Iranian Journal of

Background and Objective: Heavy metals contaminations are readily bioaccumulated in aquatic systems and lead to increased concentrations in food chains, posing a serious threat to human health, water-related organisms and aquatic ecosystems. The purpose of the present study was to determine the concentration of heavy metals in surface sediments of CheshmehKile River, to evaluate environmental and ecological risk and to determine the degree of contamination of the elements studied.
Materials and Methods: In this study, 25 samples of surface sediment were collected from the CheshmehKile River. The heavy metals content of the samples was measured by inductively coupled plasma-optical emission spectrometry. According to the content of heavy metals in sediment samples, environmental and ecological risk indices were calculated. Also, river contamination was evaluated by comparing the elements studied values with the sediment quality guidelines values.
Results: The mean concentration of chromium, manganese, iron, cobalt, nickel, zinc and arsenic were 41.27, 356.35, 16756.32, 9.17, 11.87, 41.24 and 24.60 µg/g, respectively. Based on the values of the CF and I_geo indices, all of the elements, with the exception of arsenic, showed a low degree of contamination. The indices of Eⁱ_r and RI also showed the lowest ecological risk at all stations.
Conclusion: The results of this study showed that the surface sediments of CheshmeKile River in Mazandaran province were somewhat contaminated with arsenic. However, fortunately, the river sediments were of good quality from the point of view of the content of chromium, manganese, iron, cobalt, nickel and zinc.

Background and Objective: Considering the toxicity, health and ecological hazards of heavy metals in the environment and the impact on organisms, it looks essential to measure and evaluate their concentrations at the various levels in indigineous ecological strctures. The present study evaluated the concentration of Lead, Nickel, Copper and Zinc and their ecological risk assessment in surface sediments of Sezar River in Lorestan province.
Materials and Methods: 16 stations along the Sezar River were selected for sampling. After preparation and acid digestion of the samples, the concentrations of these metals were determined by Atomic absorbtion.
Results: The average total concentration of the detected metals Ni, Zn, Cu and Pb in the sediment was 71.84 > 40.56> 7.75 > 5.61 mg/kg, respectively. In addition, the evaluation of the Potential acute toxicity, ecological risk, and Pollution Load Index represented a low pollution in the sediments. The environmental risk of the metals in the sediment was evaluated as: Ni> Pb> Cu> Zn. The findings showed that among metals, the contamination factor and modified hazard quotient (mHQ) for nickel was moderate and in the mediun to severe pollution level to the contamination, respectively.
Conclusion: According to the results, it can be concluded that Potential acute toxicity, pollution and ecological risk in the region for investigated metals were low. However, a rapid expansion of various human activities in the area and the pollution of nickel in the river along with the probability of its biological effects require continuous monitoring of the river in order to assess the health risk and its ecological risk.
 

Background and Objective: This study conducted to assess ecological risk of an important group of pollutants called polycyclic aromatic hydrocarbons (PAHs) in offshore sediment of the Persian Gulf deposits in Bushehr province. The aim of this study was to model the toxicity of PAHs for aquatic organisms in the study area.
Materials and Methods: In the first step of the applied risk assessment model in this study, the unit of toxicity for each PAH and solubility were calculated by Quantitative Structure-Activity Relationships (QSAR) model. In the second step, the pore water concentration of all compounds in sediment was calculated as an available fraction. Finally, the proposed model was used to evaluate the offshore sediments of the Persian Gulf. Sediments in 19 stations and 7 transects were studied to assess the ecological risk of 21 PAHs. The extraction and clean up method was based on pressurized liquid extraction (PLE) with packed clean up cell. Compounds were analyzed by GC-MS.
Results: The toxicity and solubility of PAHs were modeled. The Pearson correlation for the predicted and measured data was more than 0.93. The amount of total toxicity was introduced as a risk index. The maximum and minimum total toxicity values for the sediments were found as 0.018 and 0.147, respectively. The results from this study indicated that although the concentration of PAHs in the sediments may not cause significant concern in the study area, they may affect benthic organism at the sub-lethal levels. According to the applied risk assessment model for 21 unsubstituted PAHs, the offshore sediments of Bushehr are in low-risk range.
Conclusion: The result of this study indicated a low risk of the sediments. The hazard index decreased as the distance from coastal and oil and gas industry increased, indicating the high impact of anthropogenic activities on the contamination of the study area.
 

