• Title/Summary/Keyword: Secondary air

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Evaluation of the Effect of Traffic Control Program on the Ambient Air Quality in Seoul Metropolitan Area Using the Lower Level Stability Index of Atmosphere (하층대기의 연직 안정도 지표를 이용한 차량 2부제의 수도권 대기오염도 저감효과 분석)

  • Kim C.-H.;Park 1.-S.;Lee S.-J.;Kim J.-S.;Hong Y.-D.;Han J.-S.;Jin H.-A.
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.2
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    • pp.243-257
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    • 2005

  • The effects of Traffic Control Program (TCP) on the ambient urban air quality of SO$_{2}$, NO$_{2}$, O$_{3}$, and PM$_{10}$ were evaluated in Seoul metropolitan area by using the lower atmospheric vertical stability index and daily mean wind speeds. The vertical stability index; temperature lapse rate between 1000 hPa and 850 hPa geopotential height fields, were used to identify daily vertical stability index during the 2002 World Cup period where traffic amount was reportedly reduced to half the number of vehicles. The indicated air quality levels of TCP days were then compared with those of the cases observed with analogous vertical stability during the recent 3 years from 2000 to 2002. The result indicates that the effect of TCP on the primary air pollutants are found to be approximately 39$\%$, 23$\%$ and 20$\%$ lower for SO$_{2}$, NO$_{2}$ and PM$_{10}$, respectively. The secondary air pollutant; ozone, showed relatively smaller decreasing rate (13$\%$) of daily mean concentrations (even increased during the night time). The comparison of daily maximum or peak concentrations reveals that the pronounced decreasing effects of TCP on the ambient air quality for both primary and secondary air pollutants, suggesting that TCP is one of the effective strategies to control peak or higher concentrations for most urban scale air pollutants in and around the Seoul metropolitan area.

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Videothoracoscopic Surgery for Secondary Spontaneous Pneumothorax (비디오 흉강경을 이용한 이차성 자연기흉의 치료)

  • 양현웅;정해동;최종범;최순호
    • Journal of Chest Surgery
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    • v.31 no.7
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    • pp.692-696
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    • 1998

  • For the management of a secondary spontaneous pneumothorax, videothoracoscopic surgery may offer the potential therapeutic benefits of a minimally invasive approach. We report on a series of 36 patients(33 men and 3 women) with a mean age of 56.3 years(range, 31 to 80 years) who underwent thoracoscopic surgical procedures for the treatment of secondary spontaneous pneumothorax. Twenty-one patients had emphysema and 20 patients had old pulmonary tuberculosis. Nineteen patients presented a persistent severe air leak more than 3 days preoperatively and 15 patients had more than one recurrence. Bullectomy or exclusion of the lesion was performed in 33 patients. Mechanical pleurodesis was performed in the entire patients, talc was sprayed in 22 and vibramycin in 14. Mild pleural adhesion at the upper lobe was shown in 10 patients and severe pleural adhesion in 7 patients. One patient with persistent air leak died of persistent air leak and respiratory failure. The mean postoperative stay was 7.0 days(range, 2 to 17 days). At a mean follow-up of 15.8 months (range, 5 to 45 months), no pneumothorax had recurred. In comparison with the result of the treatment for 112 patients with primary spontaneous pneumothorax, the operating time was not significantly longer and there were no more primary treatment failures, but the duration of postoperative chest drainage and hospital stay was longer. Videothoracoscopic surgery has proved to be an effective treatment for secondary spontaneous pneumothorax in elderly patients who represent high-risk candidates for thoracotomy.

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