Health risk assessment and spatial distribution of nitrate, nitrite, fluoride, and coliform contaminants in drinking water resources of kazerun, Iran.

Exposure to nitrate, nitrite, and fluoride through drinking water consumption, especially in arid and semi-arid regions, has been considered by many researchers. Therefore, the present study aimed to investigate the status of nitrate, nitrite, fluoride, and total coliforms in water supply sources of Kazerun located in Fars province, Iran, determine their spatial distribution, and perform health risk assessment in four age groups (infants, children, teenagers, and adults). In this research, the concentration data of 25 groundwater wells were examined. Then, the spatial distribution of the contaminants was determined using the Arc GIS software (v. 10.5) and their health risk assessment was performed via the standard method of the US Environmental Protection Agency. The maximum concentrations of nitrate, nitrite, and fluoride were 25.5, 0.056, and 0.72 mg/l, respectively and their mean concentrations were 13.5, 0.008, and 0.52 mg/l, respectively. In addition, the mean and maximum concentrations of coliforms were 371.21 and 2694.50 CFU/100 ml, respectively. The total coliforms value was higher than the permissible limit in 60 % of the cases. The highest Chronic Daily Intake (CDI) of the studied contaminants was related to nitrate among children (range: 0.21-1.45, with an average value of 0.77 mg/kg-day). Moreover, the Hazard Quotient (HQ) values were below 1 for all contaminants and in all age groups. The highest HQ value (0.9) belonged to nitrate amongst children. Furthermore, the Hazard Index (HI), as a cumulative effect of HQ, was calculated for all three contaminants and the results showed that it was greater than 1 in 56 % of the cases among children, which was considered a serious risk. The findings revealed no significant relationship between nitrate and nitrite concentrations and total coliforms. Overall, nitrate seemed to play a more critical role in the health risk of the exposed age groups in comparison to nitrite and fluoride. Hence, appropriate managerial measures are recommended to be taken.

Non-carcinogenic risk assessment of exposure to heavy metals in underground water resources in Saraven, Iran: Spatial distribution, monte-carlo simulation, sensitive analysis.

Groundwater aquifers are considered the second most abundant water supply for drinking water all over the world. In Iran, ground waters are commonly employed for drinking water, irrigation, and industrial purposes. Heavy metals (HMs) pose human concerns about the groundwater contamination; these pollutants are recognized to be capable of bio-accumulation, long persistence in the natural environment, and toxic effects. In the present research, the content of HMs: Chromium (Cr), Cadmium (Cd), and Lead (Pb) were detected in 89 water samples collected in 2018 by underground water supplies (active wells) of Saravan city. Hazard Quotient (HQ) and Monte Carlo Simulation approach with 10,000 repetitions were applied to discover the human non-carcinogenic impacts of HMs in four groups of ages (adults, teenagers, children, and infants) of consumers. The concentrations of Cr, Pb, and Cd were in the range of 0.49-20, 0.1 to 58.34, and 0.11-12.8 µg/L, respectively. The mean HQ calculated due to exposure to Pb (0.0018-0.0023), Cr (0.0112-0.0186), and Cd (0.0370-0.0615) were lower than one. The findings of sensitivity analysis revealed that HMs concentration had the most contribution effect on human non-carcinogenic risk analysis in four different exposed populations. This study could assist researchers to perform more comprehensive studies with more samples. Therefore, further research is required for decision-makers to plan proper measurements properly.

Health risk assessment of exposure to atrazine in the soil of Shiraz farmlands, Iran.

