Objective - To analyze the relationship between cobalt level of post shift urine and individual exposure level of ， cobalt and its compounds in cobalt exposed workers and to explore the feasibility of using urine cobalt as a biomarker. Methods - A total of 148 occupational cobalt exposed workers from a new material company were selected as the exposed ， - - group and 44 non occupational cobalt exposed workers from the company were selected as the control group using the typical sampling method. The exposure concentration of time weighted average of cobalt and its compounds in the workplace air of the - two groups was determined by inductively coupled plasma mass spectrometry as the individual exposure level. The cobalt levels - - of pre shift and post shift urinary samples of the two groups were detected by this method. The linear relationship between the - cobalt level of post shift urine and the individual exposure level of cobalt and its compounds in the air of the workplace was Results - 3 analyzed. The individual exposure level of cobalt and its compounds in the exposed group was 1.10 131.71 μg/m with （M） 3 the median of 12.23 μg/m. No cobalt and its compounds were detected in the workplace air in the control group. The cobalt - - levels of pre shift and post shift urines in exposed group were higher than those in the control group at the same time point （M： vs ， vs ， P ） - - 1.54 0.56 μg/L 8.77 0.83 μg/L all <0.01 . The cobalt level of post shift urine was higher than that in pre shift （M： vs ，P ）， urine in the exposed group 8.77 1.54 μg/L <0.01 and it was positively correlated with the individual exposure level （ ，P ） ， of cobalt and its compounds Spearman correlation coefficient=0.86 <0.01 . After common logarithm conversion the linear regression equation of the cobalt level of post shift urine and the common logarithm of individual exposure level of cobalt and （x） ：ŷ x（ ；F ， its compounds in the exposed group was as follows = −0.178 + 0.988 coefficient of determination=0.72 =374.75 P ；t ， P ） Conclusion - <0.01 = - 19.36 <0.01 . There was a linear correlation between cobalt level of post shift urine and occupational cobalt exposure level of cobalt exposed workers. Urinary cobalt can be used as a biomarker of occupational cobalt

OBJECTIVE: To analyze the occupational hazard factors and their critical control points in the process of construction of a large-scale construction project.METHODS: The engineering analysis, worksite survey occupational health and occupational hazard factor testing were conducted in a large-scale construction project, and the results were analyzed. RESULTS: During the process of construction of this large-scale construction project, there were many occupational hazard factors such as silicon dust, welding smoke, wood and other dusts, inorganic compounds of manganese, carbon monoxide, carbon dioxide, nitric oxide, ozone, noise, high temperature, hand-transmitted vibration and ultraviolet irradiation, among them, silicon dust and noise were the most common ones. The over standard rates of exposure concentration of short term of total dust and respirable dust in the workplace were 68.2%(15/22) and 40.9%(9/22), and the over standard rates of exposure concentration of time weighted average were 54.5%(12/22) and 13.6%(3/22), respectively. The over standard rates of the noise intensity of area sampling and personal sampling in workplace were 69.2%(45/65) and 61.0%(25/41) respectively. The four hours energy equivalent frequency-weighted acceleration to vibration of three hand-transmitted vibration positions has been detected, and the result has surpassed the occupational exposure limit.The results of other occupational hazard factors such as high temperature, ultraviolet radiation, wood dust, welding smoke, other dust, manganese inorganic compounds, carbon monoxide, carbon dioxide, nitric oxide, nitrogen dioxide, hydrogen sulfide, hydrogen cyanide and ozone all met the occupational exposure limits. CONCLUSION: There are various occupational hazard factors in the process of construction of this large-scale construction project, among them, noise, dust and hand-transmitted vibration are the most prominent hazards.These hazards are the critical control points of this type of construction projects.

Objective To understand the biochemical characteristics and 16S rDNA genetic sequence evolution of strains isolated from diarrhea specimens so as to provide basis for classification and identification of Klebsiella pneumoniae. Methods Specimens were cultured using MacConkey and SS medium. All isolates were identified as K. pneumoniae by automated biochemical tests. DNA was extracted, 1500 bp fragments of the 16S rDNA gene were by amplified PCR and sequenced with K. pneumoniae 16S rDNA primer, after being cut. Fragments of 1000 bp overlapping sequences were analyzed by Blastn to confirm the identity of the isolates. A phylogenetic tree was constructed by PHYLIP process to analyze the 16S rDNA sequence of the isolated strain with other relative bacteria species in the GenBank databases. Results Among 113 specimens of infectious diarrhea, 25 K. pneumoniae strains were identified by biochemical tests, of which 21 subsp, pneumoniae and 4 subsp, ozaenae, no subsp, of rhinoseleroma were isolated. Strains of subsp, pneumoniae were found having nature of resistance. All isolates were resistant to penicillin G and susceptible to polymyxin with some strains were resistant to Nitrofurantoin, Cephalothin, Kanamycin, Tobramycin. After searching in GenBank of 16S rDNA, strains biochemical identified as subsp, ozaenae shared high similarity with Salmonella strains and other intestinal bacteria. 16S rDNA phylogenetie analysis could be used to confirm subsp, pneumoniae, but could not separate other subspecies of K. pneumoniae completely. Conclusion 16S rDNA phylogenetic analysis useful in identifying and classifying K. pneumoniae.

OBJECTIVE: To establish a method for testing tetrahydrofuran( THF) in workplace air by solvent desorption gas chromatography. METHODS: The air samples were collected by activated carbon tube,desorbed with carbon disulfide solution,then separated by capillary column and detected by flame ionization detector. RESULTS: The linearity range of THF concentration was 1. 78-8 892. 00 mg / L,and the correlation coefficient was 0. 999 9. The minimum detection limit of THF was 0. 09 mg / m3. The minimum quantitative concentration was 0. 27 mg / m3( 3. 00 L air collection). The average desorption efficiency of THF was 94. 29%-96. 46% when placed overnight at the room temperature. The within-run and the between-run relative standard deviation were 0. 30%-0. 91% and 0. 66%-1. 23% respectively. THF sample could be stored at room temperature for at least 8 days. CONCLUSION: The method could be widely applied in sampling and detection of THF in workplace air.