Background and Objective: Nowadays, the demand for seawater desalination plants (SDPs) has risen worldwide. However, there is a lack of knowledge on the effects of discharging the SDPs brines into the Persian Gulf marine environment and its aquatics health. Therefore, this research was performed to examine the effects of SDPs brines discharged from this facility in the ecosystem of the Persian Gulf on survival and electrolytes in the Blue swimmer crab, Portunus segnis (Forskal,1775) under laboratory conditions. Materials and Methods: Brines of two types of active SDPs in Hormozgan were collected; then,75 crabs of (P.segnis), with mean (±SD) carapace width of 9.71±2.18 cm and total weight of 61.22±1.04 g, were collected and transported to the laboratory from the Bandar Abbas coast. As a completely randomized design, the samples were tested in 5 treatments (with three repetitions). Mortality was recorded, and at the end of the experimental period (60 days),the level of some electrolytes of the hemolymph (sodium, calcium, magnesium, and potassium) was measured. Results: Crabs' survival percentage in treatments containing SDPs effluent decreased compared to control (86%), which was more evident in RO 100% and MED 100% treatments with 46.7% and 40%, respectively (p <0.01). The examined electrolyte levels in treatments containing SDPs brine increased compared to control, which were more significant for RO 100% and MED 100% treatments (p <0.01). Conclusion: This study showed that the SDPs brines would have physiological consequences on aquatic organisms. In nature, the synergy of SDPs effluents with other sources of ecological stress will have severe impacts. Therefore, the necessary regulations and actions should be taken to minimize the environmental effects of SDPs.
Background and Objective: Outsourcing services to the private sector can be a step towards achieving the goals of community health promotion, job creation, better access to health services, and improving the quality of health services. In this regard, health service offices were established in Tehran to improve the health status of food preparation, distribution and sale centers and increase food safety based on government approval. This study aimed to evaluate the roles of health services offices on environmental health indicators. Materials and Methods: In this descriptive-comparative study, nine health service offices supervised by Tehran University of Medical Sciences (located in South Tehran Health Center, Eslamshahr city, and Shahr-e Rey) were surveyed. Seven environmental health indicators measured in the years before the establishment of these Health Service Offices (2015-2017) were compared with those obtained after their establishment (2018-2019). The indicators data were analyzed using Excel, SPSS software, and statistical tests. Results: The result showed no significant difference in public places and centers for food preparation and distribution offenders, public places with health criteria, percentage of employees with a health training certificate, health care, and percentage of inspection coverage before and after establishment of health service offices (p >0.05). However, the relationship between the food preparation indicators and distribution centers with health criteria and public places and closed food preparation and distribution centers were significant (p > 0.05). Conclusion: This study is one of the first researches conducted to evaluate the effectiveness of health services offices on health-safety indicators in Iran. Therefore, more comprehensive monitoring and studies should be done to evaluate these offices' performance quality and their related cost-benefit analysis.
Background and Objective: Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants produced by anthropogenic activities that contaminate all environmental matrices, including soils, and can enter the food chains. Therefore, this study was conducted for the analysis of PAHs compounds content in agricultural soils of Hamedan city, west of Iran, in 2021. Materials and Methods: a total of 36 surface soil specimens were collected from 12 sampling sites in agricultural soils and after extraction of analytes based on the soxhlet method, the gas chromatography/mass spectrometry (GC–MS) method was used for the determination of PAHs compounds in the samples. Furthermore, soil samples were further analuzed for the amounts of pH, electrical conductivity (EC), and total organic carbon (TOC). Statistical analysis was performed using SPSS software. Results: Results showed that 16 PAHs (∑16PAHs) total concentrations ranged from 435 to 3292 µg/kg with an average value of 1806 µg/kg. PAHs with higher molecular weight (≥ 4 rings) were dominant in PAHs profiles accounting for 78%. Based on the results, the mean concentrations of all 16 PAHs were lower than MPC established by MHWaS. Furthermore, the mean concentrations of Pyr, B(a)A, Chy, B(b)F, B(k)F, B(a)P, and B(ghi)P were higher than the MPC established by the Iranian Department of Environment. Conclusion: Based on the results obtained, as the mean contents of some PAHs were higher than the MPC, therefore, periodic monitoring of soil contamination with PAHs is recommended for the environmental and human health aspects.
