Variability and Trend of Heat Index in Thailand during 1975-2017 and Their Relationships with Some Demographic-Health Variables
Wutthichai Paengkaew1*, Atsamon Limsakul2, Rittirong Junggoth1, and Somsak Pitaksanurat1
1Faculty of Public Health, Khon Kaen University, Thailand
2Environmental Research and Training Center, Department of Environmental Quality Promotion,
Ministry of Natural Resources and Environment, Thailand
* Corresponding author:
This email address is being protected from spambots. You need JavaScript enabled to view it.
Received: November 22, 2018; 1st Revised: August 8, 2019; Accepted: September 26, 2019
Abstract
Variability and trend of Heat Index (HI) in Thailand during 1975-2017 and their relationships with some demographic-health variables were analyzed. Results revealed the spatially coherent and widespread significant increase in Thailand’s HI, consistent with significant country-wide warming. Thailand’s HI as a whole significantly increased by 0.53°C per decade, and it was in the caution level but will gradually rise to the extreme caution level in the near future. Accompanying this trend, the HI distribution and characteristic have significantly shifted towards a higher health impact level in the recent decades. In addition, year-to-year HI variability significantly correlated with the El Niño–Southern Oscillation (ENSO) index, providing additional evidence that ENSO events are an important source of Thailand’s climate variability including extremely hot weather. Further analysis showed that Thailand’s HI had good positive associations with some demographic-health variables. These results provide some clues that increasing HI may contribute to elevated cases of heat-sensitive illness and pose an additional health risk to Thai people especially the elder persons which have rapidly grown under the aging society era. To better understand how heat and health in Thailand are linked, however, further detection and attribution studies based on newly available long-term health data are needed.
Keywords: Heat index; Trend; Demographic; Health
