Enhanced exopolysaccharide production by multi metal tolerant Klebsiella variicolaSMHMZ46 isolated from mines area and application in metal bioremediation.

The current study aimed to enhance exopolysaccharide production by Klebsiella variicolaSMHMZ46 isolated from the Zawar mines area in Udaipur, Rajasthan, India, by optimizing the medium with OFAT and a central composite design. The trial including sucrose (9.5%), casein hydrolysate (3%), and NaCl (0.5%) yielded the maximum EPS production as indicated by applying the CCD-RSM biostatistical program. The composition of exopolysaccharides produced by Klebsiella variicolaSMHMZ46 culture was characterized. Growth under Pb(II), Cd(II), and Ni(II) metal amended conditions induced EPS production relative to control. TLC was used for identifying the sugar residues of EPS, in addition to determination of both total carbohydrate and protein contents. According to FT-IR analysis, EPS can interact with metal ions via their functional chemical groups, thereby supporting their bioremediation potential. The metal removal efficiency of bacteria and their produced EPS in broth individually spiked with Pb(II), Ni(II), and Cd(II) was 99.18%, 97.60%, and 98.20%, respectively, and powdered EPS from contaminated water was 85.76%, 72.40%, and 71.53%, respectively. According to FEG-SEM observations, the surface morphology of EPS becomes rough, demonstrating sharp bumps after metal binding. A FEG-SEM analysis of the structure of EPS was performed; the surface structure of EPS (with metal) was more rigid than that of control EPS (without metal). The interaction between the EPS system and Pb(II) ions was investigated using FEG-SEM coupled with energy dispersive X-ray spectra, and a strong peak of C, O, and Pb elements was observed, indicating successful Pb adsorption. These findings suggest that EPS from Klebsiella variicolaSMHMZ46 has a good metal adsorbing nature and could be a promising biosorbent for metal bioremediation of contaminated water.

Environmental impact of endocrine-disrupting chemicals and heavy metals in biological samples of petrochemical industry workers with perspective management.

Exposure to endocrine disrupting chemicals (EDCs) or heavy metals are synthetic compounds that can lead to negative effect on health, including immune and endocrine system disruption, respiratory problems, metabolic issues, diabetes, obesity, cardiovascular problems, growth impairment, neurological and learning disabilities, and cancer. Petrochemical industry drilling wastes, which contain varying levels of EDCs, are known to pose a significant risk to human health. This study aimed to investigate the levels of toxic elements in biological samples of individuals working in the petrochemical drilling sites. Biological samples, including scalp hair and whole blood, were collected from petrochemical drilling workers, individuals residing in the same residential area, and control age-matched persons from nonindustrial areas. The samples were oxidized by an acid mixture before analysis using atomic absorption spectrophotometry. The accuracy and validity of the methodology were verified through certified reference materials from scalp hair and whole blood. The results showed that the concentrations of toxic elements, such as cadmium and lead, were higher in biological samples of petrochemical drilling employees, while lower essential element levels (iron and zinc) were detected in their samples. This study highlights the significance of adopting better practices to reduce exposure to harmful substances and protect the health of petrochemical drilling workers and the environment. It also suggests that perspective management including policymakers and industry leaders should take measures to minimize exposure to EDCs and heavy metals to promote worker safety and public health. These measures could include the implementation of strict regulations and better occupational health practices to reduce toxic exposure and promote a safer work environment.

Analysis of heavy metals and toxicity level in the tannery effluent and the environs.

Heavy metals have found a large number of applications in the recent times. These heavy metals are being continuously added to our environment through various natural and anthropogenic activities. Industries employ heavy metals to process raw materials into final products. Effluents from these industries carry heavy metals. Atomic absorption spectrophotometer and ICP-MS (inductively coupled plasma-mass spectrometer) are of great help in detecting various elements in the effluent. They have been extensively applied to solve problems related to environmental monitoring and assessment. Heavy metals like Cu, Cd, Ni, Pb, and Cr can be easily detected using both the techniques. Some of these heavy metals are toxic to both humans and animals. They can have significant related health effects. Presence of heavy metals in the industrial effluent has gained varied attention in the recent times and it has become one of the major causes of water and soil pollution. Significant contributions can be linked with the leather tanning industry. As the effluent from the tanning industry has been found to contain a large number of heavy metals in many studies. Continuous monitoring and treatment of the effluent is necessary to keep a check on the concentration of heavy metals in these effluents. This study focuses on the analysis of the various studies available on tannery effluents, methods used for heavy metal analysis, toxicity of these heavy metals, and the related major health effects. Data for heavy metals in the tannery effluent from different studies in last two decades has been collected and analysed. The data from various studies indicates that Cr, Cd, Pb, Zn, Cu, Fe, and Ni are the most commonly found heavy metals released from the tanning industry. Proper management of the tannery effluent is thus very essential for saving the environment.

