Graphite Furnace Atomic Absorption Spectrometer Research Articles

Assessment of potential health risks associated with heavy metal concentrations in leafy vegetables in Kerman, Iran

ABSTRACT Despite the growing awareness of the nutritional benefits of leafy vegetables, there is a lack of information about the presence of heavy metals and the associated risks in these products. This study aimed to investigate the concentration of heavy metals in leafy vegetables in Kerman City. The research also assessed the intake of heavy metals and the associated drisks for children and adults who consume these vegetables. The study followed the recommended methods by the US Environmental Protection Agency (USEPA) to evaluate both carcinogenic and non-carcinogenic diseases. A total of 400 leafy vegetable samples, including parsley, coriander, Persian leek, and basil, were randomly collected from agricultural farms in the outskirts of Kerman City. The samples were analysed using a graphite furnace atomic absorption spectrometer to measure the concentrations of lead (Pb), cadmium (Cd), iron (Fe), and copper(Cu). The results revealed that the levels of heavy metals in leafy vegetable samples exceeded the recommended standards set by international organisations such as FAO/WHO, European countries, and Iran. The total target hazard quotient (THQ) for non-carcinogenic diseases resulting from the consumption of leafy vegetables was higher than one for both children and adults in all studied areas, indicating a potential risk of non-carcinogenic diseases associated with the consumption of these vegetables. Furthermore, the average Incremental Lifetime Cancer Risk (ILCR) resulting from exposure to agricultural soil through leafy vegetable consumption exceeded the hazardous and unacceptable range of 104− × 10−6 in both children and adults. This suggests the possibility of carcinogenic diseases caused by Pb and Cd through the consumption of leafy vegetables in all studied areas, with a higher overall risk observed in children compared to adults. In conclusion, while leafy vegetables are widely recognised for their nutritional benefits, our study underscores a critical gap in understanding the presence of heavy metals and the associated risks in these products. The findings reveal that the concentrations of heavy metals in leafy vegetables from Kerman City exceed international standards, posing potential health risks, particularly in children. Further research and regulatory actions are warranted to address this pressing issue and ensure the safety of our food supply.

Impact of welding occupation on serum aluminium level and its association with physical health, cognitive function, and quality of life: a cross-sectional study.

There is an occupational health concern about welders' inhalation of toxic aluminium fumes. We investigated whether serum aluminium level (SAL) and demographic variables can significantly predict physical health parameters, cognition, and quality of life (QoL) among welders. The cross-sectional study involved 100 age- and location-matched men (50 welders and 50 non-welders). SAL obtained using a graphite furnace atomic absorption spectrometer, and data collected using blood pressure and body mass index (BMI) apparatuses, biodata form, pain rating scale, General Practitioner Assessment of Cognition, WHOQoL-BREF, and Nordic musculoskeletal symptoms (MSS) questionnaire were analysed using independentsamplest test, chi-square, Pearson's correlation, and hierarchical linear regression. Welders had significantly higher SAL (mean difference [MD] = 1.77µg/L, p < 0.001), lower QoL (MD = 3.92, p = 0.039), and higher prevalence of MSS on the neck (χ2 = 10.187, p = 0.001), shoulder (χ2 = 9.007, p = 0.003), upper back (χ2 = 6.832, p = 0.009), and knee (χ2 = 12.190, p < 0.001) than non-welders. There was a significant bivariate association between SAL, systolic blood pressure (β = 0.313, p = 0.002), and BMI (β = 0.279, p = 0.005), but not pain intensity, cognition, or QoL. SAL remained a significant predictor of systolic blood pressure after adjustment for physical health and QoL parameters (β = 0.191, p = 0.044). The association between SAL and social QoL became significant after adjustment for physical health and other QoL domains (β = - 0.210, p = 0.032) and demographic variables (β = - 0.233, p = 0.046). Welders had significantly higher SAL, musculoskeletal symptoms, blood pressure, and lower QoL than non-welders. SAL was associated with adverse physical health parameters and social-related QoL, not cognition. We recommend routine aluminium bioavailability and physical health checks among welders.

Human Health Risk Assessment of Arsenic and Other Metals in Herbal Products Containing St. John's Wort in the Metropolitan Area of Mexico City.