Atrazine-contaminated soils can pose a carcinogenic and non-carcinogenic health risk through different routes for exposed people. This study aimed to assess the health risk of exposure to atrazine-contaminated soils through direct ingestion and dermal contact in farmlands nearby Shiraz. Atrazine concentration was measured in 22 selected sites using grid sampling. The carcinogenic and non-cancer risks associated with dermal and ingestion exposure in children and adults were estimated. The lowest and highest atrazine concentrations were in S1 (0.015 mg/kg soil) and S22 (0.55 mg/kg soil). Hazard Index (HI)1 values ranged from 0.007 to 0.25 for children, and the values ranged from 0.0008 to 0.03 for adults. The mean cancer risk for children and adults was 6.01 × 10-4 and 7.40 × 10-5, respectively. The HI value was less than 1 for all sampling sites, indicating that exposure to atrazine does not threaten children and adults. However, the cancer risk exceeds the United States Environmental Protection Agency (US.EPA)2 threshold risk limit (10-6 to 10-4) in all sampling sites. Therefore, it is recommended that children should avoid playing on atrazine-contaminated farms or soils near anywhere atrazine may have been used.

The residual nitrate and nitrite levels in meat products in Iran: A systematic review, meta-analysis and health risk assessment.

This study was designed to investigate the mean residual nitrite and nitrate levels in meat products, in Iran and to evaluate their health-related risks. After reviewing 799 studies, 15 were finally selected, their information was recorded and examined using Stata software. The results of the present study show that the mean residual nitrite and nitrate levels in meat products was about 55.18 and 95.09 ppm, respectively. The residual nitrite level is different in various meat products, so that the residual nitrite level in sausages and kielbasa is 54.52 and 56.87 ppm, respectively. Also, the present study shows that the mean residual nitrate level in sausages and kielbasa was 77.21 and 121.49 ppm, respectively. Health Risk Index (HRI) of nitrite and nitrate were 0.1541 and 0.0050, respectively, which were lower than 1 value. Therefore, there is no considerable carcinogenic risk for consumers in Iran. Taking together, these residues must be continuously monitored by relevant authorities.

Spatial distribution and correlations among elements in smaller than 75 µm street dust: ecological and probabilistic health risk assessment.

This study aimed to investigate spatial distribution, correlations among elements and ecological and probabilistic health risk assessment in smaller than 75 µm street dust in Kerman city, Iran. Street dust samples were collected from 35 different points. Elements were detected by ICP-AES. Pollution degree was characterized through Enrichment Factor (EF), Contamination Factor (CF), Geo-accumulation Index (Igeo) and Potential Ecological Risk (PER). The health risk was assessed using the Monte Carlo simulation method. The mean values of elements were in the order of Al > Mn > Zn > Cu > V > Pb > Cr > Ni > Li > As > Co > Mo > Sb > Cd > Ag. The results of Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) showed that Al, As, Co, Li, Mn and V were possibly derived from natural sources (local soil), while traffic and mining activities were proposed as the main source of Cd, Cr, Cu, Mo, Ni, Pb, Sb and Zn. The order of EF and CF mean values decreased as follows: Mn > Ag > Cu > Zn > Pb > Sb > Mo > Li > Co > V > Cd > As > Cr > Ni. In addition, 73% of Cu and 35% of Zn, Ag and Mn had significant enrichment in the street dust samples. Also, Ag and Mn were categorized in the significant and very significant pollution category. In terms of the PER index, all samples could be classified at low-risk category. Ingestion of street dust was the significant route for exposure of residents of Kerman to the elements studied. No significant ecological hazards and health risks were observed from street dust in the study area in the period of the study. The improvement in the fuels quality and development of green spaces can be suggested to control natural and anthropogenic street dust pollution sources in the Kerman city.

Chemical Characterization and Quantification of Titanium Dioxide Nanoparticles (TiO2-NPs) in Seafood by Single-Particle ICP-MS: Assessment of Dietary Exposure.