Heavy Metal Concentrations of Beeswax (Apis mellifera L.) at Different Ages.

Beeswax is a naturally occurring product that worker bees produce. Beeswax is used in a variety of industries and pharmaceuticals. Humans utilize it extensively in cosmetics, medicinal formulations, and food manufacturing. Beeswax is an essential component of advanced contemporary beekeeping. Beekeepers, in particular, utilize significant amounts of beeswax to make beeswax comb foundation. In its natural condition, beeswax is white, but it becomes yellow then dark in color when it comes into touch with honey and pollen. The ongoing use of wax comb in bee activities (such as brood rearing, storage honey and bee bread), combined with environmental factors such as heavy metal and pesticide residues, resulted in a black color. Because of heavy metals can accumulate in wax for decades, beeswax can be a helpful tool for gathering data on hazardous contaminants in the environment. Because of their lipid-based chemical composition, beeswax combs act as a sink for numerous ambient pollutants as well as poisons when in the hive. The current study aims to measure nine heavy metals and important elements, including iron (Fe), chromium (Cr), zinc (Zn), copper (Cu), nickel (Ni), manganese (Mn), lead (Pb), cadmium (Cd), and cobalt (Co) in beeswax collected in the Behaira governorate region of Egypt between 2018 and 2022. Sample collection was conducted each year in triplicate. The samples were analyzed using an atomic absorption spectrophotometer. The quantity of metals in beeswax at different ages differed significantly. Depending on the wax age, Fe has the highest concentration in the range of 2.068 to 5.041 ppm, while Cd has the lowest ratio at 0.024 to 0.054 ppm from the first to fifth years old of comb age. The findings showed that as beeswax combs aged, the concentration of heavy metals rose. According to the study, it should gradually recycle beeswax combs each year and also adding new foundations.

Quantitative evaluation of mercury adsorption and removal efficacy of Spirulina (Arthrospira platensis) powder in mice.

Spirulina is a blue-green alga, grown in alkaline water and used for detoxification of several toxic metal ions. Apart from its nutritional value, it is also used for the decontamination of toxic metal ions. Therefore, present study was envisaged to evaluate the adsorption and removal efficiency of Spirulina powder for mercury. The adsorption efficiency of Spirulina was evaluated in terms of weight of adsorbent, contact time, simulated gastric (SGF) and intestinal (SIF) fluid, and mercury concentration. In vivo removal efficacy of Spirulina for mercury was evaluated in mice. The mercury content in major tissues, urine and feces was estimated. The whole tissue retention and excretion of mercury after treatment with Spirulina were taken as a measure of its metal ions removal efficacy. Activated charcoal was taken as a standard adsorbent for comparative study. The maximum adsorption capacity of Spirulina and charcoal for mercury was found to be 66.667 and 158.730 mg g-1 in water, 83.33 and 94.340 mg g-1 in SGF and 125.0 and 133.33 mg g-1 in SIF, respectively. In mice, Spirulina and activated charcoal were significantly reduced the mercury deposition in tissues and facilitated their excretion through feces. Spirulina has shown good adsorption and removal efficacy like activated charcoal. Therefore, Spirulina can be used as a potential adsorbent to remove mercury from the body.

Prolific contribution of Pseudomonas protegens in Zn biofortification of wheat by modulating multifaceted physiological response under saline and non-saline conditions.