Consumption of St. John's wort plant is high worldwide due to its various medicinal properties. However, herbal products containing St. John's wort may be contaminated with toxic metals. This is often related to contamination of both water and the atmosphere, lack of proper cultivation methods, and inadequate plant storage conditions, as well as a lack of stricter sanitary supervision. A safety assessment of copper (Cu), lead (Pb), cadmium (Cd) and arsenic (As) content in 23 products containing St. John's wort (pharmaceutical herbal products, food supplements and traditional herbal remedies) sold in the metropolitan area of Mexico City was conducted. The analysis of metals was determined using a graphite-furnace atomic absorption spectrometer. All herbal products were contaminated with Cu, Pb, Cd and As. The pharmaceutical herbal items showed less contamination by metals. The daily human intake (DHI) values for Pb exceeded the permissible limits in the group of traditional herbal remedies. The DHI calculation for As exceeded the permitted intake values for all items in the group of traditional herbal remedies, five food supplements and one pharmaceutical herbal product. The hazard indicator calculation of the non-carcinogenic cumulative risk values for traditional herbal remedies was greater than 1, suggesting a risk to human health.

Immobilization of Alpha‐Amylase onto Ni2+ Attached Carbon Felt: Investigation of Kinetic Parameters from Potato Wastewater

Abstractα‐amylase is an important enzyme for textile, food, paper, and the pharmaceutical industrial areas. In this study, Ni2+ attached carbon felt structures with nitrogen active site (Ni2+‐N‐ACF) are produced. The surface morphologies of the N‐ACF and Ni2+‐N‐ACF are investigated by means of scanning electron microscopy (SEM) analysis. Ni2+ ions binding on the N‐ACFs are determined by energy dispersive X‐ray (EDX) analysis and a graphite furnace atomic absorption spectrometer (AAS). The effect of pH, ionic strength, initial α‐amylase concentration, and temperature parameters is investigated for α‐amylase immobilization on Ni2+‐N‐ACF structures. In addition, pH and temperature effect on the activities of the free and the immobilized amylase, kinetic parameters, storage, and operational stabilities are made. Lastly, starch degradation in potato waste water is tested on Ni2+‐N‐ACF. The obtained results show that α‐amylase immobilized Ni2+‐N‐ACF can be used for starch degradation on an industrial scale.

Exposure Assessment of Heavy Metals and Microplastic-like Particles from Consumption of Bivalves.

The aim of this study was to determine the contamination of lead (Pb), cadmium (Cd) and microplastic (MP)-like particles in bivalves and estimate the exposure of the Thai population to these contaminants due to bivalve consumption. Clams, mussels and cockles were purchased from five wholesale seafood markets located on the upper Gulf of Thailand during the period 2017-2019. Determinations of Cd and Pb in the bivalves were conducted using a graphite furnace atomic absorption spectrometer (GFAAS). Visualization was conducted using a stereomicroscope to investigate the morphology and content of MP-like particles in the bivalve samples. The average Pb contents in clams, mussels and cockles were 112, 64 and 151 µg/kg wet wt., respectively. The average Cd contents were 126, 107 and 457 µg/kg wet wt. for clams, mussels and cockles, respectively. The average number of MP-like particles in bivalve samples varied from not detected to 1.2 items/g wet wt. and not detected to 4.3 items/individual. The exposure to Pb, Cd and MP-like particles due to bivalve consumption varied between 0.005 and 0.29 µg/kg bw/day, 0.017 and 28.9 µg/kg bw/month and 0.015 and 27.5 items/person/day, respectively. There was no potential health risk of exposure to Pb and Cd due to bivalve consumption in any age group. However, a high consumption of cockles with high Cd levels (the worst-case scenario) in children may be of concern.

