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Urine

  • Determination of mercury concentration in the air of dental clinics

    Determination of mercury concentration in the air of dental clinics

    A b s t r a c t

    Background: Dental clinics are known to be one of the largest users of Toxic inorganic mercury. It is well documented that dentists and dental assistants who work with amalgam are chronically exposed to mercury vapor. This study investigates exposure to mercury vapor in a dental clinic. Methods: GBC cold vapor atomic absorption spectrometry (AAS), using sodium borohydride as the reducing agent, was employed to determine mercury concentrations. The determination of mercury in urine and air was carried out using a flow injection system after sample treatment according to the standard procedure. Result: In this study mercury exposure in some dentist and dental office personnel was examined. We studied 495 persons (280 dentists and 215 dental personnel) occupationally exposed to mercury while working at 58 dental clinics in Tehran. In addition 305 samples from dental office’s air were taken and their mercury was measured with HG-AAS. Conclusion: In this study, mercury levels in dentists urine and dental office atmosphere were lower than occupational safety and health administration (OSHA). Results acquired from this study show that the amount of mercury were in normal range and it is lower than to the potential for adverse exposure to elemental mercury vapor concentration in a dental office.

    Authors

    Hassan Zavvar Mousavi, Ahmad Rouhollah, Hamid Shirkhanloo

    MATERIAL AND METHODS

    Urine sampling: 24-hour urine samples were obtained from dentists and their colleagues who had several months of steady exposure, at the end of a working week in 2.5 lit. polypropylene sampling vessels and after the addition of conc. HCL to yield a final acid concentration of 1-3% v/v were stored at -20°C prior to analysis.

    Air sampling: All samples were collected in an employee’s breathing zone according to OSHA analytical method. Each personal sampling pump was calibrate with a representative sampler and the end of sampler was broken immediately prior to sampling. Samplers were attached to the pumps with flexible tubings and air was colleted at a rate of 0.15 to 0.25 L/min

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  • Occupational Exposure to Mercury: Air Exposure Assessment and Biological Monitoring based on Dispersive Ionic Liquid- Liquid Microextraction

    Occupational Exposure to Mercury: Air Exposure Assessment and Biological Monitoring based on Dispersive Ionic Liquid- Liquid Microextraction

    A b s t r a c t

    Background: Exposure to mercury (Hg) as a heavy metal can cause health effects. The objective of this study was to assess occupational exposure to Hg in a chlor-alkali petrochemical industry in Iran by determining of Hg concentrations in air, blood and urine samples. Methods: The study was performed on 50 exposed subjects and 50 unexposed controls. Air samples were collected in the breathing zone of exposed subjects, using hopcalite sorbents. Analysis was performed using a cold vapor atomic absorption spectrophotometer (CV-AAS) according to NIOSH analytical method 6009. For all participants, blood and urine samples were collected and then transferred into sterile glass tubes. After micro-extraction with ionic liquid and back extraction with nitric acid, Hg concentrations in blood and urine samples were determined by CV-AAS. Results: The mean concentration of air Hg was 0.042± 0.003 mg/m3. The mean concentrations of Hg in blood and urine samples of exposed subjects were significantly higher than unexposed controls (22.41± 12.58 versus 1.19± 0.95 μg/l and 30.61± 10.86 versus 1.99± 1.34 μg/g creatinine, respectively). Correlation of air Hg with blood Hg, urine Hg and blood Hg-urine Hg ratio were significant statistically (P< 0.05). Conclusions: The values of Hg in blood and urine samples of chlor-alkali workers were considerably high. Correlation coefficients showed that blood Hg and blood Hg-urine Hg ratio are better indicators than urine Hg for assessing occupationally exposed workers in terms of current exposure assessment.

    Authors

    Hamid SHIRKHANLOO, Farideh GOLBABAEI, Hamid HASSANI, Farrokh EFTEKHAR, Mohammad Javad KIAN

    Results and discussion

    Based on the preliminary experiments, the retention of Pb (II) and Ni (II) ions on a GO-packed micro-column was chosen for preconcentration of the metal ions and their subsequent determination by FAAS. Hence, in order to obtain quantitative recoveries of Pb (II) and Ni (II) ions with good sensitivity and precision, the presented SPE system was optimised for various analytical parameters.

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  • Relations of biomarkers of manganese exposure and neuropsychological effects among welders and ferroalloy smelters

    Relations of biomarkers of manganese exposure and neuropsychological effects among welders and ferroalloy smelters

    A b s t r a c t

    The objective of present study was to assess relationship between biomarkers of Manganese (Mn) and neuropsychological effects. The study was carried out on 27 welders and 31 ferroalloy smelters as Mn-exposed groups and 30 office workers as unexposed controls. Air Mn concentrations were determined according to NIOSH method 7300. The biological samples were prepared using microwave assisted acid digestion and all samples were analyzed by graphite furnace- atomic absorption spectroscopy (GF-AAS) in order to determine manganese. Questionnaire 16 (Q16) and Cambridge Neuropsychological Test Automated Battery (CANTAB) were used to evaluate the neuropsychological effects. The mean concentrations of air Mn for the welder and ferroalloy smelter groups were 0.023 ± 0.012 mg/m3 and 0.008 ± 0.005 mg/m3, respectively. Manganese concentrations in blood, urine, and toenail samples of exposed workers ranged between 1.80–32.60 (μg/l), 1.00–42.50 (μg/l), and 0.10–6.08 (μg/g), respectively. Mean Mn concentrations in all biological samples of cases were significantly higher than unexposed controls (p<0.05). A moderate relationship was observed between biomarkers of Mn exposure, air Mn, Q16 as well as some neurocognitive outcome measures. The present study shows that blood Mn, urine Mn and toenail Mn could be used to distinguish Mn-exposed workers from unexposed population at the group level.

    Authors

    Hamid HASSANI, Farideh GOLBABAEI1, Hamid SHIRKHANLOO, and Mehdi TEHRANI-DOUST

    Discussion

    The results of this study showed that the concentrations of Mn in biological samples (blood, urine, and toenail) of both welder and ferroalloy smelter groups were significantly higher than the unexposed-control group.

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