The current study aimed to characterize the contribution of bacterium CP17 in zinc (Zn) biofortification in wheat under saline and non-saline conditions. This bacterial strain effectively solubilized Zn and tolerated up to 20% NaCl concentration. The Zn-solubilization potential was also quantified using AAS in a liquid broth supplemented with zinc oxide and zinc carbonate at various NaCl concentrations. Lowering the pH of liquid broth and analyzing a wide range of organic acids (thioacetic acid, glutamic acid, carboxylic acid, propionic acid, and so on) using UPLC-MS provided mechanistic insight for zinc solubilization. This strain was also shown to possess plant probiotic characteristics like phosphate solubilization, production of siderophore, indole acetic acid (IAA), exopolysaccharide (EPS), ACC deaminase, and ammonia. CP17 was identified as a Pseudomonas protegens based on the 16S rRNA gene analysis. In addition, the amplified product of the ACC deaminase producing gene (acdS) provided a molecular indication of the strain's endurance towards stress. The towel paper assay confirmed that the inoculation of Pseudomonas protegens CP17 significantly increased wheat seedlings' germination, growth, and biomass under different NaCl concentrations (0 mM, 100 mM, and 150 mM). Afterward, In situ pot experiment study was designed with the inoculation of Pseudomonas protegens in wheat under saline and non-saline conditions. The harvested wheat plants showed an elevated pattern of zinc content in the grain (i.e. 24.33 and 29.33mg/kg), straw (i.e. 45.73 and 50.23mg/kg) and soil (i.e. 0.978 and 1.32mg/kg) under saline and non-saline conditions, respectively and shown significant improvement over control. The results of the pot study revealed the amelioration in plant health, yield and uptake of available zinc from rhizospheric soil to straw and grain, along with enhanced dehydrogenase and phosphatase activities of rhizospheric soil under saline and non-saline conditions. This study supports the integrative role of Pseudomonas protegens CP17 as a bioinoculant for the efficacious strategy of zinc biofortification and growth promotion in wheat and ensures sustainable nutrient quality production under salinity stress.

Role of Intestinal Helminth Parasite of Macrobrachium vollenhovenii-Cucullanus sp. in Host Metal Accumulation in Epe Axis of the Lekki Lagoon, Lagos, Nigeria.

This paper assesses the role of intestinal helminth parasite of Macrobrachium vollenhovenii on host metal accumulation in Lekki lagoon, Lagos, Nigeria. Lead, zinc, copper, chromium and iron concentrations were determined in water, sediment, intestinal parasite, intestine of infected and non-infected prawns. Intestinal nematode parasite Cucullanus sp. was identified. Pb and Cr were not detected in the water and sediment. The sediment had higher concentrations of the metals than the water medium, and exceeded the WHO limits for Zn, Cu and Fe. Cucullanus sp. accumulated Zn 19 times, Cr several thousand times more and Fe 11 times more than the host intestine (wet wt). This parasite could have accumulated these metals from its host, reducing the concentration of these metals in the tissues of the infected prawns compared to non-infected ones. The infected and non-infected prawns accumulated Zn and Fe several times more than the water medium. The parasite influenced metal accumulation in the host tissue and pose ecological risk.

Verifying measurements of residual calcium content in demineralised cortical bone.

Calcium contents of demineralised human cortical bone determined by titrimetric assay and atomic absorption spectrophotometry technique were verified by comparing to neutron activation analysis which has high recovery of more than 90%. Conversion factors determined from the comparison is necessary to correct the calcium content for each technique. Femurs from cadaveric donors were cut into cortical rings and demineralised in 0.5 M hydrochloric acid for varying immersion times. Initial calcium content in the cortical bone measured by titration was 4.57%, only 21% of the measurement by neutron activation analysis; while measured by atomic absorption spectrophotometer was 13.4%, only 61% of neutron activation analysis. By comparing more readings with the measurements by neutron activation analysis with 93% recovery, a conversion factor of 4.83 was verified and applied for the readings by titration and 1.45 for atomic absorption spectrophotometer in calculating the correct calcium contents. The residual calcium content started to reduce after the cortical bone was demineralised in hydrochloric acid for 8 h and reduced to 13% after 24 h. Using the linear relationship, the residual calcium content could be reduced to less than 8% after immersion in hydrochloric acid for 40 h. Atomic absorption spectrophotometry technique is the method of choice for calcium content determination as it is more reliable compared to titrimetric assay.

Evaluation of scalp hair nickel and chromium level changes in patients with fixed orthodontic appliance: a one-year follow-up study.