Amino-functionalised chrysin as adsorbent in dispersive micro-solid phase extraction of selected heavy metal ions from stingless bee honey

The study includes the preparation, characterisation, and application of a new adsorbent, 3-aminopropyltriethoxysilane modified chrysin (CHY-APTES), to extract Pb(II), Cr(III), and Cd(II) from stingless bee honey samples using dispersive micro-solid phase extraction (d-µ-SPE) and detected by graphite furnace atomic absorption spectrometer. Characterisation techniques of CHY-APTES including Brunauer-Emmett-Teller surface area analysis, Fourier transform infrared spectroscopy, scanning electron microscopy-energy dispersive x-ray imaging and point of zero charge determination. Several parameters were studied and optimised, such as a desorption time of 15 min, an adsorption time of 3 min, the use of nitric acid solution as the desorption solvent, 120 mg of adsorbent mass, solution pH adjusted to pH 5, and ethanol employed as the dispersive solvent. The results demonstrated good relative recoveries for Pb(II), Cr(III) and Cd(II) in the range of 74.76–116.34 %, 83.59–115.83 % and 89.03–117.66 %, respectively, with good precision at a relative standard deviation≤11.46%. For method sensitivity, the method showed acceptable detection limits (3 S/N) for Pb(II), Cr(III) and Cd(II) extracted from stingless bee honey samples at 43.6, 348.9 and 56.7 µg/kg, respectively. The preconcentration factors calculated for Pb(II), Cr(III), and Cd(II) were 111, 9.5, and 49, respectively. The newly developed CHY-APTES was successfully applied in d-µ-SPE for the first time. It was adequate in terms of analytical performance and simple in preparing stingless bee honey samples via dilution.

Monte Carlo-based probabilistic risk assessment for cement workers exposed to heavy metals in cement dust.

This study assessed the carcinogenic and non-carcinogenic health risks of cement plant workers exposed to chromium (Cr), arsenic (As), cadmium (Cd), and lead (Pb) in cement dust using a probabilistic approach. Air samples were collected according to NIOSH 7900 and OSHA ID-121 methods and analyzed by an graphite furnace atomic absorption spectrometer. The EPA inhalation risk assessment model and Monte Carlo simulation were utilized to assess the health risks. Sensitivity analysis was used to determine the influencing parameters on health risk. The average concentrations of As and Pb exceeded the occupational exposure limit (OEL), reaching a maximum of 3.4 and 1.7 times the OEL, respectively, in the cement mill. Individual metals' cancer risk exceeded the 1E-4 threshold in ascending order of Cd < As < Cr. The mean cancer risk of Cr ranged from 835E-4 (in raw mill) to 2870E-4 (in pre-heater and kiln). Except for Cd, the non-cancer risk of metals exceeded the standard (hazard index, HQ = 1) in the ascending order of Pb < As < Cr. The mean HQ of Cr ranged from 162.13 (in raw mill) to 558.73 (in pre-heater and kiln). After adjusting for control factors, the cancer and non-cancer risks remained over the respective recommended levels. Sensitivity analysis revealed that the concentration of Cr was the most influential parameter on both carcinogenic (78.5%) and non-carcinogenic (88.06%) risks. To protect the health of cement factory employees, it is recommended to minimize cement dust emissions, implement job rotation, and use raw materials with low levels of heavy metals.

The effect of comorbidities on periodontal and hygiene indices, and oral fluid mineral composition

Relevance. In patients with comorbidities, the barrier resistance of periodontal tissues decreases due to oral homeostasis damage, which increases the severity of inflammatory periodontal diseases and needs the interaction of dentists and internists to develop common approaches to such patients' treatment and management.Aim. The study aimed to study the periodontal and oral hygiene indices and the oral fluid mineral composition in dental patients with comorbidity.Materials and methods. The study examined 63 dental patients with comorbidities: coronary artery disease, chronic gastritis, chronic nephritis, and chronic sinusitis. The Green-Vermillion oral hygiene index (OHI-S) detected the oral hygiene status, and the CPITN index of the WHO and the PMA index revealed the periodontal status. Electrothermal atomic absorption spectroscopy using QUANTUM.Z1 graphite furnace atomic absorption spectrometer determined the amount of calcium, magnesium, zinc and copper in the oral f luid.Results. Patients with coronary artery disease and chronic nephritis demonstrated a statistically significant decrease in oral hygiene associated with severe periodontal inflammation. Analysis of the oral fluid mineral composition showed that patients with coronary artery disease had decreased calcium, magnesium and zinc levels. The chronic nephritis patients had a copper and zinc decrease in the oral fluid. In patients with chronic gastritis, there was a lack of magnesium and copper in the oral fluid. The patients with chronic sinusitis showed a decrease in copper.Conclusions. Dental professionals should consider patient systemic diseases and oral fluid mineral composition at a dental appointment, during treatment and during preventive measures prescription.

