in head circumference at birth respectively. Our results suggested that prenatal triclosan and parabens exposure might be associated with head circumference at birth. Furthermore, we observed a sexually dimorphic pattern between maternal triclosan and parabens exposure during pregnancy and fetal growth. However, these findings must be interpreted while taking into account the limitations of this study.

Comprehensive systematic review and meta-analysis of dyes adsorption by carbon-based adsorbent materials: Classification and analysis of last decade studies.

Carbon-based materials and their modifications have received significant attention over the last decades given the outstanding adsorption behavior toward various dyes from aqueous solutions. In this systematic review and meta-analysis, the adsorption capability of dyes on carbon-based adsorbent materials (CBAMs) has been compiled. Further, the effects of process variables i.e., pH, adsorbent dosage, contact time, and initial concentration), adsorption kinetics, and isotherms were investigated while considering the classification of different groups of dyes and adsorbents. The Metafor package provides functions for conducting meta-analyses in R software. Electronic databases, including PubMed, Web of Science, and Scopus were systematically searched based on Medical Subject Headings (MeSH) from January 1, 2009 to May 1, 2018. The following parameters were evaluated according to predetermined inclusion and exclusion criteria. After detailed screening and analysis, 835 articles were eligible for the review section. Among them, 87 studies met all quantitative criteria for the meta-analysis. The meta-analysis was performed using a random-effects model with a high heterogeneity (I2 = 99.99%). According to the evidence, basic dyes with n = 661 (∼50%) and powder activated carbon (PAC) sorbent with n = 752 (∼57%) have received the most attention among researchers. The results revealed that the mean of removal efficiency-based dyes classification was between 79.9 and 93.7% and the adsorption capacity was lied within the range of 76.8-303.6 mg/g. Meanwhile, the maximum adsorption capacity belongs to graphene families with Qm > 320 mg/g, while the minimum Qm was related to G and GAC with capacities of 108.5 and 110.7 mg/g, respectively. Pseudo-second-order kinetic model with 88.7% and Langmuir isotherm with 74% had the best fitting with the data studied. Baujat plot revealed that two studies (ID: 75 and 12) had the minimum influence on adsorption capacity with the highest dffits and cook's distance. According to the pooled data, the mean adsorption capacity varied between 140.90 and 208.25, with a mean of 174.57 mg/g across all studies. The results of Egger's test (t = 0.1332, p = 0.0844) and Begg's test (z = 0.8458, p = 0.3977) were not statistically significant, suggesting that no potential publication bias existed.

Photocatalytic degradation of ketoconazole by Z-scheme Ag3PO4/graphene oxide: response surface modeling and optimization.

Ketoconazole is an imidazole fungicide which is commonly used as pharmaceutical and healthcare products. Residual amount of this compound can cause adverse ecological health problems. The present study investigated ketoconazole photocatalytic degradation using Ag3PO4/graphene oxide (GO). Ag3PO4/GO and Ag3PO4 as visible light-driven photocatalysts was synthesized using the in situ growth method. Degradation of ketoconazole at the concentration of 1-20 mg/L in aqueous solutions was optimized in the presence of Ag3PO4/GO nanocomposite with the dosage of 0.5-2 g/L, contact time of 15-20 min, and pH of 5-9 using response surface methodology. A second-order model was selected as the best fitted model with R2 value and lack of fit as 0.935 and 0.06, respectively. Under the optimized conditions, the Ag3PO4/GO catalyst achieved a photocatalytic efficiency of 96.53% after 93.34 min. The photocatalytic activity, reaction kinetics, and stability were also investigated. The results indicated that the Ag3PO4/GO nanocomposite exhibited higher photocatalytic activity for ketoconazole degradation, which was 2.4 times that of pure Ag3PO4. Finally, a direct Z-scheme mechanism was found to be responsible for enhanced photocatalytic activity in the Ag3PO4/GO nanocomposite. The high photocatalytic activity, acceptable reusability, and good aqueous stability make the Ag3PO4/GO nanocomposite a promising nanophotocatalyst for photocatalytic degradation of azoles contaminants.

Sun exposure and health safety practices of high school students in an urban population of Iran.

BACKGROUND: Skin cancer attributed to sunlight exposure has an increasing trend worldwide, resulting in increased problems for healthcare services. This study aimed to evaluate the health safety practices of high school students in Saveh, Iran according to a sun protection guideline produced locally for Iran. METHOD: This cross-sectional study was done in 31 government and private high schools of Saveh, a central city of Iran. A sun protection questionnaire was designed in accordance with Iran sun protection guideline which has been developed based on the World Health Organization and US Environmental Protection Agency guidelines. The questionnaire consists of four sections of demographic information, knowledge, attitude, and protection behavior. A total of 504 students were selected by simple random sampling method. Pearson correlation coefficient and multiple linear regression analysis were used to assess the correlation between knowledge, attitude and behavior of the participants. RESULTS: The mean score of the students' knowledge, attitude, and behavior regarding harmfulness of ultraviolet radiation was 50.79 ± 14.64, 60.41 ± 15.04, and 45 ± 11.59, respectively. A significant association was observed between attitude and knowledge, behavior and knowledge as well as attitude. There was a significant correlation between sex and protective behaviors, sex and knowledge (p ≤ 0.001), and education level and knowledge (p = 0.002). CONCLUSION: students who protected themselves from sunlight less than others believed that their protection level was adequate. Health concerns related to sun exposure suggest the need for increasing the student's awareness in sun protection area. As behavior is influenced by cultural aspects, implementation of the current guideline can be effective in reducing the health effects of sun exposure.

Health Risk Assessment of Dermal Exposure to Heavy Metals Content of Chemical Hair Dyes.

BACKGROUND: Contamination of hair dyes to heavy metals can threaten consumer's health. We investigated the concentrations of some important heavy metals in hair dyes and evaluates their non-carcinogenic effects. METHODS: The most commonly used hair dyes were determined through questioners and 32 samples were collected from the market of Tehran in 2014. The concentration of 10 heavy metals (Fe, Ag, Co, Cr, Mn, Ba, Cd, Cu, Pb, and Al) was determined using ICP-MS. Based on the obtained data from distributed questionnaires and Monte Carlo simulation, the exposure to the evaluated heavy metals was estimated. Besides, using hazard quotient (HQ) and chronic hazard (HI), the risk of non-carcinogenic effects of investigated hair dyes consumption was specified. RESULTS: Results indicated the average concentrations of Al, Ba, and Fe as 0.54, 0.86, and 1.19 mg kg-1 and those of Cd, Cu, and Pb as 0.45, 61.32, and 185.34 µg kg-1, respectively. Pb with HQ of 7.46e-4 had the highest risk and Fe with HQ of 3.4e-6 had the lowest level of risk. Among the investigated dyes, the ones made by Iran (HI=2.8e-4) and the dark brown color (HI=1.93e-4) had the highest level of risk among all the studied samples. CONCLUSION: Two indices of HI and HQ showed that heavy metal contents in the investigated samples had not probable non-carcinogenic risks for the consumers of these products.