Climate variability and human health in Southeast Asia: A Taiwan study

The local, regional, or global climatic conditions may alter atmospheric compositions and chemical processes and are implicated in increasing frequencies of extreme temperature and precipitation, which can also be intensified through varying urbanization, economic development, and human activities. Adverse health consequences related to such exposures are often of primary concerns for their immediate and sustaining impacts on the general welfares. In Taiwan, higher cardiovascular or respiratory mortality appears to derive more from low temperature than does from the exposure to high temperature for the general population. Rural residents are less affected than urban dwellers under extreme temperature events if cardiovascular or respiratory mortality is benchmarked. In towns and villages with a high percentage of the elderly living alone, the senior and the disabled people and the aborigines will present a higher mortality associated with extreme temperature. Extreme rainfall events may also interrupt the chain of food supply and life support and lead to reporting malnutrition of people in affected regions. In addition, contaminated water sources for drinking and recreation purposes, due mostly to flooding after extreme precipitation, are known to be associated with disease outbreak and epidemics. In Taiwan, for waterborne infections, extreme torrential precipitation (>350 mm/day) was found to result in the high relative risk for bacillary dysentery and enterovirus infections when compared to ordinary precipitation (<130 mm/day). Yet, for vector-borne diseases, the relative risk of dengue fever and Japanese encephalitis increase with precipitation up to 350 mm/day. Differential lag effects of precipitation appear to be associated with varying risk levels for respective infectious diseases. Changing patterns of temperature and precipitation have influenced geographical distribution as well as prevalence and incidence rate of climate-related diseases. Availability of medical resources or sanitary capacities is to be taken into account in further analyses before the final adaptation.