Cold Vapor Atomic Absorption Spectrometer Research Articles

The levels of mercury (Hg) and arsenic (As) in wild boar’s liver (Sus scrofa) in eleven hunting areas from the Republic of North Macedonia

The monitors have recently been defined as the organisms in which changes in known characteristics can be measured to assess the extent of the environmental contamination. Among the numerous game species, the wild boar as omnivore is characterized as an exceptionally good biomonitor. The concentrations of one heavy metal (Hg) and one metalloid (As) were measured using cold vapor atomic absorption spectrometer and atomic absorption spectrophotometry in the liver tissue of free-living wild boars. From 11 hunting areas locations that cover the whole territory of North Macedonia in a period of 7 years (2016-2022) a total of 608 wild boar liver samples were harvested during the regular hunting season. The mean concentration of Hg from 11 hunting grounds ranged from 12.7 μg/kg to 68.8 μg/kg, and mean concentration for all was 45.67 μg/kg. The average concentration of As ranged from 22 μg/kg to 55.3 μg/kg, and mean concentration for all was 33.1 μg/kg. For mercury, 6.56% or 40 of the total number of samples (608) exceeded the maximum allowed limits, and for arsenic none of the examined samples exceeded the allowed limit. For both elements a statistically significant difference was determined in relation to the years, with irregular oscillations from year to year. The mean values for mercury and arsenic are encouraging and generally indicate the relatively low contamination in the territory of the Republic of North Macedonia. However, the statistical differences due to the year as a factor suggest there is the need for the further research.

A new magnetic metal–organic framework composite synthesized via a post-synthetic functionalization approach for ultra-trace extraction/determination of mercury in real matrixes

Herein, a novel magnetic metal–organic framework (MMOF) composite was prepared via a post-synthetic modification method was employed to the ultra-trace determination of mercury in food samples. At first, magnetite nanoparticles were fabricated and afterward functionalized with a SiO2 layer (MNPs@silica). After that, MIL-101(Fe) as a MOF was synthesized in the presence of MNPs@silica to obtain magnetic MIL-101 (MMIL-101). Finally, MMIL-101(Fe) was functionalized with dithizone as a chelator via diazonation reaction. The nanomaterial fabrication was approved by diverse techniques including, SEM, EDX-mapping, TEM, XRD, FT-IR, VSM, BET, and CHNS. Optimizing of affecting experimental factors on the extraction process was conducted via a Box-Behnken design approach. Determination of the mercury ions was conducted by a cold vapor atomic absorption spectrometer. The LOD and LOQ values were 0.015 µg kg−1 and 0.045 µg kg−1, respectively, and the method's repeatability as RSD% was evaluated for 1.0, 20, and 50 ng mL−1 standard solutions (n = 5), which were 10.1, 7.6, and 4.8 %, respectively. The new method was validated by analyzing a CRM. The maximum adsorption capacity of 213 mg g−1 was obtained, and the preconcentration factor was 316. Finally, the fabricated nanomaterials was successfully utilized to the separation/quantification of mercury in diverse food samples, and satisfactory results were obtained (RSD, 5.9–10.2 %; recovery, 82–112 %).

Determination of mercury values in urine and air of chloralkali workers by copper nanoparticles functionalized in carboxylic carbon nanotubes and the effects of mercury exposure on oxidative stress

Mercury exposure can produce toxic organic compounds in the body. Also, mercury can potentially cause oxidative damage and cellular disorders. In this study, the determination of mercury values in urine and air of chloralkali workers based on copper nanoparticles functionalized in carboxylic carbon nanotubes (CuNPs@CNT-COOH) were obtained by cold vapor atomic absorption spectrometer (CV-AAS). The urine samples were determined by magnetic solid-phase extraction (MSPE) at pH 8.0. By measuring the mercury level in the air and the urine sample of workers, the level of oxidative stress (Malondialdehyde (MDA), Superoxide Dismutase (SOD) and Catalase (Cat)), Interleukin-6 (IL-6), and Tumor Necrosis Factor α (TNF-α) as the proinflammatory cytokines were measured in the subject group. The results revealed statistically significant differences in the mercury level of the urine samples in the case and control groups (p<0.001). Similarly, the malondialdehyde (MDA) level was significantly different between the two research groups (p<0.001). Catalase concentration was not significantly different in the two groups (p=0.059). The LOD and linear range for mercury determination in urine were achieved at 0.012 µg L−1 and 0.05-7.0 µg L−1, respectively. Workers’ exposure to mercury can significantly increase oxidative stress and inflammatory cell signaling molecules such as cytokines.