BACKGROUND AND OBJECTIVES: The release of metal ions from orthodontic appliances is part of the dissolution and biomechanical processes of alloys. Nickel (Ni) and chromium (Cr) are the elements commonly used in the manufacture of various components of fixed orthodontic appliances, including bands, brackets and wires. This study was aimed to measure the Ni and Cr ions levels in the scalp hair of patients treated with fixed orthodontic appliances in comparison of the control group. MATERIALS AND METHODS: The patient group consisted of 24 patients treated with fixed orthodontic appliances for one year, while the control group included 28 healthy individuals without orthodontic appliances. Analysis of the Cr and Ni was performed using atomic absorption spectrophotometer by graphite furnace method. The data were analyzed via student and paired samples t-test and ANOVA repeated measurement test. RESULTS: After one year, the levels of Ni and Cr in two groups showed significant differences (0.086 ± 0.007 and 0.258 ± 0.009 µg/g for control group and 0.149 ± 0.010 and 0.339 ± 0.013 µg/g for patient group, respectively for Ni and Cr, p < .001). ANCOVA test by removing the effects of age, gender and the baseline levels of Ni and Cr showed that changes in these ions in the scalp hair of both groups after one year were statistically significant. CONCLUSION: Due to the slightly elevated levels of Ni and Cr ions in the scalp hair of patients treated with fixed orthodontic appliances and considering the cytotoxic and allergic effects of these ions, changing the ingredients in fixed orthodontic appliances is suggested for the future.

Demonstrating PM2.5 and road-side dust pollution by heavy metals along Thika superhighway in Kenya, sub-Saharan Africa.

This study assessed the level of heavy metal in roadside dust and PM2.5 mass concentrations along Thika superhighway in Kenya. Thika superhighway is one of the busiest roads in Kenya, linking Thika town with Nairobi. Triplicate road dust samples collected from 12 locations were analysed for lead (Pb), chromium (Cr), cadmium (Cd), nickel (Ni), zinc (Zn), and copper (Cu) using atomic absorption spectrophotometry (AAS). PM2.5 samples were collected on pre-weighed Teflon filters using a BGI personal sampler and the filters were then reweighed. The ranges of metal concentrations were 39-101 µg/g for Cu, 95-262 µg/g for Zn, 9-28 µg/g for Cd, 14-24 µg/g for Ni, 13-30 µg/g for Cr, and 20-80 µg/g for Pb. The concentrations of heavy metals were generally highly correlated, indicating a common anthropogenic source of the pollutants. The results showed that the majority of the measured heavy metals were above the background concentration, and in particular, Cd, Pb, and Zn levels indicated moderate to high contamination. Though not directly comparable due to different sampling timeframes (8 h in this study and 24 h for guideline values), PM2.5 for all sites exceeds the daily WHO PM2.5 guidelines of 25 µg/m3. This poses a health risk to people using and working close to Thika superhighway, for example, local residents, traffic police, street vendors, and people operating small businesses. PM2.5 levels were higher for sites closer to Nairobi which could be attributed to increased vehicular traffic towards Nairobi from Thika. This study provides some evidence of the air pollution problem arising from vehicular traffic in developing parts of the world and gives an indication of the potential health impacts. It also highlights the need for source apportionment studies to determine contributions of anthropogenic emissions to air pollution, as well as long-term sampling studies that can be used to fully understand spatiotemporal patterns in air pollution within developing regions.

Correlation of lithium levels between drinking water obtained from different sources and scalp hair samples of adult male subjects.

There is some evidence that natural levels of lithium (Li) in drinking water may have a protective effect on neurological health. In present study, we evaluate the Li levels in drinking water of different origin and bottled mineral water. To evaluate the association between lithium levels in drinking water with human health, the scalp hair samples of male subjects (25-45 years) consumed drinking water obtained from ground water (GW), municipal treated water (MTW) and bottled mineral water (BMW) from rural and urban areas of Sindh, Pakistan were selected. The water samples were pre-concentrated five to tenfold at 60 °C using temperature-controlled electric hot plate. While scalp hair samples were oxidized by acid in a microwave oven, prior to determined by flame atomic absorption spectrometry. The Li content in different types of drinking water, GW, MTW and BMW was found in the range of 5.12-22.6, 4.2-16.7 and 0.0-16.3 µg/L, respectively. It was observed that Li concentration in the scalp hair samples of adult males consuming ground water was found to be higher, ranged as 292-393 µg/kg, than those who are drinking municipal treated and bottle mineral water (212-268 and 145-208 µg/kg), respectively.