Sastav mikronutrijenata proizvoda mlevenja tradicionalnih sorti pšenice poreklom iz Srbije

The deficiency of micronutrients in the human diet is widely recognised as a global problem. The objective of this study was to assess the content of two essential minerals, iron and zinc, in milling streams of old heritage wheat cultivars that have not been produced for more than a half-century to discover potential parent lines with high mineral content for breeding. Kernel size of seven Serbian old wheat cultivars was evaluated for ash content, thousand-grain weight and share of specific kernel fractions. Three cultivars, Crnozrna, Rumska Crvenka and Stara Banatka, were selected as the most appropriate for milling and further analysis of mineral content in the milling streams. The cultivars were milled in a laboratory mill to obtain six flour and two by-product streams. At the same time, iron and zinc content was determined on a graphite furnace atomic absorption spectrometer. After mixing all six flour streams obtained from each cultivar, three different flour types were obtained. The flour with the highest ash content was the "1100" type originating from cultivar Stara Banatka, characterized by the highest iron and zinc content (54.9 mg/kg d. b. and 5.407 mg/kg d. b., respectively). It was estimated that consumption of a daily average bread portion (166 g according to national statistical data) made from Stara Banatka flour could provide about 90% of the recommended daily intake for iron. Therefore, Stara Banatka may be a target cultivar for wheat breeders searching for high-iron parent wheat lines.

Direct determination of ultra-trace sodium in reactor secondary coolant waters and other waters by electrolyte cathode discharge atomic emission spectrometry

A simple, rapid and sensitive method has been described for direct determination of ultra-trace sodium in reactor secondary coolant waters and other waters by electrolyte cathode discharge atomic emission spectrometer (ELCAD-AES). This method obviates the need of any sample digestion except simple dilution followed by analysis of these waters. Direct analysis of the samples for their very low level sodium is found to be feasible by ELCAD-AES with 3% v/v formic acid without going for chemical processing/treatment like evaporation of matrix or separation and pre-concentration of sodium. The 3% v/v formic acid improves the detection limit of sodium which is found to be 0.5 ng mL−1. Repeatability of the method was found to be 8% whereas the accuracy was between 10 and 20% at ultra-trace levels. As the certified reference materials for these waters are not available, the method is validated with the corresponding results determined by graphite furnace atomic absorption spectrometer (GFAAS). The proposed method is found to be useful for direct determination of trace and ultra-trace sodium in reactor coolant waters, high purity waters and in tap and ground waters. Therefore, ELCAD-AES can be an alternative analytical technique to check ultra-trace levels of sodium and quality of the coolant waters for nuclear industries.

Analytical chemistry in technical approaches: immobilization of biosorbent waste containing heavy metals in cemented materials

An ecologically safe and economically justified method of stabilization of the used biosorbents was developed. Sorbent contaminated with heavy metals has been successfully solidified/stabilized using a hydraulic binder. The test results indicated that up to 1% of the biosorbent residue used could be added without compromising the compressive strength of the mortar. The compressive strength of the modified mortars did not change significantly even after 20 freeze/thaw cycles. The analytical methods such as Flame Atomization-Atomic Absorption Spectrometer, Graphite Furnace-Atomic Absorption Spectrometer, and Cold Vapor-Atomic Absorption Spectrometry were utilized to examine the leaching behavior of selected heavy metals during harsh condition exposure. The leachability of selected heavy metals was found to be below the limit allowed by the US EPA after immersion and agitation for 10 days in artificial water solutions (seawater, groundwater, and rainwater). X-Ray Diffraction and Brunauer–Emmett–Teller data showed no significant changes in the crystalline structure and surface area of the modified mortars after treatment. Research showed that mixing the adsorbent used with mortar was effective in immobilizing heavy metals and allowed the implementation of a so-called ‘zero waste’ management method.Graphical abstract

