Patterns of medical care utilization according to environmental factors in asthma and chronic obstructive pulmonary disease patients.

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. CONCLUSION: 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.

Correction to: Perceptions regarding utilization of meteorological information in healthcare in Korea: a qualitative study.

[This corrects the article DOI: 10.1186/s40557-018-0214-3.].

Perceptions regarding utilization of meteorological information in healthcare in Korea: a qualitative study.

BACKGROUND: Health forecasting has been used in an attempt to provide timely and tailored meteorological information to patients and healthcare providers so that they might take appropriate actions to mitigate health risks and manage healthcare-related needs. This study examined the in-depth perceptions of healthcare providers and the general public regarding the utilization of meteorological information in the healthcare system in Korea. METHODS: The COREQ (Consolidated Criteria for Reporting Qualitative Research) checklist was applied to this study. We conducted three focus group discussions in accordance with semi-structured guidelines developed to deal with various aspects of the utilization of meteorological information in healthcare settings. The verbatim transcriptions and field notes were analyzed according to content analysis. RESULTS: Six physicians, four nurses, three emergency medical technicians, and seven members of the general public participated in the focus group discussions. There were some individual discrepancies among most participants regarding the health effects of climate change. Although several physician participants felt that meteorological information utilization is not a prime concern during patient care, most of the general public participants believed that it should be used in the patient care process. The provision of meteorological information to patients undergoing care is expected to not only improve the effective management of climate-sensitive diseases, but also boost rapport between healthcare providers and patients. CONCLUSIONS: More attempts should be made to provide meteorological information to groups vulnerable to climate change, and the effects of this information should be evaluated in terms of effectiveness and inequality. The findings of this study will be helpful in countries and institutions trying to introduce health forecasting services.

Relationship between reactive oxygen species and water-soluble organic compounds: Time-resolved benzene carboxylic acids measurement in the coastal area during the KORUS-AQ campaign.

This study investigated the relationship between water-soluble organic compounds of ambient particulate matter (PM) and cellular redox activity collected from May 28 to June 20 of 2016 at the west coastal site in the Republic of Korea during the KORea-US Air Quality (KORUS-AQ) campaign. Automatic four-hour integrated samples operated at a flow rate of 92 L per minute for the analysis of organic carbon (OC), water-soluble organic carbon (WSOC), elemental carbon (EC), water-soluble ions (WSIs), and benzene carboxylic acids (BCAs) were collected on a 47 mm quartz fiber filter. The influence of atmospheric transport processes was assessed by the Weather Research and Forecasting (WRF) model. OC, EC, WSOC, and BCA were determined by SUNET carbon analyzer, total organic carbon (TOC) analyzer, and liquid chromatography-mass spectrometry mass spectrometry (LC-MSMS), respectively. Twenty-four-hour integrated samples were collected for reactive oxygen species (ROS) analysis using a fluorogenic cell-based method to investigate the main chemical classes of toxicity. The results illustrate that WSOC and specific water-soluble species are associated with the oxidative potential of particulate matter. Pairwise correlation scatterplots between the daily-averaged WSOC and ROS (r2 of 0.81), and 135-BCA and ROS (r2 of 0.84), indicate that secondary organic aerosol production was highly associated with ROS activity. In addition, X-ray spectral analysis together with secondary electron images (SEIs) of PM2.5 particles collected during high ROS concentration events clearly indicate that water-soluble organic aerosols are major contributors to PM2.5 mass. This study provides insight into the components of particulate matter that are drivers of the oxidative potential of atmospheric particulate matter and potential tracers for this activity.

Impact of future urban growth on regional climate changes in the Seoul Metropolitan Area, Korea.

The influence of changes in future urban growth (e.g., land use changes) on the future climate variability in the Seoul metropolitan area (SMA), Korea was evaluated using the WRF model and an urban growth model (SLEUTH). The land use changes in the study area were simulated using the SLEUTH model under three different urban growth scenarios: (1) current development trends scenario (SC 1), (2) managed development scenario (SC 2) and (3) ecological development scenario (SC 3). The maximum difference in the ratio of urban growth between SC 1 and SC 3 (SC 1 - SC 3) for 50years (2000-2050) was approximately 6.72%, leading to the largest differences (0.01°C and 0.03ms(-1), respectively) in the mean air temperature at 2m (T2) and wind speed at 10m (WS10). From WRF-SLEUTH modeling, the effects of future urban growth (or future land use changes) in the SMA are expected to result in increases in the spatial mean T2 and WS10 of up to 1.15°C and 0.03ms(-1), respectively, possibly due to thermal circulation caused by the thermal differences between urban and rural regions.

Characteristics of malodor pollutants and aromatic VOCs around an urban valley in Korea.

In this study, the environmental behavior of malodor pollutants (MPs) [including reduced sulfur compounds (RSCs)] and aromatic volatile organic compounds (AVOCs) were investigated around urban valley areas during several field campaigns (February through December 2006). The MPs measured in the study area include the RSCs (H(2)S, CH(3)SH, DMS, and DMDS), ammonia (NH(3)), and styrene (STY); the AVOCs include benzene (BEN), toluene (TOL), ethylbenzene (EB), m,p-xylene (MPX), and o-xylene (OX). The variation of most MP concentrations (except for DMDS) was found to be larger than that of AVOCs. It was found that STY (2,346 +/- 4,867 ppbv) was the most dominant MP followed by NH(3) (447 +/- 285), CH(3)SH (16 +/- 41), and the others (<8). The magnitude of AVOCs was found in the following descending order: TOL (1.4 +/- 2.2 ppbv), EB (1.0 +/- 2.1), MPX (0.9 +/- 2.0), and the others (<0.8). The concentration levels of most MPs on industrial (I) and downwind (D) sites were up to an order of magnitude higher than those at non-industrial (N) and upwind (U) sites. For most AVOCs, the former was ~3 times higher than the latter. For malodor intensity in RSCs, CH(3)SH was the dominant contributor. The concentration difference in target compounds between the sites/periods is likely to be caused by the combined effects such as emission sources, geographical features (e.g., semi-closed topography), and meteorological conditions (e.g., wind directions) in and outside the urban valley.