Novel bimetallic nano particles for sorption of mercury (II) from drinking water: Adsorption experiment and computational studies

The current study proposes fabrication of novel manganese and copper (Mn/Cu) based bimetallic nano particles (NPs) for adsorptive removal of mercury (Hg) ions from aqueous media and examines computational models for adsorption. The Mn/Cu bimetallic NPs were characterized for Atomic Force Microscope (AFM), Energy Dispersive X-rays Spectroscopy (EDS), X-Ray Diffraction (XRD) and Dynamic Light Scattering (DLS) techniques to investigate morphology, surface elemental composition and particle size analysis. Sorption of Hg was carried out using batch experiments in triplicate and residual Hg concentration after sorption was determined using cold vapor atomic absorption spectrometer (CV-AAS). The effect of various parameters such as pH, mass of nano particles, Hg concentration and contact time were optimized. Maximum removal efficiency was 95 % with 2.89 % RSD and maximum adsorption capacity (Q max) observed was 400 mg g-1. AFM images well separated morphology and mean grain size of 450 ± 50 nm of particles, DLS measured average particles size as 110 nm while XRD pattern and EDS results showed successful adsorption of Hg on Mn/Cu bimetallic surface. Ab initio based computational models for different geometries were optimized using semi empirical method through Gaussian software. Computational molecular models were optimized for structures before and after Hg sorption and important physical parameters such as electron spin, Root mean square (RMS) gradient, Adsorption energy, Mulliken charge density (Q) and bond lengths (BL) before and after adsorption were computed. It was concluded that Langmuir adsorption isotherm was favorable for this study and interaction of Hg was more favorable with Mn than Cu because of less adsorption energy (-112.48 eV) and stronger bond formation between them having bond length of 1.6433 Å.

Assessment of heavy metals content and consumer health risk to Siganus fuscescens (Houttuyn, 1782) from Quang Binh province

Siganus fuscescens Houttuyn, 1782 is one of the common fish species in Quang Binh province and consumers are favored by its high nutritional value. However, the consumption of Siganus fuscescens may pose potential risks to human health since they can accumulate significant amounts of heavy metals in their tissues. From July to October 2019, a total of 50 individuals of Siganus fuscescens were randomly collected through fishermen at local markets in Quang Binh province. Liver, gills, and muscles were dissected and analyzed for cadmium, lead, copper, zinc, and iron contents by the flame atomic absorption spectrometer, and the cold vapor atomic absorption spectrometer for mercury content. The metal content in all tested samples was lower than the threshold limit value by the Vietnamese Ministry of Health (MoH). The risk to human health by the intake of metal contaminated Siganus fuscescens was evaluated by estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI). All the EDI values were below the provisional tolerable daily intake (PTDI) set by the MoH, and all of THQ and HI values for male and female consumers did not exceed 1, indicating that there was no potential human health risk in consuming Siganus fuscescens from coastal areas of Quang Binh province.

A new dendrimer-functionalized magnetic nanosorbent for the efficient adsorption and subsequent trace measurement of Hg (II) ions in wastewater samples