Background and Objective: Due to the negative effects of municipal waste, the need for proper management and selection of appropriate solutions to minimize these effects is strongly felt. One of the methods of recycling waste is preparing compost from organic materials. The purpose of this study is to evaluate the environmental impacts of the two options of implementation and non-implementation of the Karaj compost plant project. Materials and Methods: Based on the obtained results, the project implementation was determined by gaining more points (0.181) in terms of sustainability and having the least destructive environmental effects, and the project was not implemented by gaining more points (-0.155) in terms of sustainability and having more environmentally destructive effects. Results: Based on the obtained results, the first option (project implementation) was determined as the best option by gaining more points (0.181) in terms of sustainability and having the least destructive environmental Impacts and the second option (non-implementation of the project) was determined with a lower score (-0.155) in terms of sustainability and more environmental damage than the first option. Conclusion: According to the research findings, the results of the rapid impact assessment matrix and sustainability model are consistent in confirming the superiority of compost plant performance over non-implementation.
Background and Objective: Bioaerosols as small particles enter the body by inhalation and lead to respiratory diseases based on type, concentration, and exposure time. In sensitive workplaces such as medical centers, it is necessary to pay attention to the type and population of these pollutants and the possibility of nosocomial infections. In the present study, the population and type of bioaerosols (bacteria and fungi) in the air of different hospital wards under normal conditions, visiting hours, and Covid-19 pandemic was evaluated. Materials and Methods: Air sampling was carried out in different wards and ambient air of Valiasr Hospital of Zanjan during September 2019 (morning and visiting hours) and October 2020 (Corona pandemic) using an air sampling pump (Flite 3- SKC Ltd) with a flow of 14.1 L/min and then cultured in Sabaroud dextrose agar and nutrient agar. Results: The results showed that air pollution in wards such as infectious diseases and clinics in both periods was more than other wards. The microbial density during visiting hours (before the coronavirus outbreak) was almost 30% higher than normal conditions. In October 2020, due to the coronavirus outbreak and reduced traffic, microbial air pollution in the hospital decreased. In both periods of study, the frequency of gram-positive bacteria, especially Staphylococcus species (49%) was higher than other bacteria and among fungal species the frequency of Aspergillus (47%) was higher than others. Conclusion: This study showed that traffic restrictions caused by the coronavirus pandemic reduce microbial density in hospital space and this achievement can be used in the future with the aim of improving air quality and controlling nosocomial infections.
Background and Objective: The high concentration of petroleum hydrocarbons, along with some other parameters such as aromatics, paraffin, naphthene, and heavy metals, has led to the sludge of oil sludge listed as hazardous materials with a specific source by the US Environmental Protection Agency. Therefore, the purpose of this study is to investigate the potential of oil-contaminated soil in changing the biodegradability indices of oil sludge. Materials and Methods: Moisture, pH, total organic carbon, total nitrogen, total phosphorus, elemental analysis, and amount and type of TPH of oil sludge samples were identified. The microbial consortium was isolated from contaminated oil soil around the oil refinery and poultry manure. Finally, biodegradability indices of oil sludge were examined. Results: The results showed that the amount of organic carbon and nitrogen in oil sludge samples were 32.65 and 0.21%, respectively. Also, iron, calcium, and potassium with 5862, 2921, and 524 mg/kg, respectively, were the most elemental components in petroleum sludge. According to the SARA analysis, the highest TPH compounds in oil sludge samples included saturated compounds, aromatics, resins, and asphaltene with 70.45%, 15.2%, 10.9%, and 3.45%, respectively. Conclusion: According to the results of biodegradability indicators of oil sludge, it can be concluded that the isolated consortium can be proposed as a suitable tool for the treatment of petroleum sludge at the bottom of crude oil storage tanks.
Background and Objective: With increasing water pollution, serious water shortages and increased pressure to save water, recycling and reuse of water has attracted more attention in various industries. Removal of silica from cooling water is essential for recycling and reuse of water. The aim of this study was to remove silica from water using magnesium oxide nanoparticles (MgO) synthesized by chemical deposition method. Materials and Methods: Synthetic nanoparticles were successfully determined using field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). To determine the optimal adsorption conditions the batch system, the effect of important parameters such as pH (2-8), contact time (0-150 min), initial concentration of silica solution (50-1000 mg/L), adsorbent amount (0.01-0.14 g) and temperature (25-60 ˚C) were studied. Results: Under optimal conditions, an almost removal of 200 mg/L silica solution was achieved in 60 min reaction time. Equilibrium data were analyzed using the Langmuir and Freundlich isotherms. The adsorption process can be well described by the Langmuir model, and the maximum adsorption capacity was calculated as 75.76 mg/g. Synthetic data were analyzed using pseudo-first-order and pseudo-second-order equations. The pseudo-second-order model showed good agreement with the obtained data (R2 = 0.9949). Conclusion: Due to the high potential of magnesium oxide nanoparticles in silica removal, it can be a good candidate for the removal of silica and industrial wastewater treatment.
