ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the method for collecting NO2 in workplace air using a solid adsorbent and determining the concentration of NO2 by ion-exchange chromatography.</p><p><b>METHODS</b>NO2 in workplace air was collected using sampling tubes filled with 13X molecular sieve soaked with triethanolamine, and the samples were desorbed with a certain concentration of triethanolamine solution to obtain NO2(-). NO2(-) was separated with an anion exchange chromatography column and quantified by a conductivity detector. The concentration of NO2 was determined based on the conversion coefficient of NO2 and NO2(-).</p><p><b>RESULTS</b>Different concentrations of NO2 (standard gas) was collected using the sampling tubes at different time points, and the sampling efficiency and desorption efficiency could reach more than 90%. The penetrating capacity of sampling tubes was more than 1.1 mg. The comparative test shows that there was no significant difference between the new method and national standard method (solution absorption) (P > 0.05). The samples could be stored at room temperature for more than 16 days. The calibration curve plotted in the new method was linear in the range of 0.1∼20.0 µg/ml, with a correlation coefficient of 0.9998; the detection limit was 0.01 µg/ml; the minimum detectable concentration was 0.05 mg/m(3) (V0 = 3.0 L).</p><p><b>CONCLUSION</b>This determination method meets the requirements of Guide for establishing occupational heath standards-Part 4 Determination methods of air chemicals in workplace (GBZ/T 210.4-2008) and shows obvious advantages for determination of NO2 in workplace air.</p>
Subject(s)
Air , Air Pollutants, Occupational , Chromatography, Ion Exchange , Methods , Nitrogen Dioxide , WorkplaceABSTRACT
<p><b>OBJECTIVE</b>The purpose of this study was to explore how obesity was covered in television news in China, including the trends over time and the characteristics of obesity-related news.</p><p><b>METHODS</b>The frame analysis was adopted to assess the content of obesity-related news broadcasted in China Central Television (CCTV) from 1982 to 2009. To investigate the characteristics of the news, the obesity-related news was divided into subgroups according to populations concerned, as well as the period in which the news was broadcasted. The differences between subgroups were examined.</p><p><b>RESULTS</b>A total of 1 599 pieces of news reported obesity, in which 1 278 pieces (79.92%) aired in "wealthy" period (2006-2009). More news was concerned with adults (1 134, 70.92%). "Individual behavior" dominated most of the cause frames (389, 24.33%), solution frames (522, 32.65%), and responsibility frames (860, 53.78%). There was more news mentioning individual factors in news aired in "wealthy" period and news concerning children. The coverage of social-structure causes was higher in news concerning children, while the coverage of social-structure solutions was higher in news concerning children and news aired in "wealthy" period.</p><p><b>CONCLUSION</b>Although the coverage of obesity was modest, it showed an incremental trend as the economy grew. Obesity was mostly depicted as an individual problem in terms of responsibility, causes and solutions.</p>