• Asian Journal of Atmospheric Environment
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• v.12 no.2
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• pp.165-177
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• 2018

Particulate matter (PM) measurements are important in air quality, public health, epidemiological studies and decision making for short and long-term policies implementation. However, only few cities in the word have advance air quality-monitoring networks able to provide reliable information of PM leaves in the ambient air, trends and extent of the pollution. In Colombia, only major cities measure PM concentrations. Available measurements from Bogota, Medellin and Bucaramanga show that PM concentration are well above World Health Organization guidelines, but up to now levels and trends of PM in other cities and regions of the country are not well known. Satellite measurements serve as an alternative approach to study air quality in regions were surface measurements are not available. The aim of this study is to perform a spatial and temporal assessment of PM in the ambient air of Colombia. We used Aerosol optical depth (AOD) retrieved by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite of NASA and surface measurements from the air quality networks of Bogota, Medellin and Bucaramanga. In a first step, we estimated the correlation between MODIS-AOD and monthly average surface measurements (2000 to 2015) from these three cities, obtaining correlation coefficient R values over 0.4 for the cities under study. After, we used AOD and $PM_{10}$ measurements to study the temporal evolution of PM in different cities and regions. Finally, we used AOD measurements to identify cities and regions with the highest AOD levels in Colombia. All the methods presented in this paper may serve as an example for other countries or regions to identify and prioritize locations that require the implementation of more accurate air quality measurements.

• Journal of Environmental Health Sciences
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• v.7 no.2
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• pp.89-95
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• 1981

A Continuous monitoring of Air Pollution in city of Seoul was carried out from January 1 to December 31 of 1979 at two selected sites, Kwanghwamun observatory and Kwanag observatory. The measured data were averaged on monthly basis. The maximun value of oxidant pollution was observed in July, and the minimum in February. It is the purpose of this study to determine the effect of hydrocarbon, nitrogenoxide, wind velocity and ambient temprature on the observed values of oxidant pollution for the above two months. The results of the study may be summarized as follows. 1) The oxidant concentration in February was higher than in July by about 2 times in both downtown area and the suburbia. The concentration in downtown area was $25.75\pm 4.75ppb$, and that in suburbia was $29.83\pm 5.16ppb$. As for the oxidant concentration in July, it was observed that the suburban area ($26.464\pm 7.59ppb$) had about 2.8 times higher value than the downtown area ($9.284\pm 1.55ppb$). 2) The peak oxidant concentration of suburban area during the daytime is occured from noon to 5:00 P.M.. These patterns are similar to the classical patterns, but the peak Oxidant Concentration of downtown area in February was occured at 9:00A.M. 3) The overall level of nitrogen oxide pollution was much higher in downtown area than in suburban area. Two peaks of nitrogen oxide concentration occured at 10 A.M. and 12 midnight in downtown area. This observation agrees with the report that the air pollution is higher in the area where the pollution sources are concentrated. 4) The multiple correlation analysis for the oxidant and the other variables measured in February in downtown area showed close correlation with nitrogen oxide and ambient temprature. The multiple correlation coefficient of oxidant with nitrogen oxide was 0.872, and that with nitrogen oxide and temperature simultaneously was 0.903. The multiple correlation equation used for this study may be expressed as follows:

• Environmental Engineering Research
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• v.23 no.2
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• pp.143-149
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• 2018

Air quality conditions and pollution status have been evaluated in the industrial area between Sharjah and Ajman border in UAE. Daily concentrations of $O_3$, CO, $NO_2$, $SO_2$, $PM_{2.5}$, $PM_{10}$, Total Volatile Organic Compounds (TVOC) and Total Suspended Particulate (TSP) have been monitored from Sept. 2015 to April 2016. The monthly average concentrations of $O_3$, CO, $NO_2$, $SO_2$, TVOC were within the UAE ambient air quality standards during the survey period. However, $PM_{10}$ and TSP levels exceeded the recommended limits in Sept. 2015, Oct. 2015 and March 2016. Temporal variations in air quality parameters showed highest levels in March 2016 for $PM_{2.5}$, $PM_{10}$, $NO_2$, TVOC and TSP, whereas $O_3$, $SO_2$ and CO showed relatively low values in this month. $PM_{2.5}$ levels in ambient air were above the EPA guideline of $35{\mu}g/m^3$ in all months. $PM_{2.5}$ was the critical ambient air pollutant with Index for Pollutant ($I_p$) values varying from 103-209, indicating Air Quality Index categories of unhealthy for sensitive groups (62.5%) to unhealthy (25%) to very unhealthy (12.5%). The $I_p$ average values of $PM_{2.5}$ decreased from Sept. 2015 to reach lowest value in Dec. 2015 before increasing gradually, peaking in March 2016. These results suggest the potential health risks associated with $PM_{2.5}$ is low in winter, where the prevailing meteorological conditions of lower temperatures, higher humidity, higher wind speed reduced particulate matter. The results revealed the industrial area is impacted by anthropogenic and natural sources of particulate matter.