Especiação de estanho no plasma sanguíneo de trabalhadores expostos ocupacionalmente em uma indústria de processamento de minério de cassiterita

ABSTRACT Mining is a high-risk activity due to its dangerous processes. Tin (Sn) is obtained from cassiterite ore and mining activities expose workers to the metal. Chronic exposure to Sn may cause pneumoconiosis, gastrointestinal and hematological effects, among others. This work aimed to assess the exposure of workers to tin in a cassiterite ore processing industry, using the speciation analysis in blood plasma. Twelve subjects donated the blood samples; six were occupationally exposed to Sn. Size exclusion chromatography separated proteins in blood plasma; a graphite furnace atomic absorption spectrometer determined total tin in the plasma and eluted fractions, while SDS-PAGE determined molecular masses of proteins. Tin levels in the workers’ plasma were four times higher than in the reference individuals. After fractionation, the metal only appeared in the total inclusion volume, not being possible to confirm the binding of tin to proteins, which certainly modifies their functions and impair workers’ health. Despite that, the work process needs to change since Sn levels in the workers’ plasma pointed to metal exposure. Further works are necessary to clarify whether the metal is free or bound to small proteins in blood plasma and understand the true impact of tin on workers’ health.

Cadmium Investigations in Lahore Soil and Other Regions of Pakistan

Cadmium (Cd) is toxic even in the very trace amounts and shows adverse effects on the human being and his environment. Current studies were performed to evaluate the Cd concentration in soil of Lahore (Pakistan) and the results were compared with those reported from other cities of Pakistan. The metal concentration evaluated by graphite furnace atomic absorption spectrometer (GFAAS). Cd concen- tration was found to be 1.39-20.82 µg/L, 1.38-93.60 µg/L, 2.42-94.60 µg/L, 2.25-93.98 µg/L and 1.15-8.14 µg/L in GT road, Misri shah, river Ravi, fertilized land of Raiwind side and unfertilized land of Raiwind side, respectively. The higher Cd concentration (2.42-94.60 µg/L) at "River Ravi" as compared to the other investigated areas (1.15-93.98 µg/L) is owed to the dumping of untreated waste from all industrial, sewage, domestic and agricultural zones in "River Ravi". The fertilized land was found to possess higher amount of Cd as compared to the unfertilized land. The awareness in farmers and the periodic monitoring of soil are important to eradicate the sources of Cd poisoning.&#x0D; &#x0D;

The assessment of lead concentration in raw milk collected from some major dairy farms in Iran and evaluation of associated health risk.

Milk is one of the most consumed sources among people, especially children. hence, its contamination with heavy metals can pose a serious risk to children. Therefore, this study aimed to measure the lead concentration as one of the most dangerous heavy metals in the raw milk of several major animal husbandries in Tehran province from Iran. A total of 57 raw milk samples were collected from different regions of Tehran province. The lead contents were measured using a graphite furnace atomic absorption spectrometer. To evaluate the risk of the samples and hazard quotient (HQ) were calculated. The results showed that HQ for all samples was lower than 1 which was found within the acceptable level. Because the absorption of Pb is higher in children and this metal has a cumulative property in the body, even its small weekly intake can be dangerous in long-term consumption.

Undergraduate Analytical Laboratory Experiment: Determination of Arsenic in Rice with Graphite Furnace Atomic Absorption Spectroscopy and a Novel Digestion Method

By focusing on food and a pervasive contaminant, this experiment engages student interest and effort while providing essential instruction and experience. As institutions are challenged by existing and emerging budgetary constraints, this experiment offers a determination approach employing commonly available instrumentation, the graphite furnace atomic absorption spectrometer. The module provides a broad range of experiences: it introduces the lyophilizer, offers practice in a multistep novel digestion method, presents the theoretical foundation and practical application of atomic absorption spectroscopy, and provides an opportunity to record, calculate, and report findings. Students whose math skills are in development can complete it successfully because algebraic calculations are used at each stage of the materials’ examination. Finally, when their reports align with extensive international research, the lab offers students assurance of their growing scientific competence.