Background and Objective: Nowadays linear alkyl benzene sulfanate (LAS) is widely used in the production of various detergents. The purpose of this study was to assess the health and ecological hazards of this pollutant on target organisms such as fish and daphnia in the Doroodzan Dam water.
Materials and Methods: According to the research objective and given existing restrictions, 21 water samples were collected in September 2018 from 7 selected stations based on the source of contamination in Doroodzan dam.  Water quality parameters including pH, Dissolved Oxygen (DO), potential Redox (ORP), Total dissolve solid (TDS) and Electrical conductivity (EC) was measured at the site. The amount of linear alkyl benzenesulfonate (LAS) was measured using an optimized methylene blue method after transferring samples to the lab. Then ecological and health risk assessment was performed by calculating the RQ index (risk index).
Results: The results showed that the mean of  pH, EC, TDS, salinity and DO were 8.88, 732.19 µs/cm,  482.49, 366.16 and 6.87 mg/L, respectively. The highest and lowest concentrations of LAS were 0.039 and 0.055 mg/L, respectively. The results also showed that there is a significant relationship between LAS concentration and pH. The results of the risk assessment showed that the health risk index in all stations is less than 0.1, while the ecological risk index except at station 7, are in low risk level.
Conclusion: In general, the results show that the RQ index in the Droodzan Dam water is in appropriate range and in the low risk level. Therefore, it is necessary to conduct long-term studies in this field to ensure the persistence of optimal water conditions in the dam ecologically and health-wise.

Background and Objective: Heavy metals enter to water resources through various ways, causing dangers such as illness, cancer, and, in general, a disorder in the body of living organisms. Mullet (Liza aurata) is highly consumed by the people living in Guilan province, Iran. Therefore, the amount of heavy metals included copper, zinc, and nickel was investigated in the muscle tissue of mullet.
Materials and Methods: A total number of 11 mullet were obtained from Bandar Anzali.  After a preparation step, the fish samples were digested using chemical digestion, and the amounts of heavy metals were determined by atomic absorption.
Results: The average concentration of copper, zinc, and nickel in muscle tissue was 10.07±0.93, 28.39 ±3.99, and 4.01 ± 0.55 μg/g dry weight, respectively. The concentrations of the studied metals were lower than the FAO, WHO, FDA, NHMRC and UKMAFF international standards, except for the nickel. The daily absorption rates of the studied metals (EDI) for children and adults were lower than the reference dose set by the EPA and the TI provided by the FAO / WHO Organization. The risk potential (THQ) of seven days, three days and one day consumption per week of Golden grey mullet for both adults and children were found less than 1. The hazard index (HI) of 7 days a week consumption of mullet for children was greater than 1.
Conclusion: According to the results of the present study, the consumption of this fish has a harmful effect on consumer health in children age group.
 