The significant increase in the production and variety of nanoparticles (NPs) has led to their release into the environment, especially into the marine environment. Titanium dioxide nanoparticles (TiO2-NPs) are used in different industrial sectors, from the food industry to several consumer and household products. Since the aquatic environment is highly sensitive to contamination by TiO2-NPs, this work aimed to give a preliminary assessment of the contamination of packaged seafood, where the food additive TiO2 (E171) is not to be intentionally added. This allowed providing a chemical characterization and quantification of TiO2-NPs in processed canned fish products belonging to different trophic positions of the pelagic compartment and in canned clam. The new emerging technique called single-particle inductively coupled plasma mass spectrometry (spICP-MS) was applied, which allows the determination of nanoparticle number-based concentration, as well as the dissolved titanium. This study highlights how processed food, where the pigment E171 was not intentionally added, contains TiO2 in its nanoparticle form, as well as dissolved titanium. Processed clam represented the seafood with the highest content of TiO2-NPs. In pelagic fish species, we found progressively higher levels and smaller sizes of TiO2-NPs from smaller to larger fish. Our results highlight the importance of planning the characterization and quantification of TiO2-NPs in food both processed and not, as well as where the pigment E171 is intentionally added and not, as it is not the only source of TiO2-NPs. This result represents a solid step toward being able to estimate the real level of dietary exposure to TiO2-NPs for the general population and the related health risks.

Probabilistic risk assessment (Monte Carlo simulation method) of Pb and Cd in the onion bulb (Allium cepa) and soil of Iran.

Recently, the exposure to heavy metals through the consumption of vegetables has become a global concern. In this regard, the current study was aimed to measure the concentrations of lead (Pb) and cadmium (Cd) in the collected onion bulb samples as well as the surrounded soil using a flame atomic absorption spectrometer (FAAS). Additionally, the target hazard quotient (THQ) for males and females in all age groups of consumers were estimated by using Monte Carlo Simulation (MCS) method. Furthermore, the soil threshold values (STVs) were evaluated to investigate the heavy metal contents in the soil based on the established standard limits. In this context, 45 onion bulbs (HashtBandi region, 25 and Ravang region, 20) and 41 soil (HashtBandi region, 21 and Ravang region, 20) samples were collected (March-May of 2016). The average concentrations of Pb in the onions from HashtBandi and Ravang regions were determined as 0.0052 ± 0.0011 and 0.0061 ± 0.0022 mg/kg, and for Cd were 0.0095 ± 0.0024 and 0.0011 ± 0.0035 mg/kg, respectively. The average concentration of Pb in the soil from HashtBandi and Ravang regions were measured as 3.99 ± 3.77 and 2.03 ± 0.69 mg/kg, and for Cd, the corresponding values were determined as 2.21 ± 3.17 and 2.22 ± 0.92 mg/kg, respectively. The average concentration of Pb and Cd in both investigated onion bulb and soil were lower than Iranian national (onion bulb: Pb = 0.1 mg/kg, Cd = 0.05 mg/kg) and FAO/WHO (onion bulb: Pb = 0.3 mg/kg, Cd = 0.1 mg/kg; soil: Pb = 50 mg/kg, Cd = 0.3 mg/kg) standard limits. Moreover, the THQ and total target hazard quotient (TTHQ) for males and females in all age groups were less than 1 value. Therefore, no risk of the exposure to Pb and Cd as result of onion bulb consumption was reported. STVs for Pb and Cd in the HashtBandi region were calculated as 3.99 and 2.21 mg/kg, and Ravang as 2.03 and 2.22 mg/kg, respectively. Due to the higher calculated STVs for Cd while compared with the established standard limit for the soil, the further revisions regarding the heavy metal standard limits in the soil were recommended.

The Concentration of BTEX in the Air of Tehran: A Systematic Review-Meta Analysis and Risk Assessment.

In the current study, the concentration of some pollutants which are categorized as volatile organic compounds (VOCs), including benzene (B), toluene (T), ethylbenzene (E), and o-xylenes (o-X), in the air of Tehran was evaluated by the aid of a systematic review and meta-analysis approach. Also, the health risk for the exposed population was estimated using the recommended methods by the Environmental Protection Agency (EPA). The rank order based on their concentration in BTEX was benzene (149.18 µg/m³: 31%) > o-xylene (127.16 µg/m³: 27%) > ethylbenzene (110.15 µg/m³: 23%) > toluene (87.97 µg/m³: 19%). The ratio B/T in this study was calculated as 1.69, repressing that both stationary and mobile sources of emission can be considered as the main sources for benzene and toluene. Moreover, strong photochemical activity in Tehran was demonstrated by the high ratio of E/o-X. Meta-regression indicates that the concentration of BTEX has insignificantly (p-value > 0.05) increased over time. The BTEX compounds based on the target hazard quotient (THQ) were ordered as benzene > o-xylene > ethylbenzene > toluene. Percentile 95% of THQ due to benzene (4.973) and o-xylene (1.272) was higher than a value of 1. Percentile 95% excessive cancer risk (ECR) for benzene (1.25 × 106) and ethylbenzene (1.11 × 106) was higher than a value of 1.00 × 106. The health risk assessment indicated that the population of Tehran are at considerable non-carcinogenic and carcinogenic risks.