A new dendrimer-functionalized magnetic nanosorbent for the efficient adsorption and subsequent trace measurement of Hg (II) ions in wastewater samples was successfully synthesized. The synthesis is accomplished via the Michael addition reaction of the amino groups of the silica-coated magnetic nanoparticles (APTES-modified Fe3O4@SiO2) with the double bond of methyl acrylate followed by the amidation of the resulting methyl ester with ethylene diamine. Following that, some donor functional groups were attached to the dendrimer via a specific chemical reaction to offer a further selectivity to the dendrimer-based nanosorbent. Once the synthesis is accomplished, the as-prepared nanosorbent was characterized by several analytical techniques such as FT-IR, SEM, VSM, TGA and EDX. Following that, Hg (II) ions were adsorbed onto the active sites of the sorbent through the complexation with the dentates (-N, -S) of the dispersed sorbent, which seems to be the cornerstone of the adsorption process. In the next step, the ions were desorbed off the sorbent and measured by a cold vapor atomic absorption spectrometer (CV-AAS). The impact of a number of influential variables such as pH, sorbent dosage, adsorption time, elution features were assessed and subsequently optimized. Under the optimal conditions, a relatively wide linearity was obtained for the analyte of interest in the range of 0.08–6.0 μg/L with the correlation coefficients (R2) of 0.9922 and the method detection limit (MDL) was determined to be 0.03 μg/L. Satisfactory relative recoveries of the analyte varied within 90.0–106.7% with the relative standard deviations (RSD%) of 2.1–5.3%. In addition, a number of experiments with regard to the equilibrium adsorption isotherms of the target ion was performed which well fitted to the Langmuir isotherm model. Finally, the results indicated that the whole method was sensitive, effective and practical for the adsorption and trace measurement of Hg (II) in wastewater samples.

Application of a new N,S-containing silica-coated nanomagnetic sorbent for the trace quantification of Hg(II) ions in aquatic samples: evaluation of adsorption mechanism

Herein, an effective µ-dispersive solid-phase extraction (µ-dSPE) for the adsorption of Hg(II) ions from various water samples was implemented using a N,S-containing silica-coated nanomagnetic sorbent (Fe3O4@SiO2-N/S). Initially, the sorbent was synthesized via N-substituted amide reaction followed by the characterization by several analytical techniques such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), vibrating sample magnetometer (VSM) and X-ray diffraction (XRD). After that, Hg(II) ions interacted with the dentate (N,S) of the dispersed sorbent, which seems to be the cornerstone of the extraction concept. Then, Hg(II) ions were desorbed off the sorbent and quantified by a cold vapor atomic absorption spectrometer (CV-AAS). A number of influential factors impacting the analyte extraction/desorption efficiency were fully investigated, and subsequently, the optimal conditions were established. Under the optimal conditions, the calibration curve was linear over the concentration range of 0.1–5.0 µg L−1, and based on a signal-to-noise ratio of 3 (S/N = 3), the method detection limit was determined to be 0.05 µg L−1 for the analyte of interest. The µ-dSPE method was applied for the determination of Hg(II) in various fortified real aquatic samples to test its performance. The average relative recoveries obtained from the fortified water samples varied in the range of 93–107% with the relative standard deviations of 2.8–6.4%. In addition, an investigatory approach regarding the equilibrium adsorption isotherms of the target ion was performed which fitted best to the Langmuir isotherm model. Finally, the method is assumed to have a great potential to be implemented in environmental/other laboratories for the monitoring trace level of Hg(II) ions.

Selenium functionalized magnetic nanocomposite as an effective mercury (II) ion scavenger from environmental water and industrial wastewater samples

A novel core-shell magnetic-selenium nanocomposite (Fe3O4@SiO2@Se) was synthesized for fast and effective removal of Hg (II) ions from various industrial and environmental water samples. The composition, property, and structure of Fe3O4@SiO2@Se were characterized by spectral and microscopic techniques. The key parameters affecting the removal were evaluated and optimized. The concentration of residual Hg (II) ions in the solution was measured using a cold vapor atomic absorption spectrometer. At pH = 3.0, Fe3O4@SiO2@Se was capable to remove Hg (II) ions ranged from 100 μg L−1 to 10 mg L−1 within 20 min with the efficiency of approximately 99% in a way that residual concentration levels matched international standards. This level of removal efficiency was well maintained up to salinity of 25 g L−1. Kinetic investigations revealed compliance with a second-order kinetic model. The linear regression coefficient suggested the adsorption of Hg (II) ions by the adsorbent followed the Langmuir isotherm model (R2 > 0.997). The maximum capacity of the adsorbent obtained through investigating the isotherms was 70.42 mg g−1. The Fe3O4@SiO2@Se adsorbent effectively removed the Hg (II) ions spiked to different samples, including tap water, river water, seawater, and industrial wastewater. Therefore, this nano-adsorbent can be used as a good alternative for Hg (II) removal, in practical applications.