Background and Objective: Environmental burden of disease (EBD) studies are one of the most important needs for determining the current situation, increasing the effectiveness of health policies and programs and prioritizing environmental health interventions. This review article was evaluated the status of the EBD in Iran based on the results of the latest Global Burden of Disease (GBD) Study, other international studies and national estimates in the country.
Materials and Methods: In this study, the researches on the EBD in Iran were identified by searching in the international and national scientific databases and the search results were studied and analyzed.
Results: The review of the EBD studies showed that based on the results of the GBD study, the share of environmental risk factors in the total burden of diseases in the country in 2017 according to the disability-adjusted life years (DALYs) and deaths were about 8 and 13%, respectively. According to the results of the GBD study, the contributions of environmental risk factors in the attributable DALYs in the country in 2017 (a total value of 1,648,329) were as follows: ambient air PM_2.5 for 45.0%, occupational risk factors for 25.1%, exposure to lead for 19.4%, unsafe water source for 5.0%, tropospheric ozone for 1.7%, lack of access to handwashing facility for 1.5%, unsafe sanitation for 1.4%, residential radon for 0.6%, and household air pollution from solid fuels for 0.3%. The total DALY rate and death rate attributable to solar ultraviolet radiation in Iran in 2000 were estimated to be 46.2 and 0.7, respectively. The DALY and the DALY rate attributable to elevated levels of fluoride in drinking water due to dental fluorosis in the country in 2017 were 3,443 and 4.14, respectively. The evaluation of the effect of water fluoridation as an environmental protective factor showed that the intervention by reducing the risk of dental caries could fall the DALY and DALY rates in the country by 14,971 and 18.73, respectively. In the period of 2005-2017, the DALY rate (per 100,000 people) attributable to ambient air PM_2.5, tropospheric ozone, residential radon, and occupational risk factors rose that the result increases the importance of the preventive measures and controls of these risk factors.
Conclusion: There was a considerable difference in the burden of disease attributed to each risk factor in various international studies as well as between national and international studies. The results of national studies on the burden of diseases attributable to environmental risk factors are considered to be more reliable and practical due to the application of more detailed data and conducting subnational evaluations; therefore, the strengthening and continuing these studies at the national and sub-national levels with regard to priorities, needs, and spatiotemporal trends using domestic reliable data and information are necessary and strictly recommended.
 

Background and Objective: Non-biodegradation in nature and creation of adverse health effects in humans is important features of heavy metals. The main objective of this study was to determine the level of contamination, carcinogenic and non-carcinogenic risks of falling dust containing heavy metals on residents around the industrial areas of Ardakan. Another objective was to identify potential sources of heavy metal release into the environment.
Materials and Methods: In this cross-sectional analytical study, the falling dust was collected in summer around Tile and Ceramic, Khak-e-chini, sand and gravel and glass industries by installing 35 Inverted Frisbee traps with artificial grass cover. The concentration of Cd, Ba, Cu, Ni, Cr, Mn and V were measured by ICP-MS. Probable sources of the heavy metal of the dust were evaluated using Pearson correlation coefficient and cluster analysis. Ecological risk indices for determining the level of contamination and proposed relationships proposed by the US Environmental Protection Agency were used to assess the carcinogenic and non-carcinogenic risks.
Results: The highest and lowest mean concentrations of heavy metals were measured for Cd and Ba, respectively. The results of Pearson correlation analysis and cluster analysis revealed three anthropogenic and also natural sources for heavy metals of the falling dust. According to the Ecological Risk Potential Index, Cd in 45.10% of the samples was in a very high class and in 54.88% of the samples was a high class. Pollution class of the ecological risk index of all the heavy metals was medium to high. The carcinogenic risk of Cr and Ba in children and adults was estimated to be higher than 10^–4. In both age groups, the Hazard index for each metal was less than 1 and its sum was measured as 1.29 for children and 0.16 for adults.
Conclusion: Cd increases the ecological risk of the falling dust in the area. Ther heavy metal carcinogenic risk results showed that the concentrations of Cr and Ba were higher than standard. Also, the non-carcinogenic risk was higher in children than in adults.