The concentration and probabilistic health risk assessment of pesticide residues in commercially available olive oils in Iran.

This study was undertaken to analyze 29 pesticides residues in 37 commercially olive oil collected samples from Iran's markets using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) approach along with acetonitrile for the extraction, surface adsorbents for clean-up procedure, following with a gas chromatography-mass spectroscopy (GC-MS). In order to eliminate the matrix effect, the calibration curves were drawn using spiked samples with the Area under curve (AUC) portion calculation of pesticide residue to AUC internal standard (Triphenyl Methane (TPM)). Moreover, the probabilistic health risk assessment includes non-carcinogenic and carcinogenic risk were estimated by target hazard quotient (THQ), total target hazard quotient (TTHQ) and cancer risk (CR) using the Monte Carlo Simulation (MCS) method. The calibration curves were linear in the range of 10-1500 ng/g, and R2 was higher than 0.994. All pesticides recoveries as average were in the range of 77.97-112.65%. The respective numbers attributed to LOD and LOQ were 3-5 ng/g and 8-15 ng/g. Results showed that 29.7% of samples were contaminated by pesticides which according to Iranian regulation, while in 7 cases banned pesticides were detected. Only 4 samples are noncompliant with EU regulation. The rank order of pesticides based on THQ was Heptachlor > DDT > Pretilachlor. Also, TTHQ for adults was 0.139; and children 0.467. The rank order of pesticides based on CR was Heptachlor > DDT. Consumers (adults and children) are not at non-carcinogenic risk due to ingestion of oil olive content (THQ and TTHQ < 1 value) but are at considerable carcinogenic (CR > 1E-6). According to the observed profile of pesticide in olive oil samples, which are mostly banned according to Iranian regulation, further improvements in agriculture procedures of cultivated olive in Iran, as well as required assessments of imported olive oil, was recommended.

Probabilistic non-carcinogenic and carcinogenic risk assessments (Monte Carlo simulation method) of the measured acrylamide content in Tah-dig using QuEChERS extraction and UHPLC-MS/MS.

A modified "Quick, Easy, Cheap, Effective, Rugged, and Safe" QuEChERS in combination with Ultra-High Performance Liquid Chromatography/tandem mass spectrometry (UHPLC-MS/MS) method was optimized for the determination of acrylamide content in different types of tah-dig (rice, bread, and potato). Also, the non-carcinogenic and carcinogenic risks (target hazard quotient (THQ) and incremental lifetime cancer risk (ILCR)) due to ingestion of acrylamide via tah-dig in the adults and children were assessed by Monte Carlo simulation (MCS) method. The recoveries of acrylamide at five concentration levels (n = 3) ranged from 83.82% to 106.41%. The repeatability of the proposed method was demonstrated with RSD% in the range of 11.3-20%. In addition, the limits of detection and quantification were reported as 5 ngg-1 and 15 ngg-1, respectively. The mean levels of the acrylamide contents in rice tah-dig, bread tah-dig, and potato tah-dig were measured as 24.65 ngg-1, 39.48 ngg-1, and 714.11 ngg-1, respectively. The highest acrylamide content was determined in potato tah-dig (2100 ngg-1) and the lowest acrylamide in rice tah-dig (≤LOQ). Based on the conducted risk assessment, the P (95%) of cumulative probability in the MCS method, the lowest and highest THQ was observed in the adults (ingestion bread tah-dig: 1.29E-2), and children (ingestion potato tah-dig: 1.90E+00), respectively. Additionally, the lowest and highest ILCR were reported in adults (ingestion bread tah-dig: 1.29E-5) and children (ingestion potato tah-dig: 7.49E-3), respectively. The rank order of type tah-dig based on THQ and ILCR for all groups of consumers was potato tah-dig > rice tah-dig > bread tah-dig. There is a considerable non-carcinogenic risk for the children due to ingestion potato tah-dig (THQ > 1). Additionally, the significant carcinogenic risk for the Iranian adults and children due to consumption of rice, bread, and potato tah-dig (ILCR > 1.00E-5) was observed.