Statistical analysis of arsenic contamination in drinking water in a city of Iran and its modeling using GIS.

In this research, probable arsenic contamination in drinking water in the city of Ardabil was studied in 163 samples during four seasons. In each season, sampling was carried out randomly in the study area. Results were analyzed statistically applying SPSS 19 software, and the data was also modeled by Arc GIS 10.1 software. The maximum permissible arsenic concentration in drinking water defined by the World Health Organization and Iranian national standard is 10 µg/L. Statistical analysis showed 75, 88, 47, and 69% of samples in autumn, winter, spring, and summer, respectively, had concentrations higher than the national standard. The mean concentrations of arsenic in autumn, winter, spring, and summer were 19.89, 15.9, 10.87, and 14.6 µg/L, respectively, and the overall average in all samples through the year was 15.32 µg/L. Although GIS outputs indicated that the concentration distribution profiles changed in four consecutive seasons, variance analysis of the results showed that statistically there is no significant difference in arsenic levels in four seasons.

Scalp hair and blood cadmium levels in association with chewing gutkha, mainpuri, and snuff, among patients with oral cancer in Pakistan.

BACKGROUND: It has been reported that smokeless tobacco (SLT) chewing can lead to caners of oral cavity. In this study, the relationship between cadmium exposure via consumption of different SLT products by patients with oral cancer with related to referents belongs to different cities of Pakistan are investigated. METHODS: The cadmium in different types of SLT products (gutkha, mainpuri and snuff) consumed by studied population and biological samples (scalp hair and blood) of cancerous and healthy subjects were analyzed. Both referents and patients with cancer have same age group (ranged 30-60 years), socioeconomic status, localities, and dietary habits. The concentrations of cadmium in SLT products and biological samples were measured by electrothermal atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by certified reference materials. RESULTS: It was estimated that 10 g intake of different types of gutkha, mainpuri, and snuff could contribute, 18-40%, 15.7-33.6%, and 14-68% of the provisional maximum tolerable daily intake of cadmium, respectively for adults (60 kg). The results of present study showed that the mean value of cadmium was significantly higher in scalp hair and blood samples of patients with oral cancer as compared to those results obtained for referents (P < 0.001). CONCLUSIONS: The high exposure of cadmium due to consuming different SLT products may have synergistic effects with other risk factors associated for oral cancer.

Occupational lead toxicity in battery workers.

OBJECTIVE: To estimate blood lead level (BLL) and to assess the features of lead toxicity among lead acid battery (LAB) industrial workers. METHODS: This prospective study was carried out in the medical centre of PCSIR Laboratories, Karachi from March 2012 - March 2013. Fifty LAB industry workers, males and females between 17-65 years were included in the study. They were divided into group 1 with 40 workers- directly related and group 2 with 10 workers -indirectly related, (administration staff members) to LAB manufacture. Detailed history, complete physical examination and BLL estimation by flameless atomic absorption spectrophotometer was done. RESULTS: Total 34 patients in group 1 and 3 patients in group 2 had elevated BLL. Comparison of group 1 and 2 revealed anemia (40v/s4), bone pain (38v/s7), abdominal pain (38 v/s 2), nausea (32v/s6), head ache & irritability (24v/s6), weakness & lethargy (21v/s6), tremors (13v/s0) insomnia (5v/s4), lead line (4v/s 0) and blood pressure above 140/90 mm of Hg (12v/s0) respectively. CONCLUSION: High blood lead level and features attributable to lead toxicity were prevalent among LAB industry workers of Karachi.

Rapid and sensitive in situ detection of heavy metals in fish using enhanced Raman spectroscopy.

Heavy metals have been widely applied in industry, agriculture, and other fields because of their outstanding physics and chemistry properties. They are non-degradable even at low concentrations, causing irreversible harm to the human and other organisms. Therefore, it is of great significance to develop high accuracy and sensitivity as well as stable techniques for their detection. Raman scattering spectroscopy and atomic absorption spectrophotometer (AAS) were used parallelly to detect heavy metal ions such as Hg, Cd, and Pb of different concentrations in fish samples. The concentration of the heavy metals is varied from 5 ppb to 5 ppm. Despite the satisfactory recoveries of AAS, their drawbacks are imperative for an alternative technique. In Raman scattering spectroscopy, the intensities and areas of the characteristic peaks are increased with increasing the concentration of the heavy metals. For Hg concentration ≥ 1 ppm, a slight shift is observed in the peak position. The obtained values of peak intensity and peak area are modeled according to Elvoich, Pseudo-first order, Pseudo-second order, and asymptotic1 exponential model. The best modeling was obtained using the Elovich model followed by the asymptotic1 exponential model. The introduced Raman spectroscopy-based approach for on-site detection of trace heavy metal pollution in fish samples is rapid, low-cost, and simple to implement, increasing its visibility in food safety and industrial applications.