Background and Objective: Heavy metals contamination, particularly in aquatic environments, is an important concern.  Since Mahbad river is the source for supplying drinking water to the city and the dam established on it is used for catching fish and sale in the market, heavy metals concentrations in the sediments of Mahabad River and the Dam, and the possible health risk of the fish consumption were investigated.
Materials and Methods: Sediment samples from 21 sites in Mahabad dam, and river, and 16 fish samples (Sander lucioperca and bramis brama species) were collected. After preparation, the samples were analyzed using ICP-MS method. For data analysis, enrichment factor (EF), potential ecological risk index (RI), health risk indices, principal component analysis (PCA) and Mann-Whitney test were used.
Results: The EF and RI values of the studied heavy metals in the sediments were low. The max concentrations of lead, zinc, copper, arsenic and manganese were 36, 162, 74, 22.8 and 3221 mg/kg, respectively. This was more obvious in the samples taken from the downstream of the dam. However, accumulation of the heavy metals in fish tissues resulted in high values for total hazard quotients (THQ), particularly for As (1.19); high hazard index (above 1); and high estimated daily intake (EDI) for copper (1.64) in the study area.
Conclusion: The results of this study revealed that the conditions for elements’ mobility and bioavailability was suitable in the river and Mahabad Dam. Therefore, assessing the mobility and bioavailability of the heavy metals in the sediments of the region, and measurement and continuous monitoring of the heavy metals concentrations in the water, sediment and fish of the study area are needed.

Background and Objective: Application of sewage sludge contaminated with heavy metals may cause health and ecological concern. Ecological risk and heavy metals content of sewage sludge from wastewater treatment plants of East Azerbaijan province were evaluated in the present study.
Materials and Methods: Nine composite samples were taken and analyzed for heavy metals. The geo-accumulation index (Igeo), contamination factor(CF) , and potential ecological risk index were calculated.
Results: Variation of the heavy metals concentrations were in the following order: Zn>Cu>Pb>Cr>Ni>As>Hg>Cd. The contents of some heavy metals were several order of magnitude higher than the crustal average (CA) values. Considering the Maximum Permissible Standards (MPS) and the Muller's index, the Cd, Cu, and Zn pollution were found to be in the moderate range, whereas As and Pb were in strongly polluted category; and Hg was in extremely polluted category. Considering MPS, the single-factor pollution index (PI) and the Nemerow’s synthetic pollution index (PN) were lower than 1 and 0.7 respectively. This indicated that the sludges were unpolluted with most heavy metals and could be safely applied for agricultural uses. However, a high potential ecological risk for As and Cd; very high risk for Pb; and extremely high risk for Hg were calculated when considering the CA values. There were significant differences between the levels of heavy metals and MPS (p <0.05).
Conclusion: Although the metal concentrations were below the MPS according to the US EPA regulations, sludge samples showed a high degree of potential ecological risk for the environment in comparision with the CA values,. Periodic monitoring of sludge quality are strongly recommended.  

Background and Objective: Vegetables are an essential part of our diet and a major dietary exposure route to heavy metals. Therefore, this study aimed to investigate the concentration and potential health hazards of heavy metals in the vegetables sold in Kashan markets.
Materials and Methods: 4 types of widelyraw-consumed vegetables, including parsley, coriander, basil, and fresh chives, were investigated in this study. Questionnaires were randomly given to individuals to determine vegetable consumption rate. Heavy metal were quantified using inductively coupled plasma- optical emission spectroscopy. Monte-Carlo Simulation was utilized to identify the associated health risks.
Results: Among tested heavy metals, Pb showed the highest concentration in parsley (4.8 ± 0.98 µg/g), coriander (3.8 ± 1.3 µg/g) and basil (3 ± 0.94 µg/g). Cr levels in fresh chives (2.8 ± 1.6 µg/g) was higher than other heavy metals. Also, the highest total hazard quotient values among examined heavy metals (Taking into account 95% confidence interval) were found for Pb (0.7), Cr (0.39), and Pb (1.034) in coriander, basil, and fresh chives, respectively.
Conclusion: Cr and Pb concentrations were generally beyond WHO/FAO guidelines in the samples. The THQ value for Pb in parsley was greater than 1, suggesting elevated adverse health effects due to parsley consumption.

