Objective To explore the relationship between the concentration of t, t-2, 4-DDE in cooking oil fume(COF) and the cooking temperature. Methods The temperature control system of oil heating was developed, the activated carbon was used to collect gaseous pollutants. Six samples were prepared at 60, 90, 120, 150, 180, 210, 240 and 270 ℃. The concentration of t, t-2, 4-DDE in COF was analyzed by GC-FID. Results The concentration of t, t-2, 4-DDE in COF was below the detection limit when the oil temperature was not higher than 120 ℃. Among the 150 ℃ and 270 ℃ groups, the concentration of t, t-2, 4-DDE showed a significant increase. Conclusion The concentration of t, t-2, 4-DDE in COF may obviously increase as the cooking temperature is not lower than 150℃.

Objective To establish a method of GS-MS for determination of polychlorinated biphenyls (PCBs) in human cerumen. Methods The PCBs in cerumen samples was separated by n-hexane extraction, liquid-liquid extraction separation and column chromatography purification, then was analyzed quantitatively by gas chromatography and affirmed qualitatively by mass spectroscopy. Results The detection limit, average recovery rate and precision of this method were 0.15 ?g/g fat, 92.1% and 3.0%-4.6% (n=12) respectively. The contents of PCBs in 90 cerumen samples collected in polluted and control areas were detected. The levels(0.00-18.42 ?g/g fat) of PCBs in cerumen collected in polluted area were significantly higher than that in the control area(P

Objective:To connect with the measurement data of asbestos dust fiber concentration in foreign countries, improve the accuracy of asbestos fiber detection in China, and understand the dust exposure in the working environment of asbestos and man-made mineral fiber production and processing sites in Zhejiang Province. The fiber count concentrations of working environment in glass fiber, ceramic fiber and asbestos processing plants were measured and compared.Methods:The dust concentration in the working environment of two glass fiber factories, one ceramic fiber factory and eight asbestos products processing factories was measured. The total dust mass concentration was measured according to GBZ/T 192.1-2007, and the fiber count concentration was measured by phase contrast microscope. Kruskal Wallis was used to test and compare the dust concentration in the working environment of each post. The correlation between asbestos mass concentration and fiber count concentration was analyzed by Spearman correlation.Results:Under the phase contrast microscope, there were many short and fine asbestos fibers in the field of vision, and there were many impurities around. The average dust concentration of asbestos processing plant was 3.2 f/ml, and the dust concentration of cotton ginning was the highest (6.68 f/ml) . There was a significantly positive correlation between asbestos fiber count concentration and mass concentration ( r=0.535, P=0.033) . The average fiber count concentration of glass fiber factory was 0.001 f/ml, and the highest was 0.005 f/ml. The average fiber count concentration of ceramic fiber factory was 0.001 f/ml, and the highest was 0.006 f/ml. Conclusion:The fiber count concentration in the working environment of asbestos factory in Zhejiang Province is obviously over the standard, which is one of the important reasons for the high incidence of mesothelioma in this area. Short and small asbestos fibers are easy to be ignored when counting. It is necessary to improve the actual operation process of fiber counting to form a laboratory standard in China.

Objective:To connect with the measurement data of asbestos dust fiber concentration in foreign countries, improve the accuracy of asbestos fiber detection in China, and understand the dust exposure in the working environment of asbestos and man-made mineral fiber production and processing sites in Zhejiang Province. The fiber count concentrations of working environment in glass fiber, ceramic fiber and asbestos processing plants were measured and compared.Methods:The dust concentration in the working environment of two glass fiber factories, one ceramic fiber factory and eight asbestos products processing factories was measured. The total dust mass concentration was measured according to GBZ/T 192.1-2007, and the fiber count concentration was measured by phase contrast microscope. Kruskal Wallis was used to test and compare the dust concentration in the working environment of each post. The correlation between asbestos mass concentration and fiber count concentration was analyzed by Spearman correlation.Results:Under the phase contrast microscope, there were many short and fine asbestos fibers in the field of vision, and there were many impurities around. The average dust concentration of asbestos processing plant was 3.2 f/ml, and the dust concentration of cotton ginning was the highest (6.68 f/ml) . There was a significantly positive correlation between asbestos fiber count concentration and mass concentration ( r=0.535, P=0.033) . The average fiber count concentration of glass fiber factory was 0.001 f/ml, and the highest was 0.005 f/ml. The average fiber count concentration of ceramic fiber factory was 0.001 f/ml, and the highest was 0.006 f/ml. Conclusion:The fiber count concentration in the working environment of asbestos factory in Zhejiang Province is obviously over the standard, which is one of the important reasons for the high incidence of mesothelioma in this area. Short and small asbestos fibers are easy to be ignored when counting. It is necessary to improve the actual operation process of fiber counting to form a laboratory standard in China.