Application of the Quartz Crystal Microbalance Method for Measuring Mercury in the Air of Working Environments Involved to Artisanal and Small-scale Gold Mining (ASGM).

Artisanal small gold mining (ASGM) is responsible for approximately 40% of the total Hg emissions into the atmosphere worldwide. In developing countries, many people are engaged in ASGM activities. We developed a small, simple Hg measuring device, which detects Hg in the air based on the change of the oscillation frequency of an Au electrode on a quartz crystal microbalance (QCM). This device is called QCM-Hg. We tested the viability of the QCM-Hg in various work settings including a gold mining area and gold shops. In working environments with an airborne Hg concentration of several μg m-3, the changing rate of the oscillation frequency for either 2 or 3 min corresponded with the Hg concentrations measured using the conventional method of gold amalgamation and cold vapor atomic absorption spectrometer (CVAAS). The results revealed that the QCM-Hg is a useful device for real-time Hg monitoring in actual working environments related to ASGM activities and Hg treatment facilities.

Air pollution Analysis: Nickel paste on Multi-walled carbon nanotubes as novel adsorbent for the mercury removal from air

Mercury as a hazardous material caused health problem in humans.In this study,mercury vapor removed from air by nickel-coated on multi-walled carbon nanotubes(Ni-MWCNTs)as a novel sorbent.Amalgamation of mercury with Ni-MWCNTs was achieved by solid-gas phase removal method(SGPR).In bench scale set up, the mercury vapor generated and moved to sorbent at optimized flow rate.After thermal desorption of Ni-MWCNTs at 200oC, the mercury vapor flowed to quartz glass cell with argon gas and determined by cold vapor atomic absorption spectrometer technique(CV-AAS).In optimized conditions,25 mg of Ni-MWCNTs and MWCNTs with different size from 30-100nm was used.The adsorption capacity of sorbents was obtained 194 mg g-1 and 64 mg g-1,respectively.The efficient recovery was obtained at optimized conditions such as, temperature of 25-40 and flow rate of 200 mL min-1.So, Ni-MWCNTs had good potential for removal of mercury vapor from the air and can be used as a low cost and efficient sorbent in industrial workplace

Prenatal Exposure to Polychlorinated Biphenyls and Mercury Are Associated with Insulin-Like Growth Factor 1 and Thyroid-Stimulating Hormone in Cord Plasma

Impact on maternal endocrine system during pregnancy may also affect growth and development of a fetus. Certain toxic elements and polychlorinated biphenyls (PCBs) are known to disturbe human endocrine system. In our previous study, we showed that birth weight were affected by prenatal PCBs and methylmercury exposure. In this study, we used the data from the Tohoku Study of Child Development in Japan. The objective of the study was to evaluate the effect of prenatal exposure to methylmercury, arsenic, cadmium, lead, and PCBs on insulin-like growth factor 1 (IGF-1) and thyroid related hormones (TSH, T3, freeT3, T4 and freeT4) in cord blood. Those factros are considered to be associated with fetal growth. Elements except for mercury were analyzed by an inductivity coupled plasma mass spectrometry. Mercury levels were measured using a cold vapor atomic absorption spectrometer. IGF-1 and insulin-like growth factor binding protein 1 (IGFBP1) were detemined by an enzyme-linked immunosorbent assay (ELISA). Thyroid related hormones were assessed by an electrochemiluminescence immunoassay. The data were examined by Pearson’s correlation and multiple regression analyses. The IGF-1 in cord plasma was negatively associated with PCB concentrations in cord blood, especially with tri-, tetra-, penta-, hexa- and hepta-chlorobiphenyls. Cord plasma free T4 was negatively associated with mercury concentrations in cord blood. This study indicated PCBs and mercury could affect birth weight through altering the IGF1 and T4 mechanism. Further studies are necessary to investigate the effect of decrease in IGF-1 and thyroid hormones on birth weight.

Urinary Mercury Levels Among Workers in E-waste Shops in Nakhon Si Thammarat Province, Thailand.