Background and Objective: pesticides are essential to protect plants from pests and diseases. Extensive and unsafe use of pesticides by farmers pose various risks to human health and the environment. Therefore, the present study evaluates farmers' knowledge, attitudes, and behaviors regarding pesticides use and the health problems associated with their use.
Materials and Methods: In this human-research survey the target population consisted of 6170 farmers and fruit growers in Galogah County, Mazandaran province, were included. Multi-stage cluster sampling was used to select samples within 2 sub-districts and 13 villages, and the information was collected through 379 questionnaires. Statistical tests such as Mann-Whitney U, Kruskal-Wallis H, Spearman Correlation and Linear Regression were used to analyze the obtained data.
Results: The respondents have no sufficient knowledge regarding the safe use of pesticides. Respondents' attitudes toward the impacts of pesticide use were positive. The safety measures were less considered by majority of respondents. Moreover, the results revealed that personal protective equipment (mask, gloves and, goggles) and safe disposal of pesticide residues are not fully taken into consideration. The dizziness, skin problems, headache and vomiting were the most common symptoms of pesticide-related illnesses. The findings of regression analysis showed that wide range of knowledge and proper attitudes about the safe use of pesticides are beneficial and can act as the promoting factor in farmers' safety behavior regarding pesticides use.
Conclusion:  In conclusion, providing pesticide users with sufficient knowledge, safety information and effective personal equipment such as wearing masks, goggles and gloves should be given highest priorities.

Background and Objective: Landfills as municipal solid waste are considered as the source of pollution. The present study aimed to assess the ecological risk of heavy metals in Tehran landfill soil and the adjacent residential area.
Materials and Methods: Having consulted with the specialists and considered the waste processing facilities, 12 sampling points were selected and sampled in four seasons. Soil samples were digested using HNO₃: HClO₄: HCl: HF. The levels of metals were measured using ICP-OES which further applied for the calculation of ecological risk. Kolmogorov-Smirnov, Kruskal-Wallis, and Pearson correlation coefficient analyses were run to determine the significant differences between metals concentrations in various seasons and sampling points. 
Results: Metal concentration showed to follow theorder: Al > Fe > Mn > Zn > Cr > Pb > Cu >Ni > Co > As > Cd. Kruskal-Wallis results and pairwise comparison showed a statistically significant difference between metal concentrations across sampling points and seasons, especially in rainy seasons. Pearson correlation coefficient displayed a strong relationship between the mean concentrations of Cu - Pb, Cu - Zn, and Pb - Zn with obtained values of 0.932, 0.874, and 0.883, respectively. Cu exhibited the highest contamination factor at the compost and fermentation sites (13.2 and 9.89, respectively). The geo-accumulation index proved the anthropogenic sources of pollution. The potential ecological risk index (ERI) for the sampling sites ranged from 67.3 to 154, with the order of Cd > Cu > Pb > Ni > As > Cr > Zn > Co > Mn. 
Conclusion: Due to the obtained moderate to severe ecological risk and exceeded background concentrations of heavy metals, it can be concluded that metal changes and soil pollution are both affected by landfill activities.

Background and Objective: Due to the importance of Mordab river, the concentration and distribution of heavy metals in sediments and part of Caspian sea coast, mostly affected by the Mordab river, were evaluated. Additionally, considering the possibility of heavy metals release from sediments to water column and transfer to crops, the health risk of rice consumption in the region was assessed.
Materials and Methods: 21 sediments samples and 4 rice samples from paddy fields along the Mordab River were collected. Heavy metal contents of the samples were measured using ICP-MS. Data analysis was performed using enrichment factor (EF), ecological risk index (RI), health risk index, principal component analysis (PCA) and Mann-Whitney test.
Results: The maximum concentrations of elements was higher in coastal sediments than the Mordab River. The results showed low to moderate risk of elements in most stations except for two coastal stations which exhibited considerable risk of contamination with regard to Cr. Principal component analysis categorized the elements into three components of different origin. Moreover, the estimation of weekly intake of elements through rice consumption were less than their permissible concentration set by World Health Organization.
Conclusion: The concentration of chromium in sediments, especially coastal sediments, is high, which may be partly due to the concentration of heavy minerals (chromium) in this fraction. Therefore, the origin of elements, particularly chromium, should be determined through sequential extraction methods. On the other hand, despite the pollution of river sediments and high consumption of rice among the residents of the study area, there is no danger to rice consumers in terms of heavy metals.