• Journal of Preventive Medicine and Public Health
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• v.36 no.1
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• pp.47-53
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• 2003

Objectives : I used a case-crossover design to investigate the association between air pollution, and hospital admissions for asthmatic children under the age of 15 years in Seoul, Korea Methods : I estimated the changes in the levels of hospitalization risk from theinterquartile (IQR) increase in each pollutant concentrations, using conditional logistic regression analyses, with controls for weather information. Results : Using bidirectional control sampling, the results from a conditional logistic regression model, with controls for weather conditions, showed the estimated relative risk of hospitalization for asthma among children to be 1.04 (95% confidence interval (CI), 1.01-1.08) for particulate matter with an aerodynamic diameter less than or equal to 10m (IQR=40.4ug/m3); 1.05 (95% CI, 1.00- 1.09) for nitrogen dioxide (IQR=14.6ppb): 1.02 (95% CI,0.97-1.06) for sulfur dioxide (IQR=4.4ppb): 1.03 (95% CI, 0.99-1.08) for ozone (IQR=21.7ppb): and 1.03 (95% CI, 0.99-1.08) for carbon monoxide f10R=1.0ppm). Conclusions : This empirical analysis indicates the bidirectional control sampling methods, by design, would successfully control the confounding factors due to the long-term time trends of air pollution. These findings also support the hypothesis that air pollution at levels below the current ambient air quality standards of Korea is harmful to sensitive subjects, such as asthmatic children.

• Environmental and Resource Economics Review
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• v.30 no.2
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• pp.207-235
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• 2021

This paper examines the effects of ambient air pollution by ozone and particulate matter on traveling by mode of transport. We estimate the SUR model of travel time by different modes of transportation using individual level data of travel diaries. We find that, as air pollution levels rises, traveling by privately-owned vehicles increases but traveling by bus decreases. Our results also show that, when an air quality alert is issued, bus traveling increases in an effort to reduce pollution levels, but traveling by own car does not change and traveling by train declines. This suggests that alert programs may not be highly effective in reducing air pollution emissions from vehicles because voluntary switching to public transportation induced by air quality alerts is outweighed by individual effort of avoiding exposure to pollution.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.215-216
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• 2003

대기환경에 대한 오존의 영향이 증대되면서 오존에 대한 관심이 증대되었다. 이에 따라 대기중 오존 농도를 정확히 측정할 수 있는 오존 측정기에 대한 관심도 고조되고 있는 실정이다. 오존을 측정하기 위한 방법은 분석하는 방법에 따라 Ion Chromatography, UV/Vis Spectrometer, Spectrofluorimeter, Spectrometer(reflection)방법 등을 들 수 있으며(Zhou and Smith, 1997, Geyh etal. 1997), 이들 중 Spectrometer(reflection)를 이용하는 방법이 비교적 간단하다. 이 방법은 대기 중 오존과 반응하여 색도가 변화하는 착색제를 사용하여 색도 변화를 관측하여 오존 농도를 평가하는 방법이다. (중략)

• Journal of Preventive Medicine and Public Health
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• v.31 no.1 s.60
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• pp.82-90
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• 1998

A large number of studies have indicated associations between particulate air pollution and daily mortality. Daily measurements of total suspended particulates (TSP) by high volume air sampler were matched to daily death counts supplied by the National Statistics Office, Korea. All deaths, except deaths from accidents, occurred at Ulsan from 1 January 1991 to 31 December 1994 were considered in the poisson regression analysis. The multiple regression models were used to investigate a main effects of air particulate pollution controlling for $SO_2$ levels, air temperature, relative humidity, seasonal variation, and calendar year. The results indicated that the effects of TSP, $SO_2$, temperature, and relative humidity were not significantly associated with all cause mortality. It could, however, be emphasized that the size of the parameter estimate of TSP was very similar to that of previous studies. An increase in particulates of $100{\mu}g/m^3$ was associated with a 3% increase in mortality. This relationship was observed at TSP levels well below the current National Ambient Air Quality Standard of $150{\mu}g/m^3$ in Korea as well.

• Environmental Engineering Research
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• v.20 no.3
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• pp.260-267
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• 2015

The $PM_{10}$, $SO_2$ and $NO_2$ mass concentrations were obtained over five years from monitoring stations across Nanchong, a southwest city in China. Changes in urban air quality over time, as well as the factors influencing that change, were evaluated based on air pollutant concentrations, the Air Pollution Index (API), and the Comprehensive Pollution Index (P). The results showed that the total annual mean $PM_{10}$, $SO_2$ and $NO_2$ concentrations over the five years studied were $61.1{\pm}1.1$, $45.0{\pm}3.9$ and $34.9{\pm}4.9{\mu}g{\cdot}m^{-3}$, respectively. The annual mean concentrations displayed a generally decreasing trend; lower than the annual mean second-level air quality limit. Meanwhile, the annual mean API values were in a small range of 52-53, the air quality levels were grade II, and P values were 1.06-1.21 less than the slight level ($P{\leq}1.31$). Total monthly mean $PM_{10}$, $SO_2$, $NO_2$ concentrations, and API and P values were consistently higher in winter and spring than during autumn and summer. The results of a correlation analysis showed that temperature and pressure were the major meteorological factors influencing pollution levels. Pollution sources included industrial coal and straw burning, automobiles exhaust and road dust, fireworks, and dust storms.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.518-520
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• 2008

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.199-201
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• 2008