Background and Objective: Among the emerging contaminants, microplastics threaten public health. This study aimed to determine microplastic and mesoplastics in soil of residential areas adjacent to Tehran Landfill and assess its ecological risk. Materials and Methods: The present descriptive cross-sectional study was conducted on 20 shallow and deep soil samples from residential areas near the Tehran landfill in July 2021. The microplastics were floated in NaCl and ZnCl2 solutions, and the mesoplastics were separated manually. The identification of physical and chemical properties of polymers was performed by stereomicroscope and FTIR analysis, respectively. Results: The average amount of micro-plastics in shallow and deep soils estimated 76±34.98 and 24.7±19.79 particles/kgsoil, respectively. The average amount of mesoplastics obtained 5.25±2.91 and 3.55±1.09 particles/kgsoil, in shallow and deep soils, respectively. Paired-samples T-test showed significant differences between shallow and deep soil in terms of plastic particles (p<0.001). The most abundant microplastic particles were the fragment-shaped with the particle size of 0.1-0.5 mm and LDPE polymer types with the percentage of 37.75, 44.64, and 46.15, respectively. Mesoplastic particles, the 0.5-1 cm film-shaped particles and LDPE polymer types with the percentage of 62.76, 61.46, and 50.7 were found as the most prevalent. Microplastics and mesoplastics' potential ecological risks value in all sampling points was less than 150, indicating low ecological risk. Conclusion: Despite the low PERI of microplastics and soil mesoplastics in residential areas, the Eri index for LDPE was high. Thus, Ecological risk is probable if control measures are not taken against plastic pollution.
Background and Objective: Nowadays, the application of procedures to minimize oxidative and microbial spoilage in marine products is economically and hygienically important. This study was performed to determine the effect of free and nanoliposome forms of poneh (Mentha pulegium L.) essential oil to increase the shelf life and improve the sensory characteristics of silver carp minced fish (Hypophthalmichthys molitrix) during storage time. Materials and Methods: In this study, the antibacterial properties of 1 and 2% essential oil and nanoliposomes form on the microbial population of minced silver carp fish inoculated with Bacillus cereus and Escherichia coli were measured. Also, chemical tests (DPPH (2,2-Diphenyl-1-picrylhydrazyl assay, measurement of iodine peroxide (PV), pH, total volatile nitrogen (TVB-N) and thiobarbituric acid (TBARs)) and sensory properties of minced silver carp were evaluated during 12 days of refrigerated storage. Results: The results showed that the addition of poneh essential oil (free and nanoliposomes) according to the microbial results and the results of chemical experiments can effectively prevent microbial growth and chemical spoilage (p<0.05). Treatment containing 2% nano essential oil of poneh showed the greatest effect on the chemical, microbial and sensory properties of minced fish during the experimental period in comparison with control treatments, 1% poneh nanoliposomes essential oil and 2 and 1% free essential oils. Conclusion: Therefore, the nanoliposomes form of 2% poneh essential oil can be used as a suitable additive to increase the shelf life of Silver carp fish in the fish industry.
Background and Objective: Nowadays, in metropolitan areas, principled and hygienic waste management is very important. Recycling is one of the most appropriate options in waste management. Hereof, the present study was aimed to investigate the possibility of using textile waste fibers in the manufacture of Medium Density Fiberboard (MDF). Materials and Methods: This experimental study was performed on lab-scale. Fabric waste was prepared by separation method at source from a clothing manufacturer in Tehran and converted into fibers. Test boards were made with weight percentage of mixing textile waste fibers to industrial fibers at three levels of 0:100, 10:90 and 15:85, respectively, 10% urea-formaldehyde adhesive, with 16 mm thickness and 0.7 g/cm3 density by hot press. Then, properties of the boards were measured including bending strength, modulus of elasticity, internal bond, hardness, water absorption and thickness swelling. The results were analyzed with ANOVA test. Results: The results of ANOVA showed that the effect of textile waste fibers on the bending strength, modulus of elasticity and swelling thickness of 2 and 24 hours of boards made at 5% probability level was significant. Additionally, the highest values of physical and mechanical properties are related to made boards with 10% of textile waste fibers. Conclusion: The results showed that it is possible to make MDF with textile waste fibers. The use of wastes such as fabrics in the production of new functional products can be considered as one of the strategies to reduce waste and thus to maintain human health and the environment.