Background and Objective: Understanding the factors contributing to the mortality of COVID-19 patients can provide comprehensive information for preventive decisions and public health, and will help in better management of the epidemic. In this regard, the present study was conducted with the aim of identifying and introducing risk factors affecting the mortality of COVID-19 patients by modifiable and non-modifiable factors.
Materials and Methods: In this review study, according to the objectives of the study, related papers on risk factors affecting the mortality of COVID-19 patients were searched and collected in the international databases of Web of Science, Scopus, Embase, PubMed, and Google scholar. Then the results were extracted and reported by modifiable and non-modifiable factors.
Results: The results showed that almost all studies conducted in this field address non-modifiable risk factors such as age, sex, and underlying diseases including cardiovascular disease, diabetes, hypertension, respiratory diseases, cancer, self-diseases, autoimmune, and neurological diseases. Although few studies have been conducted on modifiable risk factors, lack of early admission or long waiting for hospital admission, occupancy of hospital beds and ICUs, as well as lack of equipment in hospitals were associated with increased mortality in these studies.
Conclusion: Regarding the situation of different countries in this epidemic, improving the control of the COVID-19 epidemic and reduce the mortality rate is possible by considering modifiable factors and taking appropriate measures. According to the results of studies, allocating sufficient financial, personnel and equipment resources can be effective in reducing COVID-19 mortality. However, controlling the COVID-19 epidemic to reduce morbidity and mortality as well as its economic and social consequences is possible by integrated management in the country. Also, using the experiences and guidance of the World Health Organization and successful countries, and stability in measures with a comprehensive approach should be considered.

Background and Objective: Heavy metal (HM) pollution of settled dust on the interior surfaces of elementary schools may affect the health of young students; hence, the health risk of such pollution should be assessed. Therefore, the aims of this study were to measure the content of heavy metals in the settled dust in the indoor of elementary schools in Bandar Abbas and to assess the attributed health risks.
Materials and Methods: In this study, dust samples were collected from the interior surfaces of elementary schools in Bandar Abbas. Settled dust samples were digested using aqua regia solution and then their metals contents were measured using ICP-OES. To assess the health risk attributed to this pollution, daily intake doses through ingestion, inhalation and skin absorption routes were estimated. Then, non-carcinogenic and carcinogenic risks were calculated considering the daily intake doses and toxicity factors.
Results: The average concentrations of arsenic, cadmium, cobalt, chromium, nickel and lead in settled dust were 5.45, 0.58, 11.44, 69.72, 83.95 and 66.72 mg/kg, respectively. The non-carcinogenic risk level for all metals was below threshold, while the carcinogenic risk level for arsenic (2.18×10^-6) exceeded the threshold.
Conclusion: This study showed that the settled dust in elementary schools of Bandar Abbas is polluted with various levels of heavy metals. Health risk assessment showed that the exposure to dust containing heavy metals in the elementary schools of Bandar Abbas does not pose significant non-carcinogenic risk, but the carcinogenic risk of As exceeded the threshold limit and should be considered.

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 (Eⁱ_r) 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 Eⁱ_r  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: 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/kg_soil, respectively. The average amount of mesoplastics obtained 5.25±2.91 and 3.55±1.09 particles/kg_soil, 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 E_rⁱ index for LDPE was high. Thus, Ecological risk is probable if control measures are not taken against plastic pollution.
 

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.