Thiol modified bimodal mesoporous silica nanoparticles for removal and determination toxic vanadium from air and human biological samples in petrochemical workers.

Investigation of exposure to toxic vanadium (V) in petrochemical workers is very important for human health, and it must be removed and determined in workplace air and human biological samples. In this research, the enriched adsorbent based on the thiol modified bimodal mesoporous silica nanoparticle (HS-UVM7) was used for the extraction vanadium in human blood by the dispersive sonication ionic liquid micro solid phase extraction (DS-IL-µ-SPE) at pH of 4.5. In addition, the vanadium (V) was removed from the industrial workplace air based on HS-UVM7 adsorbent by the liquid-solid phase-gas removal (LSP-GR). In the static and dynamic system, the vanadium (V) was removed from artificial air with HS-UVM7 and compared with the polyvinyl chloride membrane (PCM, sorbent in 7300 NIOSH). The LSP-GR procedure based on HS-UVM7 had more recovery and adsorption capacity as compared to PCM. The adsorption capacity of HS-UVM7 and UVM7 adsorbents were obtained 144.1 mg g-1 and 23.3 mg g-1, respectively. In addition, the main parameters effected on extraction vanadium in blood samples and removal from air were studied and optimized by ET-AAS. The LOD, RSD%, linear range (LR) and enrichment factor (EF) was achieved 0.03 µg L-1, 3.1, 0.1-4.5 µg L-1 and 48.7, respectively for extraction of vanadium in 10 mL of blood samples by the DS-IL-MSPE procedure. The validation of the methodology was confirmed by standard addition to gas phase and using certified reference materials (CRM, NIST) or ICP-MS in human blood samples.

Neuropsychological effects of long-term occupational exposure to mercury among chloralkali workers.

BACKGROUND: Mercury is one of the most well-known toxic metals for humans. Chloralkali workers are exposed to mercury vapours extensively, which may be associated with neurotoxicity. OBJECTIVE: The aim of this study was to determine the associations between mercury concentration in blood and air samples, and mercury's neuropsychological effects among chloralkali workers. METHODS: This study was conducted on 50 chloralkali workers as the exposed group and 50 non-industrial office workers as the unexposed group. All subjects were assessed using the Hamilton Depression Rating Scale, Piper Chronic Fatigue Scale and Essential Tremor Rating Scale. Mercury concentration was measured in blood and air samples using cold vapour atomic absorption spectrometry. RESULTS: There was significantly more severe fatigue, depression and tremor in the exposed group compared with the unexposed group. The mean concentration of blood mercury in the exposed group was 22.59±12.5µgL-1 which was significantly higher than the unexposed group (1.28±1.05µg L-1). Based on multiple linear regression, shift work, smoking, fatigue, depression and tremor were predictor variables for blood mercury concentration. CONCLUSIONS: This study indicated that this sample of chloralkali workers suffered from neuropsychological problems such as fatigue, depression and tremor, which is probably related to mercury exposure.