ObjectivesTo determine urinary mercury levels in e-waste workers in Southern Thailand and the airborne mercury levels in the e-waste shops where they worked, to describe the associations between urinary and airborne mercury levels, and to evaluate the prevalence of mercury exposure-related health effects among e-waste workers.MethodsA cross-sectional study was conducted by interviewing 79 workers in 25 e-waste shops who lived in Nakhon Si Thammarat Province, Thailand. Information on general and occupational characteristics, personal protective equipment use, and personal hygiene was collected by questionnaire. Urine samples were collected to determine mercury levels using a cold-vapor atomic absorption spectrometer mercury analyzer.ResultsThe e-waste workers’ urinary mercury levels were 11.60±5.23 μg/g creatinine (range, 2.00 to 26.00 μg/g creatinine) and the mean airborne mercury levels were 17.00±0.50 μg/m3 (range, 3.00 to 29.00 μg/m3). The urinary and airborne mercury levels were significantly correlated (r=0.552, p<0.001). The prevalence of self-reported symptoms was 46.8% for insomnia, 36.7% for muscle atrophy, 24.1% for weakness, and 20.3% for headaches.ConclusionsPersonal hygiene was found to be an important protective factor, and should therefore be stressed in educational programs. Employers should implement engineering measures to reduce urinary mercury levels and the prevalence of associated health symptoms among e-waste workers.

Distribution of total mercury in surface sediments and African catfish (Clarias gariepinus) from Akaki River catchment and Aba Samuel Reservoir, downstream to the mega-city Addis Ababa, Ethiopia

Abstract Total mercury (THg) levels were determined in sediment (n = 22) and muscle of Clarias gariepinus (n = 36) in dry and rainy seasons from Akaki River catchment and Aba Samuel Reservoir, Ethiopia in 2016-2017. The analyses of THg were performed using cold vapor-atomic absorption spectrometer (CV-AAS) after acid digestion technique. The relationship of THg levels to size of the fish has also been investigated. The THg levels in sediments range from 9.5–43.8 mg/kg dry wt in the dry and 20.6–175.4 mg/kg dry wt in the rainy seasons. This study indicated that the levels of THg in sediments varies spatially and seasonally. In both seasons, THg levels increased from upstream to downstream areas, revealing increased anthropogenic inputs of mercury pollution. It was also found that the THg concentrations in all the sediment samples were below the US EPA guideline value of 200 mg/kg dry wt. The THg levels in Clarias gariepinus were in the range from 360–924 mg/kg dry wt in the dry and 325–1233 mg/kg dry wt in the rainy seasons, and had positive relationship to the total length and body weight. The THg concentrations found in Clarias gariepinus were within the acceptable guidelines of the FAO/WHO. Therefore, the muscle of Clarias gariepinus from the study area is not hazardous to human health with respect to mercury. However, the average value of THg seems to be slightly higher than results reported from other Ethiopian freshwater bodies. Thus, monitoring of mercury species in sediment and different organs of fish are strongly recommended.

Evaluation of mercury and physicochemical parameters in different depths of aquifer water of Thar coalfield, Pakistan.

In the current study, mercury (Hg) and physicochemical parameters have been evaluated in aquifer water at different depths of Thar coal field. The water samples were collected from first aquifer (AQ1), second aquifer (AQ2), and third aquifer (AQ3) at three depths, 50-60, 100-120, and 200-250m, respectively. The results of aquifer water of three depths were interpreted by using different multivariate statistical techniques. Validation of desired method was checked by spiking standard addition method in studied aquifer water samples. The content of Hg in aquifer water samples was measured by cold vapor atomic absorption spectrometer (CV-AAS). These determined values illustrate that the levels of Hg were higher than WHO recommended values for drinking water. All physicochemical parameters were higher than WHO permissible limits for drinking water except pH and SO42- in aquifer water. The positive correlation of Hg with other metals in aquifer water samples of AQ1, AQ2, and AQ3 of Thar coalfield except HCO3- was observed which might be caused by geochemical minerals. The interpretation of determined values by the cluster technique point out the variations within the water quality parameter as well as sampling location of studied field. The aquifer water AQ2 was more contaminated with Hg as compared to AQ1 and AQ3; it may be due to leaching of Hg from coal zone. The concentration of Hg in aquifer water obtained from different depths was found in the following decreasing order: AQ2<AQ1<AQ3.