Chemical speciation and comprehensive risk assessment of metals in sediments from Nabq protectorate, the Red Sea using individual and synergistic indices.

The study evaluates metal concentrations, distributions, contamination, risk, sources, fractionation, and mobility in Nabq Protectorate sediments, revealing a metal content order of Fe, Mn, Pb, Ni, and Cd. Metals are dominated by residual fractions, with Cd (83.70 %) > Ni (82.98 %) > Pb (80.96 %) > Fe (80.31 %) > Mn (76.65 %) reflecting the natural sources of investigated metals. Mn (23.35 %) was the most abundant mobile metal, and the sediments of the protectorate had low toxicity and moderate risk according to the synergistic indices (1 ≤ mRAC<10 and ERM; 5-10). The results from the proposed individual indices showed that Mn, Fe, and Pb are the most bioavailable (BIM 0.1-0.4), Cd, Mn, Ni, Fe, and Pb are of moderate mobility (MIM 0.1-0.4), and Cd is the most available (ARIM 5-10), with Cd posing the most ecological risk. The total hazard quotient (THQ) for child was greater than one, exposure to manganese through ingestion and skin contact while swimming may endanger human health.

Assessment of heavy metals migrated from food contact plastic packaging: Bangladesh perspective.

Plastic-based food-contact materials are potentially threatening the environment and public health by releasing toxic heavy metals. This study aimed to identify the types of plastic commonly used in Bangladesh as food-contact materials (FCMs) and assess the migration of heavy metals from these FCMs. Plastic types were identified using attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR), and 25 samples were selected based on the category, including Polyethylene Terephthalate (PET), Polyethylene (PE), Polypropylene (PP), Polystyrene (PS), and Polycarbonate (PC). Distilled water, 3% acetic acid, and 15% ethanol were used as food simulants to assess the overall migration of chemicals at 70 °C for 2 h. The concentrations of heavy metals (Pb, Cd, Hg, Cr, and Sb) were analyzed using an Atomic Absorption Spectrophotometer (AAS). Results revealed that the highest overall migration occurred in coffee cups measuring 3.50 ± 0.17 mg/kg (using water simulant) and in yogurt containers with a measurement of 9.17 ± 0.1 mg/kg (using 3% acetic acid). The highest concentrations of Pb, Cd, Hg, Cr, and Sb were found in PP-2 (0.45 ± 0.01 mg/kg), PP-2 (0.36 ± 0.01 mg/kg), PC-5 (0.27 ± 0.01 mg/kg), PET-2 (0.12 ± 0.01 mg/kg), and PET-1 (0.09 ± 0.01 mg/kg), respectively. The concentration of heavy metals migrated from the containers is likely to induce a health risk due to bioaccumulation from long-term ingestion of food packaged in them. The findings of this study added knowledge about harmful heavy metals leached from the FCMs in Bangladesh.

Quantification of Calcium Ions From the Irrigants Activated With Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) Laser in the Root Dentin: An In Vitro Atomic Absorption Spectrophotometer Study.