Groundwater vulnerability assessment in karstic aquifers using COP method.

Access to safe and reliable drinking water is amongst the important indicators of development in each society, and water scarcity is one of the challenges and limitations affecting development at national and regional levels and social life and economic activity areas. Generally, there are two types of drinking water sources: the first type is surface waters, including lakes, rivers, and streams and the second type is groundwaters existing in aquifers. Amongst aquifers, karst aquifers play an important role in supplying water sources of the world. Therefore, protecting these aquifers from pollution sources is of paramount importance. COP method is amongst the methods to investigate the intrinsic vulnerability of this type of aquifers, so that areas susceptible to contamination can be determined before being contaminated and these sources can be protected. In the present study, COP method was employed in order to spot the regions that are prone to contamination in the region. This method uses the properties of overlying geological layers above the water table (O factor), the concentration of flow (C factor), and precipitation (P factor) over the aquifer, as the parameters to assess the intrinsic vulnerability of groundwater resources. In this regard, geographical information system (GIS) and remote sensing (RS) were utilized to prepare the mentioned factors and the intrinsic vulnerability map was obtained. The results of COP method indicated that the northwest and the west of the region are highly and very vulnerable. This study indicated that regions with low vulnerability were observed in eastern areas, which accounted for 15.6% of the area. Moderate vulnerability was 40% and related to the northeast and southeast of the area. High vulnerability was 38.2% and related to western and southwestern regions. Very high vulnerability was 6.2% and related to the northwest of the area. By means of the analysis of sensitivity of the model, it was determined that the focus factor of the flow has the greatest impact on the creation of vulnerability in the region. Also, these results were validated through electrical conductivity and discharge time series of the regional springs that are located in the vulnerable zones.

Quality assessment and artificial neural networks modeling for characterization of chemical and physical parameters of potable water.

Today, due to the increase in the population, the growth of industry and the variety of chemical compounds, the quality of drinking water has decreased. Five important river water quality properties such as: dissolved oxygen (DO), total dissolved solids (TDS), total hardness (TH), alkalinity (ALK) and turbidity (TU) were estimated by parameters such as: electric conductivity (EC), temperature (T), and pH that could be measured easily with almost no costs. Simulate water quality parameters were examined with two methods of modeling include mathematical and Artificial Neural Networks (ANN). Mathematical methods are based on polynomial fitting with least square method and ANN modeling algorithms are feed-forward networks. All conditions/circumstances covered by neural network modeling were tested for all parameters in this study, except for Alkalinity. All optimum ANN models developed to simulate water quality parameters had precision value as R-value close to 0.99. The ANN model extended to simulate alkalinity with R-value equals to 0.82. Moreover, Surface fitting techniques were used to refine data sets. Presented models and equations are reliable/useable tools for studying water quality parameters at similar rivers, as a proper replacement for traditional water quality measuring equipment's.

Radon 222 in drinking water resources of Iran: A systematic review, meta-analysis and probabilistic risk assessment (Monte Carlo simulation).