Background and Objective: Pharmaceutical wastewater has a high level of pollution load that should be treated before discharging to the environment. Integrated processes using different mechanisms are one of the most fruitful methods in wastewater treatment. In this study, combined Integrated Fixed Film Activated Sludge (IFAS) and photocatalytic processes are utilized using of Fe3O4/TiO2 nanocatalysts to decrease the COD value of pharmaceutical wastewater. Materials and Methods: In this study, the variables of each process are optimized using Response Surface Methodology (RSM). In the IFAS process, the variables were dissolved oxygen (DO), media filling percentage and hydraulic retention time (HRT); while in the photocatalytic process, the effects of pH of wastewater, catalyst dose and reaction time were investigated. Results: In optimal conditions (DO 3 mg/L, HRT 24 h and media filling percentage 65%), COD removal rate was obtained 59.15%. With the initial concentration of 1725 mg/L COD and the mentioned efficiency, the concentration of COD in the effluent diminished to 704 mg/L. However, in the photocatalytic process, during optimal conditions (pH 6.8, reaction time 105 min and catalyst dose 60 mg/L), The efficiency of the process was determined 81%, which by considering the input COD (704 mg/L), the output concentration was reduced to 134 mg/L. Conclusion: According to the standards provided by the Environmental Protection Agency (EPA), the effluent from the combined process can be discharged into the environment.
Background and Objective: The consequence of using coagulant materials such as aluminum sulfate and ferric chloride in the coagulation unit of conventional water treatment plants can generate plenty of sludge that contains large amounts of coagulant, which in addition to environmental risks, will also possess disposal costs. Today, intending to preserve the environment and reduce treatment costs, researchers emphasize the recovery and reuse of coagulants from sludge. In this regard, the present study was proposed and implemented to recover and reuse water treatment plant sludge as a low-cost coagulant in wastewater treatment. Materials and Methods: This research is an experimental-laboratory study. In order to recover the coagulant from the collected sludge, acid hydrolysis method was used. The physicochemical characteristics of the recovered sludge were also determined using FTIR, FE-SEM, and BET analysis. Moreover, the efficiency of recovered sludge in different doses (50 to 300 mg/L) on wastewater treatability in terms of COD, TSS, VSS, turbidity, phosphorus, and coliform indices was compared with aluminum sulfate, ferric chloride coagulants, also the results of the study were analyzed and presented using Excel software (version, 2016). Results: According to the results, the prepared sludge had no crystalline structure with amorphous morphology. In addition, recovered coagulant from water treatment sludge has demonstrated high efficiency for wastewater treatment, so 66.6%, 82.49%, 79.66%, 80%, 65 %, 99.18% of COD, turbidity, TSS, VSS, phosphorus, total coliform were removed at the highest dosage of recovered coagulant (300 mg/L), respectively. Furthermore, the recovered coagulant dosage had a significant effect on the performance of the coagulation and flocculation process in wastewater treatment. Conclusion: The results showed that recovered coagulant from the sludge of the water treatment plant can be considered an acceptable option with appropriate effectiveness in the wastewater treatment processes.
Background and Objective: Today, the issue of health aspects in urban waste management, especially recycling, has received a lot of attention during Covid-19 around the world. Therefore, the purpose of this research is to investigate the knowledge, attitude, and performance of workers of one of the waste recycling centers in Tehran metropolis regarding health aspects during the spread of Covid-19. Materials and Methods: This was a descriptive-analytical cross-sectional study and the study population was all workers working in one of the recycling centers of Tehran Municipality. The data collection tool was a researcher-made questionnaire with validity and reliability in four sections: demographic, knowledge, attitude, and practice of workers toward Covid-19 and solid waste. Results: Findings of the study showed that the highest number of workers employed were in the age group of 20 to 40 years (60 percent). The level of knowledge was about 80 percent and the lack of awareness was 20 percent. The level of workers' positive attitude, negative attitude, and lack of attitude were 79.71, 14.56, and 5.72 percent, respectively. The level of positive practice among workers was about 67.43 percent and the negative practice was 32.57 percent. Conclusion: The results clarified that in order to succeed in waste management programs in recycling centers, municipal waste managers should pay more attention to educational aspects, especially through the focus on programs and their development and adaptation for different age groups, especially 20 to 40 years.