OBJECTIVE: The present study aims to assess the quantity of calcium cation eliminated from the root canal by 0.2% chitosan nanoparticles (CNPs) (Sigma Aldrich, Mumbai, Maharashtra, India) and 17% ethylenediaminetetraacetic acid (EDTA) (Pyrax 17% EDTA Solution, Pyrax Polymars, Roorkee, Haridwar, Uttarakhand, India) which are activated with an erbium-doped yttrium aluminum garnet (Er:YAG) laser (LiteTouch™, Light Instruments Ltd., Yokneam Elite, Israel) for smear layer removal using a flame atomic absorption spectrophotometer (AASF) (Deeksha Analytical Pvt Ltd, Gokula Extension, Bengaluru, Karnataka, India). METHODOLOGY: Using the crown-down technique, 60 non-carious single-rooted premolars were instrumented with rotary files and irrigated with 3% sodium hypochlorite. Based on the type of irrigation activation used, all the specimens were arbitrarily divided into five groups with 12 teeth in each group, as follows: G1, 17% EDTA activated with Er:YAG laser; G2, 17% EDTA without laser activation; G3, 0.2% CNP activated with Er:YAG laser; G4, 0.2% CNP without laser activation; and G5, controlled-deionized water. The AASF analysis for the removal of calcium ions in the irrigants was evaluated by collecting the overall quantity of each irrigating solution from the root canals. A one-way analysis of variance (ANOVA) and a Tukey post hoc test were done to determine the AASF data. RESULTS: 17% EDTA activated with Er:YAG laser (130.18 ± 10.3) and 0.2% CNP activated with Er:YAG laser (121.13 ± 3.9) showed the greatest concentration of calcium ions with no statistically significant difference. The lowest concentration of calcium ions was observed in 0.2% CNPs without laser activation (118.64 ± 2.9), while 17% EDTA (125.50 ± 3.0) without laser activation showed an intermediate outcome. The control group did not remove any calcium ions. CONCLUSION: The findings in the present study suggest that EDTA and CNPs, which were activated with lasers, yielded the greatest release of calcium ions equally. Hence, laser-activated CNPs can be employed for essential smear layer removal.

Impacts of Smoking and Stomach Disorders on Essential Elements in Biological Samples of Cement and Glass Industrial Workers.

The infection caused by Helicobacter pylori (H. pylori) disrupts the metabolism and absorption of essential trace elements. Stomach disorders are related to changes in essential trace element metabolism caused by increased toxic metal exposure and H. pylori infection. The aim of the work is to link the development of stomach-related illnesses to an imbalance of essential trace and toxic metals. We have investigated the variations in essential trace elements such zinc (Zn), iron (Fe), and copper and toxic metals like lead (Pb) and cadmium (Cd) in biological (scalp hair, blood) samples of glass and cement workers. The study participants are further divided into smokers and nonsmokers, as well as diseased (gastric ulcer, irritable bowel syndrome, and chronic ulcer) and exposed referents (non-diseased industrial workers). Biological samples of age-matched (40-60 years) male subjects living in non-industrial areas were gathered for comparative purposes. After a pre-concentration method, the drinking water of industrial and domestic areas was analysed for both toxic metals. Microwave-aided acid digestion was used to oxidise the matrices of biological samples before atomic absorption spectrometer analysis of selected metals. Toxic metal levels in both industries' drinking water were much higher than those found in domestically treated water (p < 0.01). Industrial workers suffering different types of stomach disorders have two to three times higher Pb and Cd concentrations than age-matched referents. Toxic metals are found in higher concentrations in smoker referents and diseased patients' biological samples than in nonsmoker subjects. The findings of this study suggested that Pb and Cd toxicity's immunological effects may be associated to an increased vulnerability to chronic infections.

Heavy metals in hair and nails as markers of occupational hazard among welders working in United Arab Emirates.

Studies have shown that hair and nail samples can be used as a marker to assess occupational exposure to heavy metals. The objective of this study was to estimate the levels of heavy metals: Lead (Pb), Nickel (Ni), Cadmium (Cd), and Manganese (Mn) in hair and nail samples of welders working in United Arab Emirates and to find an association between the heavy metal concentration with the parameters like smoking habits, exposure/day, years of experience and use of protective personal equipment (PPE). Hair and toes nail samples were collected from exposed and non-exposed subjects with respect to, social habits, exposure/day and years of welding experience. The levels of Pb, Cd, Mn, and Ni, in hair and toenails, assayed by atomic absorption spectrophotometer. We observed that the metal concentration was higher in toenail as compared to hair samples in both the groups. Cd was significantly high in both the groups whereas, Mn in the hair was high in the exposed group. The Mn in hair was notably higher among smokers and the Cd in hair and Ni in the nail samples was significantly higher in the subjects with > 8 h/day exposure. The concentration of Cd and Ni in hair increased with increasing years of experience and was maximum in the subjects with welding experience of > 20 years. Our results signify that hair and nail samples can be used as an indicator to heavy metal exposure. Given that the present study shows high level of some metals in the hair and nail of welders, awareness of occupational hazards and annual assessment of welder's health is necessary.