Optimizing experimental conditions of graphite furnace atomic absorption spectrometer using orthogonal design for determination of cobalt in urine

Objective: To select and optimize the conditions of urine cobalt determination by graphite furnace atomic absorption spectroscopy and establish a method for urine cobalt determination. Methods: In April 2020, the matrix modifier and spectrum wavelength were selected by mathematical statistics method, the heating procedure of graphite furnace was optimized, the variance of orthogonal test results was analyzed, and the working curve was quantified by external standard method. Results: The results showed that the diammonium hydrogen phosphate was a matrix modifier with a wavelength of 240.7 nm, and the optimized graphite furnace heating procedure showed a good linear relationship at 5-80 μg/L. The correlation coefficient was 0.9991. The detection limit was 0.9 μg/L, the lowest detection concentration was 1.8 μg/L. The recovery was 94.0%-101.4%, and the precision was 2.6%-5.8%. Conclusion: The orthogonal design method can efficiently and scientifically optimize the optimal combination of the various factor levels of graphite furnace atomic absorption spectrometry. The determination method established based on this has high precision and good accuracy, and can be applied to the determination of cobalt in urine.

A Health Risk Assessment of Lead and Other Metals in Pharmaceutical Herbal Products and Dietary Supplements Containing Ginkgo biloba in the Mexico City Metropolitan Area.

The use of the medicinal plant Ginkgo biloba has increased worldwide. However, G. biloba is capable of assimilating both essential and toxic metals, and the ingestion of contaminated products can cause damage to health. The aim of this study was to investigate the safety of manganese (Mn), copper (Cu), lead (Pb), arsenic (As), and cadmium (Cd) in 26 items containing Ginkgo biloba (pharmaceutical herbal products, dietary supplements, and traditional herbal remedies) purchased in the metropolitan area of Mexico City. Metal analysis was performed using a graphite furnace atomic absorption spectrometer. All of the products were contaminated with Pb, 54% of them with As, and 81% with Cd. The lowest values of Pb, As, and Cd were detected in pharmaceutical herbal products > dietary supplements > traditional herbal remedies. The daily intake dose (DID) of pharmaceutical herbal products was within the established limits for the five metals. Dietary supplements and traditional herbal remedies exceeded the DID limits for Pb. The hazard quotients estimation and non-carcinogenic cumulative hazard estimation index for Mn, As, and Cd indicated no human health risk. Our results suggest that products containing G. biloba for sale in Mexico are not a health risk.

Comparative seasonal assessment of pollution and health risks associated with heavy metals in water, sediment and Fish of Buriganga and Turag River in Dhaka City, Bangladesh

Heavy-metal pollution of surface water, sediment and fish have been seen as a major global problem, with a significant proportion of developing countries like Bangladesh. This study assessed the intensity of alarming six toxic substances (Cr, Zn, Fe, Cu, Pb and Ni) throughout the River water, sediments as well as soft tissues of three widely consumed fishes (Heteropneustes fossilis, Channa punctatus and Channa striata) obtained from two urban streams of the Buriganga and Turag in the Dhaka metropolitan. For evaluating the comparative seasonal variation of heavy-metal concentration, water and sediment samples were collected from five selected sites for two different seasons (viz. 10 from winter seasons and 10 from summer seasons). Finally, a total of 20 water samples, 20 sediment and 12 fish samples were investigated by flame atomic absorption spectroscopy (FAAS) and graphite furnace atomic absorption spectrometer (GFAAS) corrected with the Zeeman effect background correction system. The hierarchy of mean concentration of selected heavy metals in Buriganga water is found to be Fe > Cr > Ni > Zn > Cu > Pb in the winter season whereas during the summer season the order is Fe > Cr > Zn > Ni > Cu > Pb. For the River Turag, the order is Fe > Zn > Cu > Ni > Cr > Pb and Fe > Zn > Ni > Cu > Cr > Pb during winter and summer season, respectively. The level of metals studied surpassed the acceptable level of drinkable water, implying the ineptitude of drinking and cooking water from these Rivers. However, this hierarchy of heavy metals for sediments of Buriganga River changed to Fe > Cr > Ni > Zn > Cu > Pb for the winter season and Fe > Cr > Ni > Cu > Zn > Pb for the summer season. Whereas, for the Turag River, the decreasing trend of metal concentration found in sediment was Fe > Zn > Cr > Ni > Cu > Pb for both seasons. For probable human health hazard implications, contamination factor (CF) and pollution load index (PLI) were studied. The CF values revealed the low-to-moderate pollution of sediment. The PLI value above one shows the degradation of the consistency of the sediments. Fe, Ni, Pb, Cr, Zn and Cu concentrations in fish species were found to be 19.66–45.1, 0.07–12.18, 1.2–10.18, 20.18–187.07, 11.08–68.25, 2.07–10.4 mg/kg, respectively. The metals studied differed considerably among organisms and seasons. Bioconcentration factor (BCF), the daily average consumption of metal (EDI), as well as target threat quotients (THQs) for specific metal indicated that Cr and Pb are harmful in fish muscles and possible risks remain for fish consumers. The obtained concentrations of some metals are higher than the WHO/FAO’s permissible limit, suggesting that the water and fish found in these Rivers are like to be harmful to the human being. This study shows that attention should be given to the risk assessment for heavy metals in these Rivers.

