Background/Aims: Weather and air pollution are associated with the exacerbation of respiratory diseases. We investigated patterns of medical care use according to meteorological factors and air pollution in patients with asthma or chronic obstructive pulmonary disease (COPD). Methods: We analyzed the medical care utilization patterns of patients with asthma or COPD registered in the Korea Health Insurance Review and Assessment database for the period 2007 to 2013. The patterns were divided into hospitalization and emergency department (ED) use.
Results:The medical care use of patients with asthma or COPD increased when the mean temperature and relative humidity were lower, and the temperature difference and atmospheric pressure were greater. Medical care use increased with the concentrations of particulate matter and ozone. Among age groups, sensitivity to pollutants was greatest in patients aged ≥ 65 years. The effect of being elderly was greater for asthma than for COPD, with a higher hospitalization rate. ED utilization affected by environmental factors was significantly greater for females and hospitalization was significantly more common for males. Conclusions: Meteorological factors and air pollutants were shown to contribute to increased medical care utilization by patients with asthma and COPD, particularly elderly patients. The overall effect was greater for COPD, but the effect in elderly patients was greater for asthma. In addition, the patterns of change in medical care use due to environmental factors differed according to sex.
To aid the studies of long-term impact assessment of cumulative ozone (O 3 ) exposures, the representative 8-hr O 3 pollution patterns have been identified over the Greater Seoul Area (GSA) in Korea. Principal component analysis and two-stage clustering techniques were used to identify the representative O 3 patterns, and numerical and observational analyses were also used to interpret the identified horizontal distribution patterns. The results yielded three major O 3 distribution patterns, and each of the three patterns was found to have strong correlations with local and synoptic meteorological conditions over the GSA. For example, pattern 1, accounting for 46% of O 3 concentration distributions, mostly occurred under relatively weak westerly synoptic winds. The predominant features of this pattern were infrequent high O 3 levels but a distinct gradient of O 3 concentration from the western coastal area to the eastern inland area that was mainly induced by the local sea breeze. Pattern 2, accounting for 31% of O 3 concentration distributions, was found with higher O 3 levels in the western coastal area but lower in the eastern inland area. This is due to the modified sea breeze under the relatively stronger easterly opposing synoptic wind, affecting the high O 3 occurrence in the western coastal area only. However, pattern 3, accounting for 21% of O 3 concentration distributions, showed significantly higher O 3 concentrations over the whole GSA mainly due to the retarded and slow-moving sea-breeze front under the weak opposing synoptic flow. Modeling study also indicated that local and synoptic meteorological processes play a major role in determining the high O 3 concentration distribution patterns over the GSA.
INTRODUCTIONGround-level ozone (O 3 ) adversely affects vegetation and human health. 1 In assessing plant response and health effects, the duration of exposure as well as peak concentration of O 3 has been recognized to be an important factor. [1][2][3][4] In 1997, the U.S. Environmental Protection Agency (EPA) promulgated a new 8-hr standard for estimating multiple-hour exposures to moderate O 3 concentrations, and the 8-hr standard has been used in several impact assessments using data analysis and modeling studies. [5][6][7][8] Multiyear photochemical model simulation is the most promising way to address the cumulative O 3 exposure problem, done through precise, long-term impact studies of high O 3 concentrations. However, running air quality models that cover longer-periods have generally been prohibitively complicated because of incomplete emission inventories and difficulties in constructing precise wind fields. Numerical modeling studies have suggested that, because of input demand and computational load, an episode aggregation approach by identifying several representative air quality patterns is an effective alternative to developing and running a long-term air quality model. For this reason, the air quality regimes over non-urban areas utilizing the spatiotemporal variability of dai...
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