The current study was performed to review the conducted studies regarding the concentration of radon 222 in the tap drinking water; furthermore, by estimation of ingestion and inhalation effective dose, the health risk assessment in the adults and children using MCS technique was assessed. All related studies published among January 1990 to October 2016; were screened in the available databases such as Web of Science, PubMed, Science Direct, Scopus, SID, and Irandoc. The total effective dose was estimated by calculating Eing (Effective dose of ingestion) and Einh (Effective dose of inhalation) by Monte Carlo simulation (MCS) method. The range of ND ─ 40.9 Bq/L for radon 222 in water resources was proposed after evaluation of data collected from 13 studies with 1079 samples. The overall concentration of radon 222 in drinking water in Iran was 3.98: 95%CI (3.79 ─ 4.17 Bq/L). Also, the effective ingestion dose of radon 222 in adults age groups was 1.35 times higher than children. The rank order of drinking water resources based on the concentration of radon 222 was Spring > Spring and Well > Well > Spring and Qanat > Tap water. The overall concentration of radon 222 in drinking water in Iran was lower than WHO and EPA standard limits. Also, the rank order regarding area studied based on the concentration of radon 222 was Gillan > Mashhad > Mazandaran > Kerman > Yazd > Tehran > Kermanshah > Golestan > Hormozgan. The effective ingestion dose of radon 222 to consumers in the Gillan, Mashhad, Mazandaran, and Kerman were higher than WHO guidance (0.1 mSv/y). Also except consumers in the Hormozgan, inhalation effective dose radon 222, in the other investigated areas were higher than WHO guidance (0.1 mSv/y). Therefore, it is recommended to conduct the required programs regarding control and elimination of radon 222 concentration in Iranian drinking water supply.

Mortality assessment attributed to long-term exposure to fine particles in ambient air of the megacity of Tehran, Iran.

Few studies regarding the health effects of long-term exposure to particulate matter with an aerodynamic diameter of 2.5 µm or less (PM2.5) have been carried out in Asia or the Middle East. The objective of our study was to assess total, lung cancer and chronic obstructive pulmonary disease (COPD) mortality attributed to long-term exposure to PM2.5 among adults aged over 30 years in Tehran from March 2013 to March 2016 using AirQ+ software. AirQ+ modeling software was used to estimate the number of deaths attributed to PM2.5 concentrations higher than 10 µg m-3. Air quality data were obtained from the Department of Environment (DOE) and Tehran Air Quality Control Company (TAQCC). Only valid stations with data completeness of 75% in all 3 years were selected for entry into the model. The 3-year average of the 24-h concentrations was 39.17 µg m-3. The results showed that the annual average concentration of PM2.5 in 2015-2016 was reduced by 13% compared to that in 2013-2014. The annual average number of all natural, COPD, and lung cancer deaths attributable to long-term exposure to PM2.5 in adults aged more than 30 years was 5073, 158, and 142 cases, respectively. The results of all three health endpoints indicate that the mortality attributable to PM2.5 decreased yearly from 2013 to 2016 and that the reduced mortality was related to a corresponding reduction in the PM2.5 concentration. Considering these first positive results, the steps that have been currently taken for reducing air pollution in Tehran should be continued to further improve the already positive effects of these measures on reducing health outcomes.

Trace elements in seafood from the Mediterranean sea: An exposure risk assessment.

Fish and shellfish belonging to five different species among pelagic, benthonic and molluscs, were collected from the Gulf of Catania in 2017 to evaluate arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), manganese (Mn), nickel (Ni), selenium (Se) vanadium (V) and zinc (Zn). Risk of developing chronic systemic effects derived from seafood consumption was evaluated with the Target Hazard Quotient (THQ) and compared with the results obtained from the same area and the species, collected in 2012. Hg, Cd and Pb concentrations were found below the limits set by European Community for human consumption in all the analysed species. The total risk is reduced from 1.1 to 0.49, and this result is strongly associated with the lower bioaccumulations levels found for Hg, Mn, Se and V. Others metals such as As, Pb, Ni and Zn bioaccumulation levels remain approximately the same, conversely, it is revealed a slight increase of Cd and Cr. Overall, the present study show a positive picture of the studied area, the Gulf of Catania, highlighting not only a decreased metal availability of the study area, but, above all, a decreased risk to develop chronic systemic effects derived from consumption of local seafood.