The Mesoporous Porphyrinic Zirconium Metal-Organic Framework for Pipette-Tip Solid-Phase Extraction of Mercury from Fish Samples Followed by Cold Vapor Atomic Absorption Spectrometric Determination

In this study, the highly stable mesoporous porphyrinic zirconium metal-organic framework, namely PCN-222/MOF-545 (Zr-MOF), was prepared and used for pipette-tip solid-phase extraction of Hg(II). As a high-capacity sorbent, 4 mg of the Zr-MOF was placed into a conventional pipette tip and used, for the first time, for the fast extraction and preconcentration of mercury ions. For desorption, 50 μL of 10% HCl was used by 15 repeated aspirating/dispensing cycles, and Hg ions in elusion were measured by a cold vapor atomic absorption spectrometer. Affecting parameters on extraction efficiency were studied, and optimum conditions were established as amount of sorbent 2 mg, pH was adjusted to 5.0, the eluting volume was 15 μL, and extraction was performed on 1.8 mL of the sample. The optimal number of aspirating/dispensing cycles for extraction and desorption of analytes was found to be 10 and 15 cycles, respectively. The limit of detection of the method was found to be 20 ng L−1 with a relative standard deviation of ≤3.1% (for seven replicate analyses of 20 μg L−1 of mercury). Adsorption capacity and enrichment factor were 35.5 mg g−1 and 120-fold, respectively. The proposed method was successfully applied for the determination of Hg(II) ions in fish samples.

Chromatic analysis by monitoring unmodified silver nanoparticles reduction on double layer microfluidic paper-based analytical devices for selective and sensitive determination of mercury(II)

This study demonstrates chromatic analysis based on a simple red green blue (RGB) color model for sensitive and selective determination of mercury(II). The analysis was performed by monitoring the color change of a microfluidic Paper-based Analytical Device (µPAD). The device was fabricated by using alkyl ketene dimer (AKD)-inkjet printing and doped with unmodified silver nanoparticles (AgNPs) which were disintegrated when being exposed to mercury(II). The color intensity was detected by using an apparatus consisting of a digital camera and a homemade light box generating constant light intensity. A progressive increase in color intensity of the tested area on the µPAD (3.0mm) was observed with increasing mercury(II) concentration. The developed system enabled quantification of mercury(II) at low concentration with the detection limit of 0.001mgL−1 (3 SD blank/slope of the calibration curve) and small sample volume uptake (2µL). The linearity range of the calibration curve in this technique was demonstrated from 0.05 to 7mgL−1 (r2=0.998) with good precision (RSD less than 4.1%). Greater selectivity towards mercury(II) compared with potential interference ions was also observed. Furthermore, the percentage recoveries of spiked water samples were in an acceptable range which was in agreement with the values obtained from the conventional method utilizing cold vapor atomic absorption spectrometer (CVAAS). The proposed technique allows a rapid, simple, sensitive and selective analysis of trace mercury(II) in water samples.

The evaluation of sequentially extracted mercury fractions in Thar coal samples by using different extraction schemes

In the present study, various sequential extraction methods were applied to assess the mercury (Hg) contents bounded with different chemical fractions of coal samples, collected from four different seams of the blocks III and V in Thar coalfield, Pakistan. The BCR sequential extraction (BCR-SE) method and two alternative modified schemes (conventional and ultrasonic assisted single step extractions) were designed and applied on the same operating conditions for each individual BCR fraction. Proximate and elemental analyses of coal samples were also performed to point out the physicochemical characteristics of the Thar coal samples. Validation of the desired methodologies was checked by the standard addition method to the real coal samples. The Hg concentration in extractable fractions was determined by cold vapor atomic absorption spectrometer (CV-AAS). The proposed conventional (CSE) and ultrasonic assisted single step (USE) extraction methods were non-tedious and time saving, as the extraction time was reduced from 51h to 36h and 2h, respectively. The extraction efficiency of CSE and USE was comparable with those data obtained with the conventional BCR protocol. The relative mobility of Hg in coal samples obtained from different depths was found in the following increasing order: oxidizable fraction<reducible fraction<acid soluble fraction.