Identification and interpretation of representative ozone distributions in association with the sea breeze from different synoptic winds over the coastal urban area in Korea.

To aid the studies of long-term impact assessment of cumulative ozone (O3) exposures, the representative 8-hr O3 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 O3 patterns, and numerical and observational analyses were also used to interpret the identified horizontal distribution patterns. The results yielded three major O3 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 O3 concentration distributions, mostly occurred under relatively weak westerly synoptic winds. The predominant features of this pattern were infrequent high O3 levels but a distinct gradient of O3 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 O3 concentration distributions, was found with higher O3 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 O3 occurrence in the western coastal area only. However, pattern 3, accounting for 21% of O3 concentration distributions, showed significantly higher O3 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 O3 concentration distribution patterns over the GSA.

Characteristics of Asian dust transport based on synoptic meteorological analysis over Korea.

Classification of synoptic patterns and their correlation with dust events over East Asia were performed by means of cluster analysis. The average linkage and K-means clustering techniques were used to identify two major weather types during Asian dust events (ADEs; total 26 ADEs with 47 dusty days) of six spring seasons from 1996 to 2001. The first weather type mainly influenced neighboring Asian countries and frequently occurred with ADEs (approximately 23% of ADE cases). It mostly occurred under a surface high (low)-pressure system over the west (east) of the Korean peninsula coupled with an upper-level trough and cutoff low passage over the center of the Korean peninsula. It showed strong advection in the middle/ upper troposphere with both a high aerosol index and enhanced coarse particulate matter (PM) loading over Korea. In contrast, the second weather type was mostly associated with long distance or continental-scale transport and occurred less frequently with ADEs (approximately 15%). It appeared with an upper-level trough and a cutoff low vertically connected with a surface low system that was formed by a strong cyclonic vortex over the north of the Korean peninsula. There were weak advection, low aerosol index, and low coarse PM concentration over the Korean peninsula during the second weather type. In addition, it was found to be mostly associated with the trans-Pacific transport of Asian dust to the western coast of North America.

DMS photochemistry during the Asian dust-storm period in the Spring of 2001: model simulations vs. field observations.

This study examines the local/regional DMS oxidation chemistry on Jeju Island (33.17 degrees N, 126.10 degrees E) during the Asian dust-storm (ADS) period of April 2001. Three ADS events were observed during the periods of April 10-12, 13-14, and 25-26, respectively. For comparative purposes, a non-Asian-dust-storm (NADS) period was also considered in this study, which represents the entire measurement periods in April except the ADS events. The atmospheric concentrations of DMS and SO2 were measured at a ground station on Jeju Island, Korea, as part of the ACE-Asia intensive operation. DMS (means of 34-52 pptv) and SO2 (means of 0.96-1.14 ppbv) levels measured during the ADS period were higher than those (mean of 0.45 ppbv) during the NADS period. The enhanced DMS levels during the ADS period were likely due to the increase in DMS flux under reduced oxidant levels (OH and NO3). SO2 levels between the two contrasting periods were affected sensitively by some factors such as air mass origins. The diurnal variation patterns of DMS observed during the two periods were largely different from those seen in the background environment (e.g., the marine boundary layer (MBL)). In contrast to the MBL, the maximum DMS value during the ADS period was seen in the late afternoon at about sunset; this reversed pattern appears to be regulated by certain factors (e.g., enhanced NO3 oxidation). The sea-to-air fluxes of DMS between the ADS and NADS periods were calculated based on the mass-balance photochemical-modeling approach; their results were clearly distinguished with the values of 4.4 and 2.4 micromole m(-2) day(-1), respectively. This study confirmed that the contribution of DMS oxidation to observed SO2 levels on Jeju Island was not significant during our study period regardless of ADS or NADS periods.

Comparison of outdoor and indoor mobile source-related volatile organic compounds between low- and high-floor apartments.

The current study examined the hypothesis that there may be vertical variation in mobile source-related volatile organic compound (VOC) concentrations in high-rise apartment buildings. One hundred twelve homes in 56 high-rise apartment buildings with 10 or more stories participated in the study. Both the outdoor and the indoor air concentrations of three VOCs [methyl-tertiary butyl ether (MTBE), benzene, and toluene] were significantly higher for the low-floor apartments than for the high-floor apartments (P < 0.05). The median outdoor concentrations were 5.4, 6.8, and 29.1 microgram/m3, respectively, for the low-floor apartments, yet 4.4, 4.3, and 21.9 microgram/m3, respectively, for the high-floor apartments. Meanwhile, the median indoor concentrations were 6.3, 9.4, and 44.8 microgram/m3, respectively, for the low-floor apartments, yet 5.1, 7.6, and 38.8 microgram/m3, respectively, for the high-floor apartments. These findings indicate that residents of low-floor apartments are exposed to elevated residential levels of mobile source-related VOCs compared to high-floor apartment residents. The indoor concentrations of the target VOCs, except for MTBE, were significantly higher than the outdoor air concentrations for both the low and high floors (P < 0.05). Plus, the outdoor and indoor VOC concentrations were significantly different between the daytime and nighttime data sets for both low- and high-floor apartments, with a P value of less than or close to 0.05.