Background and Objective: Imidacloprid, a neonicotinide plant toxin, is used as an insecticide in agriculture. Due to its high degradation resistance and water solubility it is of highly concerns. Therefore, the aim of this study was to investigate the degradation of imidacloprid by modified magnesium oxide catalyst under irradiation of light and peroxymonosulfate. Materials and Methods: In this study, modification of magnesium oxide with nitrogen was made by sol-gel method and then iron oxide nanoparticles was used as a magnetic source. Operational parameters were catalyst loading, peroxymonosulfate concentration, reaction time and common anions (nitrate, bicarbonate and chloride). Residual concentration of contaminant was measured by high performance liquid chromatography (HPLC) and mineralization rate was evaluated by measuring TOC. Results: The results of the study showed that the photocatalytic degradation of the pollutant in the optimal condition was as following: catalyst concentration= 150 mg/L, peroxymonosulfate = 75 mg/L and reaction time= 60 min was 88%. Moreover, at optimum condition, the rate of mineralization was obtained 52%. Results comparison for prepared catalyst under light and dark condition indicated that the as-made catalyst is photocatalytic. Conclusion: The as-prepared catalyst can be activated as a photocatalyst under LED light and proxymonosulfate for removal of organic pollutants.
Surface water quality management is very important. Qualitative indicators of water pollution can indicate the trend of quality changes over time and place. The aim of this study was to evaluate the quality of Golin river using IRWQISC index. For this purpose, the Golin river water was sampled twice a month in a period of one year from May 2019 to April 2020 in Najar village station located in downstream of river. Different parameters which evaluated in this study were DO, pH, BOD5, COD, nitrate, phosphate, electrical conductivity, total hardness and turbidity. The results of the study using the IRWQISC index showed that the range of the index values in the warm months of the year was "between" 30.57 to 32.17 with relatively poor-quality category. While in the cold months of the year the index values obtained "between" 27.36 to 27.83 with poor quality category. In general, according to the results from the annual average of the IRWQISC index, the numerical value was obtained as equal to 29.62, which showed Golin river in poor quality category. The results which presented in this study can be useful for different organization decision to perform their water related projects on Golin river.
Background and Objective: Soils and sediments contamination with trace and toxic elements lead to potential ecological risk and adverse effects on human health and so have been the cause of increasing concern worldwide. Therefore, this study was carried out to potential ecological risk assessment of As, Cd, Ni and V in surface sediments of Khazar Abad, southern parts of Caspian Sea in 2019. Materials and Methods: In this descriptive cross-sectional study, a total of 36 surface sediment samples were collected from 12 sampling sites. After samples preparation, the elemental contents were determined using ICP-OES. Also, potential ecological risk factor (Eir) and cumulative potential ecological risk index (RI) were calculated. All statistical analyses were performed by SPSS software. Results: Based on the results obtained, the mean contents of As, Cd, Ni and V in analyzed samples were found to be 12.7, 0.191, 35.0, and 31.9 mg/kg, respectively. The computed values of Eir showed that factor values were decreased in the order Cd > As > Ni > V. Additionally, the mean values of RI with 53.7 indicated that all the examined elements have the "low potential ecological risk". Conclusion: Accordingly, although the examined elements have shown a low potential ecological risk, cadmium with 46.4% and arsenic with 45.4% mean values of RI can cause for concern. Therefore, source identification and management of organic and inorganic pollutants and also periodic monitoring of water and sediments as the sink of environmental pollution are recommended.
Background and Objective: The rise in the number of mobile phone subscribers has led to an increase in the number of BTS antennas and raised public concerns about the impact of radiation from these antennas on the health of a community. Therefore, the purpose of this study is to measure the pollution from electromagnetic waves of BTS antennas in Gotvand and to compare the emission of electromagnetic waves in commercial and residential areas. Materials and Methods: In this study, a systematic sampling method was used to measure the power density of BTS antennas. Using a TES-593 device, 70 samples were taken from Gotvand. Data were analyzed by SPSS version 23 and statistical tests. Results: The results showed that the most power density of electromagnetic waves is about 0.05% of the standard amount of general exposure and 0.01% of the standard amount of occupational exposure (p<0/001). Also, the power density in the commercial area is 1455.83 mw/m2 and in the residential area, it is 432.61 mw/m2, which has a significant difference between them (p<0.001), and the power density in the commercial area is higher than the residential area. Conclusion: The power density of BTS antennas in Gotvand follows ICNIRP guidelines for occupational and general exposure. Also, the power density of the commercial area is higher due to being located in a more open space with fewer obstacles than the residential area.