Determination of Mercury Exposure among Dental Health Workers in Nakhon Si Thammarat Province, Thailand

Objectives. The main objective of this study was to assess the mercury exposure levels in dental health workers that work in dental clinics. The study evaluated the airborne and urinary mercury levels, the type of work done in the clinic, and the effect of mercury exposure on health of dental health workers. Material and Methods. A case-control study was conducted with 124 exposed and 124 matched nonexposed subjects. Personal and area samplings were conducted to quantify mercury concentrations by solid sorbent tube. Urine samples were collected to determine mercury levels by cold-vapor atomic absorption spectrometer mercury analyzer. Results and Discussion. 17.6% (n = 32/182) of the air samples were higher than the occupational exposure limit (OEL). A multiple regression model was constructed. Significant predictors of urinary mercury levels included dietary consumption (fish or seafood), duration of work (yrs), work position, personal protection equipment used (PPE), and personal hygiene behaviors. Significant correlations were observed between mercury levels in urine and mercury in storage areas (r = 0.499, P < 0.05) and between mercury levels in urine and airborne mercury in personal samplings (r = 0.878, P < 0.001). Conclusion. Improvements in working conditions, occupational health training, and PPE use are recommended to reduce mercury exposure.

Mercury Exposure among Garbage Workers in Southern Thailand

Objectives1) To determine mercury levels in urine samples from garbage workers in Southern Thailand, and 2) to describe the association between work characteristics, work positions, behavioral factors, and acute symptoms; and levels of mercury in urine samples.MethodsA case-control study was conducted by interviewing 60 workers in 5 hazardous-waste-management factories, and 60 matched non-exposed persons living in the same area of Southern Thailand. Urine samples were collected to determine mercury levels by cold-vapor atomic absorption spectrometer mercury analyzer.ResultsThe hazardous-waste workers' urinary mercury levels (10.07 µg/g creatinine) were significantly higher than the control group (1.33 µg/g creatinine) (p < 0.001). Work position, duration of work, personal protective equipment (PPE), and personal hygiene, were significantly associated with urinary mercury level (p < 0.001). The workers developed acute symptoms - of headaches, nausea, chest tightness, fatigue, and loss of consciousness at least once a week - and those who developed symptoms had significantly higher urinary mercury levels than those who did not, at p < 0.05. A multiple regression model was constructed. Significant predictors of urinary mercury levels included hours worked per day, days worked per week, duration of work (years), work position, use of PPE (mask, trousers, and gloves), and personal hygiene behavior (ate snacks or drank water at work, washed hands before lunch, and washed hands after work).ConclusionChanging garbage workers' hygiene habits can reduce urinary mercury levels. Personal hygiene is important, and should be stressed in education programs. Employers should institute engineering controls to reduce urinary mercury levels among garbage workers.

Determination of total mercury in chicken feed, its translocation to different tissues of chicken and their manure using cold vapour atomic absorption spectrometer

In this study, the contents of total mercury (Hg) present in poultry feed, tissues of broiler chicken and manure were assessed. For this purpose, chicken feeds (five brands), different tissues of broiler chicken of two age groups (1–3 and 4–6week) and manure samples were collected from five commercial poultry farms of Hyderabad, Pakistan. The Hg concentrations in feeds, chicken tissues (leg, muscle, liver and heart) and manure samples were determined by CVAAS, prior to microwave assisted acid digestion in closed vessels. For validation, a certified reference material, DORM-2 was used. The limit of detection and quantitation were 0.117 and 0.382μg/kg, respectively The Hg concentration in different chicken feed were found in the range of 8.57–16.5μg/kg. The concentration of Hg in chicken tissues were found in the range of 2.54–5.54μg/kg (liver), 1.27–3.86μg/kg (muscles) and 2.13–3.27μg/kg (heart). The bioaccumulation factors (BAF) for Hg in different tissues were found in the range of 0.092–0.269. The obtained data shows the high correlation coefficient between feed and manure, while low r-values were obtained between Hg levels in feed and tissues of broiler chicken of two age groups.