Impacts of heavy rain and typhoon on allergic disease.

OBJECTIVES: Allergic disease may be increased by climate change. Recent reports have shown that typhoon and heavy rain increase allergic disease locally by concentration of airborne allergens of pollen, ozone, and fungus, which are causes of allergic disease. The objective of this study was to determine whether typhoon and heavy rain increase allergic disease in Korea. METHODS: This study included allergic disease patients of the area declared as a special disaster zone due to storms and heavy rains from 2003 to 2009. The study used information from the Korea Meteorological Administration, and from the National Health Insurance Service for allergic diseases (asthma, allergic rhinitis, and atopic dermatitis). RESULTS: During a storm period, the numbers of allergy rhinitis and atopic dermatitis outpatients increased [rate ratio (RR) = 1.191; range, 1.150-1.232] on the sixth lag day. However, the number of asthma outpatients decreased (RR = 0.900; range, 0.862-0.937) on the sixth lag day after a disaster period. During a storm period, the numbers of allergic rhinitis outpatients (RR = 1.075; range, 1.018-1.132) and atopy outpatients increased (RR = 1.134; range, 1.113-1.155) on the seventh lag day. However, the number of asthma outpatients decreased to RR value of 0.968 (range, 0.902-1.035) on the fifth lag day. CONCLUSION: This study suggests that typhoon and heavy rain increase allergic disease apart from asthma. More study is needed to explain the decrease in asthma.

The weather watch/warning system for stroke and asthma in South Korea.

Weather watch/warning systems have been established for human health outcomes. Our study aims to develop and demonstrate a weather watch/warning system for asthma and stroke within the whole of South Korea, using a stratified regression approach. We converted claim-based health insurance data covering almost all medical claims for the only health insurance system in Korea for asthma and stroke from 1996-2003 into personalized disease episode data, and combined them with meteorological data. We utilized a step-wise regression method using factors extracted from the meteorological data to develop stratified models for six (stroke) and nine (asthma) regional and day-of-week strata. Validation studies showed that the actual number of hospitalizations in 2003 increased according to the three-leveled predictions (levels I, II, and III) from the model based on the 1996-2002 data. This system is accessible via the internet (http://industry.kma.go.kr/APP/sub_APP15_H01.htm) at the Korean Meteorological Administration website.

High temperature, heat index, and mortality in 6 major cities in South Korea.

The authors conducted a time-series analysis to estimate the acute effects of high temperature in 6 cities in Korea and to compare thresholds of temperature on daily mortality among the cities. They examined the association between total mortality and the daily mean temperature and heat index during the summers in Korea from 1994 to 2003. The threshold temperature was estimated to be between 27.0 degrees C and 29.7 degrees C for 4 cities. For a daily mean temperature increase of 1 degrees C above the thresholds in Seoul, Daegu, Incheon, and Gwangju, estimated percentage increases in daily mortality were 16.3 (95% confidence interval [CI] = 14.2-18.4), 9.10 (CI = 5.12-13.2), 7.01 (CI = 4.42-9.66), and 6.73 (CI = 2.47-11.2), respectively. These city-specific threshold temperatures and the magnitude of the effects of hot temperature indicate that any analysis of the impact of climate change should take into account regional differences.