Background and Objective: Phytoremediation is one of the eco-friendly treatment methods that can play important role in removing heavy metals. In the present research that was done in 2021, the potential of 20 plant species for treatment of silver, lead, and zinc elements from the soil of Zarshouran mine area was evaluated. Materials and Methods: Sampling of the soil and plants were done following the selection of 20 sampling points. After preparing the samples, the amount of the studied elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). Metal pollution levels in the soil were assessed using the enrichment factor (EF). Moreover, the enrichment coefficient of root (ECR) and shoot (ECS), translocation factor (TF) and metal accumulation index (MAI) were calculated. Results: A high contamination of Ag, Pb and Zn elements were determined in the soil of the studied area. Two plant species Astragalus rostratus and Prangos ferulacea had ECS and TF higher than one for Ag. Also, only Eryngium billaridieri and Scrozonera latifolia had ECS/ECR >1 and TF <1 for the three elements. The highest amount of MAI in root and shoot belonged to E. billardieri with values of 29.7 and 16.2, respectively. Conclusion: A. rostratus and P. ferulacea had the potential for phytoextraction of Ag from the soil. Also, only two species E. billaridieri and S. latifolia were able to phytostabilization all three elements. Based on MAI values, E. billardieri had the greatest ability to bioaccumulate Ag, Pb and Zn elements.
Background and Objective: Toluene is one of the most important volatile organic compounds that threaten human health and introduce many environmental problems. Therefore, the present study aims to determine the performance of a biofilter based on pine cones/compost to remove toluene vapors from polluted air streams. Materials and Methods: In this research, a biofilter with a volume of 19.468 L was designed and built. The biofilter bed consisted of two parts 26 cm in height and packed with a mixture of compost and pine cones in 1:1 volumetric ratio. After inoculating the bed with sludge from a municipal wastewater treatment plant and making it compatible with toluene, the performance of the biofilter in different parts of the bed was investigated at the inlet toluene concentrations of 2.5-5.5 g/m3 and Empty Bed Retention Times (EBRTs) of 1.3, 1.7, and 2.43 min. Also, the results were analyzed statistically. Results: At EBRT of 2.43 min and different inlet toluene concentrations of 2.5-5.5 g/m3, the removal efficiency reached 100 percent. Also, the removal efficiency decreased with the reduction of EBRT. The results showed that removal efficiency was higher in the first part of the biofilter bed relate to the second part. At an inlet toluene concentration of 2.62 g/m3 and EBRT of 1.7 min, the maximum elimination capacity (ECmax) of 2.74 g/m3.min was obtained. Conclusion: In all experimental conditions the outlet concentration of pine-cone/compost biofilter was below the WHO standard (260 µg/m3). Also, the high elimination capacity of biofilter verified its capability toward toluene removal from polluted gas streams.
Background and Objective: The aim of this study was to investigate the concentration of potentially toxic elements (arsenic, lead, copper, cadmium and mercury) in black tea imported to southern Iran and to assess the risk of carcinogenic and non-carcinogenic exposure to consumers. Materials and Methods: For this purpose, 94 samples of black tea from 15 brands imported from India in 2021 were selected. Heavy metals concentrations were measured using an atomic absorption spectrometer (GBC model SAVANTAA). After determining the concentration of heavy metals in black tea samples, health risk assessment was determined using Montocarlo simulation technique. Results: According to the results, the average concentrations of heavy metals namely arsenic, lead, copper, cadmium and mercury were 0.03±0.02, 0.02±0.16, 15.67±7.69, 0.02±0.01 and 0.006±0.005 mg/kg, respectively. The hazard quotient (HQ) of the heavy metals arsenic, lead, copper, cadmium and mercury were 1.07×10-2, 6.37×10-3, 3.45×10-5, 2.05×10-2 and 7.19×10-4, respectively. Conclusion: Therefore, according to the findings, it can be concluded that the concentrations of potentially toxic elements (arsenic, lead, copper, mercury and cadmium) in black tea were consistent with the standard level of Iran and World Health Organization. Additionally, the average carcinogenic risk index for arsenic metal was 4.49×10-6, which is much lower than the acceptable level of carcinogenic risk (10-6). Therefore, the concentrations of five potentially toxic elements in the studied black tea did not show any significant risk for consumers.