Concentration of cadmium, arsenic, and lead in rice (Oryza sativa) and probabilistic health risk assessment: A case study in Hormozgan province, Iran

Background: The presence of toxic heavy metals in cereal grains like rice is one of the main human and environmental health concerns. Their importance is because of their non-biodegradability nature, high half-time, and bioaccumulation ability in the human body. Among heavy metals, cadmium (Cd), lead (Pb), and arsenic (As) are most critical, so their concentrations in rice were evaluated in this study. Methods: In this study, the concentration of Cd and Pb was determined by graphite-furnace atomic absorption spectrometer (GF-AAS), while the concentration of As was measured by atomic spectrum poll after acid digestion of the milled rice samples. The probabilistic health risk assessment of Cd, As, and Pb through consumption of different types of rice including local rice and two types imported from India (IND) and Pakistan (PAK), was estimated for the adults in Hormozgan province using Monte Carlo simulation (MCS) technique. Results: It was revealed that the concentrations of all Cd, As, and Pb in the local rice samples were lower than those in the PAK and IND samples. The average concentration of As, Pb, and Cd in the rice samples were 0.045, 0.057, and 0.022 mg/kg, respectively. The estimated total target hazard quotient (TTHQ) for this population was lower than 1, representing negligible non-carcinogenic risk through rice consumption. However, total carcinogenic risk (TCR) via As intake showed a considerable carcinogenic risk (TCR &gt; 1E-4) for this population. Conclusion: According to the results, it is necessary to perform continuous monitoring for concentration of Cd, As, and Pb especially in the imported rice samples.

Risk of neurodegenerative disease due to tau phosphorylation changes and arsenic exposure via drinking water.

It is estimated that around 140 million people are drinking highly contaminated water with arsenic (As) as a natural earth's crust component. On the other hand, the prevalence of neurodegenerative disorders, especially Alzheimer's disease, is constantly increasing. The aim of the present study was to investigate the correlation between oral arsenic trioxide exposure and its impact on tau protein phosphorylation at Ser262. Fifty-four male mice were randomly divided into three groups and were freely accessed to food and contaminated water of 1 and 10ppm arsenic trioxide for 3months, except for control subjects. At the end of each month, As concentration and tau phosphorylation were checked with graphite furnace atomic absorption spectrometer and western blot analysis, respectively. Surprisingly, it was observed that the amount of measured brain arsenic in 10ppm-exposed subjects was significantly increased after 3months (P-value ˂ 0.0001). The significant changes in tau phosphorylation were not seen in the 1ppm-exposed subjects, and it was observed that Ser262 phosphorylation significantly increased after 2 and 3months in the 10ppm group (P-value < 0.05). Our results demonstrated that arsenic accumulated in the brain time-dependently and increased Ser262 tau phosphorylation, which is very important in several tauopathies. In conclusion, it could be inferred that environmental arsenic exposure even at very low concentrations could be considered as a reason for increasing the risk of developing neurodegenerative disease.